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PHYTOPATHOLOGY 



OFFICIAL ORGAN OF THE 
AMERICAN PHYTOPATHOLOGICAL SOCIETY 



W. A. Qrton 



EDITORS 



DoxALD Reddick G. p. Clinton 



W. H. Barre 
H. R. Fulton 
Ernst Bessey 
VVm. T. Horne 



associate EDITORS 

(\ W. Edgerton 
H. T. Gussow 
K. (\ Stakman 
V. H. Stewakt 



H. P. Harss 
H. A Kdson 
G. M. I^eed 

J. 1^. HORKR 



BUSINESS MANAGER 



(-■. L. Shear 



VOLUME VII 



JANUARY-DECEMBER, 1017 



With 11 Plates, and So Text Fujukks 



• . • 



> ■ 



• « 



PriJI.lSIIKD FOIt TIIK SnciKTV 

Williams & Wilkixs CnMr.v.w 

I^ALTIMOHK, Ml). 



254048 



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• • 



CONTENTS OF VOLUME VII 

No. 1. February 

Jens Ludwig Jensen (1836-1904). F. K0lpin Ravn 1 

The penetration of foreign substances introduced. into trees. W. H. Rankin. . 5 

The generation of aldehydes by Fusarium cubense. Albert C. Lathrop 14 • 

Does Cronartium ribicola winter on the current? W. A. McCubbin. . * 17 

The injurious effects of tarvia fumes on vegetation. A. H. Chivers 32 

Sour rot of lemon in California. Clayton O. Smith 37 

A disease of pecan catkins. B. B. Higgins 42 

Some new or little known hosts for wood-destroying fungi. Arthur S. Rhoads 46 

Notes on Cronartium comptonisB III. Perley Spaulding 49 

Further note on a parasitic saccharomycete of the tomato. Albert Schneider 52 

Phytopathological Notes 54 

Abstracts of paper presented at the Eighth Annual Meeting of the American 

Phytopathological Society, New York City, December 26-30, 1916 58 

Literature on American Plant Diseases 79 

No. 2. April 

The perfect stage of Glceosporium venetum. W. H. Burkholder 83 

Puccinia subnitens and its aecial hosts. Ellsworth Bethel 92 

Contributions to our knowledge of the white pine blister rust. W. A. Mc- 
Cubbin 95 

Species of Melampsora occurring upon Euphorbia in North America. E. B. 

Mains 101 

Recent cultures of forest tree rusts. James R. Weir and Ernest E. Hubert 106 

A Rhizoctonia of the fig. J. Matz 110 

Buckeye rot of tomato fruit. C. D. Sherbakoff 119 

Noteworthy Porto Rican plant diseases. F. L. Stevens 130 

Pycnial stages of important forest tree rusts. James R. Weir and Ernest E. 

Hubert 135 

Review 140 

Phytopathological Notes 140 

Report of the Eighth Annual Meeting of the American Phytopathological 

Society. C. L. Shear 145 

Report of the Berkeley Meeting of the Pacific Division of the American Phyto- 
pathological Society. W. T. Horxe 150 

Literature of American Plant Diseases 152 

No. 3. June 

Studies on Bacterium solanacearum. E. E. Stanford and F. A. Wolf 155 

Sparassis radicata, an undcscribed fungus on the roots of conifers. James n. 
Weir 166 



CONTENW 

Some ehanflet produced in strawberry fruits by Rhisopus nisrieans. Nbil £. 

Stb%'bns asd Low A. Hawkins 17S 

Witches-brooms on hickory trees. F. C. Stewabt ISo 

A new leaf-spot disease of cherries. Bmwrr A. RuDOLm 1k8 

Elister spot of apples and its relation to a disease of apple bark. Dban H. 

Rose 198 

The pathoKenic action of Rhisoctonia on potato. H. T. Guasow 209 

Synthetic culture media for wood-destroying fungi. Ernest J. Pieper, C. J. 

Ilmi-HRET AND S. F. ACRBB . 214 

Phy topathological Notes 221 

Literature on Plant Diseases . . 228 

• No. 4. Ai'orHT 

The cupraminonium washm. their preparation, biological properties, And 

application. <). Ri'tler 2.'i5 

IlacilluH fnorulanii N. Sp. A Imcterial organivm found associated with curly 

top of the sugar brct. 1*. A. lio.vcqrET 2f>9 

A now apparatus for aiicptic ultrafiltration. Hali-h K. Smith . 2tK) 

Factors nffrcting the |>araititiiim of Cstilago Zco*. F. (i. Pieiieibel 294 

Hclcrotium bataticola. the cuune of a fruit-rot of |M*pper8. William II. Martin .'tfK) 

A Nc^trin pnrn^itic on Norway innplc. NIel. T. Cook 314 

Phy topathological Notcii . 'M*\ 

Literature on Plant DiaoaNcs 32.3 

No. 5. CKrroBER 

Alternaria on Datura and potato. R. D. Randh 327 

Suacrptibility of non-citrua plants to Hactcrium Citri. R. A. Jeiile XV^ 

SotiK' dii>r.'uM.*H of oconoiiiic planta in Porto Rico. L. K. Mileh . . . 3I.'> 

Tm-o now fon*tit trre ruata from the northwcat. H. S. jArKrtoN. . .'i.V2 

Rolatjiin of toiii|)eraturv to the gniwth and inf«*cting |>owcr of Fiutariurii Lini. 

W. H. TiHiiALK 3.Vi 

A HiiiipU- and efT<*rtiv<* method of pn»tocting citruH fruits against 8tom-<*n(i rot. 

JiiiiN .M. HoiiKiiH A\i> F. S. Karlk 3r»l 

Arthro|MMii« iind gafltcn)|>odM aa carri<*ni of ('ronartium ribicola in gn*€ii hc»uH<*H. 

<;. FLirrn <;raVATT AND RrMII P. MAk.HIIALI 'M\S 

Pri'iiiiiinary n*|Nirr on the vi*rtirnl di.*<tribuiifin of Fuaarium in aoil. .Minmk W. 

TwLoK ;17I 

Brii*f»T .\rtii'l<"* 

Notr^ on WfMMl-ilifit roving fungi which grow im lM>th ronifi*rou?< un<i dcridii- 
oii!t tr*N'Fi II. Jami:m H. Wcir 379 

Thr "pr.'U iiii'thiHl iif :ip|ilying ronrrntratrd fonnaldi'liydt* solution in the 

rontrol iif fint Htniit. K. J. IIahkkij. 3^1 

RrvifHii 3h| 

Ph\ lopnl holiiiiir.il \«itfi« .HsS 

LitiTaturi' on IMinr Di^fuac^if . . ^V.*3 

\t». (i. Dl.i'l.XlhKK 

A twig%nd N'af diJ^iTi.-**- of K<-rri.i j:i|Ninir:t V. K. Stkw \nt 3*.#9 

Thi; rromn r;ink«T ili-**.-!**' of r**-*' L M. .M^-^^^Ki 40** 



Contents 

An epiphytotic of cane disease in Porto Rico. John A. Stevenson 418 

The effect of roentgen and ultraviolet rays upon fungi. H. L. Tbumbull and 

J. W. HoTsoN 426 

Sclerotinia Trifoliorum, the cause of stem rot of clovers and alfalfa. A. H. Gil- 
bert AND C. W. Bexnett 432 

The conduction of potassium cyanide in plants. John A. Elliott 443 

Reviews 449 

Phytopathological Notes 449 

Literature on Plant Diseases 455 



INDEX TO VOLUME VII 

New scientific names &re printed in full-faced type 



Abies, amabilis, 140; balsamea, 46, 314; 
concolor, 140; grandis, 140, 379; lasio- 
carpa, 379; magnifica, 140; nobilis, 140 

Abronia, elliptica, 93; fragrans, 92; mi- 
crantha, 93 

Acalypha, bachmeroides, 160 

Acer, negundo, 445; rubnim, 48; sac- 
charin um, 48 

Agree, S. F., see Piepbr, Ernest J. 

Acrosporium, fasciculatum, 39 

Actinomyces, scabies, 212 

Adiantum, 35 

iEcidium, Abroniae, 93; fumariacearum, 
93 

Ageratum, conyzoides, 160 

Aegle, glutinosa, 59 

Agriolimax, agrestis, 369 

Agropyron, smithii, 73, 226 

Alerodes, citri, 132 

Alfalfa, leaf spot of, 70; lightning injury 
to, 142; stem rot of, 432 

Alsike, 70 

Altemaria, 63; Citri var. Cerasi, 188; 
crassa, 329; cucurbits, 196; Solani, 
316, 327; on Datura, 327; on potato, 
327 

Amaranthus, blitoides, 92; retroflexus, 
92 

Ambrosia, artemisisfolia, 157; trifida, 
445 

Amelanchier, alnifolia, 109 

American Ph ytopatho logical Soc'iety, 
abstracts of papers presented at eighth 
annual meeting, 145-149; Report of 
the Pacific Division, 150-151. 

Amsonia, 67; cliate, 69 

Angular leaf spot, of cotton, 64; of cu- 
cumbers, 61 

Anthracnose, beah, 61; of camphor, 59; 
cucumber, 62; of onion, 59; raspberry, 
83 



Aplanobacter, agropyri, 226 

Apple, blister spot, 198; bitter rot of, 
132; fruit-rot of, 59; Hypochnus 
ochroleucus on, 130; root-rot of, 77, 
223; rot of, 76; rough-bark or scurfy- 
bark canker of, 202; scab, 76, 221 

Arachis, hypogsa, 156, 160 

Arbutus, menziesii, 380 

Armadillidium, vulgare, 369 

Armillaria, mellea, 175 

Arthropods, carriers of Cronartium ribi- 
cola in greenhouses, 368 

Aschersonia, on Guava, 132 

Aspidium, 35 

Aster, 67 

Atriplex, canesccns, 93; confertifolia, 
93; hastata, 92 

Auerswaldia, palmicola, 131 

Avocado, Mycosphserella persese on, 350; 
Phyllachora gratissima on, 350 

Azalea, viscosa, 32; effect of tar smoke 
on, 32 

Bacillus, amylovorous, 75, 200; calif orni- 
ensis, 285; coli, 200; coli communis, 14; 
mesentericus aureus, 285; morulans, 
269 

Bacterium, Citri, 58, 339; Dianthi, 284; 
herbicola aureum, 285; Malvacearum, 
64; mesentericus, 159; Phaseoli, 61; 
solanaceanun, 155; viridilividum, 392 

Bailey, Ernest, see Jones, L. R. 

Banana, disease of Cuban, 14 

Barley, blight, 69 

Bean, anthracnose, 61; blight, 61, 65; 
Cercospora canesccns on, 349; Di- 
morium grammodes on, 131 ; Isariopsis 
on, 345; loaf blotch of, 345; loaf spot of, 
345; mosaic, 60, 61; root rot, 61 

Begonia, effect of tar smoke on, 35 

Bennett, C. W., see Gilbert, A. H. 



u 



Index 



Bethel. Kllawortii, Pucciniasubiutens 

and itjt a<>cial luMta, 92--4M 
B«tula. lutca, 47. 48; occidcntalis, 379 
BidcDfl. hipinnata, 163 
Birch, vHlow. 4K 
BiABY. ( I. H.. The nhort -cycled rromyccs 

of North America (abstract), 74 
Bitter rot, of apple. 132 
Bjerkandera. aduMta, 47 
Black heart, of orange, 190 
Black H|Mit. of |M>pf>er. (>3 
Blakk. M. a.. Cook, Mkl T., and 

H(*HWARZE. (\ A., Studies on peach 

yellows and little |>each (abstract), 76 
Blatta. orientalis. 370 
Blight, on barley. 69; on liean, 61, 65; 

on rhcHtnut. 313; on eggplant, 60, 78; 

on jM'arj*. 7.5; on |M)tato. 374 

BlistfT }«|M»t. of HftplcM. 19S 

Blurne:t. ImlHainifrra. HiO 

Boletus. rfir(»in.'i|N>H. 74; frost ii. 74; gra- 

cilij*. 71; ind('t«t^UM. 74; purpureus, 74; 

s(>eriiif«UM, 74 
B()N'(iri:T. V. A.. Baeilluj* nionilans \. 

Hp.. 2iM> 2s«» 
BotrvtiH. rin«T«':i. '.i*M 
Brawiira. oliTacru var. aeephnla. 141 
Bread fruit, runt of. 131 
Br<m K. \\ . .*^.. and HiTH. W. A.. Con- 
trol of ;ipplr rtrub by bleaching [m>w- 

der :ib-tr.irt •. 7»i 
Broniuh. h<Mikcrianu.*<, 14.3; marginatur*. 

60; Mtrhi'uj*!?*. ♦'»•.* 
BiMMiks. Cii\HLKs. and ('o<»LKY, J. S.. 

Jf>nathnii Mfwit •jtlM*tnict >. 7i): TfUi- 

fienttun* n*l:ition.*« of apple rot fungi 

(abstract . 7»» 
Brom.'iili.'t. drtiiiNftn. 161 
Bhows. Xh.i.ik a., a b.'ict<TijiI Hti'in and 

leaf iliM'aj'r of li'ttuci* al»Mtra<*t ■, <».'{ 
Bt'KKii<»i.i»» i(. W. I!.. Ii«'an «lis<'aj««*M in 

Nm ^ ork St«t«* in n»l»i abstract •, 61; 

TIm» jK-rfrrt f*tag»* of < tlii-oM{M>riuni 

vem-tuin. M •»! 
Bl'Tl.l.H ( K . rh«' ('(ipraiitiiioiiiuni u ;u*h«*M. 

Zl'f Jt;s 
Buttf-rnut. 17 
Byakn. L I* . 'rvl<*firliu«» tntiri on \%hfat . 

•Vi; n ni'liiatodi- di*i'a-«* of t\\r da**h«>«'li 

and it» miitrol \t\ hot uatt-r tr«-at- 

nirnt abftrart . «»»i 



Cabbage, wilt, 375 

Calendula, officinalis, 32 

Calonyction, 67 

Camellia, sooty mold on, 133 

Camfmnula, 68 

Camphor, anthracnose of, 59; limb can- 
ker of, 59 

Canfiytuft. effect of tar smoke on. 32 

Canker, of camphor trees, 59; citrus, 58; 
Illinois, 205; rough bark or scurfy 
bark, '202 

Canna, rust on, 132 

Capno<lium, brasilicnsc, 134;coflreie, 134; 
footie, 134; mangiferum, 134; stella- 
tmn, 134 

Capsella, burMa-pastoris, 92 

Ca|)«icum, annuum, 160, 312 

(^arica, papaya, 349 

Carpinus. 314 

Carrot, lightning injury, 142 

C'akhn'kk, Ktbanks, Do the bacteria of 
angular leaf spot of cucumber over- 
win t<'r on the seed? (abstract), 61 

Carya, illinoenHis, 42; ovata, 185 

('aasava, CercoH|)ora hcnningsii on, 349 

(*astanea, dentata, 47 

Cai4t<»lleja, angustifolia, 106; miniata, 

C<*h'ry, bartrrial heart wilt, 64; crown 

rot. t»l; croun n)t wilt, 64 
Ct'phuh'ururt, virrHceni4, 1.32 
Crrcospora. Apii, tV5; cancHcenn, .349; 

rotTra-. .'ill*; craasa. .'i.*i5; cruenta, .'M6; 

Datura*. .Ti.'); hcnningrtii, 319; Hibisci, 

.'<r.»; IbiridiH, ,'i.37; Lunaria', .'i.37; \ico- 

tiaiw. .34s ; Solaninigri, .TJ7 
CfTcal pathologists, field conference of, 

4,7.3 4.'>4 
Charcoal rot. of Hweet |K)tatoe«, 312 
ClK'noiNNliuin. alburn, 92; glaucuni, 92; 

lanceoliituni, \f2', pagonuni, 92 
Cherry, h'af H|>ot, 7.*), ISS; witches- 

br<N>rn.*4 on. 1V» 
ChcMtnut. Iilmht. 313 
Ciii\Mt>«. A. II.. The injurious efTectM of 

T.-ifMi furnr.M on vegetation. 32-»'ki. 
Chr\>Miri\ \.i. Abietin, 78, XVJ; I*iceie, 

.'CiJ. wiirii. ii.K{ . 
( 'hr>-«»pM.M. 67; niariana, 6S 
CitruM, trifoliata. .VJ, .*i.'J9; canker, 58 



Index 



ui 



Cladosporium, Citri, 60; cucumerinum, 

62 
Clavaria, amethystina, 171; aurea, 171; 

formosa, 171 
Cleome, serrulata, 93 
Clover, leaf spot of, 70; Nigredo fallens 

on, 70; rust, 75; stem rot of, 432 
Cnicus, americanus, 44 
Coccomyces, hiemalis, 75, 404; KerrlsB, 

405 

COERPER, FLOR*feNCE M., SCe JOHNSON, 

A. G. 

Coffea, arabica, 115; liberica, 115 

Coffee, Cercospora coffeae on, 349; dis- 
eases of, 130 

Coleosporium, Apocynaceum, 69; deli- 
cat ulum, 68, 225; Elephantopodis, 66; 
Helianthi, 67: inconspicuum, 68; Ipo- 
mseae, 67, 132; Laciniarise, 68; Solida- 
ginis, 20, 68, 225; Terebinthinaceae, 67; 
Vemoniae, 67 

Colletotrichum, cereale, 450; circinans, 
59; falcatum, 423; fructum, 59; solani- 
colum, 226 

CoLLEY, Reginald H., Mycellinm of the 
white pine blister rust (abstract), 77; 
Pycnial scars, an important diagnostic 
character for the white pine blister 
rust (abstract), 77 

Collins, J. Franklin, On using an 
ether freezing microtome in warm and 
damp weather, 222 

Colocasia, esculenta, 66 

Commelina, nudiflora, 35 

Comptonia, asplenifolia, 49, 108 

Conifers, Sparassis radicata on, 166 

Convolvulus, 67 

Cook, Mel. T., see Blake, M. A.; and 
ScHWARZE, C. A., Apple scab on the 
twigs, 221; A Nectria parasitic on 
Norway maple, 313-314. 

Cooley, G. S., see Brooks, Charles 

Coreopsis, 67; dclphinifolia, 69; lanceo- 
lata, 69; major, 69; major semeri, 69; 
major rigida, 69; tripteris, 69; verti- 
cillata, 69 

Coriolellus, sepium, 47 

Coriolus, abietinus, 46; nigromargina- 
tus, 46; prolificans, 46; versicolor, 46 



Corn, Phyllachora graminis on, 55, 131; 

smut, 73 
Corticium, javanicum, 115; Isetum, 115; 

ochralcucum, 113; salmonicolor, 111; 

vagum. 111, 209 
Cotton, angular leaf spot, 64; lightning 

injury, 140; rust on, 133 
Corylus, avellana, 52 
Cratsegus, douglassi, 109, 223 
Cronartium, cerebrum, 135, 450; coleo- 

sporoides, 106, 135; Coiflandrae, 135; 

Comptoniae, 17, 49, 106, 135; Quer- 

cuum, 20; ribicola, 17, 58, 77, 95, 135, 

225, 368. 391, 449 

Croton, glandulosus var. septentrional is, 

161 
Crown canker, of rose, 408 
Crown rot wilt, of celery, 64 
Crown rot, of celery, 64 
Cucumber, angular leaf spot of, 61; 

anthracnose, 62; mosaic on, 61; new 

leaf spot, 62, scab on, 62 
Cucurbita, maxima, 32; pepo, 32 
Cuprammonium washes, 235 
Curly dwarf, of potato, 71 
Curly top, of sugar beet, 269 
Currant, Cronartium ribicola on, 17, 58; 

effect of tar<smoke on, 32; rust on, 17, 

225 
Cycas, revoluta, 44 
Cylindrocladium, 410; scoparium, 409 
Cylindrosporium, onKerria japonica, 399 
Cystospora, batata, 74; Sacchari, 424 

Daedalea, confragosa, 379; heteromor- 

pha, 380; unicolor, 379 
Dalbby, Nora E., Corn disease caused 

by Phyllachora graminis, 55 
Dale, E. E., see Melchbrs, L. E. 
Damping-off, of tomatoes. 319 
Dasheen, nematode disetis? of, 6(5 
Datura, cornucopia, 160; fastuos'i, 160. 

327; ferox, 327; incrnus, 327; licvis, 

327; metelloides, 160; quercifolia. 327; 

stramonium, 327; stramonium gi>?an- 

teum, 327; stramonium inermis, 327; 

tatula, 65. 163. 327; tatula inermis. 327 
Davis, W. H., and Johnson, A. G., The 

aecial stage of the red clover rust 

(abstract), 75 



^MAMhl 



IV 



Index 



Dianthuii. incamata, 289 
DiEHL, William, see Melhur, I. K. 
Dimerium, fcrammodes, 131 
Diplocladitiin, 410; cylindroflponun, 410 
Diplodia, cacaoicola, 423; Camphonp, 

60; rot of citrim fruits, 301 
Distichlifl, spicata, 02 
Dothichiia, populoa. 4^ 
DiRRELL. W. L., Notos on curly dwarf 

nymptomson Irish potatoes (abstract), 

71 

Karl, F. S.. seo Kcmikrs, John M. 
Karly bliKht, on Datura, 327; on potato, 

327 
I'}chino<iontium. tinctoriurn. 170 
Kclipta, alba, 1.57 
KixiEKToN, (\ W., A (rnomonia on ogj?- 

plant (abstract). 78 
Kdhon. H. a., nn<i S<-iirki.\kr, Ohwald, 

A malnutrition diwiiMo of the Irish 

|>otato and its control (abstract), 70 
I*>lwomi. attacking the dasheen. 00 
Kionilant. ( -olletotrichum solanicoluin 

on. 2'2i)', (»nomonia on. 7K; Lifchtnin^ 

injury to. 1 10; stem blight of, 00. 78; 

wilt on. 227 
Klephantopus, tomentosus, 07 
KlfvinKta. mcKaloma. 47 
Ki.LioTT. John a., A new parasitic slime 

mold suitable for class work (alwitract ), 

74: Thi> conduction of |H)tassium cya- 

nidi* in plants. 44.'i-448. 
Klymus. americanus, 143; canadeiutis, 

73; condensatiis, 73; rIaucus. 09, 73; 

macounii, 7Ii; nibustus, 0!) 
Kndothia. |>arasitica. 313 
F'riKcnm. ranad«*nsis, 10.3 
Krvsiniiiin. as|N*rum, 92 
Kupatoriijin. OS 
Kuphorbia. lOl ; commutata. 101; rypa- 

rissia}*. 101: rxif^ua. lOl; falcata. UT2; 

fCcrardiaria. lOTi: mutatis, lOJi: |M*pliiH. 

lot: riibuHta. 101 
Kuti»tti\. t«'ni'lla. -7:{ 
Kuthaniia. OS; r:ir<»litiiari.'t, OS; Icpto- 

ri'phala, *kS 
K\«»:i5»ru«i, <'«Ta»i. Isji 

FAfLWRTTIK, It. <\, l)l«».»i«iiiiiiul|on «if 



Bacterium Malvacearum (abstract), 
04 

Fern, effect of tar smoke on, .34 

Ficus, 133; carica, 110 

Fields, W. S., Method for photograph- 
ing plate cultures, 388 

Fig, Rhisoctonia of, 110 

Flax, 359; wilt, 375 

Fomea, annoeus, 175, 210; applanatus, 
217; pinicola, 210, 420 

Forest trees, rust on. 100, 135 

Formaldehyde solution, for control of 
oat smut, 381 

FraRaria, .32, 178 

Fromme, F. D., Tylenchus tritici on 
wheat in Virginia, 452 

Fromme, F. D., and Thomas, H. E., A 
Xylaria root-rot of the apple (ab- 
stract), 77 

Fruit rot, of pepj>ers, 308; of tomato. 00 

Fi'LTON, If. H., Manual of Fruit Dis- 
eases, Hehlkr. Lex U. and Whetzel, 
Hkrhert HirK, (Review), :W0-388 

Fusarium, conglutinans, 358; cubense, 
14; distribution in soil, .374; Lini, .3.50; 
martii, 01 ; oxys|K)rum, .375; radicicola, 
.375; roseuin, 384; Solani, .375; subula- 
tum, .385 

(Ialloww. H. T., Newton. H. Pierce. 

143 
(ttiniMlerma. Tsug:e. 47 
(lARDNKR. M. \V.. I)iss4'mination of the 

organism of cucuml)er anthracnose 

tal>stract), 02 
(Iasten>fK»ds, carriers of (Vonartium 

ribicola in gn*enhous«>s. .'(08 
(teranium, effect of tar smoke on, .35 
(liblMTella. saubinetti. .'i8."> 
(iiLHKRT. W. \V.. Virulenrr of different 

strains of C-ladoMporium rucumerinum 

(alwtrart :, 02 
(tiLiiKRT. A. H. and Hknnktt. C W., 

.*>el«' rot i Ilia Trifolioruiii. the caiisi* of 

hti*ni rnt of eloviT" and :ilfalfa, 4.32- 

112 
<;l\|)\%i\. v. K. aiicl HKDhh'K, Donald, 

Siilfuritiic <'«>ne«»rd grain's t<i pn'vent 

|N)udrry inildi'U 'abs^trart •, ♦!♦» 
(il<ro|M)rus. coriehoiih'S. IS 



Index 



V 



Glopophyllum, hirsutum, 48; trabeum, 47 

GlcDosporium, Camphorse, 59; Mangi- 
ferffi, 132; venetum, 83 

Glomerclla, 85 

Gnomonia, on eggplant, 78 

Gondule, rust of, 132 

Grapefruit, canker on, 59 i 

Grape, powdery mildew, 66; rust on, 132 

Graphiola, Phoenicis, 131 

Grasses, rust on, 73; Scolecotrichum 
graminis on, 69 

Gravatt, G. Flippo and Marshall, 
Rush P., Arthropods and gasteropods 
as carriers of Cronartium ribicola in 
greenhouses, 368-373 

Guava, diseases of, 131 

Gt'ssow, H. T., The pathogenic action of 
Rhizoctonia on potato, 209-213; The 
occurrence of Colletotrichum cereale, 
Dothichiza populea and Leptosphseria 
Xapi in Canada, 450; A thumb clip for 
use with magnifiers, 451-452 

Gymnosporangium, nelsoni, 109; tubula- 
tum, 109 

Hapalopilus, gilvus, 47 

Haskell, R. J., The spray method of 
applying concentrated formaldehyde 
solution in the control of oat smut, 
381-383 

Hawkins, Lon A., see Stevens, Neil E. 

Hedgcock, Geo. G., Edible and poison- 
ous mushrooms. W. A. "Murrill 
(review), 140; and Long, W. H., The 
aecial stage of Coleosporium Ele- 
phantopodis (abstract), 66; and Hunt, 
N. Rex, The Peridermium belonging 
to Coleosporium IpomoDse (abstract), 
67; X Peridermium belonging to Co- 
leosporium Terebinthinaceaj (ab- 
stract), 67; An alternate form for 
Coleosporium Helianthi (abstract), 
67; Some new hosts for Coleosporium 
Solidaginis (abstract), 68; Some new 
hosts for Coleosporium inconspicuum 
(abstract), 68; Notes on Razoumofskya 
campylopoda, 315 

Helianthus, 67; annuus, 321, 445; aus- 
tralis, 68; decapetalus, 68; divarica- 
tus, 68; eggertii, 68; giganteus, 68; 



. grosse-serratus, 68; hirsutus, 68; mi- 
crocephalus, 68; saxicola, 68 

Helminthosporium, mayaguezense, 351 

Hemileia, vastatrix, 130 

Hemlock, sap-rot in, 47 

Heterodera, radicicola, 66 

Hickory, 44; witches-brooms on, 185 

HiGGiNS, B. B., A disease of pecan cat- 
kins, 42-45 

Honeysuckle, effect of tar smoke on, 32 

Hordeum, jubatum, 69, 73, 143; nodo- 
sum, 69 

HoTsoN, J. W., see Trumbull, H. L. 

Ho WITT, J. E., Phytopthora infestans 
causing damping-off of tomatoes, 319 

Hubert, Ernest E., see Weir, James R. 

Humphrey, C. J., see Pieper, Ernest J. 

Humphrey, H. B., Puccinia glumarum, 
142 

HUNGERPORD, C. W., SCe JOHNSON, A. 

G. ; Puccinia graminis on wheat ker- 
nels and its relation to subsequent 
infection (abstract), 73 

Hunt, N. Rex, see Hedgcock, Geo. G. 

Hypochnus, ochroleucus, 130 

Iberis, amara, 32; umbellata, 337 

Impatiens, balsamina, 161 ; sultani, 163 

Indigofera, arreeta, 160 

Inga, laurina, 132 

Inonotus, dryophilus, 48 

Ipomcea, batata, 312; lacunosa, 67; pan- 

durata, 67; triloba, 67 
Irpex, lacteus, 379 
Isariopsis, on bean, 345; griseola, 345; 

leaf-spot, 345 
Ischnoderma, fulignosum, 47 

Jackson, H. S., A species of Chrysomyxa 
new to North America (abstract), 78; 
Two new forest tree rusts from the 
northwest, 352-355 

Jagger, Ivan C, Two transmissible 
mosaic diseases of cucumbers (ab- 
stract), 61 

Jehle, R. a.. Citrus canker investiga- 
tions at the Florida Tropical Lab- 
oratory (abstract), 58; Susceptibility 
of non-citrous plants to Bacterium 
Citri, 339-344 



VI 



Index 



Jbn'SEN, Je\h LrDWiu. Biography of. 1 

Jimson weed, leaf-Hpot of, 327 

JoiiN'fuiN, A. 13.. flee TArBENiUNR. J. J. 

JoiiXfM>N. A. <t. and ("obkpck, Flor- 
ENCK M., A bnctorial blight of soy 
bean (abntract ), (&5; and HrNOERPORO, 
C W., Scolecotrichum graminis on 
timothy, orchard graas. and other 
gramea (abstract). 69; see Joneh. L. 
R.; see Da vim. \V. H. 

Jonathan spot. 76 

JoNErt. Fred Reuel. The Pseudopexiza 
leaf spot diaeaiieH of alfalfa and red 
clover (abstract). 70 

J^.VEM. L. R.. John HON. A. (r. and 
Reddy. C. S.. Bacteria of barley 
blight «e4»d-bome (abittrnct). 60; and 
Bailkv. Krnrht. FrcMt necronis of 
pf>tato tiib«*ni (Hlmtrnrt). 71; Light- 
ning injury to Knl«>. 14(^142 

Juglanit. cinen*.!. 47 

Juni|M»ruH. commiinii*. 1(K): Hco|>uloruin. 
10!) : virginianii, 46 

Kale, lightning injury to. 140 

Keitt, <J. W.. S<M*<infl pro^n*HH rf|M)rt on 
invcMtigtitiunH of Imf H|Nit f»f chorrieH 
an<l pluriiM in WiHcnuHiii uilMtnict •. 7.*) 

Kerri:i. j:i|Hinif':i. •'{{>!< 

Kochi:i. Mcopiiria. *.^2 

KRftt'T. \V. S., Ii:i<*ti*ri:il (IiK«*tiM«>H i»f 
ri'Irry .ibsfnirf . t*\: \Viiit4*nng of 
S'pforiri |M'f ro«*«'liti.i v.'ir. Apii i:ih- 
Htr 11*1 '. ti.'i 

Ku**hiii-ol:i. I'iri. I.'U; < lof*-*ypii, l.'kJ 

Kuiii<|U:it. r:ink('r on, .V» 

I^ariiii.'iri.'i. 67; rjirlri. 6h: «*lt*g:in!4. i\S; 

rloiigat.'i. t»H: pHUnflorn. 6S; MC'irioHji. 

6s : MTi»tiii:i. i'ts 
I^arix. i-iin»iM»:i. Uis. .'{.V»: liiririiia. |0*»; 

f »rr K It'll trtliM. UWt. 17»i. .'il.'i. .'l.V» 
L%Tiiii<>i*. Ki.iiiJtT (V. Th*- gfiuTHtion of 

aldfhv<l«'«< by Ku-.'irtuiii nikN^rifM'. 14-16 
I.^f MiKht. of tig. Il'i 
Ix*.tf bl<t*rh. of iMMfi. .{|-'i 
Id'tii'TMnt. of U I II (it wht'.'lt. 2JI 
lii'af ••iNif. nlf;ilf:i. 7M; U-an. Hi'r, rhiTry. 

7.'i. Iss. «'liivir. 70: curiiiiibtT. «ij. 

Jtiii?«i>ii ui'ftl. .(.'7: phifii. 7.'i: |Mit.ito. 

•i.'7, toin:tti>. A27 



Lemon, brown rot. 37; canker on. 59; 

scab, 00; sour rot. 37 ; stem-end rot. 363 
Lentinus, 171 

Leniitcs. heteromorpha, 380;scpiaria, 217 
liCpidium, densiflorum, 02; medium, 92 
liCptoHphvria, Napi, 450; Sacchari. 131, 

424 
Lettuce, rot, 392; Sclerotinia libertiana 

on, 60; stem and leaf disease of. 63 
Levin. Kxra, Control of lettuce rot, 

392-393 
Lightning injury, alfalfa, 142; ca^-mts, 

142; cotton. 140; eggplant. 142; kale, 

141; potatoes, 140: radishes. 142; 

sugar IxH't. 141; to sugar cane, 317; 

tomato. 142: turnips. 142 
Lima Ijoan. mtNtuic on, <K) 
Lime, canker on. 59 
Literatum on plant diHeases. 79-SI ; 152- 

154; •22S-2:M; 3*22-326: ;««-.««; 455-4450 
LoNti, W. If., Hi»e Hkimmim'K, (Jko. (1. 
Ij4mic<*ra. tnrtarica. 32 
Lunar ia, biennis. .'i.'i7 
Lyco|N*rHicum, cerasifonne. 161 ; esculen- 

turn. 52, 155; pyrifonne. 161 



MarnH|M)rium. cookei. 32S; I>atunr. :i3l; 
S«>lniii. 32S 

Mains. K. li.. .SjHTii'H of MeluinfMora oc- 
curring U|Mm Kuplif»rbia in North- 
America. 101-105 

Maij^mA, J. It.. w»e Stkvkns. F. L. 

Muiidarin. ranker on, 59 

Mango. Meliola on. 132 

Manihot, IXi; utillisma. 349 

Maple. 4-H: Nectria paraHitic on Nor- 
wav, 313 

Mar:ii«inius. S.icchari. 42 1 

Marigold. efTi*ct f»f tar sinok«* on. •i2 

Makhiiall. Rihh v.. »<•«' (;i{\v\TT. <l. 
Flippo 

Maktix. Wii.i.i \\i If.. \ S<*hToriiini di?*- 
v:\M* of |H'p|HT«< ;ib'»tr;irt i, IV-I ; SrK*n»- 
tiuin li:il:itirol:i. :{i)s 'M'2 

M:irtyiii;t. proliowriilfa. pil 

M\«*'»»:v. L. M.. The crown c:ink«T •li?«- 
f:i?*i' «if row. Mis 417 

M%T/. .r. A Uhiz<M*toni:i of thr fig. 
110 lis 



Index 



vu 



McClintock, J. a., Economic hosts of 
Sclerotinia libertiana in tidewater 
Virginia (abstract), 60; Lima bean 
mosaic (abstract), 60; Will Spongo- 
spora subterranea prove serious in 
Virginia? (abstract), 72 

Myrica, calif ornica, 49; carolinensis, 49, 
108; cerifera, 49; gale, 49; inodora, 50; 
pumila, 50 

McCuBBiN, W. A., Does Cronartium 
ribicola winter on the currant? 17-31 ; 
Contributions to our knowledge of the 
white pine blister rust, 95-l(X); and 
Posey, G. G., Development of blister 
rust aecia on white pines after they had 
been cut down, 391-392 

Melampsora, 101; Euphorbiae, 101; Eu- 
phorbise-dulcis, 101; Euphorbiae-Eng- 
leri, 101 ; EuphorbisB-Gerardianae, 101 ; 
Gehnii, 101; Helioscopise, 101; Me- 
dusae, 108; monticola, 103 

Melanconium, Sacchari, 423 

Melchers, L. E., and Dale, E. E., 
Black spot of pepper (abstract), 63; 
Puccinia triticina Erikss. Leaf-rust 
of winter wheat causes damage in 
Kansas, 224; see Potter, Alden A. 

Melh^s, I. E., Notes on mosaic symp- 
toms of Irish potatoes (abstract), 71; 
and Diehl, William, The develop- 
ment of the aecial stage of Nigredo on 
red clover (abstract), 70 

Melia, 133 

Meliola, Camellaj, 134; Citri, 134; fur- 
cata, 131; Mangiferae, 132; Psidii, 131 

Methods, for photographing plate cul- 
tures, 388; for the differentiation of 
pathogenic fungi in the tissues of the 
host, 389 

Microtome, ether freezing, 222 

Microstroma, 132; album, on oak, 42; 
Juglandis,- 185; Juglandis var. robus- 
tum, 45 

Miles, L. E., Some diseases of eco- 
nomic plants in Porto Rico, 34:V-351 

Mistletoe, 315 

Monolepis, nuttalliana, 92 

Mosaic, on cucumbers, 01; on liiiui bean, 
60; on pea bean, 61; on potatoes, 71, 
72; on muskmclons, 01 



Mucuna, 160 

Murphy, Paul A., Seed potato certifi- 
cation in Nova Scotia (abstract), 72; 
The economic importance of mosaic of 
potato (abstract), 72 

Murraya, exotica, 339 

Mushrooms, edible and poisonous, 140 • 

Muskmelons, mosaic on, 61 

Mycorhiza, 74 

Mycosphaerella, Perseae, 350 

Myriogenospora, 132 

Nasturtium, wilt of, 160 

Naumov, N. a.. Intoxicating bread 

(review), 384-386 
Necrosis, of potatoes, 71 
Nectria, <;occinea, 314 
Nematode, disease of the dasheen, 66 
Nematospora, Coryli, 52; Lycopersici, 52 
Nicotiana, 160; tabacum, 155 
Nigredo, fallens, 70 
Norton, J. B. S., Host limitations of 

Septoria Lycopersici (abstract), 65 
Nummularia, discreta, 205 



Oak, 42, 74 

Oat, smut, 381 

Oberly, Eunice R., (compiler), and 
Smith, Florence P., Literature on 
American plant diseases, 79-81; 152- 
154; 228-234; 322-326; 393-398; 455-458 

O'Gara, p. J., Notes on the distribution 
of the bacterial disease of western 
wheat-grass, 225; The occurrence of 
Colletotrichum solanicolum O'Gara on 
eggplant, 226 

Oidium, citri-aurantii, 39; fasciculata, 
39; tigitaninum, 39 

Oospora, citri-aurantii, 39; fasciculata, 
39; lactis, 40 

Okra, Cerocospora Ilibisci on, 349 

Onion, anthracnose, of, 59; pink rot of, 
59 

Oosporoidea, citri-aurantii, 39 

Orange, black heart, 190; canker on, 59; 
sooty mold on, 13.3 

Osner, CJko. a., Preliminary notes on a 

• new leaf spot of cucumbers (abstract), 
62 



VUl 



Index 



Palm, diseaBes of. 131 

PantomuruB, fulleri. 369 

Papaw, Pucciniopsifl Caries* on, 349 

Parsley, Hclerotinia libertiana on, 60 

Parthcnium, intern folium, 67 

Paspalum, 132; conjugatum. 351 

Peach, brown rot, 179; little, 76; yel- 

lowfi, 76 
Peanut, rust on. 132; wilt, 156 
Pear. bliRht. 75, 130 
Peean, dineane of, 42 
Pellicularia, koleroga. 130 
Peltier, (J. L., boo Stkvexh, F, L. 
Pennington, L. H.. Boleti and myco- 

rhtia upon foroBt tnn^ and an unuBual 

mycorhiia upon white oak (abBtract), 

74 
Peony, effect of tar imioko on, 32 
Pepper, black spot of. 63; fruit-rot of, 

308; Bclerotium diBcaBo of, 64 
Peridermium. acicolum. 20. 68; cameum, 

66; cerebrum. 315; delicatulum, 68; 

harkncBBii. 20. 315; Helianthi, 67; in- 

conapicuum, 68; ipomcrfp, 67; Btrobi, 

17. 225; terebinthinaceum. 67 
Persea, americana. 350 
Petunia, 160 
Pesiia ciborioidefl. 433 
PharbitiB, 68; barbixera. 67; hederacca, 

67 
PhaaeoluB. vulgaritt. 01 
Pheidolo, anaataBBii. 'M\U 
Phyllachora, KruniituM. .Vi. 131; grntiB- 

Btma, ^i50 
PhylloMtictu. hortorum. 7H; ftolitaria. 202 
PhyBalift. alkokongi. 161; angulata, 160; 

craBBJfnlin. 160; philadolphira. 160 
PhyBo|M»llft, vitJH, 132 
Phy tophi horn, rnrtorum, 126; crythro- 

B<»|»tira. 12«i; inf««j«!an». 122. 262. 319; 

terreitria, I'JO 
Picea. cngf*liii:innii. 7s. 17«». .'Ci2; oxrolMa. 

47; iiiorin<lii. .V)2; ruU'iiM, 47 

PiKMKlHKl.. F. J., WM* .STAKyA.V. K. ('.! 

FactorM nfforting th<* paniHitiBni of 
I'litilaico «oa*. 21^1 .'Ul7 

PlEPKk. KhNKHT J.. Hi \IPHIIKY, C .1.. 

and AiMKF.. S. F.. Synthetic rultun* 
nic<iiii ft»r \%*MMl-<li'^trcninpc fungi. 
21 f '220 



Pierce, Newton B., Biography of, 143 

Pierce, Roy G., Albany conference on 
white pine bliBter rust, 54; Early diB- 
covery of white pine bliBter ruBt in the 
United States, 224; see Hpauloino, 
Perley 

Pine, mistletoe on, 315; rust on, 17, 58, 
67, 77, 95; white, 17, 54, 58, 319; yel- 
low, 140 

Pink root, of onion, 59 

PinuB, attenuata, 107, 140; austriaca, 
49; banksiana, 107. 137, 140, 315, 451; 
caribsa, 67, 68, 315; clausa, 67; con- 
torta. 49, 68, 106, 135, 140, 315; coul- 
teri, 107, 315; densiflora, 49, 315; 
divaricata, 49, 68; echinata, 49, 67, 
68; elliotii, 68 

Pithecolobium, saman, 132 

Plant diseaseB, literature on, 79--81, 152- 
154; 22H-234; 3*22-326; 393-398; 45S- 
458; Porto Rican, 66, 130 

Plasmopara, viticola, 258 

Plectodiscella, Piri, 90; veneta, 91 

Pluchea. indica, 160 

Plum, leaf spot, 75 

P(xl blight, on Datura fastuosa, 328; on 
Datura stramonium inermis, 328; on 
Datura tatula inermis, 328 

Polygonum, aviculare, 92; erectUITi, 92; 
ramofliBflimum, 92 

Polyi>oruB. baBiiapidioilcB, 171 ; berklcyi, 
171; frondoBUB. 171; goetzii, 171; 
Mylittae. 171; Polyjwrus, 47; rhino- 
cerotiH. 171; sacer, 171; Sapurema, 
171 ; Bchwrinitzii, 426; sulphureuB, 172; 
tulKTaster. 171; umbellatus, 171 

PolvBtictUB, abietinus, 380 

Poppy, effect of tar smoke on, 32 

PopuluB. acuminata, 353; angustifolia, 
3.'>.'i; balBamiffTH, 3.5.3; tremuloides, 
108. .rvl. .380; trichorarpa. 108. 223, 353, 
380 

Poria. weirii, 176 

PonMliBculuB, iM'n<iuliH. 47 

PoHKY. (1. O.. tH'V M<<'riiBiN, W. A. 

PotaMitum ryanidr. conduction in 
pl.HntM. 443 

Potato, curly dwarf, 71 ; effect of tar 
Biiioke on. 32; leaf roll, 72; lightning 
injury to, 140; malnutrition disease 



Index 



IX 



of, 70; mosaic, 71, 72; necrosis, 71; 

powdery scab, 72; Rhizoctonia on, 74, 

209; rot, 178 * 
Potter, Alden A., and Melchers, Leo 

E., Ecological observations on Usti- 

lago Zeai (abstract), 73 
Pouzolzia, 160 

Prunus, avium, 48; ilicifolia, 191 
Pseudomonas, Citri, 58; fluorescens, 200; 

papulans, 200 
Pseudoperonospora, 133 
Pseudopeziza, 70 
Pseudotsuga, taxifolia, 108, 176, 315, 380, 

426 
Pteris, 35 

Puccinia, Antirrhini, 265; triticina, 224 
Puccinia, 18; Canns, 132; glumarum, 73, 

142; graminis, 30, 73; graminis tritici, 

73; luxuriosa, 93; rubigo-vera, 143; 

subnitens, 92 
Pucciniastrum, pustulatum, 109 
Pucciniopsis, Caricffi, 349 
Pycnoporus, cinnabarinus, 47 
Pynis, malus, 445 
Pythiacystis, citrophthora, 37, 126 
Pythium debaryanum, 126, 391 

Quamoclit, coccinia, 67 
Quercus,'agrifolia, 20; rubra, 107 

Radish, lightning injury to, 142 

Rankin, W. H., The penetration of for- 
eign substances introduced into trees, 
^13; The control of white pine blister 
rust in small areas (abstract), 58 

Rands, R. D., The production of spores 
by Altemaria Solani in pure culture, 
316; Alternaria on Datura and potato, 
327-338 

Raspberry, anthracnosc, 83; effect of tar 
smoke on, 32 

Ravn F. K0LPIN, Jens Ludwig Jensen, 1-4 

Razoumofskya, americana, 140; campy- 
lopoda, 315; occidentalis abietina, 140 

Reedy, C. S., see Jones, L. R. 

Reddick, Donald, see Stewart, V. B. ; 
see Gladwin, F. E. 

Rhamnus, cathartica, 391 

Rhizina, inflata, 175 

Rhizoctonia, 74; crocorum. 111; micro- 



sclerptia, 116; Solani, 111; of the fig, 
110; on potato, 209 

Rhizopus, nigricans, 178, 391 

Rhoads, Arthur S., Some new or little 
known hosts for wood-destroying 
fungi, 46-48 

Ribes, 17, 32, 58, 77; tenuifolium, 372; 
nigrum, 449 

Ridgwat, Charles S., Methods for the 
difTerentiation of pathogenic fungi in 
the tissues of the host, 389-391 

Rogers, John M. and Earle, F. S., A 
simple and effective method of pro- 
tecting citrus fruits against stem-end 
rot, 361-367 

Root rot, of apple, 77, 223 

Roripa, palustris, 93 

Rosa, 32 

Rose, crown canker, 408-417; effect of 
tar smoke on, 32 

Rose, Dean H., Blister spot of apples 
and its relation to a disease of apple 
bark, 198-208 

Rosenbaum, J., and Shapavalov. M., 
Strains of Rhizoctonia (abstract), 74 

Rough-bark or scurfy bark canker, of 
apples, 202 

Rubus, 32; idaeus var. aculeatissimus, 86; 
neglectus, 86; occidentalis, 86 

Rudbeckia, 68 

Rudolph, Bert A., A new leaf -spot dis- 
ease of cherries, 188-197 

Rust, 92, 352, 368; on bread fruit, 131; 
on canna, 132; on clover, 75; on cot- 
ton, 133; on forest trees, 106, 135; on 
grapes, 132 ; on grasses, 73 ; on Gondule, 
132; on peanut, 132; on Pinus resinosa, 
225; on sweet potato, 132; on wheat, 
73; white pine blister, 17, 54, 58, 77, 
95, 135, 224, 319, 368 

Ruth, W. A., see Stevens, F. L. ; see 
Brock, VV. S. 

Salix, cordata mackensiana, 109 
Salpiglossis, sinuata, 161 
Salsola, pestifer, 92 
Sarcobatus, 92 

Scab, on apple, 76, 221 ; on potato, 72 
Sclerotium, bataticola, 65, 308 
ScHWARZB, C. A., see Blake, M. A., see 
Cook, NTel T. 



Index 



Schixanthus, pinnatufl. 161 
Hchixophyllum, rointnunp, 380 
HcHNciDEK. Albeht, Further note on a 

parasitic saccharomycet-e of the to- 
mato. 52-53 
ScHKCiNKR, Oswald, see Edson. H. A. 
8coleeotrirhuni, graminis, 69 
Senecio. 6K 
Septoria. Lyro|>orstci, 65; petroselina 

var. Apii, 65 
Hereh. 423 

Sesamuin. orientate, 160 
Hhapavalov, M., see Ho8cnbai:m, J.; 

Intoxicating broad, Nai'mov, N. A. 

(reviews aS4-.WJ 
Siicrbakopk, (\ I).. Buckeye rot of 

tomato fruit, llD-129 
Silphiuin. anKUstuin, 67; asteriscus, 67; 

c(>rn|>osituni. 67; dent at um, 67; gla- 

hrurit. 67; intcKrifoliuiii. 67; pinnati- 

fidurn. 67; trifol latum. 67 
Silvenlraad, diHras<' on CofTea, 115 
Sisymbrium. altlHuimum. Ik'i 
Smith. Clayton <).. Sour rot of lemon 

in California. 37-41 
Smith. Fum»:\<K P.. we Oiikkly. 

KlNKK. fl. 
SyiTH. Halph K.. a new apparatus for 

aiM*ptir ultrafiltration. 2tK>-2!)3 
Smut, oil corn. 73; on oats, .'isi 
Snap Iwan. mosaic. 61; Sclerotinia 

lib«'rtiaiia oti. M) 
Solaiium. rantlincmw*. 6.'>. 163; melon- 

Kcna. 157: niKrum. ItU), .'Wl ; tuU'ro- 

utiin. 3 J. 157, 17K 
S<»lidnKo. r»7 
S<M>ty iiifild^. fin (*amcllia. \'X\: on 

oraiiic*'. 1<{<'{ 

S<iphi:t. |:iiiriata. \r2 

Sour rot. of ItMiion. 37 

S*»y kn'tin b;irt«Tial bliuht of. Ik'* 

Spar:iN«in. rn!»pa. 167; hcrlM'^tii. 161»; 
laiTiinoM.i. liV'J; ridicats, l(W'i:raiiioHa.l69 

Sp\t i,i»iN<.. I'liiu.i.v \ot«H <»n Cronar- 
tiuiii Cniiiptotii:!' III. !'.» 51 : K\i<icnn» 
of ih«' 'tviT uiiii«rm>: of Cronartium 
ribii'ola alKftract . 5s : \«M'dU« runt on 
PiTiu- n-finotia. iri5: and PiKiu i.. Hn\ 
it. S':iti' ami National <|uarantini'«< 
:»i:;tjn-f tlir wliit#- |iin«' bli»»t«T ni-f, 3|0 



Spilanthes, acmella, 160 

Spongospora, subterranea, 72 

Sporobolus, airoides, 93 

Squash, effect of tar smoke on, 32; 
mosaic on, 61 

Stakmax, K. C, and Piemeisel, F. J., 
A new strain of Puccinia graminia 
(abstract), 73 

Stanford, K. E. and Wolf, F. A., 
Studies on Bacterium solanacearum, 
155-165 

Stanleya, pinnata, 93 

Stem rot. of clovers and alfalfa, 432 

Stem-end rot. of cirtus fruits. 361 

Stercum, frustulosum, 217;spathulatum, 
169 

Stkvenh, F. L., Noteworthy Porto Hican 
Plant diseas(;s (abstract). 66; (ar- 
ticle). 1,30-134; and Hi-th. \V. A., 
Pkltikk, (J. L.. and Mall<kh, J. U., 
()l>servations on |M>ar blight in Illinois 
(abstract), 75 

Stkvknh, Nkil K.. and Hawkins, Lon 
A.. S<ime changes prcKluced in straw- 
U'rry fruits by Uhizopus nigricans, 
17H-184 

Stkvknhon, John A.. Lightning injury 
to sugar cane. 317; an epiphytotic of 
cane <li»eaMe irt Porto Hico. 4JS-425 

Stkwaht. F. ('.. \S it(lH's-br<M>m8 on 
hickory tn^^'H. IV* IS7 

Stkwakt. V. B.. A twig and leaf dis- 
fa>M* of Kcrria ja|M»nica. 3t>{^ M)7; The 
fM'H'nnation of (Vonartium ribicola on 
rurraiit, H1M5(); and UKi>i)irK. Don- 
am*. li<*an mosiiic iabHtract>. 61 

Stin>ella. Havida. 131 

StrawlM»rrv, effect of tar smoke on. 32; 
rot of. 17S 

Stizolobium, nivcum. H>1 

Subulina. o<'tona. 371 

Sugar \H*i*\. curly top of. JtiO; light- 
ning injury to. Ill 

Sugar cam*. ilisiM.***-. lis; leaf spot of. 
131; linhtning injury t«». 317 

Suntloui-r. elTiTt of tar snn»k«" on. 32 

S\Nr«f p<»t:iio. ihan*«»nl rot of, 312; 
< '>^to.^|lora batata on. 71; rust on, 132 

Svnt-dn'lla, n<MliMt»r:i. Hi() 



Index 



XI 



Tarvia fumes, effect on vegetation, 32 

Taubbnhaus, J. J., Two new camphor 
diseases in Texas (abstract), 59; and 
Johnson, A. D., Pink root, a new root 
disease of onions in Texas (abstract), 
59 

Tatlob, Minnie W., Preliminary re- 
port on the vertical distribution of 
Fusarium in soil, 374-378 

Tea, disenfie of, 132 

Tectona, grandis, 160 

Thlaspi, arvense, 93 

Thomas, H. E., see Fromme, F. D. 

Thrinax, ponceana, 131 

Thuja, occidentalis, 47 

Timothy, Scolecotrichum graminis, 69 

TiSDALE, W. H., Relation of temperature 
to the growth and infecting power of 
Fusarium Lini, 35^360 

Tobacco, wilt, 155; Cercospora nico- 
tiansB on, 348 

Tomato, buckeye rot of, 119; damping- 
off of, 319; fruit rot of, 60; leaf-spot of, 
327; lightning, injury to, 142 parasitic 
saccharomycete of the, 52; Phyto- 
phthora infestans on, 319; wilt, 155 

Trametes, camea, 380; heteromorpha, 
380; hispida, 380; lacerata, 380; peckii, 
380; Pini, 176; rubescens, 379; serialis, 
380; trogii, 380; variiformis, 380 

Trichoderma, lignorum, 424 

Trifolium, hybridum, 70, 432; incama- 
tum, 70, 432; pratense, 70, 432; repens, 
70,432 

Triticum, vulgare, 73; compactum, 73 

Tropseolum, lobbianum, 161; majus, 160; 
peregrinum, 161 

Trumbull, H. L., and Hotson, J. W., 
The effect of roentgen and ultraviolet 
rays upon fungi, 426-431 

Tsuga, canadensis, 46; caroliniana, 109; 
heterophylla, 108, 380, 426 

Tuberculina, maxima, 139 

Turnip, lightning injury to, 142 

Tylenchus, tritici, 56, 452 

Tyromyces, ca;sius, 47 

Uncinula, necator, 66 
Uredo, Artocarpi, 131 
Uromyces, Arachidis, 132; Dolicholi, 132; 
fallens, 70, 75; JaniphsB, 133 



Ustilago, Avenge, 381; Isevis, 381; Zeae, 
73,294 

Venturia, pomi, 221 
Verbena, erinoides, 161 
Verbesina, 67 
Vemonia, 67 
Verrucosis, GO 
Volutella, fructi, 59 

Walker, J. C, Studies upon the an- 
thracnose of the onion (abstract), 59 

Waite, M. B., Common and scientific 
names of plant diseases (abstract), 60 

Wandering-jew, effect of tar smoke on, 
35 

Weir, James R., Notes on wood-de- 
stroying fungi which grow on both 
coniferous and deciduous trees, II, 
379-380; and Hubert, Ernest E., 
Recent cultures of forest tree rusts, 
106-109; Pycnial stages of important 
forest tree rusts, 135-139; New hosts 
for Razoumofskya americana and R. 
occidentalis abietina, 140; Sparasis 
radicata, an undescribed fungus on 
the roots of conifers, 166-177; Note on 
Xylari^ polymorpha and X. digitata, 
223; Cronartium cerebrum on Pinus 
resinosa, 450-451 

Western wheat-grass, bacterial disease 
of, 225 

Wilt, cabbage, 375; flax, 375 

Wheat, Tylenchus, tritici, on, 56, 452; 
leaf-rust of, 224; rust, 73 

Wilt, Bacterial heart, of celery, 64; 
crown rot, of celery, 64; of nastur- 
tium, 160; of peanut, 156; of tomato 
and potato, 155 

Witches-broom, on cherry, 185; on hick- 
ory, 185 

Wolf, F. A., see Stanford, E. E. 

Wood-destroying fungi, 46, 214 

Xylaria, polymorpha,77,223; digitata,223 
Yam, Cercospora carbonacea on, 351 

Zantho^ylum, fagara, 339 
2iebrina, pendula, 35 
Zygosporium, oschioides, 350 



KHHATA FOR VOLUMK VII 

Pa^o 4i^ line 27, for urtnlinospores read urediniospores. 

I'agc 113, 114, and 115, for C(»rticum read Corticium. 

Pago 113 lino 9 and page 114 line 4, for ochraUucum read oc/iro/cucum. 

Page 132 line 5. for CrphaUurujt read Cephaleuros. 

Page 134, for Illinois Tniversity read University of Illinois. 

PaKo 1H4 line 7, for frum rea<l from. 

Page ia3 line 1, for 30 read 50. 

VHge 208, section 6 of Huinniary, line 3, for diseases read diseased. 

Page 350. legend for figure 3 should read Zygo»porium anchxoides. 

Page 360, 370. and 371, in table headings for uredinospores read urediniospores. 

Page 370, table 1, column K, for JG* read 26. 

Page .'Wi line 10. for Tomasski read Pomasski. 

Page 3110 line 12, strike out comma after water/ 

Page 418 line 1, after cane insert di.-ease. 



' •* , ■^ 



PHYTOPATHOLOGY 

VOLUME VII NUMBER 1 

FEBRUARY, 1917 

JENS LUDWIG JENSEN 
(1836-1904). 

F . K0LPIN R A VN 

With Portrait, Plate I 

The introduction of "hot-water treatment" is one of the most impor- 
tant steps forward in practical plant pathology, for it means a new prin- 
ciple both from a theoretical as well as from a practical point of view. 
Therefore it will surely interest the readers of Phytopathology to be- 
come acquainted with the originator of the method, because in it we 
find an example of progress due to a man from practical life, who had 
scientific qualifications as well, and the ability to carry on independent 
research. 

Jens Ludwig Jensen was born January 9, 1836, near the little town of 
Odder in the Danish province of Jutland, where his father was forester. 
In 1855 he passed a normal school examination and later supplemented 
his education by studying natural science. He taught school imtil 1872. 
In 1868 he started a weekly agricultural magazine, of which he remained 
the editor imtil 1880, and from 1879 until his death, he was the publisher 
of a widely circulating advertiser. 

In 1872 Jensen resigned his position as teacher, and together with a 
colleague started a company for selling scientifically tested seed. This 
has had a great influence on the development of modern agriculture in 
Denmark. He took part in the daily routine of the business until 1881, 
and remained one of its directors until 1896. 

Jensen never held any official government position but he managed 
to arrange his practical affairs in such a way that he could spend much 
time in study, and in 1881 he organized this work as a private statistical 
institute which he called Bureau Ceres. Its object was a systematic 
collecting of observations made in practical agriculture and an experi- 
menting both in field and in the laboratory, which he had equipped in 
his private home. Although many of Jensen's methods were primitive, 



•• .•••• • * » 1 • m #••••• • • 

••'•••• •••• % ••*••' '•••*••• •* 

• ••• »..•• • ••••,.• ••_••• ••• 

• ••• ••••••••• ••••*•* •••• •• •• 

2 Phytopathology [Vol. 7 

yet his work is so exhaustive and original that his investigations of potato- 
late-blight fungus (Phytophthora infcsians) and smut in cereals are among 
the most important contributions to our knowledge of these diseases. 
Jen8<»n*H incentive for investigating the potato disease was the work 
done by his company in introducing new varieties of potatoes into Den- 
mark. In the years 1878-1881 more than one thousand experiments 
were made in all pjirts of the country and wliile inspecting these Jensen 
had an opportunity of studying the appearance of the disease under 
various conditioius. This suggested infection experiments in which he 
studied the spread of the infection from the leaves to the tubers rjid 
more particularly the ability of the soil to retain the s|K)resof the fungus 
by filtration. 

In 1882 Jeii.**en published \\\^ exixjriments which resulted in the develop- 
ment of a methoil, "protective moulding/' to prevent the tulxjrs from 
infection. He discovered. tcK>, that by postponing digging for two weeks 
after the wilting of the top, tul)ers otherwi.se subject to late attacks of 
the du^ease might Im» kept from infection. 

In June 1882 Jen.*4en U^gan his imi)ortant exi)eriments concerning the 
influence of tem|)erature on the development of the fungus. He dis- 
covere<l among other things, that this could not grow in a temperature 
of under 5°(\ or over 2-r(\ Therefore the storage temjKTature of po- 
tatoi^s during the winter should never go liigher than bW These ex- 
periments gave Jen.**en the clue to understanding why the fimgus attack 
is severe only in temixjnite (*limates, and he formed an hypothesis for 
explaining why the iK)tato di.*it*jise was not o!)served in North America 
and KurofH* before 1840. First then was the development in the means 
of trans|M>rtati<»n such that the |)otatoes from the plateau regions of iSouth 
Ameri<*a, the original home of the |K>tato an<l the potato fungus, might 
l)e carric<l .•io (|ui('kly through the tropical zone that the hyphae in the 
tulK»rs di<l not die on the way. 

In ()(*tolMT 1882 Jeimen succee<le<l in demonstrating that the hyphae 
an<l s|)on*s which were found in and on the dise:ised tul)ers could \ye killed 
by applying a temi)eratun» <»f M)W for four Jiours to the potatoes with- 
out affecting their germinating iH)wer. The heat must 1k» applied as hot 
air for the germinating |H»wcr sufTered too much when the tubers were 
immersed in hot water. 

In 18K;J-1H8-1 JeiLK^'u published his method for <lisinfecting seed jx)- 
tato«»s by heat. When this was wskhX it was |)o.*isible to prevent the pri- 
nuirv attacks of the diM»ase and to delav the se<*ondarv attacks at least 
one to two ww»ks. 

Until )H>rdeaux mixture ap|M'ared for the first tune in 188G as a preven- 
tive of disease. Jeri.Hen's system for fighting the jKitato fungus was the 



1917) Ravn: Jens Ludwig Jensen 3 

best established method both practically and scientifically. In 1886 his 
work received recognition from La Soci6t6 Nationale d' Agriculture de 
France, and he was awarded the large gold medal of the society. 

In 1885 Jensen began to investigate smut in cereals, and by means of 
cross-inoculation experiments he succeeded in demonstrating that the 
old well-known species Ustilago segetum should be divided into four varie- 
ties which he named, tritici, avence, hordei nuday and hordei tecta. The 
distinctiveness of these varieties was later confirmed by the mycological 
research of Rostrup, Brefeld, and Kellermann and Swingle. These in- 
fection experiments made it appear most probable that smut on barley 
and oats was caused by infection during the blossom period and that 
the smut spores (or hyphae) are to be found under the glumes in the 
ripe kernels. The importance of the r61e played by infected seed was 
further demonstrated by experiments proving the impossibility of in- 
fection through the soil and manure. 

In 1887 and 1888 the most important experiments in disinfecting seed 
were published. Jensen compared' the chemical remedies proposed by 
others (copper sulphate, sulphuric acid, quicklime, salt) with the hot 
water treatment he himself had found. He first applied hot air during 
a long period as for the potato fungus, but the results were for the most 
part unsatisfactory. However, an experiment made in the summer of 
1887 in treating oats with hot water, circa 55°C. for five minutes, resulted 
in killing the sniut without affecting the germinating power of the oats. 
This experiment forms the starting point for the development of the 
"Jensen hot-water treatment." 

Jensen now made this interesting observation: Smut in barley is not 
to be killed by the same treatment as smut in oats, but if damp barley 
seed has been subjected to a temperature of 53®C. for five hours in a corked 
bottle the smut disappears. Jensen explained this phenomenon by sup- 
posing that a five minutes^ immersion in hot water was insufficient to 
moisten the smut germs hidden in the seed and that they therefore were 
treated in a dry condition which could not occasion their death. By the 
slow heating of wet barley the moisture had time to penetrate and soften 
the smut germs and these were therefore killed by the temperature ap- 
plied. If this were true Jensen thought that smut on barley could be 
prevented by soaking the seed in cold water and then applying the usual 
hot-water treatment for five minutes. Experiments made in 1888 proved 
the truth of this theory. 

As we see, Jensen had now discovered two variations of a method 
according to which all forms of smut on cereals might be fought. He 
also proved that hot-water treatment could be used for smut on Bromus 
and Arrhenatherum and that it might be used as a preventive measure 
against certain types of damping-off in sugar beets and mangels. 



4 Phytopatholoot [Vol. 7 

Jensen's method won and deserved much recognition both in Denmark 
and abroad. However, it was a great disappointment to him to see that 
many farms which had introduced the method abandoned it later. It was 
too complicated for general practical use where no steam was available. 
Nor was he successful in his attempt to form a company for building a 
factory for applying the hot-water treatment of cereals on a commercial 
scale. 

After this Jensen discontinued his work with the hot-water treatment 
and devoted himself to experiments with chemical remedies. Among 
these he preferred potassium sulphide, first tested by Kellermann and 
Swingle. This sul)stance was the main ingredient in the so-called Ceres- 
powder, manufactured by Jensen and placed on the market in 1895. 
The last years of his life until hLs death, August 10, 1904, were largely 
devote<l to exjieriments with this remedy and agitation to bring it into 
practical use. 

During the yean* since Jensen's death the hot-water treatment has 
again come to the front. In connection with many of the Danish dairies 
and breweries, coojierative institutions have l)een established for dis- 
infecting Heed with hot water. During the past year several seed firms 
have built factory plants for the hot-water treatment in combination 
with a plant for drying the seed. The seed which has been thus treated 
is sold with a guarantee for its freedom from smut and leaf-stripe disease. 



THE PENETRATION OF FOREIGN SUBSTANCES INTRODUCED 

INTO TREES 

W. H. Rankin 

With One Figure in the Text 

Meyer^ in 1808 succeeded in introducing a dyeing liquid into the roots 
of a small tree by cutting the stem and immersing the upper part of it 
in the liquid. The solution penetrated after some time into all the roots 
with the exception of their tips and the slenderest rootlets. 

Boucherie* about 1840 patented his method of preserving timber for 
building purposes. He made a shallow groove around the tree and 
covered it with a belt. The space under the cloth was then connected 
with a barrel containing the preserving liquid. The solution was absorbed 
and ascended to the branches and leaves. Later, he modified his method. 
A canal two centimeters in diameter was made through the stem and 
from the latter cuts were made with a saw on both sides as far as possible 
without allowing the tree to fall over. The liquid was distributed up and 
down the stem. The area saturated, however, decreased rapidly in 
breadth in the downward direction. He states that the best seasoit for 
thorough penetration by this method is autumn. It is doubtful as to the 
meaning of the expression "thorough penetration" since he further states 
that if there are hard knots or rotten spots at the base of the tree the whole 
strip of wood above them did not become saturated at all and the same 
was true with the central part of the core of deciduous trees. 

Hartig' introduced colored solutions iiito the growing stems of treed. 
He bored two holes at right angles to each other in the trunk and intro- 
duced the colored solution into them. It was carried to the top of the 
tree but in transverse sections made of the tnink the coloring of the wood 
was not uniform. Only those vessels directly above the canals were 
colored, forming a cross in the sections. 

* Meyer, J. C. F. Naturgetreue Darstellung der Entwickelung, Ausbildung und 
des Wachsthums der Pflanzen und der Bewegung und Functionen ihrer Safte. Leip- 
zig. 1808. 

' Boucherie, M. A. Mdmoire sur la conservation des bois. Annales de chemie 
et physyque 74: 113-157. 1840. 

Nouvelles recherches siir la conservation des bois. Comptes Rendus 12: 

337-339. 1841. 

* Hartig, T. (Discussed by Shevyrev 1903: 6-7, but the direct citation to Hartig 
is not given.) 



6 Phytopathology (Vol. 7 

Sachs* in experiments on the rate of ascent of sap in woody plants 
used lithium nitrate. He allowed the plants to absorb this through the 
roots and found the lithium present at intervals along the stem and at the 
tips of the branches. He performed laboratory experiments in which he 
showed that such a substance as lithium would progress in the stem almost 
as rapidly as water itself, while solutions which dye the cell walls along 
its upward coiu-se do not rise nearly so rapidly nor so far, since they are 
largely filtered out. 

Shev>Tev* was the first to utilize the original negative tension of gases 
in the tree as a force for distributing the introduced foreign substance. 
He attributes the failiu-e of Hartig and others to get penetration, except 
immediately above the incised vessels, to the neglect of this factor. His 
method was to attach a funnel or half-funnel to the tree, fill it with water 
and then make an opening in the tree with a chisel or auger, underneath 
the surfaw of the liquid. As a modification of this he devised a metal 
tulx; which wjis jireviously connected with a reservoir containing the feed- 
ing solution. This was forced at one end into the bark. The other end 
wa.s closed with a rul)l)er stopjx^r through which a bit was inserted. Thus 
when the lx>riiig wjis done the solution from the reservoir penetrated 
immediately into the wound and the sucking jKJwer due to the negative 
tension of the gii.**es in the tree was utilized to pull in the solution. He 
states that by this method the dye penneates not only the iierial but 
also-the radicate i>jtrts of the plant. .\s to the results, he states: **The 
absorl)ed li(|uid luid risen to the top and colored all the veins of the leaves 
and even the veiru* of the !>orries on th(» gra|K» vine. The dye could be 
det<M'te<l five feet Ik»1ow the surface on all of the roots of the birch, apple 
and itsh trees. Thus the first part of the problem is solved; we can in- 
tnxluce a licpiid in a <li!!sired quiuitity into all iMirts of a tree. '* Further 
he states: '*The vessels iiicise<i in the licjuid, al)«orl>ed and distributed 
it to all parts of a living tree. Only the pithy, dead portion of the tree 
was not saturated with the li(|uid althougli its absorption by the rays oc- 
curred (with an oak). The li(|uid entered the roots as well as the leaves, 
twigs and fruit." The data given for ea<*h tree fed do not indicate tliat 
he obtaine<l anything more than the satunition of the sap wood and bark 

• Sarh?*, J. Kin H«*itrag xur KcnritnifiK livn aurHtcMgendrn Suftntrorii in trun»piri- 
nmivu Pflanien. .\rb. lM»t. Innt. \Vuril»urK 2: IIH-IM. 187S. 

* Shi'vvrc'v, Ivan. <Kxtrara4lirati» nutrition of <liMeaJ*ni Xrvvn with the aim of 
curinic thrni and (i«»j*tn»yinK their paruiiitejf. ) M. Z. and (1. I. Foreatry Dept. Re- 
port to Foreatry Department al>out injuriouh iiiHerts, pp. 1-51. 1903. (Roprintinl 
from SeUk. Khoi. i. LyetMiv. VMKi: 5H la'M 

(Supplement** to the "Fxtraradirate nutrition of <liHoaMe<l trees with the 
aim <if runng thefii and <le<«troviriK their (xiriudte?*". i Zemledelt<*heskala Kaiota 
(Agrirultufal (iaieti** No- .'{. I. .'>. ft ItKM. ^Reprint eonHuite<l. pp. 1 \li). 



1917] Rankin: Penetration op Substances 7 

of root and stem and the leaves, for he mentions specifically that the 
medullary rajns in the case of a single oak were colored. 

Roth,* Goff,' Mangin,^ Mokrzecki,® BoUey,^® Simon," Fron,^ and others 
have fed trees with various types of solutions, including colored and 
nutritive substances. The majority of them have used nutritive salts or 
poisons in anticipation of curing physiologic ailments or inhibiting plant 
pathogenes and insects. No accurate data are given on the penetration 
except that the solutions in many cases were found to reach the leaves 
and some obtained penetration of the roots. 

choice of substances for experiment 

It seems from the very nature of colored solutions, such as methyl 
blue and eosin, that they would not be suitable for determining accurately 
the greatest possible penetration obtainable by introducing a foreign 
substance. The staining quality is very helpful in tracing the rate and 
distance which the substance has advanced, but at the same time much 
resistance must be encountered by such substances and finally much of 
the original quantity absorbed will be adsorbed, filtered out and chemi- 
cally united with the different plant parts which it will stain. The utili- 
zation of substances such as the lithium salts overcomes these disadvan- 
tages although the actual ascent is not visible. The salts of Uthium are 
for the most part soluble in water, they are not used up rapidly in the 
metabolic processes of the plant and most important of all the minutest 
trace can be detected with the spectroscope. Lithium nitrate in solution 
was used m the experiments reported below. 

* Roth, Carl. (A method for artificially feeding trees.) Chem. Ztg. 20: 344- 
345, fig. 2. 1896. 

^ Goff, E. S. The application of artificial root pressure to recently transplanted 
trees. Wisconsin Agr. Exp. Sta. Ann. Rept. 14: 272-282, fig. 4. 1897. 

*Mangin, L. Sur la nutrition et la defense de la vigne par injection. Jour. 
Agr. Prat. 1898: 918-920. 

^Mokrzecki, S. A. (A new method of healing and nourishing trees.) Vyest- 
vik Tavr. Zenistvo. nos. 11 and 12. 1903. 

Uber die innere Therapie der Pflanzen. Zeitschr. Pflanzenkr. 13: 257-265, 

fig. 1-5. 1903. 

*" Bolley, H. L. (Artificial feeding of trees.) Report of the botanist. North 
Dakota Agr. Exp. Sta. Ann. Rept. 14: 42-58. 1903. Ibid 16: 33-65. 1904. Ibid 17: 
35. 1906. 

" Simon, J. M. (Hypodermic injection in plants.) Jour. Soc. Nat. Hort. France. 
(Abs. in Card. Chron. 3:41:8. 1907.) 

" Fron, G. (Contributions to the study of the injection of nutrients into fruit 
trees.) Jour. Soc. Nat. Hort. France 4: 10: 54^59, fig. 2. 1909. 



8 Phytopathology [Vol. 7 

forces aiding distribution in the tree 

There seem to be three forces which must be depended upon for the 
rapid distribution of any foreign substance throughout a tree. (1) By 
taking advantage of the negative tension of the gases in a tree in the sum- 
mer, when transpiration exceeds the intake of water through the roots, 
the solution containing the substance is quickly intromitted. Undoubt- 
edly, the currents set up by supplying this ready access to a quantity 
of liquid ser\'e to distribute the substance to a certain degree. (2) Most 
important of all, however, are the translocating streams of sap in the 
tree. The upward movement of raw sap will soon carry the substance 
to the leaves and the downward movement of the modified food materials 
in the phloem will undoubtedly csLTiy the substance back down to all 
parts of the bark. The constant translocation of materials between such 
active cells as phloem parench>Tna and medullary ray cells will serve 
to distribute it in time throughout these tissues and the downward move- 
ment of modified food into the roots would also be expected to ultimately 
carry the substance through the root tissues. (3) Except by diffusion, 
which is a ver>' slow process, the only movements which can be counted 
on to distribute the substance in the heart wood are the translocation 
currents in the medullary rays and the alternate withdrawal and renewal 
of the water in the heart wood. The water in the center of the tree is 
said to act as a reser\'e supply upon which the tree draws during the day 
in dry weather. The normal water content of the heart wood is again 
restored at night. It wquld apf)ear then that such an oscillation of 
currents might 8er\'e evei tually to distribute the substance throughout 
the wood. 

In other words there is no reason to l)elieve that a foreign sul)stance 
intrcnluced into a tree cannot penetrate to all parts provided it possesses 
certain properties in itself. 

METHOD OP FEEDI.VG 

Ten chestnut trees var>'ing from two and one-half to nine inches in 
diameter wore fed. The trees were growing in the forest and had small 
crowns. Shevyrev*s methods with slight modifications were used in 
the«<» ex|)orinH»ntjt. .\ haif-funnel was attached to the tree with putty. 
The funnel wiis then fille<l with water and a one-half inch hole was bored 
un<l(T the surface of the water with a bmce and hit. The hole was l)ored 
to rrach Xhv c<»nter of the tree. .\ one-gallon l)ottle containing the lithium 
nitrate* solution had previously lK»en suspended so that the l>otton of the 
Ijottlf w'lin slightly hij^her than the hole in the trunk. The solution 
was tlu'ii connected with the tree by means of a siphon, made of glass 



1917] 



Ranxin: Penetration op Substances 



9 



and rubber tubing, one^iuarter of an inch in diameter. In order to keep 
out air and prevent the leaking of the solution the apparatus illustrated 
by Rumbold" was used. The rubber siphon was connected to a short 
piece of glass tubing inserted through a one-inch rubber stopper. In 
attaching the siphon to the tree the solution was first started running and 
as the half-funnel was knocked from the tree the rubber stopper with 
the glass tubing of the siphon inserted was pressed against the tree so that 
it covered the hole. The end of the glass tubing was allowed to pro- 
ject into the hole about one inch. The rubber stopper was then held 
firmly against the tree by the use of wooden frames and a piece of No. 8 
spring-steel wire. Thus the opening was perfectly sealed and after being 
once properly adjusted, needed no further attention. The glass siphon 
tube, reaching to the bottom of the bottle, was held in place by a loosely 
fitting stopper. By slightly raising this stopper a new supply of the solu- 
tion could be poured into the bottle. 



AMOUNT AND STRENGTH OP SOLUTION PED TO TREES 

No attempt was made to keep careful records on the periodicity of the 
intake *or to correlate it with any of the factors influencing the rate of 
intake. The accompanying table gives such data as were taken. Tree 
1 had two days of clear, hot weather on July 15 and 16, when it absorbed 











TABLE 1 








Amount of lithium nitrate in liters of solution taken up hy chestnut trees 




TBBB 


I1R8T FBBDINO 


BBOOND rSBDINO 


THXBD XBDXNO 


TOTAL 


KUIC- 














BBB 


0.002 per cent 


0.025 
percent 


0.1 peroent 


0.1 percent 


Liters 


GraniM 




Jy. 16-16 


Jy. 16 


Jy. 16-20 


Jy. 90-26 


Jy. 26- A. 7 


A. 19-0. 10 






1 


3 


2 


2 


1 


2 


3 


13 


3.39 


2 




2 


1.5 
Jy. 16-17 


1.5 
Jy. 17-26 


1 


2 


8 


2.45 


3 




2 


i 


3.5 


2 


1 


12.5 


2.00 


4 






Jy. 17-18 


Jy. 18-26 


3 


2 


5 


5.00 


5 




1 


3 


2 


2 


3 


11 


5.58 


6 










3 


1 


4 


4.00 


7 












4 


4 


4.00 


8 












2 


2 


2.00 


9 












2.5 • 


2.5 


2.50 



" Rumbold, Caroline. Report of the physiologist. Report of the Pennsyl" 
vania Chestnut Tree Blight Commission, July 1 to December 31, 1912, pp.45-47» 
figs. 39-49. 1913. 

Methods of injecting trees. Phytopath. 6: 225-229, pi. 13. 1915. 



10 Phytopathology [Vol. 7 

five liters of solution in twenty-six hours. Then followed a period of 
cloudy and cooler weather which caused a marked decrease in the amount 
absorbed by trees 1, 2, 3, and 5 during July 17 to 20. The largest amount 
of solution was absorbed inmiediately after attaching. Tree 2 absorbed 
two liters the first three hours and tree 3 absorbed five liters the first 
nineteen hours. However, the hole in tree 3 reached to decayed heart 
wood and the punky wood absorbed an unusual amount. The amount 
absorbed diminished rapidly after the first two days and in most cases 
practically ceased after the fifth or sixth day. Trees fed the second and 
third time did not take in as much as they did the first time. The in- 
creased strength of the solution used in the later feedings may hav^ ac- 
counted for this. However, no detrimental effect on the tree was ob- 
8er\'eil and the one-tenth per cent solution allowed the feeding of a suf- 
ficient amount in a shorter time. After the feeding on August 13, all 
the trees were allowed to stand until October 10 so that a chance was 
affonliHl for more complete distribution. The leaves were just begin- 
ning to fall when the trees were cut. A burning of the margins of the 
leaves occurred in the case of the smaller trees which had taken up as 
much lithium a.s some of the larger trees. 

MFrrnoD of analysis of trees 

The trees were cut as near to the ground as possible. Cross-sections 
about one-half inch thick weie cut from the base, at the point of feed- 
ing and ever>' ten feet up the trunk. A few leaves were taken from the 
to|>s of the trees. The section.s were then seasoned. To obtain small 
block.s from these sections for s[)ectroscopic analysis, a strip al>out one 
centimeter wide was sawecl out along the diameter of each section. Where 
the bark was thick the cork layer was separated from one end of the strip, 
starting with the end which n»pR»sentod a iH)int din^ctly al)ove or lx*low 
thr phuT of fet^ding. This >\*as place<l in a viiil and lalM^led. Next the, 
inner bark wjis H]>lit off from the wood. Then a small block alx)ut one- 
half reiitimeter thick n*pn»senting the sapw(K)d was cut from the strip. 
Similar blcM*ks wen* c\it fmm the strip at intervals of al>out two centi- 
meters until the sapwcHHl, inner bark and cork was rea(^hed at the other 
end (»f the strip. In this way it was considen^d tliat representative por- 
tions of the tree wen? obtain(*d for analysis wliich would show rather 
accunitely X\u* |)enetration .s<Mnin»d. The l)lo(!ks wen? then incinerated 
in ran»fullv clean(»<l rniciblc*s in the bunsen fhiine. The ash was btuned 
on a platin\im nc^edle in a colorl(*ss giis fbme and the spectrum observed. 
Thr pn»si»nce or alisena* of th<» n»d lithium line indicated whether or not 
the lithitim had |x»netnite<l to the \mn of tlie tree represented by the 
block U*ing analy.sed. 



1917] Rankin: Penetration of Substances 11 

RESULTS 

The results obtained were practically uniform. The blocks in which 
UtUum was found are shown graphicaUy in Ulustmtions 1 to 9 in figure 1. 
In all of the trees except 3 and 6 complete penetration of the bark and 
sapwood was obtained at and above the point of feeding. In trees 3 
and 6, for some reason, the lithium did not penetrate the sapwood on 
the side opposite the point of feeding. In all the trees except 1 and 4 
the lithium had completely penetrated the sapwood and inner bark of 
the sections taken at the surface of the groxmd. In the case of trees 
1 and 4 the solution had penetrated the bark and sapwood immediately 
below the point of feeding but did not appear in bark and sapwood on 
the opposite side. In trees 1 to 6, which varied in diameter from 5 to 9J 
inches, the Uthium had penetrated the heart wood only in a few cases, 
notably the basal sections of trees 1, 3, 4 and 5 and the section twenty 
feet above the point of feeding in the case of tree 2. Tree 4 showed more 
heart wood penetrated than any of the others. In this tree the heart 
wood was decayed where the basal and breast-high sections were taken 
and the bark and sapwood of the basal section on the side opposite to the 
point of feeding was not penetrated. However, in the first two sections 
alcove the point of feeding the lithium had penetrated for at least two 
centimeters inside of the sapwood in sound heart wood. In the case of 
the trees of smaller diameter (7, 8 and 9) complete penetration of the en- 
tire wood and bark was obtained. These trees (7, 8 and 9) were from 
2| to 3 inches in diameter and contained several layers of heart wood. 

The leaves and twigs from the very tops of all the trees showed a large 
amoimt of lithium present. 

conclusions from data obtained 

From the above results it may be stated, therefore, that: 

1. Lithium nitrate when fed to chestnut trees by Shevyrev's method 
penetrates to all places in the tree where there is an active translocation 
of food materials, that is, to all parts of the bark and sapwood above 
and below the point of feeding. 

2. Complete penetration of the heart wood is obtained in trees less 
than three inches in diameter. In trees of greater diameter the process 
of penetration is slow and does not seemingly follow any definite rule. 

Cornell University 
Ithaca, New York 



12 Phytopatuologt [Vol. 7 



EXPLANATION OP PIGURE 1 

The fig:ur(« rcfircAont the Atrip8 of wood bewchI out along the diameter of each 
croMHtertion rut from tho trees. The blockii analyicd are shown in correct pro- 
portion as to siie and position in the strip. Those blocks represented by shaded 
areas Rave positive tests for lithium; those represented by white areas contained 
no lithium. All the figures are reproduced to a scale which equals one-fourth the 
site of the original sections. 

The sets of sections are numbered according to the trees which they represent. 

The sirctions from each tree are lettered as follows: 

.4. Section from base of tree (at ground) • 

B. Section at |>oint of feeding (breast high) 

C. Section ten feet above B 
I). Section ten feet above C 

E. Section ten feet al>ovc D 

F. Section ten feet al>ovc E 

(S. I^*Aves taken from top of tree 
When* three blocks are shown at the ends of the strips they represent from the 
outside inmard. cork, green bark and sapwood respectively. Where only two are 
shown they rrpnttcnt bark and sapwo<Ml. 



19171 



Rankin: Penetration of Substances 



13 



inr 



I II II II 1 

II II II ir~rT 




TT-TT 



II II II 



II ■ II nnn 



mnr 



n 



II II II 





c 
■ 



A 



r 



n 



II II II 



IE 



IT 



'I 'I II II !•■ 

e 



II II II !■ 



A 
S 



n-p-TT 



i 



I I n I I 

••r 

A 
S 



n 



mi 



TTTT 



n 



n 



n 




IE 



TT— n 



II II n rr 



Fig. 1. Diagrams Illustrating the Penetration of Chestnut Trees 

WITH Lithium Nitrate 



THE GENERATION OF ALDEHYDES BY FUSARIUM 

CUBENSE 

Klbert C. Lathrop 

The possibility of aldehyde occurrences in cultures of the organism 
from the CuImui banana disease Wiis called to the attention of this labora- 
tory by Dr. (\ Rumlx)ld localise of the odor accompanying its growth. 
The possibility of aldehyde production by the fungus was further suggested 
by the work of the author on color production through interaction of 
aldehydes and certain plant constituents in connection with the investi- 
gation of humus iKxlicH. One of the cliaracteristics of the Cuban banana 
disease, whicli according to Smith* is due to the fimgus, Fxisarium atbense, 
is the purple, purple-brown, or blackish stain produced in the vascular 
bundles of the dise^ised banana plant. This Fusarium also reddens or 
purples various culture media. Numerous experiments carried on in 
this lalx)rator>' on the action of aldehydes of various chemical constitution 
in respect to their effect on plant growth have demonstrate<l that alde- 
hydes are uniformly deleterioiLs in action. The generation of aldehydes 
by Fusarium cubettM' might therefore account, at least in a measure, for 
its pathological action as well. 

In reg]ird to the generation of aldehydes by microorganisms Grey' has 
shown that acetaldehyde is a product of the action of B. coU cammuntM 
on glu<*ose muler anaerobic conditions. That acetaldehyde is a product 
of the alcoholic fermentation by yeast was discovered by Roeser,* and 
more recently (\ Neul)erg and his co-workers have very fully studied 
the mechanism of this reaction. Neuberg and Hildesheimer^ have shown, 
for example, tliat acetaldehyde is pro<luced by the action of yeast on 
p\Tuvic acid, while NeulM»rg and Kerb' have been able to produce propi- 
oni<' aldehyde* by the action of yejist on a-keto but>Tic acid. 

Tliat aldehydes are generated during the growth of Fumrium cubenm 
on synthetic culture media was experimentally shown in the following 
way. Eleven 2-liter Eriemneyer fliisks, each containing nhoui seven 
hundred cubic <H»ntimeters of Tschinsky's solution were sterilized in the 

» r^ivnce 81: 7.'>l :.V>. VMO. 
» HiiK-hem. Jour. 7: :i"»!» 3t«. I*»i:{. 
•Ann. Innt. pHMtnir 7: 41. ls<J3. 
«Z«Mt. phvHiol. ('h<m. 31: 174. HUl. 
•/>>it. phyHiol. ('hem. 47: 413 429. 1012. 



1917] Lathrop: Generation op Aldehydes 15 

autoclave and inoculated with a pure culture of Fusarium cubenae on 
May 28, 1915. The flasks were set a§ide in a dark closet and the Fusarium 
was allowed to grow at room temperature until January 21, 1916, at the 
end of which time the Fusarium was still growing. The liquid culture 
media, which had darkened a httle and which had taken on a slightly 
penetrating odor, was filtered from the sediment and growing Fusarium. 
The clear filtrate, alkaline in reaction, was sUghtly acidified with dilute 
sulfuric acid and the acid Uquid was shaken out a number of times with 
ether which had been carefully freed from aldehydes. The aldehydes 
were removed from the combined ether extract by shaking with a freshly 
prepared, saturated solution of sodium bisulfite. The bisulfite solution 
was then acidified with dilute sulfuric acid, the sulfur dioxide removed 
by aeration under a long ice cold reflux condensor, and the volatile alde- 
hydes, boiling under 75°, were separated from the solution by fractional 
distillation, and collected in about fifty cubic centimeters of ice cold 
distilled water. The aldehyde fraction so obtained was then treated with 
a httle soUd barium carbonate and redistilled in order to hold back any 
volatile acids. This distillate was tested for the presence of aldehydes. 
A few cubic centimeters of the distillate when treated withSchiflf 's f uch- 
sine aldehyde reagent gave a red color inunediately . The distillate reduced 
anmioniacal silver nitrate solution, slowly in the cold, and very rapidly 
when gently warmed. The odor of the solution was that generally given 
by aldehydes, especially the lower aldehydes of the aliphatic series. On 
boiling a little of the solution with a strong solution of sodium hydroxide 
a pale yellow color was produced which disappeared on longer heating, 

ft 

and the odor of the solution strongly resembled that of lemon. This 
reaction is characteristic of propionic aldehyde, as distinguished from 
acetaldehyde or formaldehyde. All attempts to form the phenylhydra- 
zone or the p-nitrophenylhydrazone compounds failed, probably owing 
to the small quantities of the aldehyde which had been obtained. The 
aldehyde in the remaining portion of the' distillate was oxidized by means 
of dilute sulfuric acid and potassium permanganate solution to a volatile 
fatty acid, which was obtained in amounts too small to be identified by 
means of the formation of the metallic salts. By the method of obtain- 
ing the aldehyde the fatty acids obtainable by the oxidation with the 
acid permanganate mixture are limited to formic, acetic, propionic, butyr- 
ic, isobutyric and trimethyl acetic acids. The odors of piu-e hot dilute 
solutions of formic, acetic, propionic and butyric acids are so suflSciently 
characteristic as to be readily distinguished from each other. Hot dilute 
solutions of these acids were then compared with the solution of the un- 
known acid and the odor of the pure propionic acid and of the unknown 
acid were so exactly similar that they could not be differentiated. This 



16 Phytopathology [Vol. 7 

would indicate that the volatile acid formed by the oxidation of the al- 
dehyde is propionic acid. These reactions show that a volatile aldehyde 
is formed during the growth of Fusarium cubense on Uschinsky's solution 
and that this aldehyde may be propionic aldehyde, although the amount 
of the aldehyde which was obtained was too small to make absolutely 
certain its identification as propionic aldehyde. The solution remaining 
in the flask after the fractional distillation of the volatile aldehydes gave 
no reactions for aldehydes either of the aliphatic or aromatic series. 

A badly infected banana stalk received from Trinidad by the Labora- 
tory of Plant Pathology was examined for the presence of aldehydes. 
The stalk was finely chopped and pressed in a fruit press, and the juice 
so obtained was examined by the method given above, but no aldehyde 
reactions were obtained. 

Since propionic aldehyde is a very volatile compound it is possible 
that appreciable quantities were formed during the growth of the Fusa- 
rium and escaped from solution. The author had hoped to take up this 
question and also establish absolutely the identity of the aldehyde formed, 
but circumstances do not permit of this at present. The observations 
made seemed of sufficient interest to call to the attention of other workers 
on this subject. The author wishes to thank Dr. Caroline Rumlx>ld 
and Miss Florence Hedges for their kindness in growing the Fusarium 
and for furnishing the diseased and healthy banana stalks. 

U. 8. Department op Agriculture 
Washington, D. C. 



DOES CRONARTIUM RIBICOLA WINTER ON THE 

CURRANT? 

W. A. McCuBBIN 

With One Figure<in the Text 

In the literature at the writer's disposal very little mention has been 
made of the over-wintering of Cronartium ribicola on the currant. 
In a few cases there has been a suspicion of over-wintering on this host 
but either the evidence was too meagre to be satisfying, or else other 
facts appeared later to explain the circimistances so that the general' 
opinion at present favors the entire dependence of the currant stage on 
a yearly infection from the pine. 

In some of the records, however, there are mentioned puzzling occur- 
rences of the rust on ciu'rants, either at long distances from pines, or in 
circimistances otherwise so suspicious as to suggest that the fungus might 
have passed the winter on the currants themselves. Spaulding (5a) has 
mentioned, in connection with the distribution of the Peridermium stage 
that judging from analogy with Cronartium CompUmiae, the spores of 
which are similar in size and shape to those of P. strobiy it is probable 
that the latter would be blown only relatively short distances; but he 
records two cases in which no diseased pines were to be found near rusted 
currants. In another article the same author (5) lists a reference to an 
observation made by Nilsson in 1893, where rusted Ribes were found 
over three quarters of a mile from any pines. 

Eflforts have been made to settle the question experimentally, both by 
planting out badly rusted currants in a disease-free neighborhood after 
wintering, and by inoculation with over-wintered spores. So far as is 
known the latter method has given only negative results. The former 
method was employed by Stewart and Rankin (9) using five hundred 
rusted currant plants. None of these developed any rust during the 
succeeding summer, and the conclusion is drawn that the fungus rarely, 
if ever, over-winters on the currant. In 1914 Spaulding (6), in recording 
the negative results from similar experiments with two hundred plants, 
says, "The practical conclusion is that Ribes plants do not carry the 
fungus over the winter and that an outbreak of this disease on Ribes is 
to be attributed to the presence of neighboring white pines which have 
the blister rust." 



18 Phytopathology [Vol, 7 

In a former article (3) the writer has detailed some of the circumstances 
of the Ontario outbreak which engendered a suspicion that the rust in 
question might have ])as8ed the winter on currants, and in the work with 
this disease in 1916 additional evidence has appeared to strengthen this 
suspicion. The evidence at present available can not be considered 
sufficient to establish the point beyond question, but it is important 
enough to be worth careful consideration. 

In the discussion following several points which have a bearing on the 
question are considered: (1) A hypothesis to account for the various 
phenomena observed. (2) Agreement of this hypothesis with known 
conditions in other rusts of a similar nature. (3) The general and irregu- 
lar appearance of the currant stage over large areas in which there is 
reason to believe no pine infections are responsible for the disease. (4) 
Special cases, where rust has occurred on currants which are far distant 
from any possible source of infection. (5) The occurrence of currant 
rust in one instance on two out of four plants in a plantation in which 
the same four plants, and these only, were badly diseased in the preced- 
ing year. (6) The occurrence of a case of currant rust on plants set out 
in a rust-free district in order to test over-wintering. 

1. HYPOTHESIS TO ACCOUNT FOR VARIOUS PHENOMENA OBSERVED 

On account of the difficulty arising from the loss of all the currant leaves 
in the fall, thus separating the fungus from its host, no satisfactory hy- 
pothesis has been brought forward to account for suspected cases of hi- 
bernation. Spaulding (1911) has suggested the possibility of this hiber- 
nation, and has put for\^'ard the idea of a hil>emating mycelium, justify- 
ing it by reference to ol)served cases where pustules of Puccinia occurred 
on currant shoots. The presence of Cronartium ribicola in such suspicious 
locations docs not seem to have been established, although the same 
author (5a) records the finding of the telial stage of Cronartium ribicola 
on |)etio]es and stipules of Ribes. 

Judging from ol)servation8 made during the last two years, the only 
hy|)othosis which seems to account for all the ol)serv'ed phenomena in 
connection with supi)Osed cases of wintering over, is the hibernation of 
the mvcelium in infected buds. 

A feature of the disease previously mentioned by the writer (3) has an 
im|K)rtant l)earing on this phase of the question: Early and complete 
defoliation by the rust, followed by a secondary production of leaves, 
due to the premature o|)ening of winter buds. It has often been observed 
that such secondarj' leaves are also rusted, even when they are only par- 
tially opened, and considering tliat the incul)ation period of the fxmgus 



1917] McCubbin: White Pine Blister Rust 19 

is from ten days to two weeks or more, it must be evident that infection 
can take place very close to the bud stage, perhaps as soon as the bud scales 
are parted enough to expose the young leaves within. Now in the case 
of a shoot producing secondary leaves in this way, the terminal bud 
opens first and makes most growth; the one next below it opens to a 
lesser extent; and those farther down exhibit diminishing degrees of ac- 
tivity, until towards the base of the shoot buds are foimd which still re- 
main in a quite dormant condition. It is true that leaves produced in 
this way from buds opening late in the fall are killed by the first severe 
frost, and often several of the uppermost buds also perish, but some of 
these forced buds, without doubt, are able to survive the winter. 

The fact that each shoot producing secondary leaves has its buds ar- 
ranged in a series extending from the fully opened condition to the dormant 
state, shows that there is ample opportunity for such a favorable com- 
bination of circimistances to occur, while the actual presence of the rust 
on very young leaves is evidence of the capability of the fungus to infect 
at this season of the year. The only step that need be taken outside the 
realm of fact concerns the assimiption that an infection can take place 
early enough in the development of a bud to still leave it capable of pass- 
ing the winter. 

The field conditions demanded by the above hypothesis are quite ade- 
quate for the purpose. The early defoliation mentioned is general in 
some plantations, and in a large percentage of others a smaller or larger 
area of plants lose their leaves in midsummer on account of rust starting 
from one center. The total number of such cases where secondary foliage 
has been produced is many times the number of suspected cases of winter- 
ing-over, so that even allowing for a lack of infection in some instances, 
dying out of the mycelium in winter, and so forth, there still remain several 
times the number of plantations or parts of plantations required to ex- 
plain the observed outbreaks of the rust. 

In this connection it may be noted that the climatic conditions of the 
Niagara Peninsula are extremely mild for the latitude; the autumn is 
long and open: in the last two years roses have been in bloom in Novem- 
ber; the temperature in winter rarely falls below — 12**F., and there is 
an early start of growth in the spring. Under such conditions the per- 
sistence of the rust on currant foliage until late in the fall, and its ready 
occurrence on the secondary foliage, is not a matter of wonder. In addi- 
tion the buds are advanced in this mild fall weather far beyond the stage 
at which they usually go into the winter in other localities. Perhaps 
the less severe winters might also permit the mycelium to remain alive in 
infected tissues in a manner that would be impossible in colder localities. 



20 Phytopathology [Vol. 7 

2. aqrbbment op hypothesis with analogous cases 

The view that the mycelium of the fungus might successfully pass the 
winter in currant tissue is open to no a priori objection. What is the 
constant habit of the fungus in the pine might well become a temporary 
or occasional happening on the other host. In this connection it is scarcely 
nece88ar>' to point out the known habits of other rusts under like circum- 
stances, but the recent work of Meinecke (4) on Peridermium harknessti 
has a peculiar interest here. In summarizing this work he says, ''In Cal- 
ifornia Peridermium harknesm and Cr&nartium Qiiercuum are to a high 
degree independent of each other;" and again, **Cronartium Quereuum 
over-winters on Quercus agrifolia; new urediniospores form in spring 
around the old, dead sori on old, living leaves, and infect the young leaves." 
He believes that since the crop of new spores is formed around the old 
dead spots, that therefore the myceliimi must over-winter in the leaf 
tissue. The same over-wintering of the myceliimi has l>een found by 
Mains (2) to take place in Coleosporium SolidaginiSy the perfect form of 
Peridermium acicolum. In this case the pustules of the fungus were 
found to arise in spring in the rosette leaves of the Solidago host, in which 
the myceliimi had apparently over-wintered. He was able to prove this 
point by sectioning the leaves, and finding therein the rust hyphae in 
limited areas. 

3 AND 4. APPEARANCE OF CURRANT STAGE WHERE PINE INFECTIONS 

DO NOT OCCUR 

(hi'ing to the suspicions that arose in 1915 concerning the possibiUty 
of over-wintering on the currant, a careful inspection was planned for 
lOIt), in onler to <letennine whether ca^es of early infection could be 
found, which were either so far away from pines as to preclude the pos- 
sibility of pine infection, or which were* close only to pines of small siie, 
whosi* fn»<Miom from disease (*ould Ih» al>solutely establLnhed. In general 
there arc nuvh nuinlM^rs of large pines scattered over the whole of the 
Niagara Pcininsula that, even should cas<»s suspi(*ious of over-wintering 
Im* found to occur on curnints, the n(*arness of the other host would ren- 
der thcw» c:l*m*s valueless from this |Kiint of view. In two areas, how- 
ever, the pin<»s were so few in nmiiUT that an early ap|H»arance of the 
curniiit ^tag(* in them would Im* difficult to c^xplain on the gnumd of pine 
infection. 

One «if thi'H* areiu« (comprises that part of (irantham and Niagara town- 
ships included within the d(»tted line on the map (fig. 1), which it will be 
nf>ted also n^f^ords the (K)sition f»f all |>ine and currant plantations. In 
191') the rust in this area did not start inmi a |)articular (*enter or centers 



1917] McCvbbin: White Pine Busteb Rost 



I -3 



I. i 
is -8 



22 Phytopathology [Vol. 7 

and spread outward therefrom, but it appeared simultaneously and ir- 
regularly over the whole district, totally without reference to the few 
pines to be found there. In 1916 the very same irregular occurrence was 
noted. Ibccept in the Secord case hereinafter mentioned, there were 
nowhere any signs which would indicate pine infection; the infection areas 
in the plantations of currants were usually few, often only one or two; in 
no case was early infection general over a munber of adjacent plantations, 
or even plentiful in one; and in most cases the only pines that could be 
suspected were more or less surrounded by disease-free currants. 

Of the twenty-nine cases of currant rust (plantations) found in the 
area indicated, sixteen were so situated as to be regarded with strong 
suspicion. Eight of the sixteen are over a^nile distant from any pine 
which could possibly be a source of infection, and in all the twenty-nine, 
except in the Secord case noted below, the rust started without any ap- 
parent reference to the pines in the neighborhood. Eleven of the twenty- 
nine cases originated on cither one or two bushes in a plantation, and in 
all of these eleven the primary source could still be distinguished on the 
early leaves of the shoot. In sixteen other cases of the twenty-nine the 
origin frohi a similar small beginning was evident, but owing to lack of 
certainty in these cases they are not included as evidence. 

Three of the cases occurring in this area deserve special mention on 
account of their typical character, and because of the strong evidence 
they bring on the question. 

\o. /, Lot 17 y Con, 5, Grantham, In this plantation there were present 
on July 6, two Imdly diseased bushes, on both of which the early infec- 
tion had started on the second leaf of the shoot and had spread from 
there over the rest of the bush and to the adjoinitig bushes only. There 
are about twenty young pines four hundred feet from these currants^ 
but they have been examined several times in 1915 and in 1916, and are 
all entirely free from the disease. Aside from these the nearest pinee 
are over a mile distant with disease-free currants intervening. 

So. 2, Lot f). Con, S, Grantham. Here are four old black-currant plants 
in a H*)mewluit neglected garden. On July 6 two leaves on one of them 
had very old infection spot«, while around these on the bush secondary 
unHlincKfnwtules were present. The other bushes were absolutely free 
fn)ni the ruj<t. As may l)e MH»n by reference to the map, there are three 
lots of pines southeast of thus place, and one northeast. All these are 
young pines and are fn»e fn>m any signs of the l)li.ster rust. This disposes 
of all the white pines for nearly two miles in every direction except one 
forty-yi»anM>ld tree in I>ot KM, Niagara Tp., which is one and a fourth 
milc*s distant. 



1917] McCubbin: White Pine Blistek Rust 23 

No, S, Lot S6y Niagara Tp, The map shows the infected plantation 
to be over a mile from any pines whatever. It is moreover in the center 
of a currant area of which it alone is rusted. On July 15, the disease was 
found at one end of this plantation and the outbreak was traceable to 
several very old spots on early leaves. 

In the second of the two areas mentioned, which includes the town- 
ships of Willoughby, Crowland and Bertie, in Welland Coxmty, the con- 
ditions are exactly the same as have just been outUned for the Grantham- 
Niagara district. The 1916 infection is irregularly scattered over the 
whole territory without any reference to the pines. Out of 185 currant 
plantations examined here seventeen were foimd to be diseased, of which 
fourteen were suspected to be cases of wintering over. In four of the 
cases the currant rust was found from one to two miles from the nearest 
pines, and even then these pines were not \mder suspicion, being either 
themselves far from a source of infection from currants, or else having 
disease-free currants near them. 

Although the evidence adduced has been confined to the rust outbreaks 
in these limited and favorable districts, it must be understood that the 
same conditions prevail in other parts of the peninsula, and it is only the 
near presence of so many pines in all these districts which precludes add- 
ing a large number of other cases of a like suspicious nature. Unless 
either the aeciospores or the uredinospores are carried by the wind to much 
greater distances than we are accustomed to think, or than our limited 
experiences would indicate, the occiUTence of currant rust in this area 
in 1916 is very puzzling on any other hypothesis than that of wintering 
over on the currant. 

In addition to the above there is another line of evidence which has a 
direct bearing on the problem of the origin of the yearly rust outbreak 
in the Grantham-Niagara area already mentioned. This evidence is 
derived from careful examinations made of cases in the district where 
young pines and black currants are growing in close proximity, and of 
these the most outstanding instance was on Lot 13, Con. 3, Grantham, 
which for convenience of reference is called the Secord case. 

On the Pecord farm there was a row of sixteen yoimg white pines planted 
along the western boundary. These pines were obtained from a native 
wood-lot in the neighborhood, and were planted out in 1910. Rimning 
from a lane in the middle of the farm to this row of pines are 175 large 
black currant bushes in five rows. On the eastern side of the lane, and 
about ninety yards farther north, is a small nursery plot of evergreens, 
among which were included about 150 young white pines, planted in 
1912, and obtained from the Provincial Forestry plantation in Norfolk 
County, where they had been grown from native seed. 



24 



Phytopathology 



[Vol. 7 



Although the currants on this farm were badly rusted in 1914 there 
was no sign of the disease on either lot of pines that year. In the season 
of 1915 the pines were all examined four times (May 5, May 14, June 14, 
August 9), but nothing remotely resembling the blister rust was found. 
The rust appeared again on the currants in the course of the sununer, 
but was late in making its appearance, and possibly came in from else- 
where. Another inspection of the young pines was made very early in 
the spring of 1916, with the same result as before: no sign of the disease 
could lx» seen. 

Owing to the close association of the two hosts, and the known occurrence 
of the currant stage for at least the two preceding years, special attention 
was judged to \ye necessary in this case, and accordingly a further inspec- 
tion was made on June 6 and 7. On this occasion there were found a 
large number of discolored swellings which were undoubtedly the early 

TABLE 1 

Total numittr of white pint blister rujtt swellings found June 6, 1916, in the Secord 
nurnenj and fence row and the age of growth on which they occurred 



TKAR or OBOWTM 


NUBSBRT 


rSNCB ROW 


TOTAL 


PBBCKMTAOB 


1015 





V 


1 


5 


1914 


43 


M* 


127 


71.7 


1913 


39 


10 


49 


27.7 


191J 














Karli«»r 















* Somewhat dnuhtful. A pwelling l)el()w the end of a broken-off terminal branch. 

* One cif thene prcHlure<i the hliMterK noted above. It waa located at the upper 
end of the interntnie developed in 1914. 



8tHg(*8 of the blister rust, and which had developed so as to be visible 
«inr<» the former visit. Only one case of the blister stage was found: 
A .sinall twig near the ground l)ore five small blisters. These had already 
shcMJ their sjxires. but were still readily recognizable by the slit-like open- 
ings. miinHnts of the |M*ri(iiuni, and by a few remaining spores. The pines 
were niitiiitely examined over ever>' part of the stems^ branches and twigs, 
and all the swellings collected for study, after which the trees were de- 
stn»viM|. The rollertion of swellings was then carefully gone over in the 
lalH)ratory, and a record was made of the age of the growth on which they 
o<vurre<l. Their position on the tree is given in tabular form below. 

Sinc<» the two hosts art» here so closely associated that the currant stage 
c<Hild hardly l>e presiMit without causing some infection on the pine, we 
are enahlcMi to fonn from this table some conclusion regarding the date 
of the first apfx^arance of the disea^* in this particular locality. As no 



1917] McCubbin: White Pine Blister Rust 25 

pine infections have been found on any growth prior to and including 
1912 it seems certain that there was no currant rust here before 1913 at 
least. It is, of course, possible that sporidia of 1913 might have infected 
twigs of 1911 or 1912, but if so it is hard to believe that all such infections 
are still dormant when later pine infections have developed regularly 
and vigorously on the same trees. This seems to hint at the absence of 
the currant rust here in 1913, but this part of the subject will be considered 
later. 

Since the currants have been known to be badly rusted in 1914, 1915, 
and 1916, it is only reasonable to suppose that plentiful infections have 
taken place in each of these years on pines so favorably situated, a point 
which is well borne out by the presence of such large numbers of them 
on the wood of 1914. These must obviously have arisen after the wood 
was formed, and are therefore leferable to the rust of 1914 or 1915. The 
above table, however, shows an entire absence of infections on 1915 
twigs (save for one very doubtful and abnormal case), and since no swell- 
ings or other indications of the disease were seen here in 1915, although 
the pines were certainly subject to infection in 1914, it seems fair to con- 
clude that during the season after infection the fungus produces in the 
twigs no symptoms of a visible nature. 

If in addition to this year of dormancy it is assumed that the swell- 
ings formed in 1916 will reach the blister stage in 1917, it is probable that 
the disease in pine limbs follows a four-year cycle, which may be thus sum- 
marized: first year, infection in late siunmeror fall; second year, dormant 
period; third year, swelling and discoloration, with possibly pycnospores; 
fourth year, production of aecia. 

This rule of development is not to be regarded as invariable. In some 
cases the dormant period may be extended considerably, and on the 
other hand cases are known where blisters have been formed in the second 
year after infection instead of the third. Under ordinary circumstances, 
however, this cycle is perhaps generally followed. 

We may therefore consider the swellings included in the above table 
as having originated from infections of either 1914, or both 1913 and 1914. 
Since no record exists of the presence or absence of the rust here before 
1914, we are unable to state that these pines were not exposed to infec- 
tion in 1913. But if they were so exposed and infections resulted, we 
are compelled to give an explanation of the sudden development into 
the swelling stage of infections of two seasons, simultaneously in the spring 
of 1916. If currant rust was present in 1913 it is obvious that every one 
of a large number of infections made in that year must have remained 
dormant for two years, while on the self-same trees a still larger number 
starting in 1914 reached the same stage concurrently, after only one 



26 Phytopathology [Vol. 7 

year's dormancy. One might imagine that adverse weather conditionfl 
might bring about such a pecuhar varation in the dormant period, but it 
must be noted that during the spring and summer of 1915 there were 
collected at Fonthill, some fifteen miles away, about two hundred pine 
infections, in all of which the swelling stage in both old and incipient 
cankers was abundantly active. Aside from this one would hardly ex- 
pect all these cankers to be affected by weather conditions; some of them 
might be retarded but others more favorably situated would have followed 
the usual course, and would have appeared as swellings in 1915. It seems 
far more reasonable to regard all the swellings in the table as the result 
of a single year's infection, that of 1914. According to this view they 
have all followed the cycle indicated (with the exception noted), and are 
due to produce accia in 1917. It would follow from this, that the cur- 
rant rust could hardly have lx»en present on these currants prior to 1914, 
the year it was first discovered here. 

Since the Secord fann, (fig. 1, -4), is ver>' centrally situated in the 
to\^aiship of drantham and in the heart of a region thickly planted with 
currants, the al)sence of currant rust here is strongly indicative of its 
al)sence in the surrounding neighborhood. Additional evidence on this 
point is fiunished by four other cases of a like nature in the same district, 
where pines of small size also grew side by side with black currants. 

In the first of these, (fig. 1, B)^ a large currant field is 25 yards distant 
from a number of young native pines, on which no signs of the disease 
could l)e found in 1915, In ()ctolx?r, 1916, there were found on fourteen 
of these pines thirty-eight cases of the blister rust swellings. Of these 
sixteen were on the growth of 1913 and twenty-two on that of 1914. 
None could Ik? found on growth of 1915 and nothing was present on any 
wood prior to that of 1913. 

In the w»cond case (fig. 1, C) there were two young pines within six 
fe<*t of the black currants. In 1916 these also developed swellings for 
the first time; of the five seen here two were on wood of 1913 and three 
on that of 1914. 

In the third case (fig. 1. />), the few young pines were about fifty yards 
fn>m a short n)w of black currants. The one case of pine infection which 
app<»are<l here for the first time in 1916 yunn on a shoot developed in 1914. 

The fourth case (fig. 1, A'), dis<'lose<l only two pine infections on a doien 
young trees which were within ten feet of a large but slightly affected 
black currant plantation. Ik>th infections wcn^ on pine shoots of 1913 
growth. There is some a<lditional evidence here in the fact that this 
n)W of pines was transplante<l to its presi^nt situation in the spring of 
1914 fn»ni a hollow alM)Ut four hundred yards fnnii these currants. Since 
there were no other currants within a quarter of a mile of this hoUow, 



1917] McCubbin: White Pine Blistek Rust 27 

there is good reason to believe that the pines received their infection after 
they were transplanted, that is, in 1914. 

In all the four cases just referred to the adjacent currants are known 
to have been diseased in 1914. Likewise the pines were in every case 
minutely examined in 1915, so that their freedom from disease until the 
spring of 1916 is well established. Since in every one of the blister can- 
kers found in these foiu' cases the disease has occurred only on wood of 
1913 or 1914, and none have been visible till ihe spring of 1916, they agree 
in every way with the evidence obtained from the Secord case, and to- 
gether with it give a very strong support to the view that the ciurant 
rust was not present in the Niagara-Grantham region before 1914. 

The bearing of this aonclusion on the question of wintering over is 
obvious. If the rust did not appear in this district until 1914, then ac- 
cording to the probable life-cycle of the fungus no pine infections could 
reach the blister stage and start new currant infection before 1917. It 
follows therefore that the currant rust of 1915 and 1916 in the area imder 
consideration must be due either to spores carried for long distances by 
the wind or to a wintering of the fungus on the currants themselves. 
Since this area is about ten miles long by five miles wide, and is distant 
from the nearest area of infection (the Fonthill district) from ten to six- 
teen miles, any attempt to attribute all these rust outbreaks to wind- 
blown spores is full of diflSculty. Aside from this there remains only the 
wintering of the fungus on the ciu'rants as an explanation. 

Objection may be made to the above reasoning on the ground that in 
some instances aecia may be produced the second spring after infection 
instead of the third. It is probable that such cases are rare. The single 
instance of this sort that was met with in the Secord case was the only 
one out of 223 blister cankers collected in these two townships in 1916. 
The small branch on which it was found was protected by high grass, 
and had the puffed, swollen appearance which normally occurs when a 
small limb is stimulated by contact with the moist earth. It was evidently 
an abnormal case, and probably had undergone a forced development 
by reason of its peculiar conditions. The writer is of the opinion that 
such abnormalities would rarely occur in large trees, and as for the small 
pines, practically all of these in the two townships have been subjected 
to such a scrutiny that the possibility of their playing a part in the yearly 
outbreak is utterly out of the question. This is especially apparent when 
the extent of the early occurrence of the currant stage is taken into con- 
sideration along with the observed rate of spread from the infection started 
at the Secord farm by the abnormal blisters just mentioned. In this 
case the rust began about June 1, at the ends of the five rows of black 
currants. By July 6, it had progressed down the rows for a distance of 



28 Phytopathology [Vol. 7 

only two hundred feet, and two adjoining plantations distant two hun- 
dred and three hundred yards respectively/ were still free from any sign 
of infection. By August 21, there was only a slight infection on these 
adjacent plantations. It is almost impossible to think that one small 
infection of this sort, or even a number of them, could have started such 
a widespread infection on currants as our survey disclosed. 

Moreover, while an objection of this nature might be vaUd for the 
rust epidemic of 1916, it could hardly apply to that of 1915 which was of 
the same extent and in the same area. Assuming that the rust entered 
this district in 1914 any explanation of the succeeding year's outbreak 
on the basis of pine infection would require the production of the blister 
stage in the spring of 1915, from a blister canker started by infection dur- 
ing the previous autumn. Even admitting the possibility of such pre- 
cocious development, the blisters formed in this way must either have 
been numerous and widespread, or the spores from one or a few of them 
must have been carried from five to ten miles. In the first case our care- 
ful examination of young pines must have disclosed some of them, at 
least ; and in the second case the general and irregular occurrence of snuill 
outbreaks without any recognizable center of infection, together with 
the known behavior of the already mentioned outbreak of this nature 
on the Secord farm, are quite against any such explanation. 

5. RECURRENCE ON SAME INDIVIDUAL 

The hypothesis advanced al)ove is capable of being tested to some ex- 
tent by field ol)8cr\'ations. If the rust winters in buds forced into late 
growth by premature defoliation, then it should be possible toestablish 
a connection l)etween suspicious early outbreaks of the rust and the 
plants or small areas which were defoliated during the preceding summer; 
if these areas showing force<l growth were marked in the fall and rust 
appeared in them in spring in a largcT percentage of cases than in the 
or<linar>' parts of the field, the case for over-wintering would be very 
stmng indwMl. Such field work would necessarily have to be done in a 
district when» the n^sults would not be interfered with by the presence 
of too many pines. 

rnfortunately no «yHtematic effort has yet l)een made along this line. 
The Humll amount of €»vi(leiire now in hand conies from three plantations 
which were niarkecl as defoliated in 1915. Out of the three, two were 
subject to early outbreaks of the rust in 1910. while the thin! was free. 
In U)th of the two cjises the infection wjis small and startec! from one or 
two renters within the defoliatcNl portion. \ |)erhaps more significant 
case came up in the field work of one of the ins|K>ctors. In one large 



1917] McCubbin: White Pine Blister Rust 29 

black currant plantation the inspector who covered the ground in 1915 
reported only four bushes, adjacent in a row, as badly rusted, with but 
slight infection elsewhere on adjoining plants. These four bushes were 
seen at that time by the owner, and when the inspector of 1916 called here, 
the owner told him where to find these bushes, which were on the side 
of the plantation opposite a small tree. The only case of rust which 
could be found in this plantation was on one of the four plants mentioned. 
It is conceivable that spores blown from some other place might start 
an infection in this one spot, and there only, in two successive years, 
but it is so utterly improbable that one can scarcely avoid turning to the 
wintering-over hypothesis for an adequate explanation of the case. 

6. RUST ON transplants IN A RU8T-PREB DISTRICT 

In a former article (3) mention has been made of a rust outbreak which 
occurred in a small plot of black currants set out in the spring of 1915 
to test for hibernation. The one hundred currant bushes used were all 
badly rusted in 1914. They were divided into five lots, of which two 
were well sprayed with lime-sulphur, two were left unsprayed, and one 
was exposed to infection from rusted currant leaves wintered out-of-doors 
and suspended among the foliage in loose wire baskets. A locality was 
chosen for the experiment far away from any known rust area; this dis- 
trict had few pines and the freedom from rust of the few existing currants 
was ascertained during the fall of 1914. 

The one case of rust which developed on these plants was on one of the 
sprayed plots. At the time of examination, October 18, it was still of 
very small extent, involving only one shoot of a single plant. There was 
a small original rust spot surrounded by about twenty others of more 
recent date. 

Owing to the limited extent of the rust here so late in the season there 
was some hesitation in attributing it to a wintering of the fungus, and 
every other possible source of infection was given due consideration. 
The only one of these possible sources that had any degree of probability 
was the carrying of aeciospores to this place in an inspection visit made on 
May 24. At this date no currant rust had been met with but some inocula- 
tions with the aeciospores 6ad been made in the laboratory on May 20. 
The writer did not do this work himself but was in the room at the time, 
and a few air-borne spores might have adhered to his clothing and have 
been thus carried to the field in question four days later. Improbable 
as this suggestion may seem, it is the only explanation on the basis Qf 

accidental infection which seems to be worth consideration, 



30 Phytopathology [Vol. 7 

On the other hand the wintering of the fungus on the curranta them- 
selves readily explains the case. The fact that the plants were well 
sprayed in spring is in perfect harmony with the hypothesis advanced. 
Even the late appearance and small spread of the infection, which would 
appear to be incompatible with wintering-over, need present no difficulty; 
it is well known that while Puccinia graminis may live independently 
of the barberry for indefinite periods, yet by undergoing its proper stage 
on this host its virulency on cereal hosts is much increased. It should 
not l)e too much to expect, then, that in the case of Cronariium ribicola 
the second successive seasonal generation on the currant should lack 
somewhat of the vigor it would possess after coming fresh from the pine. 
The results of the sur\'ey work in the Niagara Peninsula seem to hint 
at a confirmation of this view. A great many of the cases of currant 
rust observed here during the last two years have been in the type in- 
dicated : an old but very feeble rust center, which by the end of the sum- 
mer had involved only a single bush, or at most a few adjacent bushes. 
Other explanations of this seeming lack of vigor are no doubt possible, 
but such a decadence is quite compatible with a hibernation hypothesis. 

In concluding this discussion it is clearly recognized that the evidence 
submitted is inadequate to establish the point under consideration, but 
on the other hand it is considere<l that enough evidence has been adduced 
to warrant a strong suspicion of currant hibernation, and this suspicion 
holds even though the hypothesis tentatively put forward should prove 
to l>e untenable in the light of later investigation. In any case the evi- 
dence obtauiod 8er\'es to narrow the field of inquiry to a great extent; 
for the conditions outlined above are such that the question of hil>ernation 
clearly hinges on the distance aeciospores or uredinospores can l)e car- 
ried by the wind; if only for a mile or two, then wintering on the currant 
has almost certainly taken place in the area under consideration; if on 
the other hand the spores are Iwrne eight or ten miles or farther, another 
explanation of the situation in this district l>ecomes easily possible, al- 
though the question of hibeniation is not even then altogether disposed 
of. In the al)sence of definite infonnation concerning si>ore dispersal 
the cjuestion must remain o|H»n until a l>ody of trustworthy evidence can 
Ih» acnmuilated on this |)oint, or until more direct evidence is available 
on other phases of the subject. 

Dominion Fikld Lahoratory of Plant Pathoukjy 
St. Catharines, Ontario 



1917] McCubbin: White Pine Blister Rust 31 

BIBLIOGRAPHY 

(1) HowiTT, J. E., and McCubbin, W. A. An outbreak of white pine blister rust 

in Ontario. Phytopath. 6: 182-185. 1916. 

(2) Mains, E. B. The wintering of Coleosporium Solidaginis. Phytopath. 6: 

371. 1916. 

(3) McCubbin, W. A. Notes on white pine blister rust. Rept. Dominion Bota- 

nist (Ottawa, Canada) 1915-16: 

(4) Meinecke, E. p. Peridermium harknessii and Cronartium Quercuum. Phy- 

topath. 6: 225-240. 1916. 
(6) Spauldino, Perlet. The blister rust of white j}ine. U. S. D. A., Bur. PI. 

Ind. Bull. 206: 1911. 
(5a) The present status of the white pine blister rust. U. S. Bur. Plant Ind. 

Circ. 129: 15. 1913. 

(6) Notes on the white pine blister rust. Phytopath. 4: 41. 1914. 

(7) New facts concerning the white pine blister rust. U. S. D. A., Bui. 116: 

4-5. 1914. 

(8) Stewart, F. C. An outbreak of European currant rust. New York (Geneva) 

Agr. Exp. Sta., Tech. Bui. 2. 1906. 

(9) Stewart, F. C, and Rankin, W. H. Can Cronartium ribicola over-winter on 

the currant? Phytopath., 4: 43. 1914. 



THE INJURIOUS EFFECTS OF TARVIA FUMES ON 

VEGETATION 

A. H. Chivers 

The following article contains a brief description of the destructive 
efToct of tar smoke on plants which the writer had occasion to study 
during the sununer of 1914, together with a brief account of experiments 
carried on since that time in the laboratory, and under controlled con- 
ditions. 

The tar compound which was in use for building purposes, and which 
seriously affected the neighboring vegetation, is sold under the trade 
name, tarvia. For melting the compound a single kettle was set up 
alK)Ut sixty feet distant from the nearest corner, and three hundred feet 
distant from the farthest corner, of a garden which covered an area roughly 
a hundre<l and eighty feet square, and which contained both ornamental 
and cn)p plants. 

A strong and constant wind carried the fumes over the garden for about 
four hours on the afternoon of August 10 and throughout the forenoon 
of August 11, during which tune the leaves and stems of the planta l)e- 
came coated with a sulwtance of a greasy nature. 

The sulisetjuent destruction of the plants was ver>' rapid. The leaves 
scHin curled and shrivelled, dried out and fell. At least twenty species 
and numy varieties were affect €»(!. Poppies, P, soinnifirum Linn., P, rhoeas 
Linn., P, orieuUile Linn., candytuft, Ilxrin amara Linn.; marigolds, Caleri- 
dula officinaliH Linn.; azaleas, Azalea vinami Linn.; sunflowers, Helian- 
thuM anfiuuM Linn.; strawln^rries, Fragaria in varieties, and squashes, 
i^iCurhiUi jH}H) Linn., and (\ maxima Duchesn(», were killed. Pae<mies, 
Parouia in varieties, were killed to the surface ui the soil. Roses, Rom 
in varieties: hoiiey.^uckles, Ltnicrra Uirtarica in varietit*s; currants, 
Wi7x\K in vari«'ti<\s; ra.*<plM'rrieH. black ra.*<pl Harries and blacklnmes, Kubus 
in varii'tirs, were dcfoliatet), uimI in son:e instances were killed. Pota- 
toes. Snlauum tulMroftum Linn., which occujMed the greater part of the 
garden, were stunt€»<l and the yield was greatly reduced. All perennials 
showed the effects of the injury in the following season's growth. 

IIHIKF Sl'MMARY OF MTKIiATlKE 

( )bs«Tvations on the effect of vaiK)r an<l dust fnmi tarred roads, and 
smoke from melting tar on neighlK)ring vegetation, have led to extensive 



1917] Chivers: Eppbcts op Tarvia Fumes 33 

investigation of many tar compounds, and it has been found that while 
these compounds vary widely, the smoke and fumes from these are in 
general injurious to plants. 

Gatin^ investigated different substances used for the surface treat- 
ment of roads and his results tended to show that many trees, shrubs, 
garden plants and flowers suffered injury from the fumes given off by the 
tar, and also from the dust arisinjg from the treated roads. The injury 
seemed to be proportional to the distance from the road, the amount 
of phenol in the compoimd, and the isolation of the plants. The effect 
was shown in the fading of the leaves which were spotted and blackened. 
The cells were plasmolyzed and the chlorophyll disappeared. Marked 
differences in resistance to injmry on the part of some plants were noted. 

Gatin and Fluteaux^ found as a result of studies on leaves and branches 
of catalpa and locust that plants which have been submitted diu'ing the 
season to the dust from tarred roads had become considerably modified 
in respect to anatomical structure. 

Mirande^ made a study of the influence of the tarring of roads on plants, 
and concluded that the injmy was done by vapors given off in consider- 
able abundance diu-ing dry, hot weather. He stated that if trees and 
ornamental plants in cities are to be preserved the use of tar on roads 
should be made with care. The same author* investigated the effects 
on plants of a number of commercial products such as Carbonyle, Car- 
bolineum and Carboneine, all of which contained creosote, and a nimiber 
of which were used as insecticides. They were more or less injurious, 
causing the destruction of the green cells. He urged care in their 
application. 

Griffon,* as a result of laboratory work covering three seasons, confirmed 
the conclusions of Mirande regarding the injurious nature of gases given 
off from tar when used in coating roads. From extensive observations 

^ Gatin^ C. L. The efifects of tarring roads on the growth of trees in the Bois de 
Boulogn. Compt. Rend. Acad. Sci. Paris. 168: 202-204. 1911. 

The experimental reproduction of the injury to plants by the vapors and 

dust arising from tarred roads. Compt. Rend. Acad. Sci. Paris. 168: 688^90. 
1911. 

The tarring of roads and its effect on the neighboring vegetation. Ann. 

Sci. Nat. Hot., ser. 9, 16: 165-252. 1912. 

' Gatin, C. L. and Fluteaux. Anatomical modifications produced on plants 
by dust from tarred roads. Compt. Rend. Acad. Sci. Paris. 168: 1020-1021. 1911. 

* Mirande, M. The effect of tarring roads on plants. Compt. Rend. Acad. 
Sci. Paris. 161:949-952. 1910. 

* Mirande, M. The effect on plants of certain substances extracted from coal 
tar. Compt. Rend. Acad. Sci. Paris. 162: 204-206. 1911. 

* Griffon, £. The influence of tarring roads on neighboring vegetation. Compt. 
Rend. Acad. Sci. Paris. 161: 1070-1073. 1910. 



34 Phytopathology [Voi^ 7 

he concluded that the probable injury to vegetation in the open coun- 
try would be small. 

CMaussen* exposed plants to vapors of several coniniercial tars, and 
found that the various kinds of tar sold for building highways differed 
widely as to their effects on plants. The nature and extent of the in- 
jury' were closely related to the concentration, thus depending on vola- 
tility and temperature, and that species of plants differed widely as to 
their susceptibility to the vapors. Certain recommendations were made 
in respect to the proper handling of such products. 

Gabnay' gave a brief account of the injury to trees by tar used on the 
trunks as protection against the ascent of caterpillars, which involved 
not only the cambium but also the sap wood, and extended beyond the 
limits of the tarred areas. The injury was ascril)ed to the exclusion of 
air and the action of acids and salts. 

Ewert' investigated the injiu^ to vegetation by smoke-borne products, 
and reported a peculiar lacquered appearance on the upper surface of 
leaves of a number of economic plants, frecjuent rolling and crumbling 
of the laminae, and discoloration over part or all of the surface. Fruits 
and garden produce in such neighborhoods showed the effects. Controlled 
experiments showed that injury depended not alone upon the amount 
of material present in the atmosphere, but also ujwn the heat, dryness 
and isolation. 

A cas<* most similar to the one under discussion is recorded by Moore* 
as having occurred at Woods Hole, Massachusetts, when a collection of 
valuable roses was seriously damaged by smoke which resulted from the 
burning of a tar and gravel roof in the vicinity of the garden. The effect 
of the smoke began to be noticeable during the third day of the fire, and 
was indicated not only externally by the falling of the leaves and the 
scarring and marking of the young and tender stems, but also internally 
where large areas of growing tissue died and the contents of the cells 
were shrunken and di**torte<l, the green coloring matter luiving been 
completely <lis<irgunize<l. All plants were affected, some were killiHl 
outright, and others so weakened that they l)i»ciune much more susceptible 
to the attack of fungous db<ea«es. 

• ClaiiHHon, r. TUv infliienr<> of tar, particularly that of tarred strccta upon 
vegetation. Arl». KaiM. Hiol An«t. I^nd. u. For«tw. 8: 403-.')l4. 1913. 

' Cialinay, F. von. The patholoxical action of tar on plants. (Vntbl. Omam. 
ForMtw. S9: 497 .VM. 1913. 

• Kwert, H. Injury to vegetation by coal tar and other vapors, and protection 
therefrom. Zeitiirhr Pflani«»nk U: 257 273, 321 34(). 1914. 

• Moore. (;. T. Ho»t!J« vii. Kailroadw. Kho<!ora 5: 93-96 1903. 



iai7] CnrvERs: Effects of Tarvia Fumes 35 

The very complete bibliography of McClelland^ also should be con- 
sulted in this connection. 

RESULTS of experiments CONDUCTED IN THE LABORATORY 

It was soon found that the injury to plants by tarvia could be dupli- 
cated easily in the laboratory, and experiments have been made for the 
purpose of determining whether or not what seemed to be facts at the 
time of the accident would appear imder controlled conditions. For this 
work begonias, Begonia in varieties; ferns, Adiantiun, Aspidiiun and 
Pteris; wandering jew, Zebrina pendida Schnizl. and Commelina nvdi- 
flora Linn.; and geraniums. Geranium in varieties, were used. 

In a comparatively short time after the plants were placed in the path 
of the fumes, the same greasy covering of condensed volatile substances 
which collected on the garden plants began to appear over the plant 
surfaces. Plants three to four feet distant from the source of the fumes 
showed an appreciable covering in about three hours. 

The symptoms of injury were found to vary appreciably with the species. 
Leaves of begonias showed a characteristic sinking of the upper epidermis, 
at first in small, isolated areas, which gave a peculiar pocked appear- 
ance to the leaves. The pock marks gradually became confluent, and the 
entire area lost chlorophyll and turned brown. In the youngest leaves 
the first symptoms appeared as yellow spots, three to six millimeters in 
diameter, which when examined, were foimd in each case to be an injured 
area immediately surrounding a multicellular gland. Older leaves turned 
yellow over their entire surfaces and fell from the stem. 

Ferns treated with the fumes withered and dried as if subjected to 
extreme heat. Geraniums showed a tendency of spotting. In general, 
however, the lower and older leaves turned yellow, those of medium age 
turned dark brown over the entire surface, while the youngest and only 
partially unfolded ones showed dark brown zones on their margins. 

Experiments were performed with the purpose of determining whether 
or not the injury was due to the interchange of gases through the stomata. 
Species of begonias were particularly desirable for these experiments, 
since stomata are found only on the imder surfaces of the leaves. Plants 
with a single stem bearing about ten leaves were used. The stem was 
wound with cotton and then with waxed paper. Some leaves were left 
unprotected. For other leaves cork masks were cut to fit the upper and 
under sides, the center of the upper mask having been cut away until only 
a narrow rim remained. These masks were then pinned in place so that 
the leaves were entirely protected on the stomatal surfaces, but exposed 

^^ McClelland, E. H. Bibliography of smoke and smoke prevention. Mellon 
Inst. Indus. Research. Bui. 2: 1-164. 1913. 



36 Phttopathologt [Vol. 7 

on the upper Rurfaces with the exception of a narrow margin. The 
plants were placed so that the exposed surfaces faced the fumes. In 
all cases the injury was as marked and of the same nature as in the un- 
masked leaves. 

An experiment was tried of painting onto the siirfaces of the leaves with 
a camel's hair brush the volatile matter which condensed on the surface 
of the glass above the emanating fumes. It made little difference whether 
it was applied to the upper or lower surface of the leaf. The affected 
areas showed the same symptoms as those treated with the fumes. The 
painted spots l)ecame brown and finally dried and dead. 

It was assumed from the first that the injury in the garden was due en- 
tirely to the effect of fumes on al>ove-ground parts. To confirm this 
assiunption, however, the potii were either wrapped in several layers of 
paraffined paper, or coated with paraffin and their tops covered with 
waxed paper. With plants thus protected the results recorded above 
were obtained. 

SUMMARY 

The results may \yo sunmiarized as follows: 

1. The fumes from the compound known as tarvia are highly injurious 
to vegetation. 

2. liCaves whose surfa<*es were painted with the oily matter which col- 
lected on a ccH)l gliiw plate over the emanating fumes showed the same 
symptoms of injury as did those treated with the fumes. This, together 
with other evidenr<% indi(*ated that the injury was due in large part at 
IcNist to the c<»nstituents of the volatile sul)stances which condensed in 
the fonn of an oily c*oating on the surfaces of the plants. 

3. Plants with no stomata on the up|M»r surfaces of their leaves were 
pnitected in resjKTt to all other surfac€»s, and so placed that only the 
up|M»r leaf surface was subjected to the fumes. Such plants showed 
injury r»f exactly the s<mie nature as did tluise with unprotected stoniatal 
surface's. This indinited that the injury did not involve, to any extent 
at least, the piissiige of gases through stomata. 

4. In a ."iufficient numlxT of ex]M'rimcnts the soil and under-gnmnd 
structures were protected from the fumes, showing that the injury* wa.«* 
due t«> the action of the fumes on aerial fmrts. 

'). The injury varied with the distaixr from the escaping fumes, the 
teiii|N*rature of the melting tar, the age of the plant structures, and the 
^|M'cies used. 

DaKTMOCTII (^oLLI-^iK, 

ll-Wdvwi, N. H. 



SOUR ROT OF LEMON IN CALIFORNIA* 

Clayton O. Smith 
With Two Figures in the Text 

The fungus causing the decay described in this paper was first iso- 
lated some years ago from lemons which were originally infected with 
the brown rot fungus Pythiacystis ciirophthora. Artificial inoculations 
made at that time on green lemons with a pure culture of the organism 
gave negative results, and no further attention was given to it until in 
1915. The method of development, morphology and general charac- 
teristics of the fungus, noted at that time, were similar to those described 
in the present study. The decay has been found in many of the lemon 
packing houses of ("alifornia and probably occurs more or less in all of 
them. The fungus is not known to have caused serious losses until the 
summer of 1915, when the unusually large crop of lemons made it neces- 
sary to hold large amounts of fruit in storage for a longer period of time 
than is customary, during which time considerable loss occurred in the 
packing houses and in transportation. It seemed to be especially in- 
fectious with fruit picked in the spring, being most commonly reported 
in May fruit. The fungus has also been found causing a rot of Valencia 
oranges in transit. 

Several popular terms have been applied to this decay such as sour 
rot, slimy rot, watery rot. These terms are descriptive of different stages 
of the decay. The peculiar sour odor is so constant a characteristic and 
one so distinct from those of other decays of citrus fruits that the name 
sour rot is suggested for this decay. 

Sour rot is a soft decay, during storage, of citrus fruit, especially of 
lemons. The tissue when infected quickly softens, but for some time may 
retain nearly its normal shape. It, however, changes to a straw color*, 
later collapses, becoming more or less slimy with age, and at last is almost 
completely changed into a watery mass, which in the packing house often 
drips down into the lower fruit of the stacks. Because of these charac- 
teristics the grading and sorting of the fruit is ver>^ disagreeable. The 
softened areas of the fruit do not at first show any noticeable aerial my- 

* Paper No. 38, Citrus Experiment Station, University of California, Riverside, 
Calif. 

^ Dauthenay, Henri. Repetoire dc Couleurs, p. 31, No. 3. 



1917] Smith: Sour Rot of Lemon 39 

nally described by Ferraris^ as Oidium citri-aurantn, Saccardo and Sydow 
later transferred the fungus to the^enus Oospora. Cultures of the soiu" rot 
fungus were submitted to Professor David R. Sumstine, Peabody High 
School, Pittsburgh, Pennsylvania, for identification, and he regards this 
species as belonging to the genus Oosporoidea,' a group of fungi that is 
now separated by some systematists from Oospora because of the slight 
differentiation between the mycelium and the sporophores. The fungus 
should now probably be called Oosporoidea citri-aurantii (Ferraris), but 
for the present will be designated as Oospora. The aerial mycelium of 
the sour rot readily separates into spores when moimted in water for 
examination, as does also the mycehum growing on the substratum. 
Sporophores and chains of spores are with difficulty distinguished from 
the myceliimi. 

Ferraris* foimd from his study and inoculations, that the fimgus Oospora 
cUri-aurantti caused an infectious soft decay of oranges. The individual 
points of infection increased in size and coalesced. A strong odor of 
fermented juice and a disagreeable taste of the fruit accompanied the 
decay. No aerial mycelial growth was at first visible, but under favor- 
able conditions, a short very white, wrinkled myceUum developed, form- 
ing in contact with the substratum a gelatinous layer. The myceUum 
has a constant diameter of about 7 m being described as being perfectly 
yellow and granular when growing in the orange tissue. The color of 
the mycelium of the sour-rot fungus as observed under the microscope 
when taken from artificially inoculated oranges, shows a slightly yellow- 
ish color but could hardly be said to be perfectly yeUow. The size of the 
conidia as given agrees very closely with that of the sour-rot fungus. 
Ferraris recorded the size of cyUndrical conidia as 13.5-19 x 7-7.5 m; 
oval conidia 9-12 x 7.5 m; spherical conidia about 12 /z. 

Ferraris refers to certain other closely related fungi, causing rots of 
citrus fruits. Among these are Oidium fasciculata Berk., probably synony- 
mous with Oospora fasciculata Sacc. et Vogl. and Acrosporium fascicular 
turn Grev., which is said to occur in decaying citrus fruits in Belgium, 
Great Britain, Italy and North America. This fungus differs from Oospora 
citri-auraniii in that the mycelium is at first white but changes to glaucus 
with age. Oidium tigitaninum was described* from CaUfornia as a pow- 

* Ferraris, T. Di un nuovi ifomicete parassita nei frutti di arancio. Malpighia 
IS:. 1900. 

* Sumstine, D. R. Studies in North American Hj'phomycetes. The tribe Oospo- 
reae. Mycol. 6 : 45-61 . 1913. 

* Ferraris, T. Loc. cit. 

•Carter, C. M. A powdery mildew of Citrus. Phytopath. 5: 193-196. 1915. 



40 



Phytopatholoqt 



[Vol. 7 



dery mildew of Dancy tangerine. It diffcnt in size, in shape of span* 
Bttd in other morphological characters from tho fundus under oonsideration. 
Ootpara cilri'OUTantii is closely rolateil to Oon/jom fcidia morphologi- 
cally, a fact fully rectqpiized by Ferrarip, who found similarity in conidia 



c4 



c?'* 




.\. It. r. :ii-n:il mv. .-Iiuni ->l...uiiiii chain- -f •, 
into n-H- (h:it fill.. <■'.), a- !.|...r.-^ K. .-..ni.liii. -Ii. 
lion F. mI.I I'li^i ■'lioviMK ..11 k1..I.<iI.'v 

Ki-niiiiiiiliiiii. li\p!i:il l.niTn-liitin. iitui thr mr 
i-iuiiii^ ;iri- f<>titi.-<l. Il<- :il-^i mi'iili<>ti'< lli<- i 
wliicii tliov i»i. tiiUKi site ztl.lf to priMhict-. i- 



r in U'hirli ih<> omidiii! 
niiii'^ nuiiitxT of (tmiilia 
i:iltv whi'Ti ihf niv«*elituii 



1917] Smith: Sour Rot of Lemon 41 

itself breaks up into spores. Certain differences have, however, been 
found between these two fungi. 

Oospora lactis is probably a composite species into which a number of 
closely allied fungi have been placed by systematists. A culture of Oospora 
ladiSy with which the sour-rot fungus was compared, was furnished by Mrs. 
Flora W. Patterson. This culture was isolated from oysters. A culture 
isolated from the same source was also received from Dr. Charles Thom. 

Artificial inoculations w4th Oospora lactis from these two cultures and with 
the sour-rot fungus on citrus fruits showed that Oospora citri-aurantii ia 
pathogenic, causing the fruit to begin to decay within a few days. Oospora 
lactis at first produces some mycelial growth on the injured tissues, but 
the myceliimi does not appear to be able to attack the tissue adjacent to 
the injury and no actual decay takes place. These experiments were 
performed several diflFerent times in moist chambers on Eureka lemon. 
Navel orange and Dancy tangerine. No infection took place, although 
duplicate experiments on the same kinds of fruit with the sour-rot fungus 
gave positive results. 

The reaction of Utmus milk with the two fungi differs. The sour-rot 
organism caused no change in the reaction and probably made but slight 
growth. Oospora lactis showed an acid reaction and clearing of mediimi 
without separation of the casein. 

The spores of the sour-rot fungus appear more regular in size, and more 
cylindrical than those of Oospora lactis. 

Artificial inoculations were made by puncture with cultures of Oospora 
citri-aurantii on the following citrus fruits in moist chamber: lemons, 
oranges, grapefruit and tangerine. Positive results were secured in 
moist chamber, the rot beginning to show in forty-eight hours. The ripe 
or nearly mature fruit is more readily infected. Failure to infect the 
green fruit of lemons has frequently occurred. Inoculations on the twigs 
of a Eureka lemon gave negative results. Lemons showing the initial 
stages of the brown-rot fungus, Pythiacystis citrophthora^ were atomized 
with a suspension of spores of the sour-rot fungus. Infection took place 
quickly in the brown rot areas and continued to increase as the former 
decay advanced. Eventually the surface of the lemons was coated with 
the sour-rot fungus. Sound fruit when inoculated with an atomized 
suspension of spores or when soaked for twenty-four hours in spore-laden 
water were but rarely infected and then probably only in some superficial 
injury. Infection of lemons with the sour-rot fungus evidently only takes 
place through some injury or from contact with infected fruit. 

WnimER, California 



A DISEASE OF PECAN CATKINS 

H. H. H I G G I N 8 

With Two FiorREs in the Text 

During the latter part of April, 1916, the writer's attention was called 
to an ahnonnality of the catkins (staininate) of pecans, Carya iUinoensiSf 
on the ExpcTinient Station plats. Some, or in many cases, all of the 
flowers of a (*atkin were slightly distorted and of a paler green hue. The 
stamens and inner surfa(*e of the subtending bract were covered with a 
white sutjstance whi<'h at first glance gave the impression of white fly, 
but which on examination was found to l>e the white spore-cluster and basi- 
dia of a fungus l)eIonging to the genus Microstroma. A little later when 
the pollen was Iteing she<l the (*ontrast between healthy and diseased catkins 
wjis made mon* ronspicuous l>y the failure of infested anthers to dehisce. 

SiH'tions of dise:iscMl anthers showed that, while the tissues in direct 
contact with the mycelium were not killed outright, the pollen 
grains were mostly degenerate, empty, and often collapsed shells. The 
my(*elium is entirely intercellular, often fonning thick mats which wedge 
the host cells a|)art and cause the slight <listortion of the diseased parts. 
Thi>sc* myc<*lial nuits i)e(*ome especially prominent at points near \h» 
surfac*(* whf*n> the large basal stroma of the fruit-body is formed in the 
l(M>M* sulx'pideniuil parench>iim. Fn)m this structure the club-shaped 
Ixisidia push through tlu* epidermis fonning a small but (*ompact hymen- 
iiuii alxive the siu-face of the host tissue. The individual thre^ids of the 
inten*ellular my(*elium and ak<o of the stnimata are extremely small and 
diflirult to distinguish as »nv\\. 

Ai>iMirently no toxic sulwtancc^ or injurious enz\iiies are secreted by 
the fungus, siiu*e the protoplasts and nu<'lei in the infested tissue retain 
nearly normal apjM'arance. The clumgi^s in cells entirely isolated by 
the my<*<*lial iimts indicate starvation rather tlian toxemia. The pollen 
griiiL** pn»s4»ni similar evi(h»n«*es of starvation. The vacuole gradually 
enlarges an<l the* protophLxmic layer iM^^omes thinner until it disappears 
entirely k'aviiig the niipty |M»llen-<*<*ll walls which collafMc or retain their 
original slia|M* according to thrir degree of maturity. 

IDKNTITY OF THK PAKASITE 

Of llu* four HiMM'irs of Mi<*n)stn)ma mentioned in Saccardo's Syllcge 
Fuf\^orum, M, album (Ik^m.) Sacc. occurs <»n leaves of oak, M. CycadiM 



44 PHYTOPATHOLOaV [VoL. 7 

Allusch. on leiivest of Cyaii rei-olut^i, M. unieriainuiii Paiiimel & Hiuiie on 
U-avcB of CnicuM iinierictinus, uiiti M. Ju^iantiin (B<;riii([) Siicc. on k-avw* 
of JuKliinx uiid Citrya. Sinrc M. Juglnndin wius uhniitlunt rarly in the 
sprinK on U-uvoh of hickories, it wax iil oix-e siiHiK-ctod timt \\\c fungiin on 
)K.-(-an <'atkins was iilc-ntirul wit)i tliis sjMM'ifN. Coinjiarulivc nicusurt^ 
nicnis of llic variiiiL" Htructurcs of the funftu;' from the two hostw Hhowctl 
however Monie very markeil <ljfTerenc<'s. Tin- siMiros from [wean catkins 
.-.re eyliii.lrieal. !> to M l.y .jji, an.l tlios.^ from liirkory leav.-s are oval lo 



^ Pa 



'o9 



e CP 



m° 



^9 



,1. rtuiOIiK l""Jv -li.miiiK l.u-i.liii. Ml.Ti|iiM:iI:i. :ii>rl -|«,r.'^: H. fr.-^li -|.i.r.-<; T. 
vr».|-lil.<' r.II. rr.>ni .'itilit-.l»v»'.l.l .-iil)tir<- ..n n.rii iii.'m] -.K^af. It. <'.-IU from ..I.I 
.■»Uu,.- ..I, ,.,nt iti.-:>l i.Knr. All X T::>. 

ol.]iii>i!. l> U> S l.y i..V' The )ia><i<lta iw well as tlu' Klr<>ni:ila from which 
thiy arjsi' :iri' innili larfcer iiiiil ihe iinniNr of lia.-<i'lia fmni each stroma 
miicli icre.-iler ou ihe |M-cari. 

< nlliiro i>f Uitti forms were ohiaincil arnl eom|)arei| on v:irions media. 
'Ih.- r.-iK.ii-^v wen- verv similar in each ea--e. (In all nic.lia «. far Irictl. 
..nh A >e:iM.|ik<- growth is formc.l. The '^porc^ -well eoi.si.lerahly an.l 
wdIuii a f.'u h.inrs U-^in forminK new cells l.y a hniiiliriK jiriKi-sN, stnin 
fi.tnutiK :i Mii:<1l. i-ircnlar white c.ilnnv. Ai tirsi short hvj.hal uerm hiln'< 
^^.■„■ |.nnul ..<-'':.siunallv, l.ni ihcv HK.n .lis^ipixarcl, A-. th.' hii.l.linK 
I.MHV^s ...nil - Ihc .taiiKliter cells lM'.'<.me smaller and ..val or clUjitieal 



1917] HiGGiNs: Disease of Pecan Catkins 45 

to globose. The fungus is not long-lived in cultures, requiring frequent 
changes to new media. 

Early in May direct and cross inoculations were tried with fresh spores 
from each host, but they all resulted in failure. 

Diligent search, for diseased catkins was made over several hickory 
trees the leaves of which were infested with Microstroma but none were 
found. Neither was any disease found on the leaves of pecan trees, 
although in some instances they were almost in contact with diseased 
hickory leaves. 

Notwithstanding the apparent difference in tissues attacked, in size 
of spores, basidia and so forth, it still seems doubtful that the pecan fungus 
should be given specific rank. The more robust habit on the catkins 
may be due to the more abxmdant supply of food. Therefore for the 
present, it seems best to consider the fimgus on pecan catkins as merely 
a robust variety of Microstroma Juglandis (Bereng.) Sacc. and to present 
the following diagnosis: 

Microstroma Juglandis (Bereng.) Sacc. var. robustum n. var. 

Host tissue pale, often slightly distorted; myceliimi intercellular, form- 
ing more or less dense mats between the host cells; fruiting stromata oval 
to short conical, 60 to 100 by 55 to 150/*, compost of very slender inter- 
woven threads; basidia club shaped, 13 to 30 by 5/*, bearing apically 6 
to 8 spores on short sterigmata; spores hyaline, one-celled, cylindrical, 
rod-shaped, 9 to 14 by 3 to 5/*. 

Hab. On stamens and staminate bracts of Carya iUinoensis. 

Microstroma Juglandis (Bereng.) Sacc. var. robustum n. var. 

Stromaiibv^ frudificantibus subepidermids, ovatis vel brevo-conids, 60 to 
100 by 55 to 85 n; basidiis caespitosis, davatis, 13 to 30 by 5^., seanf. odoporis; 
sporidiis hyalinis, cylindricis, 9 to 14 by 3 to 5ti. 

economic importance op the disease 

Since pollen is always produced in super-abundance by pecan trees 
the loss of a comparatively large amoimt is of Uttle importance. Since 
however, on some trees fully one-third of the pollen was destroyed one 
can readily see how the disease may become serious in the near future. 
At present so Uttle is known as to the life history of species of Microstroma 
that any suggestion as to control measures is almost valueless. 

Observations in the Station orchard during the past spring indicated 
that few or no commercial varieties are entirely immune; but the attack 
was much more severe on some varieties than on others. Similar observa- 
tions were also made in orchards around Albany, Georgia. 

Geoboia Agricultural Experiment Station 
Experiment, Georgia 



SOME NEW OR LITTLE KNOWN HOSTS FOR WOOD- 

DESTROYING FUNGI 

Akthuk S. Rhoadb 

Despite the great extent to which wood-destroying fungi have beeo 
collected, but comparatively little attention has been paid to the host 
species on which they occur. One frequently finds in herbaria good 
collections the practical value of which is greatly reduced by being de- 
ficient in this respect. Within the last few years, however, increasing 
attention is being paid to the host species with the result that many 
new hosts have been established and many fungi which formerly were 
thought to be confined entirely to the wood of deciduous or coniferous 
trees are now kno^-n to occur on both. 

In his ovn\ collecting work the writer always has been particularly 
interested in the hosts for wood-destroying fungi and frequently collects 
for host species alone. In looking over his lists recently a few species 
were noted, some of which apparently never have been reported. All 
but two of the collections cited here have been made by the writer him* 
self or in conjunction with others, cither in the states of Pennsylvania or 
New York. The following host species for wood-destroying fungi are 
believed to be new or at least little known. 

Coriolus versicolor^ 

On dead trees, fallen trunks, and Atumpd of Tsuga canadensis* (Pa. and N. Y.). 
On rustic fence rails of Juniperus vtrginiana (Pa.). 

On fallen trunks and stump of Abies baUamea (N. Y.). This species was noted 
as a host by Dr. L. H. Pennington on two occasions in the .\dirondack region. 

Coriolus nigromarginatus 
On a dpa<l trunk of Tsuga canadensis aMsocJAtcd with Coriolus abietinus (N. Y.). 

Coriolus prolificans 

On d(*ad trunks of Tmuja canadensis (Pa. and N. Y.). Numerous sporophores 
occaAiorially are found either pure or asfl4N*iBttHl with (\yriolus aitietinus. It pro- 



* The nomenclature for fungi used in this paper is that of William A. Murrill. 
((Agaricales) Polyiwraccae (pars). North Am. Fl. 9: 1-7*2. 1907; (.\garicales) 
Polyporareae ironcl). North Am. Kl. 9: 73-131. IIKW.I 

* The nom«*nrlaturc for tr(»<*s \\mh\ in this paper xn that of George B. Sudworth. 
(Check lint of \\u* forest trees* of the Tnitwl States, their names and ranges. U. 8. 
Dept. Agr , Div. Forentry Hul 17: 144 p. IHIW.) 



1917] Rhoads: Hosts for Fungi 47 

duces a sap-rot in hemlock that is indistinguishable, macroscopically at least, from 
that caused by Cabietinus, 

CorioleUus sepium 

On rustic fence rails of JuniperiLS virginiana (Pa.). 
On stump of Tsuga canadensis (N. Y.). 

Tyromyces comus 
On rustic fence rails of Junxperus virginiana (Pa.). 

Bjerkandera adiista 

On rustic fence rails of Juniperus virginiana (Pa.). 
On stump of Thuja occidenialis (Pa.) . 

Porodisculxis pendiUis 

On branches of fallen trunks of Juglans cinerea (N. Y.). This fungus usually is 
collected on wood of Caatanea dentata but occurs commonly about Syracuse on butter- 
nut wood. 

PolyporiLS Polypcrus 
On slash of Tsuga canadensis (Pa.). 

Pycnaporus cinnabarinus 

On a fallen sapling of Tsitga canadensis (Pa.). 
On log of Picea rubens in corduroy road (N. Y.). 

Hapalopilus gihrus 
On a dead sapling of Tsuga canadensis (Pa.). 

Ischnoderma fvliginosum 
On dead trunk of Pinits strobus associated with Coriolus abietinus (N. Y.). 

Elfvingia megaloma 

On dead trees, fallen trunks, and stumps of Tsuga canadensis (Pa. and N. Y.). 
On stump of Abies balsamea (N. Y.). 

Ganoderma Tsugce 

On or in close contact with stump of Pinus rigida (Pa.). 

On stump of Picea excelsa (Pa.)- 

On a much decayed stub of Betula liUea (N. Y.). A fine large specimen was col- 
lected on the latter host at Cranberry Lake, New York, and was fully as typical as 
those frequently found on hemlock trunks in that region. 

GkeophyUum trabeum 
On rustic fence rails of Juniperus virginiana (Pa.). 



48 Phttopatholoqt [Vol. 7 

GhBophyUum hirsutum 

On A soft maple log in a wharf at Oneida Lake, New York. Occasional aporo- 
pborea were anoetated with its near relative, Gloeophyllum trabeum. Tlie wood 
was either that of Acer $aecharinMm or Acer rttbrum^ but judging from the dominance 
of the silver maple in the lowlands of this region, it probably was the former species. 

On stump and adjacent log of PrunuM avium (Pa.)* Near State College, Pa., 
•porophores were found at various times associated with Gloeophyllum irabtMm on 
a stump and nearby log from the same tree. 

On fallen trunk of Betula luUa (N. Y.). A collection of this plant was found in 
the herbarium of the New York State College of Forestry and, although no host 
was recorded, a few s|>prophoree had ample bark attached to them to be positively 
certain that they grow on yellow birch. 

GkBoporua e(mchoides 

On an old sporophore of InonoluM dryophilue (Pa.). In making a collection of 
the former plant from a black oak log an old sporophore of Inonoiui dryopkUuB waa 
found on the log that also was well covered with sporophores of OUdoporuM coneAoidss 
and seemed to be as good a host for this plant as the wood of the log. 

The New York State College op Forestry 
At Syracuse University 
Syracuse, New York 



NOTES ON CRONARTIUM COMPTONLE III 

Perlet Spauldinq 

In 1908 the writer collected a specimen of Cronartium CamptonuB 
Arthur on a young tree of Pinus rigida at Burlington, Vermont. Since 
that time all available information concerning this fungus has been ao- 
ctunulated, and all the experimental work possible has been done. Three 
brief papers^ have been published giving some of the more important 
facts which have been learned. It is proposed in the present paper to 
state very briefly some results secured in more recent investigations. 

The pine hosts of Cronartium Comptanias, which have been previously 
reported by various writers, are Pinus rigida Mill., P. sylvestria L., P. 
maritima R. Br., P. austriaca Hoess., P. divaricata Ait., P. echinata Mill., 
P. montana Du Roi, P. ponderosa Laws., P. contorta Loud., P. virginiana 
Mill., and P. tceda L. In the years 1915 and 1916 Cronartium Comp^ 
tonicB has been received by the writer from various locaUties on the follow- 
ing new pine hosts: Pinus densiflora Sieb. & Zucc. (one locality), P. 
jeffreyi Oreg. Comm. (two localities), P. larido Poir. (one locahty), P. 
mugho Poir. (three localities) and P. resinosa Alton (one locaUty; three 
other localities are known but no specimens could be secured). 

Successful inoculations have been made by the writer and his colleagues 
named below, for the first time, so far as can be determined from pub- 
lished statements, from several pines to the alternate hosts. Uredinia 
were produced on plants of Comptonia asplenifolia L. with aeciospores 
from Pinus tceda (one test made), P. austriaca (2 tests), P. rigida (4 tests) 
P. mugho (3 tests), P. resinosa (1 test), P. jeffreyi (1 test), P. larido (1 
test). Uredinia on Comptonia were successfully used to produce uredinia 
on Comptonia and Myrica gale, Uredinia from Myrica gale produced 
uredinia on Comptonia. These are the first successful inoculations with 
uredinospores to be reported. In the winter of 1914-15 a special effort 
was made to seciu'e Uving plants of all the species of Myrica growing in 
this coimtry. A stock of the following species was obtained largely 
through the efforts of G. G. Hedgcock and E. P. Meinecke: Myrica 
gale L., M. califomica Cham., M, cerifera L., M. carolinensis Mill., M. 

'Spaulding, Perley. Notes on Cronartium Comptonise. Phy topath. 8 : 62. F. 1913. 

. Notes on Cronartium Comptonise II. Phy topath. 8: 306-310. D. 1913. 

. Notes on Cronartium Comptonise and C. ribicola. Phy topath. 4: 409. D. 

1914. 



50 Phytopathology (Vol. 7 

inodora Bartr., M. pumila Michx., as well as CompUmia asplenifolia. 
Mr. G. F. Gravatt and Dr. G. R. Lyman in 1915 made inoculations under 
the writer's direction. Five different series of inoculations, with aecio- 
spores from as many different species of pine, were made. Theresulta 
were as follows: 

3 plants — CompUmia asplenifdia — uredinia produced on all. 
7 plants — Mj/rica gale — ^uredinia produced on all. 

9 plants — Myrica caroHnerms — no infection. 

4 plants — Myrica califamica — no infection. 

5 plants — Myrica inodora — no infection. 

3 plants — Myrica pumila — no infection. 

4 plants — Myrica cerifera — no infection. 

A single plant of 3/. carolinensis was inoculated repeatedly in 1916 by 
the writer without visible results other than yellow spots on the leaves, 
which are thought to be due to some other cause. Nimierous successful 
inoculations have l)een made on CompUmia asplenifoUa: i.e., a total of two 
in 1912, eleven in 1913, two in 1914, nine in 1915, and fourteen in 1916. 
A lesser numljer has been made on Myrica gafe, which gives much less 
striking results. The total number of such successful inoculations on 
Myrica gale is: seven in 1915 and four in 1916. 

In 1912 the writer l)egan a series of annual observations in an area of 
several acres near I^kc George, New York, quite thickly covered with 
natural reprcKluction of Pinus rigida, in which Cronariium CompUmia 
occurs as a native parasite. The size of the trees within the area ranges 
from twenty feet in height downward. Ver>' few are as small as two feet 
in height and there seem to l)e no ver\' young see<llings now appearing. 
Comptonia ojsplenifolia gro^-s naturally throughout the area so that condi- 
tions are excellent for the spread and development of the disease. These 
observations have continue<l until the present time, thus covering a period 
of five years. An effort has been made to keep numl)ered labels on all of 
the (iis(»jised trees, hut with indifferent success Ix^cause of curiosity or 
mischief in people who luippened to see them. Several significant facts 
liave l)een learned howevcT. On pines Cronartium CompUtnict fruits for 
a iK»ri(Ml of seven or eight w<M»k.**, the time of maximimi fruiting being 
alMMit Jiine first <'on8iderably earlier than the Tiriter at first supposed. 
The numlK»r of diseasc^d trcH»s killed annually by the fungus has been sur- 
prisingly unifonn, mnging from eight to eleven. In 1916 the obecrva- 
tion.H were made earlier than iLsual and a greater total niunber of diseased 
inN-s were unexi>e<'t<»<||y found. There is evidence that a small munber 
of tr(H»s are annually infeeted for the first time and it is hoped to learn 
this numtxT in the future. It is well establi.Hhed tliat a tree which once 



1917] Spaulding: Cronabtium Comptoniae 51 

bears fruit of the fungus almost always bears an annual crop of such fruits 
until the tree dies. In some cases a dying tree fails to produce them, 
but on the other hand, recently killed trees are often found with aecia 
on them. While the annual loss is not great, it is a serious loss when 
continued indefinitely. Moreover we have excellent reasons for believing 
that Pinvs rigida, to which the preceding statements apply, is much less 
susceptible to the disease than are P.^onderosa and P. cantarta. The loss 
in some instances, with the latter two species, has been total.' 
Ofpicb op Investigations in Forest Pathology 
Bureau op Plant Industry 
Washington, D. C. 

'Kauffman, C. H. and Mains, E. B. An epidemic of Cronartium Comptonis at 
the Roscommon state nurseries. Mich. Acad. Sci., Ann. Rept. 17: 188-189. 1915 



FURTHER NOTE ON A PARASITIC SACCHAROMYCETE 

OF THE TOMATO 

Albert Schneider 

Since the appearance of the recent article on a parasitic Saccharomyoete 
of tomato^ it has been determined that the fungus described unquestion- 
ably belongs to the genus Nematospora of Peglion.' In its morpho- 
logical characteristics it is closely similar to Nematospora Coryli PegL, 
which attacks the fruit of the hazel bush (Carylus aveUana). Peglion, 
however, makes no reference to the gametic origin of the ascus nor does 
he note the two cells of the ascospore. He also fails to recognise the 
arthroHpores and includes them imder ''Anomale vegetative Formen." 
These and other morphological as well as biological differences make it 
clear that the Xematospora Coryli of Peglion and the fungus under con- 
sideration are two distinct species. Both are true parasites and appear 
to occiu- in wanner countries (southern Italy, southern California and 
Cuba) and perhaps also in semitropical and tropical countries. 

The Nematospora of the tomato (Lycopersicum esculentum) is appar- 
ently a new species and the following name is therefore proposed: 

Nematospora Lycopersid n. sp. 

Asci of gametic origin soon becoming free from associated cells, cylin- 
drical with rounded ends, 60 to 70m in length; ascospores in two groups 
of four spores each, two-celled, slender, with pointed ends, slightly ridged 
at transverse septum, 50 by 4.5^; ascospores liberated by dissolution of 
ascus wall and held together somewhat in groups of 4 by motionless fla- 
gellae; flagellae 50 to lOO/i in length; arthrospores, of non-gametic origin, 
spherical to ampulliform, 25m in diameter. Two other cell forms also 
found: (1) much elongated, filamentous cells; (2) elliptical and ovoid cells, 
gametic in function, new celU forme<l in bipolar direction by apical bud- 
ding and also by apico-lateral budding at cell unions. The elliptical and 
ovoid cells alone are gametic in function. 

Habitat. Parasitic on nearly ripe and ripe fruit of Lycopersicum es* 
culenium, southern California, Cul>a and Mexico. 

'Srhnridcr. Alljert. A paranitic Saccharomycetc of the tomato. Phytopatholofj 
4: 395-399. 1910. 

•IVglion, Viiiorio. ToJior dir Ncmatoapora Coryli Pegl. Ccntralbl. f. Bakt. 
Abt. 2, 8: 754-761. 1901. 



1917] Schneider: Parasitic SAccHAROBiTCETE of Tomato 53 

Nematospora Lycopersid sp. nov. 

Ascis cylindratis, terminate orbiculato; 60-70/i in longitudine; sporidiis 
8; dispositis struibus duo, sporidiis 4. Ascus mox ex cellis prehensis li- 
beratus est. Tnnicae asconun in maturitate solventur et sporidiis liber- 
antur. Plurimi asci origine gametata sunt. 

Sporis ascpnim bi-cellulatis tenuibns, fusiformibus, flagello uno. Spo- 
ridiis 50 X 4.5m, flagello 50-100m. 

Arthrosporis non-gametatis, plerumque sphaeroidis, 25/i. 

Cellulis vegetativiSy eUipticis, ovatis ad filaris nonramosis, multipli- 
cantibus gemmatando apiculo-laterali apicnlatoque. Cellulis ellipticis et 
ovatis solis sunt gametatis. 

Hab. In fructo Lycopersici esculenti, terris calidis et tropieis. 

Acknowledgments are hereby made to Dr. Roland Thaxter and Prof. H. 
W. Anderson for calling the writer's attention to the Nematospora of 
Peglion. 

Uni\ersity op California 
College of PnARBiACY 
San Francisco, Calif. 



PHYTOPATHOLOGICAL NOTES 

Albany conference on white pine blister rust. A joint meeting of the 
North American Committee for the Control of the Pine Blister Rust and 
the cooperators of the United States Department of Agriculture was held 
at Albany, New York, November 20 and 21. The meeting was attended 
by a representative body of men from the states of New Hampshire, 
Vermont, Massachusetts, Rhode Island, Connecticut, New York, New 
Jersey, Pennsylvania, Virginia, Indiana, Wisconsin and Minnesota, and 
from the Dominion of Canada and the United States Department of 
Agriculture. The state foresters, pathologists, and nursery inspectors most 
intereste<l in the fight for the control of the disease were present. 

A brief re|x>rt from each state and from Canada gave the latest news 
concerning disea^ survey and eradication work. The reports show the 
general epiphytotic of the blister rust in New England and eadt of the 
Hudson River, with comparatively few centers of infection in New York, 
Pennsylvania and New Jersey, one infection center in Ohio, two in Wis- 
consin, and four in Minne«K>ta. A hasty survey made of the western 
half of the count r>' faile<l to show any blister rust of white pine present. 

It developed tliat the matter of control of the blister rust in the New 
England states resolved itself into the practicabilit>' of the eradication 
of currant and gooseberry' bushes on a large scale. The control of the 
blister rust in the I^ke States was shown to be on a somewhat different 
basis, for in that region the spots of infection known are very few. Here 
the total eradi(*ation of all white pines and Ril)e8 near the infection cen- 
ter is l>eing carried out. 

The Conmiittee passe<l resolutions favoring adequate legislation which 
would |)ennit states to carr>' out the eradication or control work neces- 
sary', following largely the Sanders model horticultural inspection bill. 
They also favored ad«|uate appropriiitions by the states to carry on 
eradication work and by the Fcnleral (Sovernment to carry on the sur- 
vey an<l ex|KTimental work. The Committee favored a Federal quaran- 
tine prohibiting shipment of five-needled pines and all species of Ribes 
from the eastern half of the countrj' to any part of the country west of 
Minm^sota, Iowa. Muwouri. Arkansas and Ix)uiBiana. A state qxiar- 
antine was also reconanended pn>hibiting shipment of five-needled pines 
and RilK»s from inf(»<'ted stat<»s to others not infected. 

A national law was urfccnl prohibiting the importation of all plants 



1917] Fhttopatholoqical Notes 55 

from any other continent into the United States except through the 
United States Department of Agriculture solely for scientific and experi- 
mental purposes. 

Rot G, Pierce 

Corn disease caused by PkyUachora graminis. During the euminer of 
1915, an apparently undescribed disease of corn was observed by F. L. 
Stevens in Porto Rico, Leaves were collected from the diseased fields 
in numerous localities in Porto Rico, and a study of the disease based 
entirely on this herbarium material has been made at the University of 
Illinois. 



Fig. 1. Pbtllacrora graiunis on Corn 
PortioD of a leaf shows strcmata on upper and lower surfaces 

The disease manifests itself as well-defined, aubcarbonaceous spots, 
either dmall and numerous or comparatively large and sparaely distributed, 
and in either cade surrounded by a narrow, yellowish-brown halo. The 
infection is local, confined to the leaf and the leaf sheaths, and is visible 
on both upper and lower surfaces. 

The spots are due to the formation of stromata in the infected tissue. 
Embedded in the stromata are perithecia consisting of depressed cavities 
surrounded by walls made up of dark-brown mycehum and bearing at 
the top a comparatively small ostiole. 

The mycehum in newly invaded tissue is slender and hyaline. It 
later becomes dark brown, filling the leaf tissue of the infected area with 
a network of hyphae. 



66 Phytopathology [Vol. 7 

The asci are numerous. They are cylindrical and in each sBcua are 
produced eight unicellular, hyaliqe, thin-walled spores. 

The fungus causing the disease has been identified as PhyUaehara 
graminus, 

A report including a detailed description of the disease and fungus, 
together with notes concerning the generic and specific relationship, will 
be read before the Illinois Academy of Science at its next meeting. 

Nora E. Dalbey 

Tylenchus triiici on wheal. In August, 1915, specimens of diseased 
wheat plants, which had just been received from Dr. J. H. Reisner, of 
the University of Nanking, Nanking, China, were kindly turned over 
to the \vTiter by Dr. H. B. Himiphrey, of the OflSce of Cereal Investigations, 
Bureau of Plant Industry. In transmitting this material by letter Dr. 
Rei^ner said, *'Tlie disease has become more widespread every year for 
the last three or four years and is causing great money losses." 

A microscopic examination of the wheat heads showed that practi- 
cally all of their glumes contained, in place of normal kernels, dark galls 
filled with an almost innimierable number of motionless but living larvae 
of the nematode, Tylenchus triiici Bauer, which has been known as a serious 
pest in Kurope since 1745. The parasite has been found in Sweden, 
Holland, (lemiany, Austria-Hungary, Switzerland, Italy, England, and 
Australia, but so far as known has never been reported from China before. 
Johnson* recorded in 1909 the occurrence of what undoubtedly is the 
same species on wheat from a few widely separated sections in the United 
States, but as no reports of its appearance l>efore or since that date have 
iK'on found, it is quite unlikely that the eelworm has become well estab- 
HsImmI in the wheat areas of this country. Whether the closely related 
siH»ci(»s of Tylenchus found by Bessey*, the writer, and others on several 
difTcrent grasses in various parts of the United States is identical with the 
fonn on wheat has not been determined. Some European investigators, 
however, regard Tylenchus triiici as a highly specialized parasite of the 
wheat. 

The infected heads of wheat are usually shorter and thicker than nor- 
mal heads and contain glumes which spread out almost at right angles 
to the fruit stem. In place of normal seed, dark, hard galls, incapable 
of g(*rmination ami full of lar\'ae, are to \ie found. Because of these 
effects on the host the disease has merited such descriptive names as ear- 
coc'kles, purples, false ergot, etc. 

* Johnwm. VAw, C NuU'S on a nomatodo in wheat. Science n. a. SO: 576. 1900. 

* B^aaey, Krneat A. A m*matodc* diaeaap of graasea. Science n. a. 21 : 391. 1006« 



1917] Phytopathological Notes 57 

Active larvae enter the young, tender tissues of the wheat flower, 
extract -food therefrom, tnature, and lay eggs, which in tiun give rise to 
another generation of larvae. After reaching a certain stage of develop- 
ment some of the subsequent generations of larvae become coiled and 
dried out in the matured seed coats of the host and are capable of re- 
maining in this inactive condition for long periods. Under favorable 
conditions of moisture and temperature the eelworms may escape from 
the seed, attack the leaf and stem parts of wheat seedlings, causing them 
to become wrinkled, distorted, or swollen, and finally enter the embryonic 
seeds. 

It has seemed desirable to bring the above data to general attention, 
in the hope that active measures will be taken both to prevent the in- 
troduction of this parasite along with wheat importations from infected 
coimtries and to stamp out the pest wherever it is foimd in this coimtry. 

L. P. Byars 

The Botanical Society of Washington. The following officers have been 
elected for the ensuing year: 

President, Mr. T. H. Kearney; Vice-President, Mr. Edgar L. Brown; 
Recording Secretary, Mr. Charles E. Chambliss; Corresponding Secre- 
tary, Dr. H. L. Shantz; Treasurer, Mr. F. D. Farrell. 

Mr. A. S. Hitchcock was nominated by the Society for the position 
of Vice-President of the Washington Academy of Sciences. 

Personals. Mr. Chas. S. Reddy, of the University of Wisconsin, has 
been appointed as assistant plant pathologist, and Mr. A. M. Christen- 
sen, of the North Dakota Experiment Station, as an agent, in Cereal 
Disease Investigations, Bureau of Plant Industry, with headquarters 
at Fargo, North Dakota, where they are engaged in the investigation 
of cereal diseases in cooperation with the North Dakota Station. 

Mr. F. A. McLaughlin, instructor in botany at the Massachusetts 
Agricultural College, has been granted a year's leave of absence for grad- 
uate study at the University of Chicago. 

Mr. W. L. Doran, for the last two years graduate assistant in botany 
at the Massachusetts Agricultural College, has been appointed instructor 
in botany and assistant botanist at the New Hampshire Agricultural 
College and Experiment Station. 



ABSTRACTS OF PAPERS PRESENTED AT THE EIGHTH AN- 
NUAL MEETING OF THE AMERICAN PHYTOPATHOLOGICAL 
SOCIETY, NEW YORK CITY, DECEMBER 26^, 1916 

Evidence oj the over wintering of Cronartium ribicola. Perlet SpaulDING 

Numcrouii inHtances have been noted whore largo lots of black currants were very 
heavily infected with Cronartium ribicola one summer and not the next. In the 
Geneva New York case the disease was present upon pines and these in the writer's 
opinion started the disease each spring. Cooperative experiments with Stewart, 
in which 500 heavily infected black currants were used, resulted in no disease. 
Furthermore, the writer has had during the past sev(*n years in the greenhouses at 
Washington, hundreds of KilK»s plants of more than thirty species, which have l>een 
UM>d in inoculation ox|>orimonts. In no case has the disease ever appeared upon 
thest* the next w^ason until artificial inoculations had l>oon made. Uniform success 
has l)e<*n obtained |]i*rs<>n»lly in locating the diseased pines from the areas occupied 
by the first gi'noration of un'doKporoM in the field. Field observations seem to indi- 
cate that the dis(*am* has lieen shipfied into now localities on infected Ril)es. In- 
fections of petioles are not as rare as at first supposed. No evidence of bud infection 
by way of the petiole has yet Ix^en s<*cured. Direct examination of buds on infected 
plants has also failod to show the presence of the disease. 

The control of white piri£ hlinter rwtt in small areas. W. H. Ra.vkin 

The control of white pine blister rust has l>een att4>mpted in eighty-five forest 
plant ingH mad<» with imported stock in New York State. Diseased or suspicious 
trees and all currants and gooseberries within five hundred feet of the plantings 
were n^nowd. Thirty-six plantings ha\'e shown diseased trees since 1909; twenty 
since HUl; sewnti^en sinci* 1912; fifteen since 1913; nine since 1914 and foursince 
1915. The HifH-9 sp. within one-half mile of all the plantings were inspected in the 
autumn of 1910. Dim>ased HH>en sp. were foumi around two, only. These were two 
of the four which had shown diseased trees in the spring. In both cases cultivated 
varieties of KiheM still existed within five hundred feet. It seems, therefore, that 
th«' n-moval of diseased trec*s and all currants and gooselK^rrios within five hundred 
fe«*t of the plantings has prc\Tnted the establishment of Cronartium ribicola in 
these an*as. 

Citrwt canker invcntigationn at the Florida Tropical lAiboratory, R. A. Jbhlb 

S<}rne cultural charuct'*ristirtt of the canker organism, Pseudamonas Citri Haase 
(Migula'rt genuH) or liactrrium (*itri (Crohn's genus Bacterium as emended by Smith) 
are as follows: (trowth f>n standard agar abundant, spreading, raised, smooth, 
glistening, transluscent, pale >-ellow, viscid, with characteristic odor in about 
6%^ days. Vitality ten to thirty day's, (trowth on |M>tato agar more abundant 
and spn*adtng with lighter color. Growth on potato slices more viscid and brighter 
>tIIow with fiifltinrt white margin on |K)tato adjaoi*nt to culture. White margin 
l»ecomes wry pn>mim*nt in forty-eight hours and do«>s not stain with iodine. On 
gra|M*fruit leaf and st4*ni decoction agar slants grom'th |Nrnet rates the agar and if 



1917] New York Meeting 59 

less raised. On oat agar slants growth is much more spreading and the color is much 
lighter. 

Positive results have been obtained from inoculations on grapefruit, ponderosa 
lemon, key lime, Citrus trifolicUOf sour orange, tangelo, sweet orange, tangerine, 
king orange, mandarin-lime, and kumquat. Disease also occurs on navel orange, 
mandarin, satsuma, conmion lemon, rough lemon, and Aegle glutinoaa. 

Studies upon the anthracnose of the onion. J. C. Walker 

A morphological study of the causal organism Colletotrichum circinans (Berk.) 
Vogl. shows the fruiting body to be an acervulus and not a pycnidium as first de- 
scribed by Berkeley, confirming the findings of Voglino who transferred the fungus 
from the genus Vermicularia to Colletotrichum. Further study has shown it to 
conform closely to the description of Colletotrichum fructum (S. & H.) Sacc. {Volutella 
fructi S. & H.), reported by Stevens and Hall as causing a fruit rot of apple. Inocu- 
lation of the fungus from onion into apple fruits resulted in a rot very similar to 
Volutella rot. Further study is necessary before the two fungi can be considered as 
identical. 

Inoculation of onion bulbs in soil held at different temperatures shows best in- 
fection to take place between 24** and 29**C. This may account in part for the rather 
sparing appearance of the disease until shortly before harvest. The fungus over 
winters in the soil and consequently the disease is most severe on old onion fields. 

Spraying the bulbs before harvest or in the crates after harvest has not proved 
beneficial. The fact that yellow and red varieties of onion are highly resistant 
offers some encouragement for the development of a resistant white strain. Work 
in this direction is to be continued. 

Pink root, a new root disease of onions in Texas. J. J. Taubenhaus and A. D. Johnson 
A new disease known as pink root is causing serious losses to onion growers of 
Webb County, Texas. The trouble seems to prevail only where onions are grown 
for two 3rears or longer on the same land. The same is also true for the seed bed 
where the same old soil is used for several 3rears in succession. The disease starts 
with the young sets in the seed bed and from there is carried to the field. 

The roots of the affected sets in the seed bed or the plants in the field turn pink 
in color then strivel and die. As fast as new roots are formed they become infected, 
turn pink and dry. The effect of pink root is to prevent the normal development 
of the bulbs in the field and to produce dwarfed undersized bulbs which are absolutely 
worthless as far as the market is concerned. The cause of the disease is still proble- 
matic. Attention is called to it at this time because of its great economic impor- 
tance to Texas onion growers. Extensive investigations are now under way to 
determine the cause and possible remedies for this disease. 

Two new camphor diseases in Texas. J. J. Taudenhaus 

Two new or little known diseases seem to threaten the existance of camphor 
trees in Texas : 

1. Anthracnose. The fungus attacks and kills the leaves and branches. Affected 
trees have a defoliated appearance at the top. The cause of the trouble is apparently 
a new species of Glceosporium tentatively named Olasosporium camphorcB. The 
organism is readily grown in pure culture and the disease reproduced at will. 

2. Limb canker. This disease is characterized by a dying of the larger limbs to 
about four to six fe^t from the top. The limbs turn dark and soon shed their leaves. 
Affected trees have a ragged and burned appearance . A fungus of the genus Diplodia 



60 Phytopathology [Vol. 7 



is &lwa3r8 aasociated with this disease. Investigations are now under way to de- 
termine whether this Diplodia is the same or similar to D, Campkorm F. Taaai, 
occurring in Italy, and whether also it is the direct cause of the disease. A full 
description of the two organisms will appear at a later date. 

Common and Bcientifie name* of plant dUeaiti, M. B. Waits 

Common names of plant diseases are used by a larger number of people than 
scientific names. Pathologists should encourage the movement to make oommon 
names definite and national. By being made definite they can attain their proper 
status in discussions, literature, dictionaries, quarantine regulations, laws, and 
legal proceedings. By agreement among pathologists they may even become more 
fixed than scientific names. 

There may be four distinct names connected with every parasitic disease; the 
oommon name of the disease, the scientific name of the disease, the common name 
of the parasite, the scientific name of the parasite. For example: lemon scab. 
Verrucosis, lemon scab fungus, Cladosporiwn Cilrx. In case of all common diseaeee 
the aim should be to provide these four names. Confusion has resulted in the fail- 
ure to recognise these four kinds of names, particularly in the use of the scientific 
name of the disease and the scientific name of the fungus as the common name of 
the disease. Scientific names may become conmion names through use but these 
cases should be clearly recognised as such and avoided if possible and vacancies in 
names also recognised. 

Nonparasitic diseases may have two names, common and scientific, and the same 
principles apply. 

Economic HomU of Sclerotinia libertiana in tidewater Virginia, J. A. McClintock 
The warm, humid climate of tidewater Virginia is especially favorable to the 
development of ScUrotinia libertiana. This fungus, long known as a serious parasite 
on lettuce, has been observed to destroy over fifty per cent of the autumn lettuce 
crop on farms where no rotation is used. In the fall of 1915 a serious disease of snap 
beans due to this organism was found. During the winter of 1915-1916 Sclerotinia 
libertiana was found to be the cause of a fruit rot of tomato in the greenhouse. In 
winter-grown parsley, under sashes, this fungus in one case caused drop of ten per 
cent of the crop in the infected frames. Sclerotinia libertiana caused the damping 
off of a large proportion of the seedling plants in several cold frames of cauliflower 
being raised for a spring crop of 1916. In the summer of 1916 this fungus caused a 
stem blight of liearing egg plants, on several farms. In each case the writer was 
able to isolate the causal organism and to reproduce the disease in the respective 
hosts, and in other hosts by cross inoculation. 

Lima Itran monaic. J. A. McClintock 

During the summer of 1916 while conducting experiments with nine varieties of 
pole, and s(*\'en varietieif of buith lima Iwans, the writer observed a serious mosaie. 
It wait olMier\'ed first on the Sieva pole lima or butter-l)ean and later on Improved 
Hendenwm'ii Biuih and Prolific bush, lima lieans of the Sieva type. 

Owr twenty-five per cf»nt of the several hundred plants of each of the above- 
mentioned varieties wen* stunted and l>ore the dwarfed, mottled, wavy leaves, ehar^ 
actertstic of this mosaic. None of the varieties of larger limas, which made up the 
remainder of the planting. showiMl signs of this mosaic, though they were grown under 
the same conditions and in many cases intertwined with the mosaic diseased plants 



1917] Nbw York Meeting 61 

of the Sieva type. Lima beans had not been grown on this land previously and no 
beans of this type were Rowing nearby, therefore, it was concluded that this lima 
bean mosaic was carried by the seed. This disease is serious because the yield on 
the infected plants is greatly decreased and the pods are smaller and malformed. 

Bean mosaic. V. B. Stewart and Donald Reddick 

Hundreds of acres of pea beans (Phaseolus vulgaris) in New York showed the mosaic 
disease in 1916 and in some fields practically every plant was afifected. Affected 
plants rarely set pods. The disease is not confined to pea beans. Numerous other 
varieties of dry and snap beans showed the disease but not so commonly as pea beans. 

The mosaic-diseased leaves on affected bean plants show irregular crinkled areas, 
somewhat deeper green in color than the surrounding 3rellowish green tissue. The 
disease is transmitted through the seed. Bean seed from mosaic-diseased plants 
developed diseased seedlings. Healthy seedlings rubbed with crushed mosaic-dis- 
eased leaves showed infection four weeks later. The first signs of the disease ap- 
peared in leaves which developed about blossoming time. Leaves which had de- 
veloped previously remained healthy. High temperature |knd humidity at time of 
inoculation slightly favor infection. 

Two transmissible mosaic diseases of ctxumbers, Ivan C. Jagger 

In Phytopathology for April, 1916, there is a group of articles, dealing with a 
mosaic disease of cucumbers, commonly known as white pickle, which causes a mot- 
ling of both leaves and fruits. In the vicinity of Rochester, New York, there occurs 
a second and distinct mosaic disease, which exhibits a mottling of the leaves, but 
shows no effect on the fruits. The latter disease has been repeatedly transmitted to 
healthy plants by rubbing with crushed diseased leaves, and has been transmitted 
to muskmelons and to summer-crookneck squashes. This may be the disease 
observed by Selby in Ohio and by Stone in Massachusetts. 

Bean diseases in New York State in 1916. W. H. Burkholder 

An investigation of the diseases of the field bean in western New York begun in 
1915 was continued during the summer of 1916. The most serious disease, a dry 
root rot, caused by a species of Fusarium, was reported last year. Morphologically 
the pathogene is nearly identical with Fusarium Martii Ap. and Wr., although 
infection was not obtained by inoculation with the latter fungus. The organism 
winters over in manure where bean straw has been used as feed, and thus may be 
spread from field to field. There is also evidence that the fungus may live for many 
years in the soil. The disease was foimd in practically all of the one hundred and 
fifty fields visited in western New York. Apparently all varieties of beans are 
equally susceptible to the disease although certain undesirable types of the white 
marrow are very resistant. A few individuals of these have been selected for breed- 
ing stock. 

The blight, caused by Bacterium Phaseoliy and the mosaic along with dry weather 
also aided in reducing the bean crop of 1916. There is some indication that Bac- 
terium Phaseoli causes a stem girdling. Anthracnose was destructive in 1915, but 
caused little damage in 1916. 

Do the bacteria oj angular leaf spot of cucumber overwinter on the seed? Eubanks 

Carsner 

This question was first suggested by the writer's observation in June, 1915, of 
the occurrence of angular leaf spot in a field on recently cleared land surrounded 



6i Phytopathology [Vol, T 

bj woods near Portsmouth, Virginia. This field was removed at least three or four 
miles from any other cucumber patch. 

In 1916 near Madison, Wisconsin, six separate experimental fields were planted 
with seed from the same source on land which had not been planted to cucumbers 
for at least three years. The disease appeared on seedlings in all of these fields and • 
in three of them it was noted on the cotyledons. In three commercial fields in the 
same vicinity, planted with seed from other sources, the disease did not appear 
at all in one case and not until late in the season in the other two. 

The fart that angular leaf spot appeared on seedlings only in the six fields planted 
with seed from the one source and not in the other fields in the vicinity furnishes 
the basis for the working hypothesis that the causal organism is seed-borne, and is 
oppo8C<i to the theory of local overwintering of the organism by means of insects or 
plant debris. 

Infrrte<l cucumber fruits in considerable numbers have been seen by the writer 
in seed fields. The method of securing and cleaning the seed affords ample oppor- 
tunity for the organisms to reach the see<l, and the process includes no operation 
that would be likely to |^ill all of the bacteria. 

Prelimiuary notcn on n ttetr leaf np<tt of cucumhern. (Iko. A. Osnkr 

During the 8oa.'<ons of 1915 and 1910. the writer's attention was called to a peculiar 
leaf spot on ruruinbcrH that was raiising more or leH.*< damage in a number of fields. 
The sp<»t8 variwi from two tenths to fiftt»en millimeters in diameter, the majority 
of the smaller spots ranging from on<' to two millimeterH and being limited in most 
cases by the veins of the leaf. The larger spots were white or tingcxi with brown 
and with rcnldish brown areas along th<' veins of the leaf which gave the sjMits a 
chararteristir mottleil appearance. 

The dinea^e was found to be due to a fungus belonging to the DematiaceavDictyo- 
spone group of the Hyphomyretes. Its exact generic position has not been deter- 
mineti a.** yet. The <irganisni was securcnl in pure culture on string bean agar and 
8uc<'e*«sful inorulntions have been made on young cucumber plants in the green- 
house, the rherkM remaining healthy in all eases. 

ViruUncf of Hiffrrrut ntraiuH of CUuiosporium ciwumrrinum. W. W. GiLBEKT 

\ considerable number of strains of the cucumber scab fungus, Cladonporium cm- 
cumrrinutn. have been isolatiNl from cucumber fruits from different localities and 
grown in culture, and many series of inoculation experiments have IxH'n mmle tm 
sei*<llings and young and old plants. It has been found that these strains vary 
widely in their ability to infect cucumber plants. Some have failtnl to prcnluce 
any infertion after many trials, while others are uniformly virulent. One strain 
in partifiilar liaj* ^iven very striking infection practirally I'very time when favorable 
conditionM were maintain***!. The virulent strains attack cotyle<lons and stems of 
young cucumber ^e<Nllings in inoi.st chamlxTs and kill them in two to four days. 
They also attack and kill vtTy rapidly the younger leav(*s, stems and growing tips 
of larger iilants under favorable moisture conditions. I'nder identical conditions 
the iionvirulent strains faihsi to prcnluce infection. Similar results were secured 
when youiiK cucunib<>r fruits were inoculated in moist cluunbers with different strain* 
of (*lado^|M>rium. 

Ihfntmxuotiitu ♦»/ Ihr nrgnninm of rurumher anlhracnone . M. \V. GARDNER 

In A fairly large acreage of cucumbers and other cucurbits under observation 
in 19HV the ap|M*arance of original centers of anthracnose in only the plots or fields 



1917] New York Meeting 63 

planted with seed from certain sources pointed suspiciously toward disease intro- 
duction with the seed. Subsequent inspection of seed farms revealed the presence 
of anthracnose on seed fruits and that the processes involved in seed extraction may 
furnish efifective means of seed contamination. 

Extensive spread from original centers of infection in the cucumber fields under 
observation followed periods of heavy rainfall. The principal direction of spread 
was that of the surface drainage. Plate isolations of the fungus were made from soil 
near diseased plants. Rows of healthy seedlings exposed to drainage water in dis- 
eased fields during heavy rains the first week of September became abundantly 
infected and many seedlings were killed outright. 

Glass tumblers were sunk in the ground at various points in two fields to intercept 
surface drainage during rains. A successful plate isolation of the fungus was made 
from water thus collected. Samples collected in one field after rains on Septem- 
ber 5 and in the other field after rains on September 12, when sprayed or sprinkled 
on healthy potted cucumber plants, produced numerous anthracnose lesions. 

A bacterial stem and leaf disease of lettuce. Nellie A. Brown 

A serious stem and leaf disease of lettuce appeared in Beaufort County, South 
Carolina, 1916. The disease occurred chiefly on two plantations, one of seven- 
teen, the other of nine acres; a conservative estimate of loss on the former was sixty 
per cent; on the latter ninety per cent. Other plantations within a radius of twenty 
miles suffered one to ten per cent loss. 

The affected plants were wilted, the outer leaves blotched and darkened. Rot- 
ting was often rapid. A cross-section of stem at an early stage of disease showed 
a blue-green color; later stage, brown. Both pith and vascular regions were in- 
volved. Later the stem usually became dry and brittle. Moderately diseased 
plants are darkened in patches in stem, and vascular region. Bacteria filled the 
cells of the blue-green and brown areas. No fungi were found. 

A bacterial organism was isolated which when inoculated into lettuce produced 
the blue-green color throughout the vascular system and pith, which later became 
brown. Disease appeared on leaves also. Eight months after isolation this or- 
ganism, which is yellow on various media and is doubtfully motile, is still infectious. 
In its morphological and cultural characters it does not correspond with any or- 
ganism recorded as pathogenic to lettuce. 

Blajck spot of pepper. L. E. Melchers and E. E. Dale 

In 1915 a striking pathological condition of fruits of peppers was noticed; the 
disease ranging as high as 45 per cent. A species of Altemaria has been consistently 
associated with diseased areas. These are slightly sunken, dark colored and not 
confined to any particular location. Inoculations show that the organism is only 
a weak pathogene when inoculated into normal tissue. When the pericarp is me- 
chanically (slightly) injured, the fungus becomes established and diseased areas 
enlarge. There are apparently two ways or combinations of factors in which natural 
injuries may occur to peppers in the field; (1) injured areas from sun-scald, (2) frost 
injuries. Artificially injuring the pericarp by means of a burning-glass and apply- 
ing the fungus superficially, produces a condition which is the counterpart of the 
symptoms occurring in the field. Varietal resistance is shown by the data of 1916. 
Sweet peppers are more susceptible than the hot varieties. Among 15 varieties 
grown, the percentage of disease ran from 0.02 to 2.7 among hot peppers and from 
0.4 to 23.07 among the sweet ones, with an average of 13.6 among the latter when 
sprayed and 11.7 in the unsprayed. Bordeaux sprays do not control the malady. 
Affected fruit is unsalable. 



64 Phytopathology [Vol. 7 

A 9cUrotium dUeoMe of pepper$. Wiluam H. Martin 

The disease is characterised by the presence of numerous, minute, blaek sclerotia 
throu|(hout the fruit as well as on the seeds. With the exception of a blackening 
of the epidermis, the disease may pervade the entire interior before any external 
symptoms are noticed. 

The fungus was isolated and grown in pure culture. The pathogenicity of the 
fungus has been fully established by numerous successful inoculations on both 
green and ripe fruit, as well as on the plant itself, and by the subsequent re-isola- 
tion in pure culture. Reinoculations with this second isolation again produced 
the typical rot. 

The identity of the pathogene has not been satisfactorily determined but there 
is evidence for the belief that it is ScUrotium bataticola Taubenhaus. 

Successful cross inoculations have been made on pepper and sweet potato as well 
as on cucumber, tomato, apple and egg plant. 

DiMfffiifui/t on of Bacterium hfalvacearum, R. C. Faulwetter 

Through investigations of the means by which Bacterium hfalpacearum may be 
disseminated, it has been concluded that wind during rainfall is the most impor- 
tant agent. Neither insects nor seed infection can account for the prevalance of 
the angular leaf spot caused by it in all varieties of cotton. An inoculation experi- 
ment consisting of one row of plants in a field free of the disease was followed within 
a month by infection of the plants to the east as far as the fourteenth row, and in 
the next month by the spread of the disease to the west. A second experiment ar- 
ranged and operating during the second month also showed spread to the west. 
Practically no disease occurred east or west of uninfected plants in the original 
rows. 

It was demonstrated experimentally that the leaf-surface film during heavy dews 
contained viable bacteria. It is to l>e expected these organisms will be present 
during rains. Westerly winds prevailed during the rains at the time the disease 
spread to the east, and during the next month the wind direction had changed, blow- 
ing from the south-east. Considering the slight disease opposite the uninoculated 
plants, and the simultaneous change of wind direction and the spread of the dis- 
ease, it is held that wind during rainfall is the most active agent in the dissemina- 
tion of the causal organism. 

• 
Bacterial dineaseM of celery. W. 8. Kroitt 

These diseases occur in a region with a deep muck soil and a very humid climate. 

Trotrn rot. This disease is prevalent in the greenhouses and fields. The symptoms 
are a yellowing of the foliage and a rotting of the crown starting through side roots. 
Plants arc destroye<l in fnim three to four wcekn after infection. The causal organ- 
isms appear to l>e a Bacterium and a Fui«ariiim working simultaneously. Steam 
steriliiation and the following rhemimls have lieen applied in varying amounta to 
the soil for the control of the disease: foniialin, calcium chloride, copper sulphate, 
ferrous sulphate, sulphur, scMliuni chloride and potash. 

Crown rot trilt. This diHoasc is intermittent in its orrurrence. It is characterised 
by a sudden wilting of the entire foliage, an oval hollow cavity in the crown and a 
ba<ily difM*ased tap r(N>t which hitvi^s as a channel of inf«*ction. 

Bacterial heart wilt. The bacteria attack only the innermost, tender leaves caus- 
ing a wet, carlKtnaceoiiH rot. The organism has l>een isolated and its pathogenicity 
proved. 



1917] New Yobk Mseting 65 

A bacterial blight of say bean. A. G. Johnson and Florence M. Coebpbb 

For a number of years this disease has been under investigation at Madison, Wis- 
consin. A malady apparently the same has also been reported from other parts 
of the United States. At Madison the disease has been common during the past 
three years, especially on the leaves. 

These leaf lesions are small, rather angular spots, in late stages, dark in color, 
brown to purplish black. In the earlier stages they are translucent and water soaked 
in appearance and yellowish to light brown in color. The lesions may be irregularly 
scattered or variously grouped and they not uncommonly coalesce. Rather incon- 
spicuous glistening films of exudate are frequently noticeable on the lowfr surfaces 
of the lesions. 

Repeated isolation cultures have yielded a characteristic, white bacterial or- 
ganism which has proved pathogenic on soy bean, producing characteristic lesions 
as described above. The same organism has been reisolated from such lesions and 
its pathogenicity in turn proved. This organism is a rod with rounded ends, motile 
by a single polar flagellum, hence referable to the genus Pseudomonas of Migula 
or the genus Bacterium of Ehrenberg as interpreted by Erwin F. Smith. 

Studies on the physiological characteristics of the organism and its pathogenicity 
on other leguminous hosts are in progress. 

Host limitations of Septoria Lycopersici. J. B. S. Norton 

Inoculations of seedlings of a number of Solanaceae and eighty varieties of tomato 
in humid enclosures, with Septoria from tomato resulted in infections on several 
species of Solanum, eggplant, Datura tatttkif and especially on potato, currant tomato 
and Solanum carolinense. Spots developed better and spores larger on potato and 
horse-nettle than on tomato, while the Datura spots were slow-growing, light colored 
and small-spored. With larger plants outdoors, infections appeared rarely except 
on Lycopersicum ; but undoubted infections resulted on horse-nettle and potato 
and occasional pycnidia developed with spores smaller than on tomato. The to- 
mato varieties in the seedling stage, showed decided differences in susceptibility 
to the Septoria, both in number of infections and time of development. Many 
dwarf varieties showed marked susceptibility. 

Wintering of Septoria petroselina var. Apii. W. S. Krout 

Heretofore, the seed has been considered the primary source for dissemination 
and wintering of this organism. The following observations and results of tests 
indicate this is not the case: (a) Pycnidia with spores are found on the pedicles 
and have been reported on seed, (b) All spores taken from the dried pedicles 
failed to germinate, (c) Spores from green celery tissues subjected to dessication 
for eight months under laboratory conditions failed to germinate, (d) Young 
seedlings in the seed-bed were never infected unless planted on soil that had pre- 
viously grown celery infected with this organism, (e) This organism forms sclero- 
tial-like intercellular bodies in the petioles, (f) Celery grown in new localities 
gradually becomes infected, (g) Seed from the same bag, but divided and sown 
upon two different farms produced the diseased seedlings in one case and healthy 
seedlings in the other. 

These studies indicate that the disease is not carried in the seed but in manures 
containing diseased, decomposed plants, and probably by other methods. 

Laboratory work has shown that heating celery seed to 50**C. for one-half hour 
will eliminate all chances (if there be any) of the disease being disseminated through 
the seed and pedicles. 

Incomplete studies on Cercospora Apii Fr., indicate similar conditions. 



66 Phytopathology [Vol. 7 

A nematode disease of the dasheen and iU control by hot water treatment. L. P. Btaks 

During the summer of 1914, a new disease of an economic aroid, the dasheen, 
Coiocasia esculenta (L.) 8chott, waa found at one point in Florida causing serioua 
damage. The malady is caused by the widely distributed nematode or eel worm, 
Hcterodera radicicola (Grcef) Moller, which causes root-knot of many wild and cul- 
tivated plantK, but which has not heretofore been authentically reported on the 
dashren. In some places it has caused almost a complete failure of the dasheen 
crop and is roffardcd as the most serious pathological factor in the successful pro- 
duction of thiH plant. 

The dit4asp has been found on dasheens in most of the South Atlantic States where 
€M*onoiiiir aroids arc grown and in a shipment of cormcls imported from Egypt for 
propagating pur]>08os. 

On <lashcon roots the nematode produces macroscopically conspicuous svi'cllings 
which hinder normal absorjition. On the surface of the tuberous growth it causes 
protuberances and definite raiscMi areas resembling open sores, through which s€M?ond- 
ary hel<l and storage parasites may readily enter. The eelworm docs not live on 
the aerial parts of the <lashet»n. but, in rase of severe infection, it causes these |>or- 
tions to be greatly r<HluriMl in size, and gives to the plant as a whole a decidedly sickly 
app«'aranec\ 

The disease has been surressfully controllcHl by planting on uninfecte<l land se- 
lected rormels from disrase-free areas, or diseaswl connels which have been treatetl 
with water at o()°(\ for forty minutes. 

Sot* worthy }*orto Rirau plant di^icaxcn. V. L. ST*:vE.\rt 

To U' printed in full in thi* April issue of Phytofathouxjy. 

Suljuriruj Concord grnjHH to prevent jHncdery mildew. F. K. CiLADWIN and Donald 

Hkoouk 

Continuing work rcfxirtcHl in Internat. Cong. Vit. Off. Kept. 1916: 117-12o. 1916, 
plats of Concord grape vines were duste<i three times, July 18, August 2 and August 
16, with sulfur-Iinie mixtures containing respectively twenty-five, fifty and seventy- 
five percent »iulfur flour, ninety-five per cent or more of which pa-sses 'J(X)-mesh sieve. 
The mixtures were applieil at the rate of forty pounds per acre. A single applica- 
tion of liordeaux mixture was made <»n one plat on August 11. Treatinl plats al- 
trrnuted uith rherk plats and all plats were separatnl by one buffer row. 

I*o\i<lerv mildew, causetl bv I'nrinula neeator, was abundant. At harvest time 
f»ne untreat<Hl plat showetl four per rent of the rlusters free from mildew and an- 
other only tl.U()7 per cent fr<*e. The lM)rdraux-!<pray<'<i vines showi*<l six per cent of 
th<* elu>«ti*rs free from mildew, the mixture rontaining sfventy-five per cent sulfur 
showeil ninety-six j)er«M*nt frer. that containing fifty per cent showtn! eighty-three 
per cent fr<*<* and that containing twenty-five per cent sIiow^hI twenty-seven i>er 
cent free. The seventy-five per cent mixture causi»<l severe burning, the fifty per 
cent mixture a small amount of biiniing and the twenty-five per cent mixture slight 
burning 

The nrrial triage of (\dtonfMtrium elephiintoiHtdin. (»Eo. (I. IlKUCK^tK'K and W. H. Ix)SO 
Voung triM»s of l*\nuA heterophylUi in the greenhouse at Washington. D. C, were 
in<HnilAti*d under cc»ntrolli*<i conditions in November. 1915. with the teliospores of 
CtUrtn^fHtnum flrphnntofMHiiM (Schw./Thnm. In February, 1910. the aecia of Pcri- 
dermtum carneum {lUtBc.) Seym, and Karle appeareti on the needles in abundance. 



1917] New York Meeting* 67 

These were fully mature late in March. Inoculations with the aeciospores March 
7 and April 5, 1916, on the leaves of plants of Elephantopus tomentosus L. produced 
in abundance the characteristic uredinia and telia of Coleosporium elephantopodia. 

During the past three years parallel sets of inoculations of plants of Vernonia 
on the one hand and of Elephantopus on the other with the aecia of Pertdermium 
carneum from a number of species of pine have resulted in producing Colesoporium 
vernonicB B. and C. on the former, and C. elephantopodia on the latter, indicating the 
identity of the two species. 

Pertdermium carneum is now reported for the first time on the needles of Pinus 
carihcBa Morel., P. clausa (Engelm.) Sarg., P. echinata Mill., P. glabra Walt., P. 
heterophylla (Ell.) Sudw., P. ponderosa Laws., P. rigida Mill., P. scopulorum (En- 
gelm.) Lemm., and P. serotina Michx. 

The Peridermium belonging to Coleosporium ipomceoB, George G. Hedgcock and 

N. Rex Hunt 

Peridermium ipomceoB a new foliicolus species on Pinus echinata Mill., P. palus- 
tris Mill., P. rigida Mill., and P. taeda L. is described, with a range from Pensylvania 
to Florida and Texas. 

Plants of Ipomcea lacunosa L., /. pandurata L., /. triloba L., Pharbitis barbigera 
(Sims.) G. Don., P. hederacea (L.) Choisy, and Quamoclit coccinea (L.) Moench un- 
der controlled conditions were successfully inoculated with the aeciospores of this 
Peridermium, producing on their foliage the typical uredinia and telia of ColeospO" 
rium ipom(EXB (Schw.) Burrill, thus proving that it is the aecial stage of this Coleo- 
sporium. Plants of species of Amsonia, Aster, Calonyction, Chrysopsis, Convol- 
vulus, Coreopsis, Elephantopus, Helianthus, Laciniaria, Silphium, Solidago, Ver- 
besina and Vernonia were unsuccessfully inoculated. 

Coleosporium ipomcece is now reported for the first time on the leaves of Ipomolea 
caroliniana Pursh., 7. trifida (H. B. K.) G. Don., and Pharbitis barbigera, 

A Peridermium belonging to Coleosporium terebinthinacece. Geo. G. Hedgcock 

and N. Rex Hunt 

Peridermium terebinthinaceumf a new foliicolus species on Pinus echinata Mill., 
P. rigida Mill., and P. taeda L., is described with a range from North Carolina to 
Georgia. 

Inoculations were made under controlled conditions with the aeciospores of 
this Peridermium on plants of Silphium asteriscus L., S. intcgrifolium Michx. ^ S. tri' 
foliatum L. and Parthenium integrifolium L. in May and June 1916. In about two 
weeks the uredinia, and later the telia of Colesporium terebinthinacea; (Schw.) 
Arthur appeared on the leaves of all these species, proving the Peridermium to 
be the aecial stage of this Coleosporium. Inoculations were made at the same 
time on plants of species of Amsonia, Coreopsis and Laciniaria without result. 

Coleosporium terebinthinacece is now reported for the first time on the leaves of 
Silphium angustum (A. Gray) Small, S. compositum Michx., S. dentatum Ell., S. 
glabrum Eggert, and S. pinnatifidum Ell. 

An alternate form for Coleosporium helianthi. George G. Hedgcock and N. Rex 

Hunt 

A new foliicolus species, Peridermium helianthi, is described on Pinus virginiana 
Mill., with a range from Pennsylvania to South Carolina and Tennessee. Inocula- 
tions made with the aeciospores of the Peridermium, under controlled conditions, 



Phytopathology [Vol. 7 

on planU of HelianthuM decapetaluM L,, H, divawieaiui h,, H. ffiganteuB L., H, gla^mu 
Small, and H, hir9utu9 Raf . produced the uredinia and telia of CoUo^porium kelianiki 
(Schw.) Arthur, usually in abundance, thus proving the Peridermium to be the 
aecial at age of this Ck>leo8poriunk. Inoculations were made at the same time on 
plants of species of Aster, Chrysopsis, Coreopsis, Elephantopus, Laciniaria, Parthe- 
nium, Rudbeckia, Silphium, Solidago, Verbesina, and Vcmonia with negative re- 
sults. The results of these inoculations indicate that the Coleosporiums on Coreop- 
sis and Verbesina arc distinct from the one on Helianthus. The Coleoeporium in 
Florida on Verbesina which has been assigned to C. heliarUki may belong to one of 
the unnamed species of Peridermium found by the writers in the south. 

CoUo9ponum heliantki is now reported for the first time on HelianthuM au9traii9 
Small, //. divaricatus L., //. eggeriii Small, //. glaucus Small, H. gro99€'9erraiu9 
Martens, //. hirsutus Raf., //. microcephalus T. and G. ,and //. aaxicola Small, and 
its range (on Helianthus) is extended to Louisiana and Florida. 

SoffM fi^tr ha$U for CoUo9parium »olidagin%$. Georqe G. Hedocock and N. Rxx 

Htnt 

Peridermium acirolum I'ndcrw. and Earlc, the aecial stage of CoUoBpcrium coli- 
daginia (Schw.) Tht'im.. is reported for the first time on Pinun carihaea Morel., P. 
coniarta Loud.. P. diraricata (Ait.) Du Mont do Cours, P. echinata Mill., P. tUioltii 
Kngolm., P, mayriana Sudw., P. nigra Arnold (P. laricio Poir.), P. nigra var. ays- 
iriaca Srhneid., P. jtaluatria Mill., P. ptpnderoaa Law8., P. acopiUarum (Engelm.) 
liPmm., P. nrrotina Mirhx., P. taeda L., and P. thunhergii Pari. 

Positive results have been obtained from inoculationfl with the aeriospores of 
Peridermium acirolum on plants of species of Aster and Solidago, and negative re- 
sults only, on plant** of Hpc*cics of Campanula, ConvolvuluK, Coreopsis, Elephanto- 
pus, Kupat<irium. Euthaniia, Helianthus, Ip<>nH>ea, Laciniaria, Parthcnium, Phar- 
bitiK. iS'iH'i'id. Verbesina. and Vcmonia. A Coleosporium on Chrytopaia mariana 
(L.) Ntitt.. found firMt by \V. H. Ixing in Florida, in tentatively assigned to this 
sperics. 

The range* of the Peridermium has be<»n cxtendwi to include nearly all States from 
Minnesota and New Hampshire on the north to Arkansa.H and Florida on the south. 

Sotrf on name tijterirn of ColroafMtrium. (iKr>K(2K (i. HKDttriK'K and N. Rkx Hunt 
ColronjHtrium delicatulum .\rth. and Kern is report (h1 for the first time on Euthamia 
earoliniaua (L.) (ireene, and E. leptorephala (T. and (•.) Greene, and Peridermium 
delicatulum (.-Xrth. and Kern) Ilfnlge. and l^uig for the fir<«t time on Pinua tariteif 
Morel.. /•. echinata Mill.. P. eUiottii Engelm.. P. hrUrophylla (Ell.) Sudw., P. may- 
riana Sudw.. P. palimtrin Mill.. P. nigra .\rnoM. /*. /tonderosa Lawn.. P. reainoaa 
Ait.. P. Htrotina Mirhx., ami /'. tarda L.. and the range of the spei*ii*s is greatly 
e\tend«l. 

CotfoffHtrium laciniarnr .Vrth. i.M reiM)rt<*<l for the first time on l^aciniaria earlei 
(•reene. L. drgann (Walt. ) Kuntze. L. ttongata (tre<»ne, L. /xtuciflora (Pursh) Kuntie, 
L. acariima < L. i Hill, and L. utrotina (!re<>ne, and the range of the specie's extended 
to Klnridu on the .^fiuth and to New Jersey un the north. 

Some ri« 1/ hit<*t)* ftn ('itl*tt*fmn turn inritntpicuum. (iKoHciK (i. Hk<iD<'<x*K and N. Rex 

Hi .ST 

Ac*<-io*>|Niri*s fr«»ni PiTxdtrmium tnconapicuum I^mg rollert4*d for the first time on 
the nc4*4lles of Ptnuf echtnata Mill, were Huce<*ftsfully inorulat<*d on the leaves of 



1917] New York Meeting 69 

both Coreopsis major omUeri (Ell.) Britton and C. verticiUcUa L. resulting in the 
fonnation of the uredinia and tellia of Coleosporium inconspicuum (Long) Hedge, 
and Long. Unsuccessful inoculations were made on plants of species of Amsonia, 
Aster, Chrysopsis, Elephantopus, Euthamia, Helianthus, Laciniaria, Silphium, 
Solidago, Verbesina> and Vemonia. The results of these inoculations indicate 
that Coleosporium inconspicuum is distinct from species found on plants of these 
genera. This Coleosporium is reported for the first time on Coreopsis delphinifolia 
Lam., C lanceolata L., C. major Walt., C. major rigida (Nutt.) Boynton, and C. 
Iripteris L. 

Coleosporium apocynaceum Cooke has been collected at Clearwater, South Caro- 
lina on Amsonia cliate Walt. 

• 
Scolecotrichum graminis on timothy, orchard grass, and other grasses. A. G. John- 
son and C. W. Hunoerford 

During the past few years Scolecotrichum graminis has been observed by the 
writers on timothy and orchard-grass at various points from Wisconsin to the Pacific 
Coast. The fungus causes a serious disease of these hosts especially in Wisconsin. 
The young lesions on the leaf are circular to elliptical in form, vary greatly in size, 
and are usually purplish brown in color, The older lesions turn grayish brown as 
the invaded tissues die. In severe cases they coalesce involving considerable por- 
tions of the leaf-blades. In the worst cases practically all of the leaves of affected 
plants are dried up at about flowering time. In moist weather the fungus sporulates 
abundantly on the older lesions. On orchard grass, the lesions are somewhat more 
distinctive and sporulation takes place more abundantly. The conidiophores come 
out through the stomata and form dark-colored tufts arranged rather regularly 
in rows. 

Other grasses observed by the writers as hosts for the fungus are Agrostis alba, 
Bromus margimitus, Bromus sitchensis, Hordeum jubatum, Hordeum nodosum, Ely" 
mus glaucus and Elymiui robustus. 

Observations at Madison have shown that the fungus over-winters readily in 
tufts of orchard grass and timothy and resumes activity early in the spring. 

Bacteria of barley blight seed-borne, L. R. Jones, A. G. Johnson, and C. S. Reddt 
* In further studies on the bacterial blight of barley, upon which reports have 
been previously made, the mode of overwintering of the causal organism and of its 
dissemination over long distances have received especial attention. Field evidence 
early indicated that in certain cases the disease doubtless was introduced with 
seed from various western sources. In following up this matter, seed was collected 
in 1914 from a field of barley in Montana severely affected by the blight. Lesions 
were evident on the glumes of these plants before maturity and showed, although 
less clearly, upon the ripe grain. Some of this seed was planted in our trial grounds 
in Wisconsin in 1915, and the blight developed abundantly upon the leaves of the 
young plants. 

Isolation cultures were made in July, 1916, from the glumes of barley kernels 
from this same 1914 Montana collection. The characteristic barley blight organism 
was obtained and its pathogenicity proved by inoculation experiments. It is thus 
apparent that the organism may be carried with the seed grain and remains viable 
after at least two years of dormancy. Preliminary trials indicate that the organism 
may be destroyed by seed disinfection. 



70 Phttopathologt [Vol. 7 

The Ptteudopeziza leaf spot diseases of alfalfa and red clover, Fred Reucl Jonks 
The PseudopeEiEa leaf ftpots of alfalfa and red clover have been studied for the 
past two yearn for the purpose of determining the following points. 

1. Are the causal organisms the same or distinct species? 

2. Is any other spore-form than the ascospore included in the life history of these 
fungi? 

3. What is the relation of these fungi to the tissues of their hosts? 

4. How do these fungi oven»inter? 

5. Can the occurrence of the alfalfa leaf spot on alfalfa sown in a new region for 
the first time he prevented by seed treatment? 

Progn^s hat* been made as follows: 

1. Both fungi have been obtained in pure cylturc. Slight morphological and 
distint't phyniologiral differences have been found. 

2. Only ftf^cosporcs have been found produced in nature. Conidia-like structures 
occur in cultures. 

3. (icnninnting aMcospores penetrate the epidermal cells directly and the mycelium 
devt'lopM within the ho»t ccIIh and penetrates the cell wuIIh. 

4. The fungtiH <)ver>»inters on dead leaves which escape <lecay, and ascospores 
developiMl either in old or new apothecia are a source of spring infection. 

5. .Mfalfa serd very th(»roughly (iisinfcrt«*<l has been sown at distances up to 15 
miles from other alfalfa. Leaf spot has occurred on all these plots. 

The development of the aeciid Mtagc of \igredo on red rlorer. I. K. Meliits and Wil- 
liam DiKHL 

Th«* orrurrence of the ure<liiio- and teli<»spore stages of Sigredo fallens (Desm.) 
Arthur \l'rom\fetn fallem* (I)esni.) Kern) on red clover {Trifolium pratense) is com- 
mon, but the aecial stagt* of this nist is apparently not well known. The ure<iino- 
spore stage di'velopi**! abundantly on re<l rlover growing in the greenhouse l>egin- 
niiig Hb<»ut Januarx 10. VJU), when ihe clovei plantswere alniut six inches tall. These 
grew in pots forming a border nearest tin* glass on a bench in a house where the 
temprrnturr rang(*il from 10" at night to '2(f(\ in the day time. On .March 26, 
Il»l*>. a«MMa Urn* nlisrrv<*<l <»n the leaves of the red cIovit plants. During the next 
two uf«*ks the aerial stag** breaine abundant. It rontinued to develop for about 
a month whrti the tmnpcrature raised in th<* h(»use due to the increaseti sunshintv 
Whit*' rIovMT \Trift'hum refnnf*), alsike ( 7\ hifhridumi, and crimhon cl<»ver (7*. i«- 
earnatumi. growing ui close proximity were c<intinually free fnmi infection. 

H<-p«*at(il att<'mpts were niadt* to transfer the rust to the above hosts by using 
the acrio?.pon'f« but no infections were obtained except on the re<i clover. It would 
appear that .Vi*;r«#/n/*i//« n/* is autm*cious and not lieter(K'cious as h<*retofore reportwl. 

.4 rnoluutrittnu timtaite of the Irish jnttnto and itf< rnntrtd. II. .\. Kl)HO.\ and Oswald 

SlIHIllNKU 

liegitiiiing eariv in the past July, potato plants in numerous eastern fields from 
Mauie to N'irginia developed a downward curling of the leaf margins accompanicNi 
by a bronzing and later a brriwning but not a yellowing of the foliage. Death of 
the leaves and sudden collapse of the stems at the ground level follow<Hl. Fungi 
of parasitic habits a|>peared at and above the |M>int of collapse. Dr. W. A. Orton 
c»b»erved the disease in New Jersey an<l note«l its absence fn»m areas treated with 
fM»tn«>h or stable manure. Similar obsi'rvations were made elsewhere. partieuUtrly 
in Mame. where Dr. Joseph l{os4*nbaum and B. K. Hrown ami L. A. Hurst have 



1917] New York Meeting 71 

undertaken a study of the disease in cooperation with the Maine Agricultural Ex- 
periment Station. These investigations are incomplete but present indications 
are that the fungi isolated are weakling parasites operating as contributing factors 
and that the primary cause is malnutrition, resulting from insufficient potash or 
perhaps an excess of nitrates in the presence of a minimimi potash supply. In Maine 
the disease appears to be correlated with certain soil types and is most marked on 
Irish cobbler, Bliss and Eureka, though not entirely restricted to these early varie- 
ties. Stable manure is an excellent corrective. 

Notes on curly dwarf symptoms on Irish potatoes. W. L. Durrell 

Plants showing curly dwarf symptoms were very prevalent in Iowa this past 
season on the varieties Irish cobbler. Rural new yorker and Early ohio. In some 
cases these symptoms were on plants grown from the progeny of plants having shown 
curly dwarf symptoms the preceding year; in others they were induced by climatic 
conditions. The disease made its appearance on the early planting about June 10 
and continued to develop throughout the season. In August, plants that had been 
normal up imtil that time, showed typical signs of curly dwarf on the foliage pro- 
duced during this period. The upper third of the plant had shortened internodes, 
crinkled and curled leaves, giving this portion of the plant a bushy appearance so 
characteristic of curly dwarf. These symptoms were induced in the field by the 
hot dry weather during August and similar ones were later artificially developed 
in the laboratory. The plants manifesting these induced symptoms of curly dwarf 
put forth normal foliage again in September with the advent of cooler weather. 

Histological studies show that the crinkling of the leaves is due to necrosis of 
certain epidermal and cortical cells of the veins, followed by the growth of the par- 
enchyma cells which induces a buckling of the leaf surface. In addition the leaves 
showing curly dwarf symptoms were characterized by a most marked decrease from 
the normal in the size of the parenchyma cells. Furthermore transpiration tests 
using the cobalt chloride paper and potometer methods indicate that curly dwarf 
plants transpire more rapidly than normal ones. 

Notes on mosaic symptoms of irish potatoes. I. E. Melhus 

The so-called mosaic disease of potatoes is characterized by yellow mottling and 
crinkling of the foliage. Its effect on the potato plant, transmissibility, and rela- 
tion to curly dwarf is very imperfectly understood. The varieties of Bliss triumph 
and Green mountain, which showed mosaic symptoms in 1914 and 1915 in northern 
Maine, were planted in 1916 at Ames, Iowa. The characteristic yellow mottling 
typical of this disease did not develop at any time during the growing season. Curly 
dwarf symptoms, however, were prevailingly present. 

(a) Plants seemingly badly affected in 1915 produced 0.237 pounds per hill. 

(b) Plants seemingly moderately affected in 1915 produced 0.29 pounds per hill. 

(c) Plants seemingly slightly affected in 1915 produced 0.32 pounds per hill. 
Healthy plants used as checks produced 0.46 pounds per hill. 

None of the plants in lots a or 6 grew as large as those in lot c, but some of the 
c-plants were like those of a. Although the typical mottling characteristic of mo- 
saic in certain northern potato growing districts may not develop, the progeny 
of plants showing these symptoms are undesirable for seed purposes. 

Frost necrosis of potato tubers. L. R. Jones and Ernest Bailet 

A peculiar type of non-inheritable "net necrosis" of potato tubers has been under 
observation for several years under conditions suggesting frost injury. Carefully 



72 Phttopatholoqt [Vol. 7 

repeated ohilliog experiments confirm this hypothesis. Tubers ''frosen toUd" are 
totally killed and collapse when thawed. If, however, the chilling stops with in- 
cipient ice-crystallisation, killing may be confined to such interior tissues as are 
most sensitiye. Such chilled tubers appear normal externally but when cut show 
the interior vascular regions to be most sensitive and hence the first to succumb 
and discolor. Therefore, moderate exposure to freesing temperature may pro- 
duce either ''ring" or "net" necrosis, the blackened vascular portions permeating 
the starchy fundamental tissues. Individual variations in sensitiveness occur be- 
tween tubers, but in general the best t3rpe8 of ''net necrosis" have been secured 
by about two hours exposure to +5*C., with similar results by exposures ranging 
from — l^C. for 8.5 hours to — 9*^0. for one hour. Slightly more severe treatments, 
or unequal exposures may give frosen spots with corresponding dark blotches in- 
volving the general parenchyma. The stem end of the tuber is always more sensi- 
tive than the other. 

Will Spongoapora subterranea prove serious in Virginia? J. A. McCuntock 

Potatoes affected with powdery scab planted in Virginia in the spring of 1916 
produced a crop free from this disease. In the spring of 1916 affected tubers from 
Maine were planted at Norfolk, Virginia, and at Tasley, on the Eastern Shore of 
Virginia. The writer examined the crop at each place but found no signs of Spon- 
gospora infection on any of the harvested tubers. Some of the infected seed from 
Maine was held over summer in cold storage and planted at Norfolk about the 
time the fall crop of Irish potatoes was planted in Virginia. On November 23, 1910, 
the tubers were harvested and examined but no Spongospora infection was observed. 
These results corroborate those of 1915 and lead one to conclude that powdery 
scab will not be prevalent either on the spring or fall planted potatoes even though 
the seed tubers are infected with Spongospora subterranea. 

Seed potato certification in Nova Scotia. Paul A. Murpht 

Many fields of Garnet chili potatoes for the Bermuda seed trade were infected 
to the extent of fifty per cent with leaf roll, and whole districts to not less than ten 
per cent, making a difficult situation when we took charge. Hill selection in dis- 
tricts proved useless in several cases tried. The scheme adopted had to be a com- 
pn»hensive and unusual one, an outline of which follows. 

It is neccHsary for growers to start with stock of good previous record. This 
provision, which is absolutely insisted on, is becoming more stringent, and in two 
years the growers will use exclusively stock which is now selected and is being given 
a three years' trial. Thereafter it will still be continuously selected, one man be- 
ing ap|H)intecl in each district to grow it for his ncigbors. 

The munriier inspection iM made jointly by officerH of the Departments of Agri- 
culture of (*anada and Bermuda, while the autumn inHpection is made by the Cana- 
dian aiithoritii*?*. The grower'n name appearH on each barrel, whereby many stocks 
are trurcd to the Bennuda pint at ions. Am a further nafeguard a sample of every 
gruwcr'M potatoes are ^eiit to Bennuda, where they are all plante<l together. 

The fcornfmw importance of mosaic of potato. Vm'L \. Mukphy 

The b<*ginning of a serii»« of experiments to inve«tigate the economic importance 
of iUin dineaite han given striking resultn. In one ex|K*rinient of eleven similar plots 
Hide by Hide, plaiit^Ml partly with ht^althy, and partly with mosaic-diseased Green 
mountains of the name strain, the dim^aiuti plants gave a yield which was on the 



1917] New York MEBTma 73 

average only 57.8 per cent that of the normal plants, the limits being 52.0 per cent 
and 63.6 per cent. Furthermore the crop of the mosaic-diseased plants was mar- 
ketable only to the extent of 82.7 per cent (limits, 74.1 and 87.3), while 91.6 per cent 
of the crop of the healthy plants was marketable (limits, 81.9 and 94.1). This means 
that in an average crop of 300 bushels there is a loss of one and one-third bushels 
of marketable potatoes for every 1 per cent of mosaic present. This coupled with 
the fact that the trouble is constant every year and that it generally affects, where 
present, not far from twenty per cent of the crop means a steady loss of from twenty 
to thirty bushels of potatoes per acre per year. The eating qualities of the pota- 
toes are not impaired. 

A new strain of Puccinia graminis, E. C. Stakman and F. J. Piemeisel 

A rust which behaves differently from any of the common biologic forms of Puc' 
cinia graminta has recently been found on club wheat and a number of wild grasses. 
It resembles P. graminia tritici morphologically and parasitically more that it does 
any other biologits form. However, the common Trittcum vtUgare wheats which 
have been inoculated are highly resistant to it. Both P. graminis tritici and the 
new strain have a niunber of hosts in common, viz: Triticum compactumf Barley, 
Agropyron smithiif Elymus canadensis, Elymus macoum't, and Hordeum jubatum. 
The new strain has also been found in nature on Elymus glattcus and E, condenscdus 
and has infected a number of grasses in the greenhouse. Extensive cross-inocula- 
tion experiments are now under way. 

The rust was found only west of the Rocky Mountains in Idaho and Washing- 
ton where it seemed to take the place of ordinary P. graminis tritici, none 6i which 
was foimd in the region mentioned. 

Puccinia graminis on wheat kernels and its relation to subsequent infection. Chab. 

W. HUNGERPORD 

Various workers have noted the occurrence of rust pustules on seeds of different 
grains and some have held that the fungus might infect the plant by this means. 
Experiments have been carried on at Madison, Wisconsin the last year to deter- 
mine if possible whether Puccinia graminis is able to infect wheat through the seed. 
Three lines of attack have been followed, (a) Rusted seed after being germinated 
at different temperatures has been fixed and examined by histological methods and 
in no case was the fungus found to penetrate the embryonic tissues, (b) Treated 
and untreated samples of rusted seed, as well as clean seed, were planted in the 
field and the first appearance of stem rust upon the plants in the different plots 
was noted at practically the same time, (c) Two lots of rust-infected seed have 
been grown to maturity in an isolated room in the greenhouse. No rust has ap- 
peared on any of these plants. Although the work has not been fully completed, 
the results so far tend to show that seed wheat infected with Puccinia graminis 
does not cause infection of the wheat plant. 

Similar experiments are being started at Corvallis, Oregon, with wheat infected 
wi th Ptu:cinia glumarum. 

Ecological observations on Ustilago Zeae. Alden A. Potter and Leo E. Melchers 
Pammel and Stewart in 1893 observed that the nodal buds of maize were particu- 
larly subject to smut and that "where one smut boil made its appearance on the 
lower nodes, others appeared further up.'' It thus becomes desirable to explain 
how the infection, shown by Brefeld to be strictly local in its development, can 
spread on the plant. The basis of study has been Brefeld' s idea of distribution by 



74 Phytopathology [Vol. 7 

air-l>orne conidia. The organism han boon iflolated in pure, conidial culture, both 
from the air and from the young plants some little time before the disease appeared. 
The com plant is thus seen to be well adapted as a spore trap. The conidia caught 
probably do not infect directly. The result is rather the development of a virulent 
culture in the leaf axil. A plant may thus become a center of aerial distribution; 
or, when rain recurs, the conidia may be washed down or splashed out upon other 
leaves. Thus it may sometimes happen that all the culms of a plant, or hill, will 
show many no<lal infections when an equal number of stalks immediately adjacent 
will not be infecte<l at all. 

The shart-cyrUd Vromycen of Xorth America. G. li. Hishy 

Only eleven species of short -<*yrle<l rnmiyces huvc boon found in Xorth America. 
Those nists are parasitic upon six families of Monocotylodons and Dicotyledons. 
Various relationships are evident botwoon those rusts and other long-cycled and 
short-cycled species of ruMts. Seven sperios arc commonly micro-forms; for four 
of th(»so, pyrnia are known. Seven sperios have strictly local mycelium. These 
nists occur mainly in WcHtcrn and Southern North .Vniorira. The specimens have 
been studied at the Arthur HerbarUim. 

Holed and mycorhiza uf)on forest trees and an unusual mycorhiza ujwn trhite oak. 

L. H. Pe.vxington 

One instance of a Boletus, li. nperiosus Frost, connect o<l with mycorhiia of oak 
was reported in VJilH. Since that time five other species, li. froHtii Kussell, B. in- 
deMiitu* I*k. li. chroma ften Frost, li. purpureus Vr. and H. gracilis Pk. have been found 
conn«»ct<»<l with mycorhiza of forest trees, usually oaks. Two of these species, 
a. froftiii and H. indecisun, have been found to produce sclerotia similar to those 
report e<l f<»r li. sfxciimuM. 

A peculiar form of mycorhiza was found upon white-oak roots in which the hy- 
p<Ttrophie<l branches are closely aggrogateii and surrounded by a peridium-like 
layer of fungal tissue. This gives them the appearance of white root tubercles, 
four to twolve millimeters in <liameter. These tuborcle-liko growths are not unlike 
thos<» uiH)n bee<'h roolH d«»scribe<i in 1890 by Von Schronk. They are also definit<*ly 
connoctecl with small sclerotia from which there in a growth of mycelium in early 
summer to prcHluoe now mycorhiza U(Mm the roots. .\t tempts to inoculate the 
nK)tH of oth(*r treses with this fungus have thus far failo<l. 

A nrw paranitic nlime mold nuitahle for class tatrk. John A. Klliott 

The Hwoot [lotato "|m>x" organi-nm, Cystosfntra haiata Klliott, as it occurs on sweet 
|x>tftt<M'?«, offors itself an an oxrollont «*xainplo of the Plu.*<mo<liophoral(*s for use in 
tho Inbonitory. Infort<'<l i>IniitM growing botwoon shoots of moist blotting paper 
afTnrd »ii abundatiro nf pnriu«itizo4l rootlets and growing i>oints of stems for free- 
hand !*«'<>! ioiiiiig or for oiiibo<idiiig in paraffin. Such matorial iH easily sectioned 
and rontaiii^ groat numborM of tin* para>ito in all stag<'H of its life cycle. The rapid- 
ity uitli \iliirh tho organism goos through its complete life history makes a study 
of living nmtoriul of ^pecial value. 

Straiuf nf Hhiztuiimia. J. RosKMiAt'M and M. Siiapavalov 

During tho mimmor of llll(> a strain of Hhizootonia was isolated from potato steins 
which showinl a girdling and hollowing at or near the surface of the ground. This 



1917] New York Meeting 75 

strain, designated R 5, differs in the following particulars from other strains isolated 
from stems and tubers of potatoes grown in Maine and Florida: 

(1) Inoculations with R 5 produced definite lesions in injured potato stems grow- 
ing in the field and greenhouse and injured tubers, while in the case of inoculations 
with other strains the lesions, if produced at all, were smaller and the results not so 
conclusive. The injured checks remained healthy. 

(2) Macroscopically R 5 can be distinguished by the darker coloration of the 
medium, especially when grown on potato agar, and by the light grayish sclerotia 
as compared with the dark-brown sclerotia of the others when grown on corn-meal 
agar. 

(3) Microscopically R 5 differs from the other strains in its finer mycelium, w>>ich 
measures 5 to 9 m in diameter while the others measure 10 to 14 /x. 

Is it not possible that different strains of Rhizoctonia may offer an explanation 
for the conflicting reports regarding artificial infection? 

The aerial stage of the red clover rust. W. H. Davis and A. G. Johnson 

The well known red clover rust, Uromyces fallens (Desm.) Kern, has long been 
suspected of having an aecial stage. Our observations and experiments have thrown 
definite light on the question. 

Aecia on red clover were first obtained experimentally in the greenhouse in Decem- 
ber 1915 and similarly again in January and February, 1916. Later in the spring 
a number of cases of aecia were observed on the same host out of doors near Madison. 
Following various sowings of aeciospores from such sources on rust-free red clover 
plants under glass, uredinospores developed uniformly. These were identical with 
those conmionly observed on that host. Sowings of viable teliospores resulted in 
the development of aecia, identical with those observed in greenhouse and field. 
It is thus evident that this rust is a long-cycled autoecious species, i.e., with 
pycnia, aecia, uredinia and telia on the same host. 

Observations on pear blight in Illinois. F. L. Stevens, W. A. Ruth, G. L. Peltier, 

and J. R. Malloch 

Experiments made by applying Bacillus amylovorous in suspension in water to 
pear buds in 1915 did not indicate in 1916 that the bacilli hibernated in the buds. 

Subcuticular infections of spurs from hold-over trunk cankers occurred in 1916, 
with a maximum number of twelve such infections from one canker. The organ- 
ism appeared to be dead in all twig cankers. A few living cankers provided exudate 
for serious well-distributed blossom infection, which in turn provided exudate for 
further infections, these continuing until early in June. 

Leaves appeared to be at no time naturally infected from the exterior and on 
June 1 blades and pedicles could not be inoculated though the fruit and pedicles 
were still susceptible. Bordeaux mixture controlled the floral infection without 
reducing the set of fruit. 

Second progress report on investigations of leaf spot of cherries and plums in Wisconsin. 

G. W. Keitt 

Comparative studies of Coccomyces hiemalis Higgins and related organisms in 
connection with leaf spot diseases of cherries and plums have been continued, and 
spraying and sanitation experiments in the control of cherry leaf spot have been 
begun. Only the control work is reported here. 

Spraying (Montmorency and Early Richmond). In early summer, the disease 
occurred in unusual severity, but, after the advent of hot dry weather in late July, 



76 Phttopatholoot [Vou 7 

it made relatively little progress. It was satisfactorily controlled by Bordeaux 
mixture, 4-4-50, 3-3-50, and 2-2-50, and lime-sulphur (commercial ooncentrmte, 
33*B.), 1-10, applied (1) when the petals fell, (2) l(m7 days later, and (3) just after 
the fruit was harvested. "Atomic sulphur," 5-50; barium-sulphur, 3-50; and aelf- 
boiled lime-sulphur, 8-8-50, in parallel applications, did not control the disease 
satisfactorily. An additional application just before the blossoms opened did not 
increase the efficiency of leaf spot control. 

Sanitaiian. Life history studies, sanitation experiments, and extensive obe erv a- 
tions indicate that, under Wisconsin conditions, the spray schedule may be strongly 
reinforced by turning under the fallen leaves as completely as feasible by clean cul- 
tivation before the blossoms open (In 1016, the first ascospore discharge was observed 
as cherry blossoms began to open). 

Jonathan spot, Charles Brooks and J. S. Collet 

The development of Jonathan spot increases with an increase in temperature up 
to 20*C., but is entirely inhibited at dO'^C. The disease can be readily produced 
in saturated air in closed moist chambers but seldom develops in a stirred air of 
70 per cent or 95 per cent relative humidity. 

Temperature relation* of apple rot fungi. Charles Brooks and J. S. Collet 

Most apple-rot fungi will grow at a lower temperature on com meal agar than 
on fruit and at a lowor temperature on ripe fruit than on green fruit. With several 
if not all of the storage-rot fungi the initial stages of rotting are more inhibited 
by low temperatures than is the germination of the spores. Rots may finally make 
a fairly rapid development at temperatures at which the fungus is at first barely 
able to make a start. Even at favorable temperatures most of the fungi pass through 
a period of incubation on apples that is not evident on culture media. 

Control of apple §cab by bleaching poicder. W. S. Brock and W. A. Ruth 
Bleaching powder when applied to apple trees in 1016 reduced apple scab from 50 

per cent to 11.2 per cent. No injury resulted to fruit or foliage. The leaves on 

trees sprayed with this material were practically free from scab. Leaves on un- 

■prayed trees showed serious seal) infection. 
In 1010 the material was applied at high concentrations alone, and with lime, 

causing little foliage injury, but no scab developed. Higher concentrations alone 

and in combination with other materials will be tried. 

Studie* on peach yello%c» and little peach. M. A. Blake, Mel. T. Cook and C. A. 

ScHm-AKiR 

S>'mptoms ver>' iiimilar to peach yellown and little peach may be due to other 
causes. Tents with healthy and diHcaiMHl trees showetl (1) pulp from healthy leaves 
retains original color longer than pulp from ditieased leaves; (2) juice from healthy 
leaves in more mucilaginous than that from diseased leaves; (3) juice from fast- 
growing trecM more niurilaginoun than juice from the leaves of slow-growing trees; 
(4) leaves taken from healthv trees after sunset showe<l a minimum amount of 
starch, leaves from little peach trees a larger amount, and leaves from yellows trees 
and from girdle<l trees the greatest amount; (5) leaves from an apparently healthy 
branch a<ljacent to a diseased branch on same tree showed a higher starch content 
than leaves from a healthy tree; (7) leaven from fast-growing trees lose starch more 
rapidly than leaves from slow-growing trees; (8) juice extracted from healthy 



1917] New York Meeting 77 

leaves showed less oxidase than juice from diseased leaves; (9) juice from healthy 
kernels showed less catalase and acid than juice from diseased kernels; (10) the tan- 
nin content of healthy fruit is less than that of diseased or forced fruit. 

Pits from diseased trees failed to germinate. Budding experiments with dis- 
eased buds indicate that the appearance of the disease in the young trees varies 
with source of bud wood. 

A Xylaria root-rot of the apple. F. D. Fromme and H. E. Thomas 

A destructive root-rot of apple trees is prevalent in the chief orchard sections of 
Virginia. The infectiousness of this condition is shown in the death of adjoining 
trees in groups irrespective of soil conditions or topography, and in the death of 
replants set in holes from which diseased trees were removed. Isolations from 
affected roots from a number of orchards have yielded cultures of a fungus which 
is apparently the conidial stage of a species of Xylaria. Perithecial stromata of 
Xylaria polymorpha have been found on roots of apple trees showing typical attack. 
Tjrpical root-rot lesions have been produced with pure cultures of the Xylaria in- 
troduced into bark woimds of living apple roots in damp chambers and in the field. 
The introduced fungus has been recovered in pure culture from these lesions. Two 
or more species of Xylaria may be involved; their interrelations are subject fgr fur- 
ther study. Apparently all varieties of apples are susceptible and probably equally 
so. Observations indicate that the organism may be spread in cultivation, in the 
removal of borers, in contact between root systems of adjoining trees and in sur- 
face washing of infective material. 

Pycnial acars, an important diagnostic character for the white pine blister rust. Regi- 
nald H. COLLEY 

After the pycnospores appear in their characteristic sweetish drops the whole 
pycnium is cut out by a protective layer of tissue which forms at a depth of* several 
cells below the pycnial layer. Everything above the protective layer drys out and 
dies. The result of this drying is a rusty brown patch or scar which indicates by 
its size the extent of the pycnium. The scars are dark brown and glossy at first. 
Later they become rusty brown with a dry dusty-granular surface. They average 
about four millimeters in diameter. Pycnial scars are a positive diagnostic field 
character for the white pine blister rust, here reported for the first time. They 
are especially valuable when the bark is but little swollen, and when there is no 
indication of aecia or of aecial scars. 

Mycelium of the white pine blister rust. Reginald H. Colley 

The uninucleate mycelium of Cronartium ribicola forces its way between the bark 
cells of white pine, frequently forming strands. As the cells are forced apart the. 
bark s\^'ells. Haustoria penetrate practically every non-woody cell in the infected 
tissue. The sieve tubes become plugged. Hyphae follow the ray cells past the 
cambium and into the wood for a distance of at least three annual rings. Thus the 
fungus derives nourishment from both the ascending and descending currents of 
sap. The morphological characters of the mycelium are definite and constant un- 
der all conditions observed. Therefore the mycelium has positive diagnostic value 
for the blister rust before there is any exterior indication of spore formation. 

The binucleate mycelium in Ribes leaves is limited in extent. Haustoria are rare. 
Uredinia and telia form quickly and burst through the epidermis easily. 

The binucleate mycelium is very abundant in cases of petiole infection and the 
haustoria are larger and more numerous than in the lamina. Normal telia are 
usually produced but sometimes they are formed internally. 



78 Phytopathology (Vol. 7 

A fpecien of Chrysomyxa new to North America, H. S. Jackson 

The KpnuB Chrynomyxa was efltablished in 1840 by Unger with C. abietis (Wallr.) 
Vng. aM the t>'pe spccieD, and has generally been interpreted as including both long 
and short cycle forms. Arthur restricted this genus to include only the micro- 
forms and established Melampsoropsis (Schrot.) Arth. for those species with a long 
life cycle. All of the latter forms are assumed to be hcteroecious and have their 
uredinia and telia on Pyrolaceae, Ericaceae and Vacciniaceac. The aecial stages 
so far as determined, have proved to \tc species of Peridcrmium on Picea. In America 
eight species have been reported, all of which are long cycle forms and are referred 
to Melampsoropsis by Arthur. Four of these have been definitely connected through 
cultures by European and American students with their aecial stages. 

A short cycle form referable to the genus Chr>'8omyxa (as restricted by Arthur) 
is recogniEcd in America for the first time and causes a disease of the leaves of Picta 
engelmannii . 

A Gnomonia on eggplant. C. W. Edgerton 

During the past three years, a species of Gnomonia has been found on old egg- 
plant stems during the winter season at Baton Houge, I^)uisiana. This fungus has 
br<»n repeate<lly cultured and it has been found to be very similar, if not identical, 
from a morphological standpoint, with the fungus causing the eggplant blight, 
Phyltontirta hnrtorum. The oval Phyllostirta spores and the long narrow Phlyctaena 
spores developc<l in culture. Cultures of the (inomonia and cultures of Phyllasticta 
hortarum cannot be told apart. Inoculation experiments, however, have always 
been negative. While it may be that the Onomonia has no connection with the 
Phyllosticta, it is very probable that the two are closely related species. 



LITERATURE ON AMERICAN PLANT DISEASES* 

Compiled bt Eunice R. Oberly, Librarian, Bureau op Plant Industry 

AND Florence P. Smith, Assistant 

October to November, 1916 

Avema-Sacca, Rosario. Molestias cryptogamicas da canna de assucar. Bol. 

Agr. [Sao Paulo] 17, no. 8: 610-641, illus. Agosto, 1916. 
Brown, F. B., and others. Discussion on decay in timber. Trans. Canad. Soc. 
Civ. Engin. 29, pt. 1 : 324r-365, 13 pi. 1915. 
Bibliography of timber destroying fungi, p. 339-340. 
Clinton, George Perkins. Report of the botanist for 1915. Connecticut Agr. Expt. 
Sta. 1916, pt. 6: 421-487, pi. 17-26. August, 1916. 

Notes on plant diseases of Connecticut; diseases of plants caused by nema- 
todes; powdery scab of potatoes; potato spraying experiments, 3d report. 
Literature, p. 461-462, 469. 
Culpepper, Charles £., Foster, Arthur C, and Caldwell, Joseph S. Some effects 
of the blackrot fungus, Sphaeropsis malorum, upon the chemical composition 
of the apple. Jour. Agr. Research 7, no. 1 : 17-40. October 2, 1916. 
Literature cited, p. 39-40. 
Fromme, Fred Benton. Facultative heteroecism (r) of Peridermium harknessii 
and Cronartium quercus. Phytopathology 6, no. 5: 411-412. October, 1916. 
Gorkum, Nicolas van. A molestia do olho da canna, ponto- de vegetaySo, corag&o 
e peciolo da bandeira. Bol. Min. Agr. Indus, e Com. [Brazil] 4, no. 2: 105-112, 
3 col. pi. Abril/Junho, 1915. 
Gtissow, Hans Theodor. The grain rust in the prairie provinces. Agr. Gaz. Can- 
ada 3, no. 10: 861-864. October, 1916. 
Hawkins, Lon Adrian. Growth of parasitic fungi on concentrated solutions. Jour. 
Agr. Research 7, no. 5: 255-260. October 30, 1916. 
Literature cited, p. 259-260. 
Hedgcock, George Grant, and Hunt, N. Rez. Dothichiza populea in the United 
States. Mycologia 8, no. 6: 300-308, pi. 194-195. November, 1916. 
Literature cited, p. 308. 
Hesler, Lexemuel Ray. Black rot, leaf spot, and canker of pomaceous fruits. 
New York Cornell Agr. Expt. Sta. Bui. 379: 49-148, fig. 18-37, pi. 7-14. 1916. 
Bibliography [annotated], p. 126-148. 
Home, William Titus. The importance and prevention of wood decay in fruit 
trees. Mo. Bui. State Com. Hort. [California] 6, no. 8: 278-282, fig. 95-96. Au- 
gust, 1916. 

1 This list aims to include the publications of North and South America, the West India Islands, and 
islanHs controlled by the United States, and articles by American writers appearing in foreisn Journals. 

All authors are urged to co5perate in making the list complete by sending their separates and by mak- 
ing oorrertions and additions, and especially by calling attention to meritorious articles published outside 
of regular journals. Reprints or correspondence should be addressed to Miss E. R. Oberly, librarian. 
Bureau of Plant Industry, U. 8. Dept. Agric, Wsshington, D. C. 



80 Phytopathology [Vol. 7 

Hotaon John WiUUm. The longevity of Bacillus amylovorus under field conditions. 

Phytopathology 6, no. 5: 40(M08, 4 fig. October, 1916. 
Johnson, James. Enfermedades del tabaco y manera de combatirlas. Pt. II-IV. 

Hacienda IS, no. 1: 26-28, illus., Octubre; no. 2: 6^-64, illus., Noviembre; no. 

3: 01-03, illus., Diciombre. 1016. 
IH. 1 noted in previous list. 
Host plants of Thielavia basicoia. Jour. Agr. Research 7, no. 6: 28^-^00. 

pi. 18-10. November 6, 1016. 
Johnston, John Robert. Phytopathological work in the tropics. Phytopathology 

6, no. 5: 381-386. October, 1016. 

Jones, Lewis Ralph, Johnson, Aaron Guy, and Reddy, C. S. Bacterial blights of 
barley and certain other cereals. Science n. s. 44, no. 1134: 432-433. Septem- 
ber 22, 1016. 

Long, William Henry. The aecial stage of Coleosporium ribicola. Mycologia 8, 
no. 6: 300 311. November. 1016. 
Peridcrmxum rihiciAa. 

Matz, J. A meth<Mi to induce HiM>ruIation in cultures of Botryosphisria beren- 
geriana. Phytopathology 6, no. 5: 387 380, 1 fig. October. 1016. 

Meinecke, Emillo Pepe Michael. I^h vanillidres dc Talnti &, de M(M)rea. Rap- 
port pr^>nt^* tt Mr le (louvcrneur des cstablissemcnts fran^ais de TOc^anie. 
& a MM. Icfl niemhrcH de la chambro d'agriculture. 44 p. Papeete, 1016. 

Maladies it leurti rauM'M, p. 13-28; suppression des causes des maladies de 
la vanille, p. 20 32. 

If elchers, Leo Edward. Diseases affecting Sudan grass. Kansas Agr. Expt. 8ta. 
Bui. 212: 16^-10, pi. 4-^5. 1016. 
Kernel smut; treatment of s4M>d to kill smut; bliglit; seedling root disease. 

Plant disease's afferting alfalfa. Upt. Kannas State Bd. Agr. 85, no. 138: 

330 ;i53. fig. 2S2 a>3. 1010. 

Vromycrn atriatuB Schrcet; IWutloprziza mediraginin (Lib.) Sacc; PhyUo$ticta 
sp; PUoaphfrrulina brionuina Pollarri; Peronospora trifoliorum De By; /?Ai- 
loelimia violarta Tul; PnewiomonaB mniicafjinis; yellow top; stem cracking 
{Phnma Hp. K 

Krrata note: V\H\n statement of the author, the geniu) Phomo|)sis, p. 330 
and .'MO, Hhould reiul Phoma. 

Melhus, Inring E., Rosenbaum, Joseph, and Schultz, Eugene S. S|K)ngos|N>ra 
Hubtorranea and l'h(»ma tulK*n»Ha on the Irinh potato. Jour. .\gr. Research 

7, nf». :>: 213 254, 1 fig., pi. A. 7 14. OctolMT .«). 1016. 

Ifash, George Valentine. Injury to evergrcenH. .Jour. New York Bot. Card. 17, 

nt>. JSri: 170 lH."i. OrtolnT. 1016. 
Ifowell, WlUlam. The dying of citrus tn^en: :i coinpariHon. .Agr. News [Barbaiios] 

15, no. 370: 'M\k\'MV:. N«»v<iii»mt 4. 1016. 
O'Gara, Patrick Joseph. Orcurrcnre of yellow leaf rust of wheat (Puccinia gluma- 

runi» in thi* Salt Lakr valley, I'tah. Science n.H. 44, no. 1130: 610-^11. Octo- 

Imt 27. 1016. 
Pammel, Louis Hermann, King, Charlotte M., and Seal, J. L. Studies on a Fusarium 

diM*as4* of corn and sorglium. il'reliminary. j Iowa .Agr. Kxpt. Sta. Research 

Bui :»: 113 VM\. \:^ fig 1016. 
Litcrattirr of corn ri»tM. p. 11') IIH. 
Reimer, Frank Charles. .\ promiiting new |>i*ar ntock. .Mo. Bui. State Com. Ilort. 

(California) 6, no. :>: \m 171, fig. oO 60. .May, 1016. 
Pyrua calUryana. Very resistant to blight. 



1917] Literature on American Plant Diseases 81 

Rumbold, Caroline. Pathological anatomy of the injected trunks of chestnut trees. 
Proc. Amer. Phil. Soc. 66, no. 6: 48^-493, pi. 15-18. July, 1916. 
Literature cited, p. 493. 

Schneider, Albert. A parasitic saccharomycete of the tomato. Phytopathology 
6, no. 5: 39^399, 4 fig. October, 1916. 

Shear, Cornelius Lott. False blossom of the cultivated cranberry. U. S. Dept. 
Agr. Bui. 444, 7 p., 4 pi. 1916. 
Literature cited, p. 7. 
Cause not known. 

Smith, Clayton Orville. Crown gall or plant cancer. Mo. Bui. State Com. Hort. 
[California] 6, no. 6: 201-211, fig. 71-72. 1916. 

Smith, Erwin Frink. Tumors in plants. Science n.s. 44, no. 1139: 611-^12. Octo- 
ber 27, 1916. 

Stewart, Fred Carlton. Observations on some degenerate strains of potatoes. 
New York State Agr. Expt. Sta. Bui. 422: 310-357, 12 pi. 1916. 

Stoddard, £. M., and Moss, A. £. Cutting out chestnut blighted timber. Connecti- 
cut Agr. Expt. Sta. Ann. Rpt. 1916, pt. 6: 488-496, pi. 27-28. August, 1916. 

Stone, George Edward. Injury to vegetation resulting from climatic conditions. 
Jour. New York Bot. Card. 17, no. 202: 173-179. October, 1916. 

Thorn, Charles, and Currie, James N. Aspergillus niger group. Jour. Agr. Re- 
search 7, no. 1: 1-15. October 2, 1916. 
Bibliographical footnotes. 

Tisdale, W. H. A Melanconium parasitic on the potato. Phytopathology 6, no. 5: 
390-394, 3 fig. October, 1916. 

Relation of soil temperature to infection of flax by Fusarium lini. Phyto- 
pathology 6, no. 5: 412-413. October, 1916. 

U. S. Department of the Agriculture. Bureau of Plant Industry. Report of the 
chief, [19151/16. 18 p. 1916. 
Plant pathological investigations, p. 3-6. 

Federal Horticultural Board. Report [1915]/16. 14 p. 1916. 

Service and regulatory announcements. August: 93-101, September 

30; September: 103-129, 1 fig., November 16. 1916. 

Weir, James Robert. Phacidium infestans on western conifers. Phytopathology 
6, no. 5: 413-414. October, 1916. 

Pinus ponderosa and P. jeff'reyi, hosts for Razoumofskya americana. Phy- 
topathology 6, no. 5: 484. October, 1916. 

Whetzel, Herbert Hice, Hesler, Lexemuel Ray, Gregory, Charles Truman, and Ran- 
kin, William Howard. Laboratory outlines in plant pathology. 207 p. Ithaca, 
New York, 1916. 



[Phytopathology, for December, 1916 (6: 419-454) was issued Novem- 
ber 29, 1916.] 



PHYTOPATHOLOGY 

VOLUME VII NUMBER 2 

APRIL, 1917 



THE PERFECT STAGE OF GLCEOSPORIUM VENETUM 

Walter PI . B u k k h o l d e it 
With Three Fkjures in the Text 

During the oarly siuniner of 1914 while studying the anthracnose 
disease of the raspberry at Brant, New York, a peculiar ascomycete was 
observed by the writer. The fungus although not of general occurrence 
was found only in the anthracnose lesions (fig. 1), and arose from the 
stroma of the pathogene GloBOsporium venetum Speg. This led to the 
belief that there was a possible connection between the two fungous 
fonns and a niunber of inoculation experiments were conducted in order 
to verify this assumption. 

It was difficult to obtain ascospores for making inoculations owing to 
the scarcity of the ascocarps. Furthermore the ascospores w^ere borne in 
the same lesion with the conidia of Glceosporium venetum and a separation of 
the two types of spores was practically impossible. It was finally decided 
to use spores from a culture of the fungus developed from a single 
ascospore. 

Several attempts were made to isolate the fungus. The poured plate 
method first employed was discarded later on account of the difficulty 
in obtaining ascospores sufficiently removed from the conidia, the latter 
usually being in great abundance. A second method and similar to one 
used by Barber^ was also tried. This consisted in crushing the ascocarps 
in a drop of sterilized water on a sterilized slide. A glass tube with a 
bore of about 3 mm. was drawn to a capillary tip at one end; to the op- 
posite end was fastened a piece of rubber tubing about 40 cm. in length. 
The free end of the rubber tube was placed in the mouth and by manip- 
ulating the glass point with the hand, spores could be drawn into the bore 
of the tube. The great difficulty in using this method with the fungus 
under consideration was the fact that the ascospores were very gelatinous 
and had a tendency to adhere to the glass slides, refusing to enter the 

* Barber, M. A. On heredity in certain microorganisms. Kansas Sci. Bui. 4: 
3-48. 1907. 



1917] Burkholder: Plectodiscella veneta 85 

globules and pigments which give color to the fungus. Only on rare 
occasions and on media containing a small percentage of agar do fila- 
mentous hyphae extend for any distance from the sclerotia-like formations. 
This growth on artificial media although identical with that of (?. venetum 
is decidedly different from that of any species of Gloeosporiimi which has 
a perfect stage belonging to the genus Glomerella. 

As the writer has continually foimd to be the case with cultmres of G. 
venetum, difficulty was encoimtered in finding conditions favorable for 
the sporulation of the fimgus. It was finally observed, however, that a 
sudden change in the humidity of the cultmre tube caused a production 
of conidia which were obtainable in sufficient numbers for use. In order 
to effect this change the fungus was grown on three-per-cent potato agar 
until large sclerotia-like masses were formed. These masses were trans- 
ferred to sterilized bean pods in tubes which contained several centi- 
meters of water. The cultures were tiien incubated at a temperatmre of 
24°C. and at the end of three days numerous conidia were produced which 
were identical with the conidia produced in cultmre by G. venetum. It 
was also observed that this sporulation was not continuous, but ceased 
after the first production of spores. Fiu-thermore, a cultiu*e of the fxmgus 
subjected from the beginning to a moist condition produced no spores or 
at least, but relatively few. This apparently indicates that the sudden 
increase in himiidity acts as a stimulus to spore formation. 

By dropping these fimgous masses bearing conidia into a small amount 
of water the spores readily fall off and can be sprayed over the infection 
court. The germination of these conidia is fairly rapid, but the percent- 
age of germination is low. In most cases not more than five or ten per 
cent of the spores germinate. 

INOCULATION EXPERIMENTS 

Early in the winter of 1914 a nxmiber of roots of the Colxmibian variety 
of the raspberry were obtained and planted in the greenhouse. Owing 
to the earliness of the dormant period and to the unfavorable conditions 
arising within the greenhouse, the plants grew slowly, and gave a very 
stxmted growth. All inoculation experiments with these plants gave 
negative results. The anthracnose lesions appear only on tender suc- 
culent canes and apparently the canes which had developed slowly on 
the greenhouse plants were too hard for the fungus to infect. 

Later, about the first of March, 1915, a few raspberry plants of a red 
variety were secured which were tender and growing rapidly. On March 
4, two canes were sprayed with a suspension of conidia from a culture of 
the fungus developed from a single ascospore and the canes were covered 



86 Phytopathology [Vou 7 

with bell-glasses lined with moist filter paper. These glasses were plugged 
at the top with cotton and allowed to remain over the canes for two days 
before removing, while two other canes in the same bed remained imtreated. 
On March 20, small purple spots had appeared on one of the canes. These 
infections grew slowly, much slower than an anthracnose lesion develops 
under field conditions, but spots typical of those caused by Gkto^porium 
venetum were produced. Miscroscopical examination of the spots showed 
conidia of G, veneium. 

Again on April 15, four very tender canes of a black-cap variety of 
raspberry were sprayed with a suspension of conidia as above. Bell 
glasses were placed over the plants as in the previous experiments and one 
check plant was tised. A sample of the conidia used was placed in a drop 
of water on a slide, and about eight per cent of the spores germinated. 
After one week, April 21, a nimiber of small purple spots had appeared on 
the four canes, and these later developed into t>'pical anthracnose lesions. 
The check plant remained healthy. 

THE DEVELOPMENT OF THE A8CIGEROL8 STAGE 

From the positive results of the inoculation experiments and also from 
the examination of the fimgus in culture it is evident that the ascomycete 
under consideration is the perfect st-age of Gkeoftporium venetum. The 
8>'stematic position of the fungus, however, is rather diflficult to determine. 
Its morj)holog>' is entirely different from the perfect stage of any species 
of (ilcDosporium previously described. This, however, is not siuprising 
as (7. veneium has always l)ec»n considenMl distinct from the other species 
of that genus. 

The ascig(»n)us stage of the fungus wjis first ol)served on the hybrid 
raspl)err>' commonly known as Kubus negleclwt. I^ter it was collecte<l 
in various |wirts of Ne^* York Stati* on the bbick rasplx»rr>' (Rubus occi- 
dentalis) and the American red rasplxTry (Kubus idceus var. aculeaiwimuB) . 
RcHis' alMo rei)orts having found it iti Washington on the blackl)err>' 
(Rubua sp.). 

During the siunmer following the* discovery of the ascigerous stage 
clos4» ol>ser\'ation was kept of the fungus on th(» young canei* to detennine 
when the Jisconiqw first lK»gan to <lcv(»lop. This pn)ve<l to be about the 
middle of August. At this time the fruiting Inxlies which greatly resemble 
those in the family Myriangiaceie apfK^iir as minute s|K)ts, deep brown to 
black, singly or in grou|>s s<'attenHl over the huff-colored and sunken por- 
tion of the anthracnose* lesion. These spots an» Imrely visible to the €>•« 

* Rm"^. H. L. Kx|N*nmental (ipra>nnK for hlarkbeiT>' anthracnose in 1915. Watt- 
em WanhinKton Kxp. Sta. Mo. Bui. 3*: 1-10. 1915. 



1917] Burkholdbb: Plectodiscella veneta 87 

and only so on account of the contrast in color with the surrounding tissue. 
After passing the winter the entire lesion assumes a dark brown color and 
then the pustules are observed with great difficulty even with a hand lens. 

A careful examination of the diseased area upon which the asco arps 
are found proves it to be a typical anthracnose lesion. The buflf-colored 
portion is fimgous tissue, more or less plectenchymatous in structiu'e. 
It is composed of very small hyphae which are difficult to distinguish 
imless carefully stained and it is the same tissue from which arise the 
conidiophores of the GlcEOsporixun stage. The ascocarps arise from the 
stroma and are pulvinate structures usually circular in outline, but they 
frequently coalesce, forming spots of various shapes. They are approx- 
imately 0.07 by 0.07 to 0.37 mm. in diameter. The tissue of the ascocarp 
is more or less pseudoparenchymatous with larger and thinner-walled 
cells than those of the stromataceous tissue (fig. 2). The outer layer of 
the ascocarp is composed of thick-walled brown cells which form a shield- 
shaped structiu'e less perfect, however, than those observed in the family 
Microtheriaceffi. When the fruiting body is matiu'e the cells of this outer 
layer split apart- in a stellate manner and crumble away. Within the 
shield the ascocarps are hyaline and contain the asci which are scattered 
irregularly through the fungous tissue. There is no differentiated cavity 
for the asci. 

The asci were first observed in the immature condition at which time 
they appeared as globose bodies containing a homogenous mass of proto- 
plasm, and greatly resembling thick-walled oogonia. These asci may lie 
in contact with each other but frequently they are separated by the fim- 
gous tissue. The mature ascus is thick-walled and measures 24 to 30/4 
in diameter. In a few cases the ascus has appeared to be slightly stalked 
and attached to the base of the cavity in which it is borne. 

In the autmnn or more often in the spring the asci matiu-e and the 
homogenous mass of protoplasm gives place to eight four-celled ascospores. 
These spores which are borne parallel to each other in the ascus, are hyaline 
with gelatinous walls, and constricted at the septa. The basal cell is some- 
what more obtuse than the apical cell. The mature ascospore measiu'es 
18 to 21/i in length by 6.5 to 8/u in diameter. 

In the formation of these spores the middle septum is laid down much 
earlier than the other two, and for this reason it is not imcommon to find 
two-celled spores. With the division of these cells giving rise to the 
foiu'-celled condition, the constrictions are not so great as at the first 
septimi. Occasionally one of the cells fails to divide and an ascospore of 
three cells is formed. During the formation of the spore the disintegration 
of the fimgous tissue about the asci takes place and with the rupturing 
of the outer layer of the ascocarp the asci are exposed. Frequently the 



Phttopatholoot 



[Vol.7 



asci lying in this exposed condition surrounded by the remainder of Um 
•scocarp give the appearance of a true discomycete. This, homrer, is 
duo to the persistency of the outer cells of the ^eld-like layer whidi 



Pia. 2. «Crou-«iction or AscocAxr or PLCcrootacsLLA vbmbta 
Vuioua itKces ia th« dcrelopmeat of the uci u« ■hown 




1917] Burkholder: Plectodiscella veneta 89 

covers the immature ascocarps. With the presence of sufficient moistiu-e 
the exposed asci elongate approximately three times their usual length. 
This process is very rapid and may be observed imder a microscope when 
a fragment of tissue containing asci is placed in a drop of water. The 
lower portion of the ascus remains fastened in the cavity in which it was 
borne, giving a conical shape to the body which raises itself above the sur- 
rounding tissue. The spores gather at the tip of the ascus and from there 
are ejected into the air. They have been caught above the lesions at 
a distance of one centimeter. 

In a single ascocarp all the asci are never in the same state of maturity 
and the ascocarps also seem to vary in this respect. Mature ascospores 
were first observed about the first of Jime while inunatiu'e spores were 
present in August. 

GERMINATION OF SPORES 

When placed in tap, rain or distilled water, or on nutrient agar, the 
mature ascospores germinate readily (fig. 3). They swell somewhat and 
within less than two hours a short sterigma is produced from one or each 
of the cells. A sprout conidiimi is formed which is oblong to elliptical 
and identical with the conidia of the fungus. When fuUy mature the 
sprout conidia drop from the sterigmata but do not germinate immedi- 
ately. After a short period of rest, twelve to twenty-four hours, a germ- 
tube is sent forth and mycelium is formed. When an ascus is placed in 
a drop of water or on agar the spores within TviU germinate by sending the 
sterigmata through the wall of the ascus and produce the sprout conidia 
on the outside. These, in turn, germinate. After Ihe production of 
the secondary spores, however, the ascospores shrivel and disintegrate. 

SYSTEMATIC POSITION 

The morphology of the fungus of the raspberry anthracnose, especially 
the character of the asci scattered irregularly through a pseudoparenchyma 
is similar to that of the old family Myriangiacese. In a revision of this 
family some years ago by von Hohnel* but five genera out of twenty-three 
were retained, and since then but one new genus, Ascostralum Sydow^ has 
been added. The perfect stage of Glceosporium venetum, however, does 
not appear to fall in any of these genera, nor in any of the genera of closely 

' Hohnel, F. von. Fragments zur mycologie VI. Mitt. 244. Sitzungsber. M-N 
Classe, k. k. Akad. Wiss. Wien. U8: 349-376. 1909. 

* Sydow, H. von and Sydow P. von. Beschreibungen neuen sUdafrikanischen Pilze. 
Ann. Myc. 10: 41-42. 1912. 



90 Phytopathology [Vol. 7 

related families. More recently Woronichin'^ described a new genus, 
Plectodiscella, based on a single species which he found occurring on the 
leaves of the apple and pear. This genus is closely related to ELdnce of 
Raciborski* butdififers mainly in that the stroma is not borne beneaUi the 
epidermis. Plectodiscella Piri, the representative of the genus, is so simi- 
lar in morphology to the ascigerous stage of GUeosporium venetum Speg. 
that apparently there is a distinct relation between the two. A brief 
description of Woronichin's species is here set forth: A more or less im- 
perfect stroma is formed in the epidennal and sub-epidermal cells of the 
leaf, which is at first sub-cuticular. From this arises a fimgous tissue in 
which are borne irregular globose asci, each containing eight four-celled asco- 
pores. In some instances the asci are separated by the fimgous tissue 
and in others they lie in contact with each other. Woronichin is uncer- 
tain as to the nature of this tissue l>etween the asci. He says, **Wa« 
fiir Elementc die z^'ischen den Ascen l)efindlichen Zwischenraume ausfQl- 
len, gelang es nicht genau aufzuklaren." He does not consider, however, 
that it is cellular. This is also the first impression received in regard to 
the raspberr>' fungus, due to the fact that the cells are minute and disinte- 
grate very ejirly. The cellular strticture of the fungus on raspberr>' 
was determined only on young material and then after it was fixed and 
8taine<i. In Plectodiscella Piri a shield-like arrangement composed of one 
layer of dark cells covers each ascocarp and later breaks apart in order 
that the asci may be ejcposed. In the perfect stage of Glaoiporium vene- 
turn this is present but is clearly seen only in the inmiature stages before 
rupturing occurs. Woronichin does not refer to an imperfect stage for 
his fungus. 

Plectodiscella Piri is considered to be far enough removed from the 
MyriangiacesB or any of its closely related families to be placed in a new 
family. Tliis, Woronichin describes as Plectodiscelle® and states that 
it occupies a s>^tematic position somewhere lx»tween the Plectascales 
and the true Discomycetes. Here he places his fungus P. Pin* but gives 
no exact characters for his genus. Only the family and species are 
descril)ed. 

Taking all characters into consideration, the pcTfcH't stage of GUto- 
sporium venetum Speg. appears to belong to this genus and therefore the 
following name is proponed: 

• Woronichin, N. M. Plertodiscella Piri, diT Vcrtrctcr einorneuen ascomyc«teii 
Gnippe Nfycol. Centralh. 4: 225-233. 1914. 

* Harikxirfiki. M. Kluiomv Har. nov. f(en. Parasitiiiche Algen und Pilte Jara't 
1: 15-16. IWO. 



1917] Burkholder: Plectodiscella veneta -91 

Plectodiscella veneta sp. nov. 

Stromattbns solitariis vel gregariis, pvlvinaiiSy epidermide fusca diacoida, 
mox dehiscerUe, intus contextu hyalinOf pseudoparenchymatico vel indistincto, 
plerumque pluriloculigeris, loculis monasciSy irregulariter sparsis; dscis 
globosis, 8 sporis, 24rS0n; sporidiis ovoideo^llipsoideis, saepe flexis, hyalintOy 
SseptatiSy canstrictis, ceUuLa basilare cbtusay 18-21 x 6,6 x 8fi. 

Hob, In ramis caulibuaque vivis Rvbi occiderUalis, R. idaei var. 
aculeatissiini et R, neglecti. New Yorky America bcreale. Status coni- 
diaphorus eat Glceosporium venetum Speg, 

Cornell University 
Ithaca, New York 



PUCCINIA SUBNITENS AND ITS AECIAL HOSTS 

Ellsworth Bkthkl 

Puccinia subnUens Diet. \b a common rust on Distichlis 9pieaia from 
the Atlantic to the Pacific coast. The telial host is especially abundant 
in the alkaline soils of the desert regions of the western United States. 
Prior to 1904, Chenopodium album was the only known aecial host of this 
rust. In the summer of 1904, Rev. J. M. Bates, from field observations 
in Nebraska, concluded that aecia on species of Cleome, Sophia, Lepid- 
ium, Erysinuim, and Salsola were related to Pxiccinia subnilens. These 
suggestions iiiTre conmiunicated to Dr. J. C. Arthur, who later in the 
summer succeeded in growing the teliospores on these hosts, thus con- 
firming the deductions made by Bates. Dr. Arthur, in giving the results 
of these cultim»s, remarks (Joiu*. Myc. 11: 50-67), *'\Ve have here a dem- 
onstration of the remarkable fact, not known for any other species of 
rust, that Puccinia subniiens has aecia growing \iith equal vigor on three 
families of plants." I-.ater, Arthur grew it on Capsella (Bursa) sp., 
AtripUz hastataf and doubtfully on Sarcobaius sp. He has grown this 
species on nine or ten genera in three families. 

For ten >'ears or nrort*, the writer has observed the aecia of this rust 
abundant in Colorado on species of Polygonum, (chenopodium, Lepidium, 
Capsella, Cleome, Salsola, and Abronia, and in 1912 made successful cul- 
tures on all of these genera except Abronia. During the past summer, 
aecia which seemed immistakably related to Puccinia subnitens were 
foimd on plants of several other genera, and cultures were made to de- 
tennine the correctness of these observations. Likewise all previous 
cultun»s i*-ere repeated with the result that the aecia were produced on 
22 s|MM*ies in 6 families, and 15 genera. The following is a list of suc- 
cessful rtiltures. 

1. Polygon ACK.*:: Polygonum aviculare L., P. erecium L., P. ramonstt- 
mum Mirhx. 

2. ('iiknoi»<>i>ia<k.k: SaUola peMiftr \. Nc»L*<., Chenopodium album L., 
r. ijhiHcxim L.. r. Uiiiceolatum Muhl., (\ pagonum Reich., Manoltpi^ 
nutUillittnn iK. iV Sj (Sreene, Kttchia scojmria (L.) Roth. 

3. .\MAliANTHArK.K: Awaranthu^i rttroflexus L., A, blitoides S. Wats. 

4. Ny( TA<flNArK.K: Ahnnn^i fnigrans S\i\{. 

5. Ckitikkk.*:: ('apsrlln liursa-iHistoris Me<lik.. Lepidium dmsiflorum 
S<'hnid., L. medium (ireene. Erysimum oHperum DC., Sophia pinnaia 



1917] Bethel: Aecial Hosts of Puccini a Subnitens 93 

(Walt.) Britt., Roripa palustris (L.) Bess., Thlaspi arvense L., Sisym- 
brium aUisaimum L. 

6. CAPPARiDACEiB: Cleomc semUata Pursh. 

It will be observed that the above six families constitute two groups. 
The first four comprise a group of contiguous families, and the last two 
another group, likewise contiguous but rather remote from the first. 
Mcidium fumaricLcearum Kell. & Swingle on Corydalis is probably ne- 
lated to P. subnitens, though no cultures were made. If this connection 
should be established it would add another family, Papaveracese, con- 
tiguous with the second group, a total of seven famiUes. 

It is not uncommon to find the aecia in abimdance on a half dozen or 
more host plants at one place, and it manifests only slight racial tenden7 
cies, though it seems to infect certain hosts, such as Thlaspi, Kochia, 
Monolepis, Amaranthus, Roripa, and Erysimum very sparingly. The 
aecia occm* in abimdance on plants of all other genera Usted above. 

Stanleya pinnata (Pursh.) Britt. bears a large orange-red aecium char- 
acteristic of P. subnitensy however, this host failed to become infected, 
though seven cultures were made under the same conditions, and with 
the same material that was used in the successful cultures on other 
hosts. Cultures were attempted on Atriplez hastata L., A. canescens 
James, A. confertifolia S. Wats., and Sarcobatus vermiculatus (Hook.) 
Torr. with no results. Arthur has reported successful cultures on Atrip- 
lex hcistata L. with teUospores from Delaware, and on Sarcobatus vermi- 
ciUatiLs (Hook.) Torr. with teliospores from Nevada. The aecia on the 
latter host, which closely resemble those of P. subnitens, are related 
chiefly, or entirely, at least in Colorado, to Pucdnia Ixixuriosa Syd. on 
Sporobolus airoides Torr., as has been shown by the writer by several 
successful cultures the past season, both from aeciospores and teUospores, 
so that there can be no doubt of this relationship. Further, many sow- 
ings of teUospores of P. luxuriosa on the aecial hosts of P. subnitens made 
through two seasons gave negative results. 

Mcidium Abronioe E. & E. was described on Abronia sp. from Fort 
Collins, Colo. Many cultures both in the field and the garden show 
that it is the aecial stage of P. subnitens. It is common on Abronia 
fragrans Nutt. in Colorado and occasionaUy collected on A. eUiptica A. 
Nels., and A. micrantha A. Gray. 

Late in the summer cultm'es were attempted on Beta, BUtum, and 
Portulaca but no infection resulted, presumably for the reason that 
the teUospores' had probably already germinated. Successful cultures 
were obtained on either Raphanus, or Brassica, but the plants died be- 
fore developing sufficiently for determination. The aecium on Cleo- 
mella, as noted by Arthur, also is probably related to P. subnitens. Cul- 



94 Phytopathology [Vol, 7 

lures vnW lie made again next Heason on Stanleya, Atriplex, Corydalis, 
ClmmicUa, Beta and plants of some other suspected i^encra, and if these 
prf)vc to be aecial hosts of this rust, which seems very probable, we shall 
have a grand total of more than a score of genera in seven families- 
remarkably large nimil)er of aecial hosts for a single species of rust. 
Colorado State Museum 
Denver, Colorado 



CONTRIBUTIONS TO OUR KNOWLEDGE OF THE WHITE 

PINE BLISTER RUST 

W. A. MCCUBBIN 



I. MODE OF INFECTION ON THE PINE 

Only indefinite references to the method of infection of the pine by Cro- 
nartium ribicola have appeared in current literature. From these refer- 
ences one gathers the impression that infection takes place through the 
bark, and probably by way of woimds or abrasions. Having an oppor- 
timity for studying a considerable nimiber of pine infections in 1916, 
some attention was given to this point, and records were made of the 
origins of cankers where such origins could be determined. 

In most cases the determination was not difficult, owing to the fact 
that in a healthy pine branch the fimgus spreads out from the court of 
entry in a very regular and equal manner, and that its progress is marked 
by swelling or discoloration or both, or else the cortical tissue is killed in 
an equally radial fashion. By taking note of this habit one can readily 
locate the point of 'original infection in most cases, especially in the 
earlier stages. 

TABLE 1 

Records of specific cases to show mode of infection of pines by Cronartium ribicola 



LOCALITY * 



Secords 

Four-mile Creek 
Cookstown 

Totals 



I>rUMBEH OP 
INPBCT10.V8 



177 

38 

792 



1007 



ORIGIN' OF LBfllON 



IjesJ fasdcleB 



148 

M 

743 



925 



Wounds 



8 
1 
5 



14 



Undetermined 



21 

3 

44 



68 



Very early in this study it became apparent that the chief mode of 
infection was by way of leaf fascicles through the so-called short shoots. 
In these pines, which were all healthy and which grew in situations where 
they were fairly free from accidents, wound infection played but a very 
small part.. 

According to the tabulated results about 92 per cent of these young 
bUster cankers originate in leaf-bundle infection. This percentage in- 



96 Phytopathology [Vol. 7 

eludes only those cases where the point of ori|^n could be confidently 
established, but it is highly probable that a large proportion of the num- 
ber listed as undetermined should also find a place here, and it might 
not be overstepping the mark to ascribe at least 95 per cent of thede 
blister cankers to leaf fascicle infection. 

One may consider that the sporidia from the currant leaves are lodged 
among the bases of the needles and from this position can then attack the 
short shoot which bears these leaves. In a number of instances a few of 
the leaves on such shoots were found to be dead while the rest of those in 
the fascicle were quite healthy; in other cases all the leaves in the fascicle 
had l)een destro>'ed and often the short shoot and even a small area in 
the cortex at its base were also killed. In milder cases, especially where 
the growth of the tree was very vigorous, the fungus did not kill either 
the leaves or the short shoot, but induced in the latter a pronounced 
stimulation of growth, so that the short shoot became enlarged and 
buU)ous in appearance. 

In these peculiarities of short shoot infection may lie a possible expla- 
nation of the year of dormancy which so evidently obtains in a great ma- 
jority of C4u*es. If. during the summer after infection, the fungus pro- 
gresses only into the short shoot or slightly beyond it into the adjacent 
cortex, it would l)e difficult to recognize these minute symptoms and 
then» would \h* the so-called dormant year. 

II. LIFE CYCLE OF THE FUNGUS ON THE PINE 

In general the tendency has been to regard the life of Cronartium rtW- 
coln on its pine host as more or less indefinite, varying from one to two 
y<»ar8 up to six years or more; that is, from the time of infection \mtil 
aeria are pnxluced from one to six years might elapse. In the study of 
this disea^ in Ontario in 1916 evidence has come to hand which indicates 
that the fungus tends to reach the aecial stage in a fairly definite period, 
but tliat this noniial course of development may l)e shortened or length- 
onetl lMH»ause of c<»rtain favorable or unfavorable factors. 

In the Niagara Penin.»<ula in 1916 there were found a numl)er of young 
pint* infections on tre<»s growing close* to black currant-s, and though these 
currants have Innnx badly nisted since and incluchng 1914, there is reason 
to think tliat no nL»»t was present on them Ix^fore that season. In any 
CUM* no >«ign of infection was visible on these pines in 1915, although they 
wen* ciTtainly ex]x)sed to infection during the previous year. Moreover, 
in the summer of 1916 no (hs4»as<» was met with on the groH'th of 1915 
although the.*^» pines must have n»c(»iv(»(l infection in 1915. On the other 
hand, th<»S4» five lots of pines dcvelo|MMi 22.3 infections in 1916, all on the 



1917] McCubbin: White Pine Blister Rust 97 

growth of 1913 and 1914. It seems reasonable to think, therefore, that 
during the year after infection there are no symptoms of a visible natxire 
in infected pine branches. Additional evidence on this point recently has 
been obtained from another district (Cookstown, Simcoe County, On- 
tario), where a young nursery row of white pines was severely infected 
from black currants growing side by side with them. Out of the 1412 
blister cankers recorded from these rows not one was found on the growth 
of 1915 although the pines were certainly subject to infection in the 
previous year. On the twig growth of 1914 there occurred some 286 
cases, which number gives a strong indication as to the yearly infection 
that might be expected here. 

While the above evidence from these two cases is scarcely conclusive, 
it is sufficiently extensive tad clear-cut to warrant the assumption that 
in the great majority of cases the season following infection is a "dor- 
mant" year. 

When the character of all the 509 infections recorded above is examined 
further another point becomes clear. With one exception all of these 
cankers were in what might be termed the swelling stage, the cortex being 
typically swollen into a spindle and usually discolored. If these cankers 
can be taken to represent the normal course of the disease, and since they 
include all the infections foimd on the 1914 twigs of these quite normal 
trees there seems to be no reason why they should not be so considered, — 
then the third season of the diseare is apparently characterized by the 
appearance of the first visible symptoms, the swellings just mentioned. 
And if the formation of aecia from these swellings be assumed to take 
place during succeeding years a fairly normal life cycle will have been 
obtained. Summarized it would run thus: first season, infection in summer 
and autumn; second season, dormant period; third season, swelling stage; 
fourth season, aecia. There is evidence, however, that in the majority 
of cases the swelling stage may last for two years before the production of 
aecia. This evidence has been obtained partly from the Cookstown case 
already mentioned and partly from the Secord case where 177 swellings 
were found in 1916 on yoimg pines growing close to black currants. 
When these 177 swellings were arranged in a curve representing the 
number of them that had occurred on each yearns growth it was found that 
the apex of the curve came in 1914; that is, there were more infections 
on the growth made in 1914 than on that of any other year. WTien a 
curve was prepared similarly from the data obtained at Cookstown, it 
was of another type, having the largest number of swellings on the growth 
of 1913 (fig. 1). The nature of this curve thus suggests very strongly 
that the swelling stage may ordinarily last two years before the aecia are 
produced. 



98 Phttopatholoot (Vol. 7 

It is to be noted that the Cookstown curve repreaenta infectiotu begun 
in several successive yean vhile the Secord curve contains infections of 
only one year, that of 1914. An attempt was made to compare the two 
wries of results on a basis of something like equality by supposing that 
in addition to the infections started in 1914 in the Secord case a similar 
series of infections had begun in 1913. Assuming that the mrellings 
which would presumably arise from these earlier infections in 1915, 
would still remain in the same stage during 1916, a curve was then con- 



Kor expluiation hc text 

Hlnirtt^d which would iiicluili' thif> h\-iMtthetiiial xeriem of cankers along 
with those sc-tually pn^etit. Surh a cnrw would contain the infections 
of two uur«*iwiv(* ypiirf and would ihuo n-wniblo ver>- closely the Cooks- 
town i-urvc. When the ntmilxTs in thi!< n-conmnicted curve were doubled 
in order 1o obtuiii ii In-ttcr roin|K>ri.-«m with the Cookstown curve, it was 
Bc«>n thsit fxcppt for minor irreKularities the two ('iir\'C!' are practically 
iilcnticul. 

The Won*- coiicordiuici: of this sup)x>«'d ciiw with the results of the 
Hctiud :tiir\'py prrtvidc:* n xtrikinK confinimtion of the indication already 



1917] 



McCubbin: White Pine Blister Rust 



99 



given in the Cookstown curve of the continuance of the swelling stage 
for two years. 

The evidence may be presented in another way, by following the course 
of the disease year by year in a number of shoots of 1911, exposed as in 
the Cookstown case to a more or less constant annual infection from cur- 
rants. The number of infections started in these pine twigs in 1911 may 
be represented by X, those started in 1912 by 7, and those in 1913 byZ. 
Later infections may no doubt take place in these shoots, but smce the 
number of such infections is known from other considerations to be very 
small, they may be neglected for the purpose in view. A small letter 

table 2 
Probable development of the blister rust in pine branches based on a four-years eyeU 



TSAR 


TBARLT PBOOBE8S OW 


NXTMBSR OF 8WKLLIN08 


ESTIlf ATBD PBOPOB- 
TIONB BASED ON BBCOBD 


COOKSTOWN SUBYBT 




DISBA8B 


PBRSENT BACH TXAB 


CA8B 


rXGUBBS 


1911 


X* 











1912 


X^-fY* 











1913 


x'+yd-hz* 


X 


300 


286 


1914 


XHY»+Z<* 


Y 


100 


390 


1915 


Xb_|.Y»>+z« 


Z 


10 


83 


1916 


X*>+Y*>+Z»> 








22 



TABLE 3 

Probable development of white pine blister rust in pine branc?ies based on a five^ffears 

cycle 



TBAB 


TBABLT PBOOBX88 OP 
DBUASB 


NDMBBB OP SWBLLINaS 
PBBSBNT BACH TBAB 


ESTIlf ATBD PBOPOB- 

TIONS BASED ON SECOBD 

CASE 


COOKSTOWN SUBTBT 
nOUBBS 


1911 


x* 











1912 


X**+Y* 











1913 


X-+Y<i-fZ» 


X 


300 


286 


1914 


X"+Y»+Z<» 


X+Y 


400 


390 


1915 


X»»+Y-+Z« 


Y+Z 


110 


83 


1916 


xHy»»+z- 


z 


10 


22 



attached to each of these symbols conveniently indicates the stage of 
development, as: t, infection year; d, dormant year; «, swelling stage; 6, 
blister or aecial stage. 

Using these symbols the accompanying tables have been constructed 
showing the development of the cankers on these twigs. The first table 
is based on a four-years cycle, where the swelling stage lasts but one year 
before aecia are formed, while the second table is based on a five-years 
cycle, where the swelling stage is continued for two years. In the third 
column of both tables are entered the number of swellings which will 



100 Phytopathology [Vol. 7 

appe:ir oiich year, exprefwed by the h>tii1)oIs adopted. An attempt hai« 
lKH»n made in the fourth eolumn to substitute values for X, }', and Z. 
bailed on the proportions obtaining in the Secord case. In the Second 
series the infections Ix'gun in 1914 on the growth of 1914, 1913 and 1912 
were 127, 49, 0. corresponding to X, y, and Z, respectively. Adopting 
JiOO as an arbitrar>' value for X, then Y Incomes approximately 100. 
Z should then be zero, but since there is good reason to think that in- 
fections sometimes occur on shoots of three years' standing, though none 
were foimd in this case, a nominal value of 10 has \iecn assigned for Z. 

Beside these* estimated pro)X)rtions in the adjoining column are 
placed the actual figures of the C'ookstown sxirvey. Since these figures 
indicate th(» swellings noted at one time on several successive years of 
gn)wth. they may l)e used fairly to represent the swellings that would 
aris<» on one y(»jir's growth in a numlK»r of successive seasons. It will Iv 
MH^n at a glance tlmt while the estimated pn)portions as obtained from the 
figures of tin* S<'C()rd case do not agrc^c at all with tho actual siu^ey fig- 
ures in the tabic* showing a four-yt^ars cycl(». there is a strong re««em- 
blance lK»tww»n thes<» simie two cohunns in tin* tabic* whore a five-yean* 
cvcle is us<m1. 

It is probable*. then*fore, that tlu^ tal)le giving a five-years cycle ex- 
pn»ss<*s mon* nc*arly the actual dc»v«»l()pment of the disease than the table 
giving a four-yc»ars cycle; in oth(*r words, the nonnal blister infection on 
thc»s<* young pifH*s passi*s two yc»ars in the sw(*lling stage, and the dcvel- 
opni(*nt of the <liM*ase as a whole follows this cours<*: First season, inflec- 
tion ; s<*cond s<*ason, donnant jK*riod; third s<»as4)n, sw(*lling stage; fourth 
si'ason, swc'lling stiige; fifth and following s<*ju<ons, ac*cia. 

The actuid time c*lapsing l)etw(*c*n inf(*ction and the first production of 
blisti*rs acconUng to this plan of development is something short of four 
vears, but sin<*e the course* of the* dis<»aM* involv<*s five* s<*asons it seems 
lM*tt<*r for ])ractical n*asons to dc*signatc» it as a fiv<*-yc*tirs cycle. 

The alxive conclusions as to the course* of development of the dis<»jise 
on young pin«*s should Ik* fairly trustworthy inasmuch as thc*y an* Iwiseei 
on a fiin^id«TaM«* numlH*r of blister cankers. On the other hand, then* i* 
certain rvidftifc in Uith the (Nnikstown an<i the Se*cord cas<*s which in- 
dicates that priTocious or delay«*<l devc*lopmi'nt may occur, and that 
wliilt' tln' lif4'-4-vcIc* (outlined mav o!)tain in the majoritv of cas<*s, it is bv 
no m<*ans to \h* n*garde<i as an invariable* nili*. 

Division of Botany 

Dkpartmknt of A<iiiiri i/rriiK 
OrrAWA. Canada 



SPECIES OF MELAMPSORA OCCURRING UPON EUPHORBIA IN 

NORTH AMERICA 

E. B. Mains 

No species of Melampsora on Euphorbia was known to occur in the 
Western Hemisphere until the present year. Collections, however, have 
been made recently in the United States both upon introduced and native 
species of Euphorbia. These collections, which Dr. J. C. Arthur has 
kindly turned over to me for study, consist of one collection upon Eu- 
phorbia eommutata Engelm. from Indiana, four upon E. robusta Small from 
Colorado and Wyoming, and one upon E. Cyparissids L. from Maine. 
Of these, it appears certain that the one on E. Cyparissias is introduced 
and those upon E, robusta and E. commutaia are native. 

Up to the present time, six Old-World species of Melampsora upon 
Euphorbia have been recognized, these being M, Gelmii^res,, M. Eup- 
horbicB-diUcis Otth, M. Euphorbice-Gerardianoe W. Miiller, M, HelioscopicB 
(Pers.) Wint., M, Euphorbiw (Schub.) Cast, and M, Euphorbice-Engleri 
P. Henn. all of which have very similar uredinia and urediniospores, 
the separation being by telia and teliospores. Of these the first three 
are well-marked and distinct species. Of the last three, 3f . Helioscopice 
and M. Euphorbias while distinguished from the rest by well-marked char- 
acters, are separated from each other, according to Miiller (1907) only 
by a rather small difiference in the length of the teliospores. This dif- 
ference may be a real one but is scarcely apparent in such European ex- 
siccati of the two rusts as the author has at his disposal for examination. 
The last, M. Eurphorbice-Engleri is a species of doubtful validity. It was 
set apart by Hennings, owing to its habit of maintaining itself wholly by 
the uredinia, other spore forms never having been found. This is only 
known on one species of host. 

A study of the North American collections of 1916 shows that they 
can be readily placed in three species, two of which correspond to two 
of the above and one of which appears to be imdescribed. The Maine 
collection, which is upon Euphorbia Cyparissias, has teliospores which 
in length and imiform thickness of wall agree very well with M. Euphor- 
bice upon the same host ih Europe, while the Indiana collection upon E. 
eommutata with its 31-58^* long and apically thickened (3-6/i) teliospores 
agrees very well with European material of M, Euphorbioe-GerardiaruBy 



• •• • •••II . ••!:••. I.. •-•• 

• 



102 Phttopathologt [Vol. 7 

the uredinioeporee of all being similar. The collections upon Euphorbia 
robiuia from Colorado and Wyoming, however, are distinguished from all 
other species of Melampsora upon Euphorbia by certain characters of the 
uredinia and uredinioepores and are considered by the writer as belong- 
ing to an undescribed species. 

The North American species of Melampsora upon Euphorbia may be 
keyed out as follows: 

Uredinioepores 1&'23m long, paraphyses 
numerous 
Teliospores decidedly thickened at the 

apex 13/. Euphorhia-Gerardiana, 

Telioepores not or only slightly thick- 
ened at the a|>ex 2 M. Euphorbia, 

Urediniospores 16-29 m long, paraphyses few.. 3 3/. moniicola. 

I. Melampsora EuphorbuB-Gerardiance W. Miiller, Contr. Bakt. 17*: 210. 
1906. 

O and I. P>''cnia and aecia \mknown. 

II. Uredinia amphigenous and caulicolous, scattered, circular, 0.2-0.5 
mm. in diameti'r, sul)epidermal, soon naked, pulverulent, pulvinate due 
to the crowded paraph>Tje8, pale yellow, ruptured c»pidermis inconspicu- 
ous; paraph>"Be8 numerous, intermixed with the spores, capitate, 16-19 
by 51 58m, the wall colorless, 2-3^ thick; urediniospores globoid to ellip* 
soid, 13 16 by 16-20m; wall colorless, 2-3m thick, finely and closely echinu- 
late, the por(»8 ol>8cure. 

III. Telia caulicolous, prolxably also amphigenous, circinating about the 
uredinia, oblong, 0.2 1 mm. long, 8ul)epidennal, slightly elevated, blackish- 
brown; teliospores prismatic, 9-15 by 31-60m, rounded at both ends; wall 
light chestnut-brown, darker towards the apex, 1.5/i thick, 3-6m at the 
apex. 

On EuPHORBiAcnSiB 

Euphorbia commulata Engc^lm., West side of High Lake, Noble Co., 
Indiana, June 11, 1916, II, III, C,C. Deam 2008SA, communicated by 
G. N. Hoffer. 

This collection, which is the first collection of a Melampsora upon 
Euphorbia to be refxirted for North America, has a range in the length 
of the teliospore somewhat less than that given by MQller (1907, p. 641) 
for M. Eupharbict-Gerardiantt in Europe. A comparison with European 
material upon E. falcata (Sydow I'red. no. 1G87) sho^-s a very close agree- 
ment, however, Uith as to the ure<iinio8|x)res and teliospores. The telio- 
spores are not quite so generally thickened at the apex as in the E^uropean 
specimen but Mill are very (ie<'ide<lly thickened, up to 3-6^, while the 
ure<iinia have the umiuiI pulvinate apiieanincc and abundant paraphyses. 

Pvcnia and aecia arc not known for this 8|>ecics Init will doubtless l^e 
fouml upon the same host, since M. Hdioscopue, M, Euphorbia and M 



1917] Mains: Melampborab on Euphorbia 103 

EupharbiaHivlcis, the three species of Melamspora upon Euphorbia whose 
pycnial and aecial stages are known, are autoecious. 

2. Mdampsora Euphorbice (Schub.) Cast. Observ. Myc. 2: 18. 1843. 
Uredo Euphorbice-HelioscopicB Pers. p Euphorbim-exigiUB Pers. Syn. 

Fung. 215. 1801. 

Xyloma (Placuntium) Euphorbice Schubert in H. Ficinus Flora der 
Gegend urn Dresden 2: 310. 1823. 

Uromyces verrucipes Vuill. Bull. Soc. Bot France 41: 285. 1894. 

Mdampsora Eup}iorbiaS''€xigiuBW. Muller, Centr. Bakt. IT*: 210. 1906 

Melampsora EuphorbuB-Pepli W. Muller, Centr. Bakt. VP: 210. 1906. 

Mdampsora EupJiorbuB-CyparissicB W. Muller,. Centr. Bakt. 19*: 453. 
1907. 

Mdampsora Cyparissias W. Mttller, Centr. Bakt. 19*: 561. 1907. 

O.^ Pycnia flattened hemispherical; ostiolar filaments none. 

I. Aecia foliicolous and caulicolous, circular to oblong, 0.2-0.5 mm. in 
diameter on the leaves, 1-4 mm. long on the stems, orange-yellow, with- 
out peridium or paraphyses; aeciospores spherical to ellipsoid, 19-24 by 
21-28m; wall closely vemicose. 

II. Uredinia amphigenous and caulicolous, scattered, circular or oval, 
0.1-0.3 nwn. long, early naked, pulverulent, pulvinate from the mass of 
paraphyses, golden-yellow fading to white, ruptured epidermis inconspic- 
uous; paraphyBes intermixed with the spores, numerous, capitate, 16^20 
by 31-51/*; wall colorless, 3-4/* thick, smooth; urediniospores globoid to 
ellipsoid, 13-19 by 17-23/i; wall colorless, 2-3/* thick, closely and finely 
echinulate, the pores obsctu'e. 

III. Telia amphigenous and occasionally cauUcolous, scattered, cir- 
cular to oval, small, 0.1-0.2 mm. long, covered with the epidermis, com- 
pact, pulvinate, dark chocolate-brown; teliospores prismatic, 7-13 by 
32-45/*; wall chestnut-brown above, lifter below, 1-1.5/* thick, not thick- 
ened at the apex, smooth. 

On EUPHORBIACEiE 

Euphorbia Cyparissias L., Bank near Turner graveyard. Isle au Haut, 
Maine. Sept. 13, 1916, II, iii, J, C. Arthur. 

3. Melampsora monticola sp. nov. 
O and I. Pycnia and aecia unknown. 

II. Uredinia amphigenous and caulicolous, scattered or in circular 
groups, circular or oblong, 0.2-2 nun. long, subepidermal, long covered 
by the epidermis, pulverulent, orange-yellow, ruptured epidermis con- 
spicuous; paraphyses few, intermixed with the spores, capitate, 13-21 
by 32-58/*, the wall colorless, 1.5-3/* thick, smooth, the stipe solid; ured- 
iniospores globoid, ellipsoid or obovoid, 13-20 by 16-29/*; wall colorless, 
1.5-3/* thick, finely and closely echinulate, the pores obscure. 

III. Telia amphigenous and caulicolous, circinating about the uredinia, 
circular or oblong, 0.1-1 mm. long, subepidermal, slightly elevated, black- 
ish-brown; teliospores prismatic, 9-16 by 27-56/*, rounded at both ends; 

^ DeBcription of pycnia and aecia adapted from Dietel (1895). 



104 Phytopatholoot [Vol. 7 

wall liRht choatnut-brown below, darker towards the apex, 1.5-^ thick, 
2-4m at the apex. 

On Euphorbiace.c: 

Euphorbia robusta Small, Carpenter, Wyoming, Aug. 18, 1916, II, iii» 
E, T, A' E, Bartholomew 6067 {Vromyces Tranzschelii Sydow, 0, III, 
also present); (Colorado Springs, Colora<lo, plains 10 miles east of citv, 
Aug. 31, 1916. II, iii, E, Bartholomew, 6104 (U-pe); Palmer Lake, Colo.. 
Sept. 23, 1916, II, III, E, Bethel (two collections). 

In the younger uredinia, es|>ccially, apparently thinner walle<l uredi- 
niosjK)res are often seen mixed with the thicker. After treatment with 
lactic acid, which serves to differentiate the wall from the cell contents 
an<l make it stand out more clearly, the apparent difference is not to \yc 
()l)serve<l. 

This species is distinct from other sjx^iMes of Melampsora on Euphorlmi. 
The unuhnia are abundant, large, and long covered by the epidermis 
and since they (*ontain l»ut few paraphyses, after the rupture of the cover- 
ing epidermis and the cscajM* of the pulverulent mass of sywres, they |x>s- 
sess a Hattcnc(i ap|H*arance when contnusted with the pulvinate mass of 
paraphys(\s (»f other species on Kuphorbia. The uretUnicxspores are much 
more variable and larger in size than those of the other si)ecies. 

No pycnia or aec'ia were found uiwn any of the collections. They are. 
how(»vcr, to be lcK»ked for upon the same host earlier in the season since 
the rusts of this group whose life cycl(» an* known are autoecious with all 
.sjMin* forms, although Jacky (1899) working with M. Euphorbict on E 
CypariMsias and Muller (HK)7 p. 449) working with the same rust on E 
Peplus claim to have obtained urtnlinia by infection from teliospores, yet 
Dictcl (189')) working with M. Enphorbuv on E. Cifparisitias.vLml Muller 
(19t)7) with the same rust on E. exigun on the other hand have shot^ii 
that pycnia and ac4'ia are prcwluce*! ujk)!! these hosts from infections with 
the telio^|M»rcs. Dictcl (1S89) has also shown that M. Euphorbitr-dulci* 
Srhr<H»t. has pyniia and aecia. Since th(»sc stages ar(» develo|HMl sparing- 
ly, it is probable that the first workers overlcH)ked them and that M. 
Euphurhyt has all s|H)r(» f<»rms. Although all the North .\merican col- 
lections wcf(» <»xamincd for pycnia a.ssociate<l with the uredinia none were 
found, and it is pn»bablc that all of thc.^' rusts will Ih* found to lie autoe- 
cious and have all s|>*jrc fonns. 

It is interesting to note that from a region in which this group has hith- 
erto not U»en kiiowti so many collect i<»ns from such widely separated 
are.is should have all Ihm^u made in one season. It is not so surprUing 
that ^f , EupKnrhitr should Ik* f(»und u|M)n E. ('ifpnrissias.iis the latter has 
lieeii brought into this country from Kuro|N* and it is likely that the rust 
was intnMlue<Ml with it. It is, however, surprising that the rust 
han not previously U»<»n foimd sim»<* the host is rather widely distributed. 



1917] Mains: Melampsorae on Euphorbia 105 

The other two species of Melampsora are upon native species of Euphor- 
bia and of these M, monticola is evidently a purely American species 
found upon a common western Euphorbia.* With its abimdant, large, 
orange-yellow uredinia, it is remarkable that this very striking rust has 
not been collected before. The other species, M. Euphorbiae-Gerardianae, 
is probably native to this country' as well as to Europe, since its European 
hosts, E. Gerardiana and E, falcata are not known in this coimtry. An- 
other argument in favor of this assumption is that the species of Mel- 
ampsora on Euphorbia have in most cases physiological races limited to 
one species of host as Miiller (1906, 1907) has shown. Consequently 
even if European hosts were foimd, it would be doubtful if rusts on 
American species could be considered as having an European origin. 

The writer wishes to express his deep appreciation to Dr. J. C. Arthur 
and Prof. H. S. Jackson for the helpful suggestions and criticism re- 
ceived in the preparation of this paper. 

Purdue University Agricultural Experiment Station 
Lafayette, Indiana 

literature cited 

DiBTEL, p. 1889. Ueber die Aecidium von Melampsora Euphorbiae-dulcis Otth 

und Puccinia silvatica Schrot. Oesterr. hot. Zeitschr. N. 7. 

1895. Ueber den Generationswechsel von Melampsora Helioscopiae und 

M. vcrnalis. Forstl. nat. Zeitschr. 6: 373. 
MttLLER, W. 1906 Versuche mit Uredineen auf Euphorbien und Hypericum. 

Centr. Bakt. 17*: 210-211. 

1907. Zur Kenntnis der Euphorbia-bewohnenden Melampsoren. Centr. 

Bakt. 19*: 441-460, 543-563. 
Stdow, p. and H. 1914. Monog. Ured. 3: 379. 
Jacky, E. 1899. Untersuchungen iiber einige schweizerische Rostpilze. Ber. 

schweiz. bot. Gesellsch. 9:49-78. 

* In a commimication recently received from Mr. E. Bethel he says, **The one 
[Af . tnarUicola] we have here is undoubtedly native as I found it in the high moun- 
tains (above 9000 feet) at Nederland, Colo." 



RECENT CULTURES OF FOREST TREE RUSTS 
James R. Weir and Ernest E. Hubert 

The determination of various species of rusts found on forest trees ol 
the general region of Montana is a difficult task when descriptive evi- 
dence and spore measurements are used. In most cases involving heter- 
oecious rusts successful inoculation is considered very necessary in 
determining the identity of the species imder consideration. Conse- 
quently, as a beginning, an attempt was made early in March, 1916, to 
secure various forms of hypertrophy formed by the bark-inhabiting Peri* 
dermia. After collecting, these were placed in the laboratory in large 
test-tubes with sufficient water to supply the branch or twig supporting 
the infection. Many needles were always left on the branches or twigs. 
In this manner the fungus in many of the infections was induced to pro- 
duce Hpores prematurely and these were available for cultiu^ work at an 
early date. This process also served to develop successfully the pycnial 
stage of Cronartium coUasporaides (D. A H.) Arth. and Cronartium 
CompUmia Arth. which stage preceded the aecial stage in both cases. In 
the search for material a foliicolous rust on the needles of Larix oecidentaU$ 
was collected for the first time in June, 1916, at various points in Mon- 
tana and Idaho. The rust was very abundant and widespread. All the 
caulicolous forms of rusts on forest trees in this region and in the states 
of Michigan and Minnesota as well as a number of the foliicolous forms 
were tried on a variety of suspected hosts. All inoculations were isolated 
at the* gnrnhoui^ at Missoula, Montana, by the use of celluloid cylinders 
and (*otton plugs. The inoculated plants were sprayed daily with tap 
water for a period of throe to five days following inoculation. The fol- 
lowing is a summar>' of the cultures to date since the last report.^ 

Five pbmts of Casiilleja angusiifolia, two on May 14, 1916, and three 
on May 8, 1916, were dustiMl with nei^ly develo|)ed neciospores (forced 
in lnl>orator\') of Cronartium coleosporoidea (D. A 11.) Arth. (P. siatacU- 
fimne ty|M») on Pinus cofUorta from Hayden I^ike, Idaho. Of the first 
two plant.** one di-v(»lojMMl uredinia on May 26 and telia on May 29, the 
n*n)aininf( plant dyin^ lK»fore May 24. ()f the other three plants, two 

' W«*ir. J. H.. And Iltibort. K. K. SuocoAflful inorulationfl of Larix occidentalit 
an<l Larix curo|N*a with Mclainp^ira l>ifcolowii. Phytopath. 6: 372-373. A^. 1016. 

Weir. J. H. and HiilHTt. K. K. .\ ftucccHsful inonilation of Abien lantocarpa with 
PurriniaMtruin pustulatuni. Phytopath. 6: 373. Ag. 1916. 



1917] Weir and Hubert: Cultures of Rusts 107 

developed uredinia on May 30, followed by abundant telia on Jime 3. 

^^ • 

The remaining plant wilted. Four control plants remained normal. 
This cheeks the cultures of 1915.* 

Three plants of CcistiUeja angustifolia were dusted with aeciospores of 
Cronartium cdeosparoides (t3rpical gall form) on Pinus carUorta from 
Sylvanite, Montana, Jime 23, 1916. Uredinia were not observed but on 
July 17, 1916, telia appeared uniformly on all three of the trial hosts. 
Three control plants remained normal. A similar result was obtained on 
Castilleja with aeciospores from the gall type on Pinus contorta from Evaro, 
Montana. Telia were recorded July 17, 1916, on orle of three trial-hosts. 
The remaining plants died. Three control plants remained normal. 

On May 23, 1916, aeciospores of Cronartium coleosporaides (blister 
type) on young seedlings of Pinua panderosa from Haugan, Montana, 
were dusted on three plants of CaatiU^a angustifolia. Heavy infections 
on two and a light infection on one with xu*edinia on June 5 and teUa on 
Jime 8 were recorded. Three control plants remained normal. This 
result also checks similar cultures made in 1915.' 

On Jime 21, 1916, aeciospores of Cronartium coleosporoides (typical 
gall form) on IS-jrears-old trees of Pinus ponderosa from Sylvanite, Mon- 
tana, were dusted on three plants of Castilleja angustifolia. The ap- 
pearance of the uredinia was not recorded owing to absence from the 
laboratory but on July 17, 1916, teUa were noted in abundance on two 
of the inoculated plants. The other trial-host died. Three control 
plants remained normal. 

The results of the season together with those of 1915 demonstrate 
that the various caulicolous forms of rusts occurring on Pinus contorta 
and P. ponderosa in the Rocky Mountain region are the aecial stage of 
Cronartium coleosporoides. It is not only possible but very probable 
that the same forms on Pinus contorta and P. ponderosa as known else- 
where in the western United States belong here also. An examination 
of the aeciospores from galls on Pinus contorta, P. ponderosa, P. attenuaia, 
P. couUeri, and P. jeffreyi, from widely separate regions has not brought 
out any specific characters different from that of the material used in the 
successful cultures on Castilleja. Attempts were made to infect young 
leaves of Quercus rubra with aeciospores from galls on Pinus contorta and 
P. ponderosa but without success. 

Aeciospores Of Cronartium Comptonice Arth. on Pinus banksiana from 
Cass Lake, Minnesota, were sown on trial-hosts as follows: On two plants 
of CastiU^a angustifolia on May 17, 1916, with negative results; on one 

' Weir, J. R., and Hubert, E. E. A serious disease in forest nurseries caused 
by Peridermium filamentosum. Jour. Agr. Research 6: 781-785. Ja. 24, 1916. 
> Jour. Agr. Research 6: 781-785. 24 Ja. 1916. 



108 Phytopathology [Vol. 7 

plant of Quercua rubra on May 18; 1916, with negative results; on one plant 
of Comptonia asplenifolia on May 18, 1916, with positive results, uredinia 
appearing on J\me 9 and teUa on June 17. All control plants remained 
normal. 

Aeciospores of Crofiartium Comptonice Arth. on Pinua banksiana from 
East Tawas, Michigan, H-ere sown on trial-hosts as follows: On three 
plants of Castilleja miniata on May 24, 1916, with negative resiilts; on one 
plant of Qtierciui rubra on May 24, 1916, with negative results; on two 
plants of Comptonia asplenifolia on May 23, 1916, and June 13, 1916, re- 
spectively. Tredinirf were noted on June 13 and telia on June 23 on the 
first plant and unnlinia on June 30 on the second. Two control plants 
remained nonnal. Aociosfwrcs were sown on one plant of Myrica earo- 
linensis and one of Myriai gale on May 26, 1916. Uredinia on Jime 13 
and telia on June* 25 wctc noted on l)oth plants. Two control plants re- 
niaincii nonnal. 

A collection of leaves of the previous sciu^^m (1915) of Populus tremu- 
loidcH lM*aring telial sori of Mclampsora rnedusw Thiini. vnis made in Pattee 
Canyon two miles .southejist of Mi.ssoula, Montana, on March 12, 1916. 
A p^irtion of the^sc* over-wintered leaves were placed in moist chamliers 
on March 15, 1916, and a few days later upon examination of the yellowish* 
brown, downy layer fonne<l on the .*<ori, it was foimd that .sporidia were 
prc»>*c»nt. Thes<» fn\sh siK)ridia were ilschI to inoculate newly formed nee- 
dles of lAirix (Kcid4mUiliH, Two separate inoculations were made on March 
22. 1916, followcnl hy two others on March 26, 1916. Individual branches 
of trees of /.. occidentalis wv.n* xh^hI for the test. On April 3, the first 
inocuLition had resulted in pycnia which w(»re accompanied by small 
droi>s of hyalines licjuid. On April 4 the aecia were present on the under 
si<le of the ni^e<llej<. The second in(K*ulation gave pycnia and aecia on April 
4. the third and fourth in(H*ulations re.nulting in pycnia and aecia on April 
8. Th<» four (*ontrol plant-s of L. occidentalis as well jis the needles on the 
inoculated tnM»s which wcn» not included within the cylinders remained 
nonnal. -\ll the ikhmIIcs .subjected to the inoculation lx?c4une infected and 
devclc»j)c<i a Lirg'j niunlx'.r of sori of l)oth .st4igi»s (O and I) of the rust. 

On April 9, 1916, germinating t<ilios|K)ric material of Afelampsara 
mt^iumr Thlim. on Populus tremuloidcs was sown on two small tre<*s of 
hirij ruroftea. On April 26. tu\ abundant <U».velopment of pycnia were 
nHMirded and on May 1 thi^ aecia ap|H^inid. The pycnia' and aecia and 
their resjK»ctive sj)ori»-formH on the two sjiecies of larch were found upon 
examination to U» i<lf»ntiral. The telial material failwl to infect Tsuqq 
hitirophylh and Pseudotsutja taxifitlia, Tlu» control plants in all casesi 
remained normal. 

TeliosjMires Uuiring .s|x>ridia of MvUimpsora mctlusa Thiim. on lea\'cs of 
Populus trichocarpa were coUf^tetl at Haugan, Montana, on June 5, 1916. 



1917] Weir and Hubert: Cultures of Rusts 109 

On June 7, these were sown on one small tree of Larix europea, two of 
L. occiderUaliSf one each of Tsuga heterophylla, T, caroliniana, and Pseu- 
dotsuga taxifolia. On June 15, pycnia appeared on the needles of L. eu- 
ropea and on the needles of the two trees of L. occidentalism Aecia developed 
on L. europea in abimdance on June 24 and on L. occidentalis on June 22. 
Negative results were secured on Tsuga heterophyUa, T. carolinianay and 
Psexidotsuga taxifolia. Control plants remained normal. 

Teliospores bearing sporidia of Melampsora bigelomi Thiim. on Salix 
cordata mackensiana from Deborgia, Montana, were sown on Larix occi- 
dentalis and L. laricina on Jime 7, 1916. One small tree of each species 
was used. Pycnia appeared on Jime 15 and aecia on June 18 on the 
needles of L. occidentalis. On L. laricina, the pycnia were noted on June 
15 and the aecia on Jime 18. A heavy infection occurred. Control 
plants remained normal. 

Aeciospores of Pucciniastrum pustulatum (Pers.) Diet, on Abies lasio- 
carpa resulting from an inoculation with the telial stage on Epilobium 
angustifolium* were sown on two plants of Epilobium angustifolium on 
May 18, 1916. Uredinia developed on Jime 4, on the underside of a ma- 
jority of the leaves subjected to the spores. Only the younger leaves be- 
came infected. Control plants remained normal. This completes the 
cycle for Pucciniastrum pustuiatum. 

TeUospores of Gymnosporangium tvbulatum Kern on Juniperus scapula- 
rum from Missoula, Montana, were sown on two plants of Cratcegits 
douglasii on April 27, 1916. Pycnia in abundance appeared on May 8 and 
11 and aecia on May 22 and 24. Control plants remained normal. This 
checks a previous culture.*^ 

Teliospores of Gymnosporangium nelsoni Arth. on Juniperus communis 
from Bonner, Montana, were sown on two plants of Amelanchier alnir 
folia on May 21, 1916. On June 9, pycnia appeared in abundance, the 
aecia developing on June 28. Control plants remained noVmal. 

Teliospores of Gymnosporangium nelsoni Arth. on Juniperus scopulo- 
rum from Bonner, Montana, were sown on two plants of Amelanchier 
alnifolia on May 21, 1916. Pycnia appeared on Jime 6; aecia were 
noted to be developing on June 28. Control plants remained normal 

Several of the cultures are still in progress of development and as soon 
as results on these are secured further information on the rusts of forest 
trees in this region will be available. 

Office of Investigations in Forest Pathology 
Bureau of Plant Industry 
Missoula, Montana 

* Phytopath. 6: 373. Ag. 1916. 

^ Weir, J. R. Telial stage of Gymnosporangium tubulatum on Juniperus sco- 
pulonim. Phytopath. 5: 218. Ag. 1915. 



A RHIZOCTONIA OF THE FIG 

J. Mats 
With Plate II and Three Figures in the Text * 

A fungiifl possessing characteristics common to Rhisoctonia was ob- 
8er\T(l to occiir in the years 1915 and 1916 on leaves, twigs and fruit of 
the fig, Ficus carica, at Gainesville, Florida. Superficial, silvery to yd* 
lowish white, thin mycelial strands of this fungus can be seen to radiate 
loosely from yellow to dirty brown infection centers in the fig leavea and 
spread over the surrounding green tissue. Later as more of the 
tissue becomes discolored by the invading mycelium, the upper suifi 
of these enlarged brownish areas become silvery white and dry, themyogj 
ial strands become less, if at all visible, while the imder surfaoes at tlie 
corresponding points remain light brown to brown and are uAially eov^ 
ere<t with a visible web of myceliimi (fig. 1). Small, immature wbhe, 
as v»r\\ as mature bro^Ti to dark brown sclerotia attached to mycelial 
threads are often foimd on the petioles and midribs of infected leaves, 
but seldom are sclerotia foimd on the blades of such leaves. Loosely 
woven, silky strands of the myceliimi of this fungus may be traced to 
some distance on the twigs. More or less dense accumulations of sclerotia 
are usually grouped on one side of the twig (plate II, fig. 2). No direct 
injurious effect was observed to have been caused to the twigs by the 
fimgus. The fruit of the fig may become more or less covered by the 
spreading mycelium. Numerous sclerotia are then produced which 
cling by mean^ of mycelial threads to the fruit and its stalk (plate II, 

fig. 1)!* 

Portions of diseased fig leaves, and parts of t^igs upon which mycelium 
and sclen)tia were plainly visible, were killed and fixed in Camoy's fluid 
and enilxHlded in paraflin. Cross-sections of the leaf tissue reveal hyphae 
)H*netrating through the ^tomata into the parench>'ma (plate II, fig. 4), 
while (*ross and longitudinal sections of the twig tissues do not show the 
prrM'iice of a |)<.*net rating mycelium. 

This fungiLH was isolated from the diseased tissues of fig leaves, where 
mycelium but no sclen)tia ^i-ere present; and fnmi single sclerotia taken 
from twigs. The pure <'ultures from lH)th sources were aUke in cvcr>' 
n*>|MTt. I^U"e cultures of this fungus wtTt* grown easily for over eighteen 
montlis on standard nutrient agar, (*orn nu^al agar, and sterilised green 



1917] Matz: Rhizoctonia of Fiq 113 

Of the previously described specieB of BMzootoiiia the follcwing should 
be considered here: 

Dr. Peltier* in a recent publication on parasitic Rhizoctonias in Amer- 
ica summarizes as follows: "At the present time there are recognized in 
America two species of truly parasitic Rhizoctonias; the common form 
RhieocUmia Solani Kilhn {Corticum vagum B.& C.) , widely distributed and 
occurring on a great number of hosts; and R. crocorum (Pers.) DC, 
with a limited distribution on alfalfa and potato tubers. A third Rhizoc- 
tonia, Corticum ockralettcum (Noack) Burt, is found on the leaves of 
pomaceous fruit trees, while a fourth species isolated from damped-off 



^ 



Fia. 3. Myceuuu of Rhieoctonia HiCBOBCLEaOTiA 
A, Short chains and a group of short cells from the margin of young sclerotia. 
X 333.3. B, Vegetative mycelium from a young agar culture on the left, and from 
ma old culture on the right. X 333.3. 

onion seedlings is of questionable parasitism." In discuseing the growth 
characters of a number of strains of Rhizoctonia, Peltier* makes the fol- 
lowing statement (p. 370) regarding the species isolated from damped-off 
onion seedlings: "The strain from onion produced sclerotia which were 
entirely different from those of other strains in that they were small 
(0.5 to 1 millimeter in diameter), perfectly round, bright colored, and 
developed submerged in the medium." None of these latter characters 
have been observed in the Rhizoctonia from the fig. The sclerotia of 

D America. Illinois Agr, Exp. Sta. 



114 Phytopathology (Vol. 7 

this fim|i^«< are roundish or oblong, from 0.2 to 0.5 millimeters in diameter, 
an» not bright colored and arc produced freely on the surface of but not 
in the medium in culture. 

The effects and manner of attack of Corticium ochraleucum (Noack) 
Burt on pomaceous fruit«, as described by Stevens and Hall,^ are similar 
to those of the fig Rhizoctonia on its host. However, the sclerotia of the 
two fungi are entirely different and the |)erfect stage of the former has 
not so far been found in connection with the fig Rhizoctonia on fig trees. 

I>uggar* in his recent paper gives sufficient evidence that the conmion 
Rhizoctonia in America is Rhizoctonia Solani Kiihn. This Rhizoctonia 
has Cftrticum vagum B. & C. as its perfect stage. In comparing the 
Rhizoctonia of the fig with the Rhizoctonia Solani Kiihn, obtained fmni 
l)ean .s<»edlings here, the two show pronounced differences on storiliied 
l)ean plug and agar slant cultures. On each medium the sclerotia of the 
first are white at first, turning dark brown with age, and remain small 
and more or less glolK)se; the sclerotia of the second are white at first, 
turning light brown to brown or dark brown and are ver>' irregular in 
size and fonn (plate II, fig. 6). Mycelium and sclerotia from pure 
niltunw of the fig Rhizoctonia and from R. Solani Kiihn were plac*od on 
moist and growing fig leaves and twigs. Both fimgi killetl areas in the 
leaf tissue but R. Solani did not produce any scleortia on the infected 
parts. Two separate flats of cowpea seedlings w<»n» inoculated with the 
two fungi. R. Solani killed 90 per cent of the scredlings, while the fig 
fungiL'^ did not produce any injur>' to the young plants. 

Shaw* in his account of a Rhizoctonia which he found on jute, nml- 
lK»rry, cotton, and cow])ea, and which he apparently misnames Rhitoc* 
tenia Solani Kiihn, illu.strates a fungiLs which is similar to the Rhizoc- 
tonia of the fig in sevenil res|x»cts, i.e., the nonnal occurn»nce of itji 
niuiiennis, com|>!iratively small, rounded wlerotia on the tips and stems of 
it*< n»s|KH'tive host plants. However, the diameter of the sclerotia of 
ShawV Rhizoctonia is alnmt half of that of the fig Rhizoctonia; the 
color <»f the .*(<!l(Totia of the former is black, while that of the latter is 
bn»wn to dark bn>wn. Shaw's illustrations (plat(» IX) indicate a distinct 
I'ort^^x in tin* srlcrotia of his Rhiz^x'tonia. which fonnation is al>sent in 

* St«'vrnJ«. F. L. ami II all. .1. (I. HypocnoM* (if poinarcHMiK fniit, North Caroltna 
Agr. Kxp .^tft. Hi-p 190e<»:.T.>. Tft Ki. fig?* II IV VMl. 

* DuKKar. H. M. Uliizoctonia rroroniiii (|Vr*4.i I). (\ and It. Holaai Kuha 
iCortiriiiiii vaKurn H. tV (' < uith iiotrM on othor mimm-Icm. Ann. MisHouri Hot. (lani. 

3: 4o:i-4,> vm:» 

•.*<haw. K. .1 K MMq»hMloKy an«i para«»iti**in of Uliizoctonia. Mc»m. Dt'pt. Afpr. 
Iniiia 4: Ml. I'.MJ. 

The (mmiii" Uhizortonia in lii«li:i Mi*in. I)i>pt.. Akt.. Iiulia.7: no. 4. I9IS. 



1917] Matz: Rhizoctonia op Fig 115 

those of the fig. The mode of origin, as described by Shaw, of the sclero- 
tia of the first, has not been observed in the fig fungus. 

In culture the sclerotia of the fig fungus develop from dense masses of 
short hyphae and thefe the young sclerotia are usually s\u*rounded by 
short chains and groups of ovoid, short, sometimes elbowed cells. 

Zimmerman^ in describing Corticum javanicum on Coffea arabica, 
Coffea liberica and several other plants, mentions the occurrence of a 
sterile mycelium and small (0.15 to 0.3 millimeter in diameter) white 
sclerotia-like bodies (weisse Kugelen) in association with this Corticum. 
He states: "dieselben treten sowohl auf der Ober — ^als auf der Unterseite 
der Zweige auf imd sind ausserdem auch namentlich haufig an den Friich- 
ten zu finden;" but no mention is made of its occurrence on leaves. In 
describing the effects of this fungus on the host, Zimmerman says, *'Die 
unter den Kugelen gelegenen Pflanzenteile sterben — zmn mindsten in den 
nahe der oberflache gelegenen schichten — ^ab und erhalten eine dimkel- 
braune bis schwarze Farbung;" but no direct injiu*ious effect from the 
sclemtia of the fig fungus was observed on the branches of its host. Re- 
garding the "Kugelen" of Zimmerman's fungus he states: "vertrocknen 
sie einfach an den zweigen, auf denen sie sitzen." No mention is made 
here of the change in color which is a dark brown in the sclerotia of the 
fig fungus at maturity. 

Edgerton* described a limb blight of the fig, due to Corticum Icetum 
Kars. This disease is characterized according to Edgerton's illustrations 
nnd descriptions, mainly by the conspicuous fruiting layer of the fungus 
associated with the diseased parts of the host, but no mention is made of 
any Rhizoctonia occiu-ring on fig trees afflicted with limb blight. 

Kuijper® describes a leaf disease of Coffea arabica and Coffea liberica 
under the name of **Zilverdraadziekte der Koffie," in Surinam. There 
is a striking similarity in the character, the manner of attack, and effects 
of the sterile fungus which causes the Silverdraad disease on Coffea, to 
the Rhizoctonia of leaf blight of the fig. In describing the Coffea fungus, 
Kuijper does not mention nor illustrate anything which approaches a 
semblance of the dark brown sclerotia which are commonly foimd in 
connection with the fig fungus on its host and in pure culture. The 
sclerotia of the latter are not identical with Kuijper's "hyphenkluwens." 
These forms occiu* also in his cultures. He states: '*0p plaatsen, waar 
veel, zijtakken ontstaan strengelen deze zich door elkaar, zoodat op de 

^ Zimmerman, A. Ueber einige an Tropischen Kulturpfianzen beobachtete 
Pilze I. Centbl. Bact. Abt. II, 7: 102. 1901. 

•Edgerton, C. W. Louisiana Agr. Exp. Sta. Bui. 126: 13, pi. VII, fig. 1. 1911. 

• Kuijper, J. De Zilverdraad-ziekte der Koffie in Suriname. Dpt. van den 
Landbouw, Suriname. Bui. 28: — 1912. 



116 Phytopathology (Vol. 7 

Waderen l)e8rhrevon khiwens ontstaan." In sonic of his cnlturos Kuijprr 
obtained **h>'phon-opconhoopinf2:en zoo st<»rk, dat bijna lH)lfomiigi' 
lichaampjos van 14 2 ni.m. doorsnedo ontstaan, die l)est{ianuit oon l>otrpk- 
kclijk los lu^phenvlechtwcrk.'* Apparently these Imdies never Uvonie 
in Knijper's cultures a.s compact and colored as do the sclen)tia of the fig 
fimicus on various media and on the host. 

Brooks and Sharpies'' in their work with Corticmm salmonicolor B. & 
Br. (C jafanicum Zini) descrilx* four forms in which the fim^^s appt^ars 
on ruhl)er trees as follows: **a pink incrustation on the branches or main 
stem; .... white or pale pink ])ustules arranged more or l<»ss in 
lines parallel with the branches; .... part of the* fim^s on the 
exterior consists of white or pale pink stnmds of a cobwel)-like texture, 
which run irrei^ilarly downwards over the surface, the strands l)einK 
.»H)metimes .<o <lelicate as to be overlooked: .... finallv th«»re is 

the Necator stag(* consists of oninf?e-n*d (not pink) pu.*^- 

tules alK)Ut «)ne-(»ij?hth inch in diameter.'* In their pure cultures of (\ 
salmonicolur, the alM)ve authors observed clamp coimections in old a> 
well as young cultmes, a pink to a bright ros(» coloration and, **aggn'ga- 
tions of hy])hae .... n^st^nbU'd a numlH»r of clos<»ly attached 
Necator ])ustul<»s." Practi<*ally iiorn* of thes<' characters were ol>served 
in the fig fungus. 

From the precciling di.*<cu.'<sion it follows then that the Khizoct(»nia 
of th(j fig leaf blight is different fnnn all the true s]H»cies of Hhizo<*toni.*t 
previously descrilxMl and thus it should Ih» considcnMl as a new organism 
which can briefly Ik» descrilHMl as follows: 

Rhizoctonia microsclerotia n. sp. 

Srh-rotia su]MTlicial. small 0.2 to 0..') millimeters in diameter, white 
when yoimg. brown to dark brown at maturity, nearly homogenous in 
sinK'lure an<l color, sub-glolM>s<', free from t\ift4'd myi*elium, not ."^nHMith 
UMmlly single, sometimes conglomerated. 

Vegetative hy])hae to H^i wide, first hyaline and granular, bniwn an«i 
more f»r le**-* empty with m.aturity, septate. 

Ilab. On living leaves, branches antl fruit of tin* cultivated fig, Ficus 
cnrioi, ( lainesvilk*, Florida, V. S. .\. 

»• Hrookii, F. r. an«l Shan)!**". A. Pink •liHoa.-MV Dopt. of .\Kri. FcvleratM 
Malav St!it«'H Hul -M : 1 -27. fig 1*». 101 1. 



1917] Matz: Rhizoctonia op Fig 117 

Rhizoctoii^ia microsclerotia Sp. Nov. 

Tuberculis super ficialibuSy minusculiSf 0,2 to 0.5 millimeters in diameter, 
primum aUns deinde fusco-bruneis (intus idem quod extus), similibus 
fere forma et colore intus ac extuSj sub^lohosis, floods myceliaribus defidenti- 
bus, non gUxbris, saepius singulatis, non-nunquam conglomeratia. 

Hyphis 6-8 li, latis, primum hyalinis granulosis deinde bruneosis, 
septatis. 

Hob. in foliis, ramis ac fructibus vivis Fid caricae cuUae, Gainesville, 
Florida, Am, Bar, 

University of Florida Experiment Station 
Gainesville, Florida 



Pl.ATK II. KlIlZtM'TONIA MirKOHC'LKROTiA ON FlO 

Vui. 1. H. iiiitTusrhTotiii rovcrinK ii tuiic ami fruit of the fif(. X 1.5. 

FiK- •• FifC twiK defoliHt(*<i l>y the fuiiKUM. XumorouN M*lerotia are arcumii- 
\iitvi\ on ono Hide of the twif^. X !..'>. « 

Ki<i. 3. Tlir(M'-wiM'kHH>l(l rultun*^ on Mtrrilizetl hotui {mmIm. U. mirrosclerotia od 
left. H. H^ilani Kiihn on right. 

Fi(i. 4. CroH.H MOf'tion of (liHo;i.'4o<l fifc hMif showinx prnotration of myootium throuich 
Htomata at a and h. 

h'ui. 5. Sf»rtion throuich a Arlcrotiuni of K. mirrosolorotia. 

Via. Ti. Srl«*rotia from a Hk hranrh. X 2r>. 



11*^ 



1917] Sherbakoff: Buckeye Rot of Tomato 121 

any fungal growth. When the affected fruit is kept in an enclosure with 
high -humidity, especially when the fruit approaches maturity, the fungus 
which causes the rot may be observed commonly on its surface (fig. 2A). 
The rot occurs on the fruit in all stages of its development, beginning 
almost invariably at the point where the fruit touches the ground. Nat- 
urally, the fruit touches the ground most commonly with the blossom-end, 
on which account this rot often appears as a peculiar form of blossom-end 
rot and for which it sometimes has been mistaken. 

NAME 

The disease is known among some of the growers on the East Coast as 
water logged fruit. This name cannot be adopted for the rot because it 
is misleading and because it has no other advantage in its use. The name 
brown rot though it would often describe the disease, ought not be used in 
reference to the disease, first, because there are even more frequent cases 
when the color of the rot is not distinctly brown, and second, because the 
name- has been applied already by Bancroft to an apparently different 
rot of tomato fruit. 

Some of the tomato buyers use the name buckeye, in reference to a rot 
of tomato fruit. The writer was unsuccessful in finding with certainty 
what particular rot is called by that name, but his indirect information 
and observations indicate that the name refers to the rot under consider- 
ation. This name describes very well the most striking feature of the 
lecaon on fruit affected with the disease, namely, its broad zonation, in which 
case the lesion indeed much suggests the eye of a large animal. The name 
also has not been used in literature before in reference to any disease of 
a similar natm-e. Therefore, it is suggested that the common name, buck- 
eye, should be used in reference to the tomato fruit rot described here. 

OCCURRENCE 

The rot was foxmd by the writer for the first time in January, 1915, at 
Goulds, Florida. Soon after the first observation and during the following 
three months it was found in every tomato field of that locality on the 
prairies — ^low marl lands usually under water during rainy summer months. 
The whole district is known as Redlands and lies at the extreme south 
end of the Florida East Coast, namely, south of Miami. 

The same rot was observed by the writer in 1916 on the West Coast 
also. In April of that year it was found in a field near Bradentown, and 
in May in a shipment of tomato fruit received by the writer from a field 
near Palmetto. In both instances the tomatoes were grown on the com- 
mon low hammock land of that vicinity. 



122 Phytopathology (Vol. 7 

The writer also found amon^ some old specimens of tomato fruit pre- 
><erved in fonnaliii and kept in the laborator>' at Gainesville, two ^fieci- 
niens which by external symptoms and microscopic examination pnived 
to Im^ affected with this same rot. One of the specimens had a lal)el indi- 
cating that it came from Little River, near Miami, in 1911. The other 
8|)ecimen l)ore no label. 

All these observations show that the rot occurs in South Florida on 
both coasts where it is common in low fields even during a comparatively 
dr>' season, such as that of 1916. No actiail observations were made of 
its occurrence in other parts of the state, but judging from its common 
presence in so widely separated parts as the east and west coasts and on 
soils s<j different in character, one might safely assume that it is much more 
generally distributcnl than observations indicate. 

HISTORY 

The ])rescTvr(i s|>(»ciin<»n of the rot found in the lal)orator>' and previ- 
<)iL*<ly mentioned, shows that the (lis<*as(» was pres<Mit in the state at least a^ 
early as 1911. An incpiiry among tomato growers of the East Coast aL«o 
indicates that it hjis existed ther(^ a long time. 

Pathological literature, with one excerption, contains no reference to any 
dis<»as(» of tomato fniit similar to the rot \mder consideration here. The 
organism which caus<»s this rot is clos(»ly related to I^hytophthora infe^ftarut 
but the latter fung\is is not the same as the one which causes the rot herein 
de.**crilxjd and the disease* prochiced by I\ infcstans is also dilTf»rent lie- 
cause it affects all aerial parts of th(^ plant and the fungus always pnNlu(^*> 
abuiulant conidia on the surface of the afT(Tted parts of the fruit. 

The previously mentioned exception is a short note by Bancroft* on llio 
Brown Rot of the Tomato, in which is descrilKMl briefly the s>'mptoms. 
orcurreiice, economic im|N)rtance, and the method of transmission of the 
dis<»a.*«4*. No illustrations of any kin<l at'company the article to assist in 
identifi<*ation of X\\v dis4*a.*<<» and in general it is t<K) brief to judge with 
rerlainty whether tlu* tomato fruit rot n'|H)rted from Knglan<l is the same 
as. or difTen*nt from the rot found in Florida. It apjX'ars tlmt the rot of 
tomato fniit re]>orted by Banrroft has thc»s4' two ft^itures similar to the 
burkeye rot : « 1 ) The dis<»as<* occurs «)nly on the fruit ; (2) the fungus asscK 
ciateil with tin* rot in Kngl.ind is closiHy related io the fimgus which 
cttUS4»s the r«»t in Florida.- 

* Hanrrnft, C. K. The Immn nit ni toninto. Jour. M. .\in'. (London) 1$: 1012. 
1910 

» Whether It i* ri'.illy thr simw fiiiiKU«t or ii«»t it is* iiiipoMiMc to determine, be- 
rnuM* ulioitt III** fuiiKa?^. Daiicroft iiicrrly nay^ "the tiHMiieit of the endosperm and 
emhryo" nf thr afTrrte*! need "contain fungal hyphae, which from their cbarmclert 



1917] Sherbakoff: Buckeye Rot of Tomato 123 

The points in which the two rots appear to differ are as follows: (1) In 
describing the rot in England, Bancroft says: "A fruit which is infected 
first shows discolored patches on its surface; these usually run together, 
so that the whole or almost the whole surface of the fruit becomes discol- 
ored." The rot observed in Florida as a rule appears in form of one, 
rarely more, gradually spreading, often distinctly zonate spot, usually at the 
blossom end of the fruit; (2) Bancroft from all his observations on the rot 
says this in regard to the way in which the disease affects the fruit: "This 
infected seed .... is known among the growers to be capable of 
germinating and is reported to produce plants which always bear infected 
fruits. These facts, coupled with the results of microscopic examination 
of the seed, suggest that the hyphae may be capable of existing in the seed 
in a resting condition, becoming active when the seed germinates, and keep- 
ing pace with the growth of the plant until the fruit is formed." That 
is, Bancroft evidently records no other method of infection of the fruit 
than the one suggested in the above citation, while it is evident that in 
the case of the rot in Florida the infection starts from outside the fruit. 
From the above citation it is also evident that the rot reported by Ban- 
croft is associated rather with the use of infected seed (the plants from in- 
fected seed "always bear infected fruits") while in our case it evidently 
is associated with the infested soil, and only the fruits which touch or 
nearly touch the ground are affected with the rot. 

On the whole, it seems that the disease described by Bancroft is differ- 
ent from the rot of tomato fruit found in Florida, and the latter should 
therefore be considered as a new one to the literature. 

ECONOMIC IMPORTANCE 

The data at hand will not justify any precise statement concerning the 
extent of damage caused by the rot. But considwing that the tomato 
crop is the most important of all vegetable crops in Florida, and consider- 
ing also, that the rot was actually observed to affect up to fifteen per cent 
of the fruit in the field and up to ten per cent of the fruit in-transit, it is 
evident that the disease is important. 

CAUSE 

Repeated isolations from the tissues of tomato fruit affected with the rot 
invariably yielded one and the same fungus, usually in pure cultures di- 

appear to be hyphae of Phytophihora omnivora.^* Hyphae of a number of fungi 
belonging to the same family do appear under similar conditions alike, the fungus 
causing the rot in Florida included; and yet they are quite different, but to differ- 
entiate them much more than appearance of the hyphae is needed. 



124 Phytopathology [Vol. 7 

rectly fn«n plantings. The firbt isolations were made from the material 
collectoil on the Kast Coast, in Janiiar>% 1915; the last in May, 1916, from 
material obtained fnnn the West Coast. 

The isolations wvre made hy planting small bits of the affe<*ted tissin*:* 
(from under the epidennis and after the fruit was disinferted in menMirir 
ehloride sohition, 1 : KNM), for aUnit fifteen minutes) into either {X'tri 
dishes with a suitable mediinn (<*orn-nieal and oat agars wen* most com- 
numly used for this pur]K»se) or into test-tulH»s with sterilized lioan |>o<l< 
or oat agar. Dilutions of swarm-si>ores wen' <Mnploved to make certain 
that the cultures were pure. This was an «»asy proci»dure l)ecauw the fun- 
gus readily s]><»rulat(»s and the swarin-s|>ores an* produced from mature 
conidia ^swannsporangia) in a very short time and practically under all 
conditions of th<* lalNuatory (under favorable <u)nditions s^'ann^pores 
were (>roduced in some instances eight minutes after the culture was plaoed 
in frrsh water). \ very successful proc(Mhire here is t<» place a ffood- 
sized pitM'c of )M'an-|)o<l (*ulture (two or nion* weeks ol<|) of the fuilglM 
into a sterilize* I watch-glass, with a frw <'ubic rciitimet«Ts <if Hterilind 
water in it. for al>out fortVH'ight hours; then, after the culture in thtt 
watrh-glass is washed a few timrs in fresh striilizrd wat<T, it is left in the 
watrh-glas?* with a frw cubir crntinu'trrs of wat«T for half an hour. In 
the first two days the lM*aii-p<»d cultun* usually produces a great masB of 
ronidia; in half an hour or an hour after it is rinsed, these im'annspcrBngMl 
will liU*rati' int(» tht> water a ronsidcpablr number of swarm-spores; this 
water with numerou'^ >warni-**|)ores in it '\< to be us«m| then for poured* 
]>late dilutions made in the ordinary way. ( *orn-meal agar was com- 
monlv :ind >uiTes««ful!v umm| I»v the writer for these dilutions. 

• • • 

Inortilution** of tomato fruit. detarh<>d from the f)laiit, and not detached, 
anil of all •'tani's from very yoinm to n'd.i'i(M' with ])ure cultures of the 
fungu**. inv.'triably n*>ulted in re])rodurtion of the rot (fig. 2). The inocu* 
lalion-i wen* made by plaeing sm.all bit< of the culture and water Hiu^pen- 
^•ion*' of *warm-^pores upnn wounded and un wounded "Surfaces of the fruit. 
In the (';i*«e of '*w:inii-^]MiM- iiiiH u]:ii ii»ii a pjerr of th«' fungus culture wa.s 
dri»]»[H-d intii a l.iii:«' j.ii nearly full nf -lerilizid w.ati-r and then the fruit 
wa*i pla<-<'d mtii thr watii. Deiarlu'd liiMiato fruit-* float in water and un- 
iletaj'heij fruit ran Im- eniiVi-nii'iil Iv ]jla«-ed in '•ueh :i way that only a part 
of It vill bi- in till- water. 

huM'ulatinns iiitii wmmdeij funr ne.trly :ih\;iy- -liowed the rot in tWt»nty- 
four hour-. Iiiorulatmn- iiiti» unwounrjrd fiuif. wliethiT myrclimn or 
-Warm— |H>rf- wiir rni]»l«»\i li. •^nmrinnr*. ohn\M-d the rot in lwi»nty-four 
hour- .ifier thr iri«»iu!:iMf»fi \\a- maiji". but oftrn the inferiion c<»uld not 
III- ijfTi itril until thn-r t»i •vi-n four ♦lay- later. \\ ]»ii*s**nt no explana- 
tii»n 1- f»lT'ri'.| for t*'is variatM»n mi the ineubalion |M'riod. 



126 Phytopathology (Vol. 7 

Th<» fungiis has Ikvii j^rown and studiiMl on various niotlia parallel with 
other organisms related to it, sueh as Pythium debaryanum He««*., Py- 
thiacystis ciirophihcrn Sin. &, Sm., and s<»veral s|)eoies of Phytophthora, 
P. cnctorum (I>»lKTt & Cohn) Sehr. and P, er y throne ptica Pethybr. in- 
rhided. Tliis eoniparative study shows plainly that the fungus causing 
till* huekeye rot of tomato fruit is different from tlM» others. Its peculiar 
tufte<l gn»wth on the corn-meal agai*^ in plates, is one* of the differentiating 
characters, <»s|KM*ially valuable* for an easy s<»paration of this fungus fnmi 
the others (fig. 3). 

Kxamination of the literature also indicates that this fungus luis no 
U»en ])reviously di'scrilMMJ. However, evidently th<' same organism wa 
isolated iH'fore. though from another host; but it has Ikvii considere<i to 
Im^ the siune as the fungus of the lemon brown rot, namely, Pythiacysth 
nirnphthorn Sm. A: Sm. The ref<»renee hen* is made to the organism iso- 
lated by II. S. Kawcett^ an<l by 11. K. St< vens from the bark of citnis 
ln»es in Flori<la affected with the foot rot. 

The writer's C4)mparativ<» study of the fungus of the buckeye n»t of 
tomato, of the fungus of the lemon brown rot. P. citrophihoro,iind o{ the 
fungus from \\\v citrous f(M>t rot in Florida shows that the tomato n>t 
organism ami the one of the citrous foot rot are morphologically aiul cultur- 
ally identical and that it is <listinctly different f nun the true /^ ri7ro/>/i//ifwci. 

.V fungus was recently isolatcvl by the writer from a lupine stem n>t 
which IS evidently the sam<' as the one of the buckeye rot of tomato fniit. 

liHM'ulations of tomato, sw<H't |M'p|M'r. watermelon fruit, of lemons and 
of iuIhts of Irish |>otat<H's with pure cultures of the s<'veral s|K»cies of 
Phvtophthora, ])reviou>lv mentioned, of the Pvthium, IMhiacvsti** and 
thn*^' strains of the fungus of the buck(\ve rot, inclu<ling one strain isolated 
by H. K. Stevens from <lis<»as4M| bark of a citrus tre<' in Florida affected 
with the f(H)t rot, sh<»w that certain organisms distinctly diffen»nt in their 
mor()hology may affect the same host and pnxluce more or lc*ss similar 
effects. The fungus of the Inickeyt* rot prcMhu'cd a rot of all the parts of 
the plants hen* n'ftTnMl to. 

These inoculations thus indicate that the organisms which do attack the 
Sjiiiie plant or ]>lants cannot on this basis alone )><* considen*d identical 
with each <»ther. 

• Thi* t<»rri-fiH*al »ic»r i?* inudr l>y hratiii)! .'lO teraiiiM of r<>rii-int>nl in inOU rr. of Ui*- 
ttllfil wnt4'r at fio ('. for an hour, then filtrriiiK tli«' li(|ui(l through i\ filter paper, 
adWiiiK to It \'» itrninn of agar and the rfciuiml amount of <iiHtill(Hl wat(*r to KrinK 
vohinu' of thr h<|tii<l to KWM) rr.. ('(Hiking the Muh?«t:uire in a doiihlr lK>ilcr until ml! 
agar in (li!*S4»lv('4l. ((Mihng <ioun to .V) i\. .vhhng the white of an egg. nutoelaviii|t 
at l.'* |KMin(l» of preHxure for alnMit fifteen iiiinute»<, filtering through a filter pa|M*r. 
tiihing and auto* laving a* Ix^fore 

• Fa^eetl. II. S. Tho known (lixtriluition of I*vthiae\>ti?« citniphthora an«l it» 
pfohahlc relati(»n to mal di goninia of rit^l^. IMiytopath. 6: tWK 07. 1915. 



1917] Shebbakoff: Buckeye Rot op Tomato 127 

On the basis of the data obtained in the course of the writer's compara- 
tive study of the fungus of the rot of tomato fruit and of the other fimgi 
related to it, it is considered an undescribed species which may be briefly 
characterized as follows: 

Phytophthora terrestria n. sp. 

Myceliiun at first continuous then septate; conidia usually terminal, 
sometimes intercalary, mostly oval, papillate at apex but variable, 42.5 
X 30.5 (36-46 X 24-35)|i| germinating mostly by swarm-spores; swarm- 
spores asymmetric, with two cilia on one side, 9.5 (&-ll)|i, when in resting, 
globoid stage; chlamydospores common, mostly globose, 34 (SO-40) /jl; oogo- 
nia common in old cultures on steamed bean pods, globose, 22 (19-24)|i 
with the stalk evidently penetrating through large, nearly globose antheri- 
dium (fig. 4); oospores globose, 20 (18-21)^; colonies on corn-meal agar, in 
petri dish, peculiarly tufted. 

Hab. Parasitic in tomato fruit causing buckeye rot, in bark of trunks 
of citrus trees causing foot rot, in stems of a Lupine causing stem rot, and 
apparently in low soils; in Florida. 

Phytophthora terrestria sp. nov. 

Mycelio priuo continuo deinde septato; conidiis fere terminaltbus aliquando 
ifUercalaribiia, pterumque ovoideis apice papiUatis sed vcUde variabUibua, 
4£'5 X S0.5 {36-46 X 24-35)yL, per zoosporos fere germinatis; zooaporis 
aeymmetris, laieraliter S-ciliatis, 9.6 {9-ll)yL diam. quum quieti, globosi statu; 
chlamydosporia vtUgarilms, plerumque gkbostbtAa, 34 (30-40) fi diam.; ooganiis 
globosis, 22 {19-24) ii diam., radicibua per amplum sub-globosum antheridium 
aperte penetrantibus; aosporis globosibus 20 {18-21)ii diam.; cohmiis in agaro 
Zeae Maydis farina, in petri patera, euo genere criakUi. 

Hab. paraaitice in frudibue Lycopercici esculenti efficiens "bitckeye rot,** 
in tmcis Citri efficiens ''foot rot," in caulibiLS Lupini sp. efficiens **stem rot," 
et aperte in humiUbus solis, Floridensibus, Am. bar. 

CONTROL 

No direct control experiments with the buckeye rot have been con- 
ducted, but the fact that the rot occiu's almost invariably only when the 
fruit touches the ground, or is very close to it, naturally suggests staking 
the tomato plants to prevent it. The staking would hold the fruit high 
enough above the ground to keep it from attack by the fimgus. 

The fact that the fungus attacks the fruit from the groimd, coupled 
with the fact that the rot, once it starts, progresses under normal condi- 
tions fairly rapidly (often nearly the entire fruit may become affected in 



Phytopathologt {Vol. 7 



1917] Sherbakopf: Buckeye Rot op Tomato 129 

three days after inoculation, the rate depending evidently on the tempera- 
ture, moisture content, and maturity of the fruit), also suggests a method 
of control of the rot while in transit. Here it probably would be very ad- 
vantageous to keep the fruit for a few days after it is picked before pack- 
ing it for shipment. All fruits that were infected in the field would de- 
velop the rot sufficiently to be detected by the packers and thus be thrown 
out without contaminating the rest of the fruit, which then could be 
safely packed and shipped. But the practicability of these methods has 
not been tested. 

SUMMARY 

1. The buckeye rot of. tomato fruit is common in certain places on the 
low lands of the east and west coasts of Florida. 

2. It occurs only on the fruit that touches or nearly touches the groimd. 

3. It is caused by the fungus Phytophthora terrestria n. sp., which is also 
found on other hosts. 

4 It causes considerable injury to the fruit in the field and in transit. 

5. Staking of the plants in the field and keeping over the picked fruit 

a few days before it is packed seem to be practical methods of its control. 

UNrvERsiTY OP FLORroA Agricultural Experiment Station 
Gainesville, Florka 



Explanation op Fig. 5 

Af conidiophores from culture on hard, oat agar, eight days old. X 100. B, 
conidiophores and C, intercalary conidia; from the same medium and of the same age 
as A, D, conidiophores from the fimgous growth on an artificially inoculated (up- 
per) and on naturally (lower) affected and nearly mature tomato fruit. Ej oospores 
within the oogonia with the basal antheridia evidently penetrated by oogonial 
stalk. Ff germinated chlamydospores. G, t3rpical and H, various abnormal forms 
of conidia, produced on surface of a mature tomato fruit affected with the buckeye 
rot. I, resting and germinating swarm-spores. Ky motile swarm-spores (fixed in 
Flemming's fluid and stained with eosin). L, conidium germinating by a single 
germ tube. M, two conidia germinating by many germ tubes (evidently each 
swarm -spore which did not escape gives its own germ tube). B-L X 500. 



NOTEWORTHY PORTO RICAN PLANT DISEASES 

F. L . Stevens 

The following diseases are of interest to pathologists of the United 
States, either because they are new, or because they are little known 
diseases of important crops belonging within the territory of the United 
States or are caused by fimgi of special interest for one reason or another. 

CoFFEB. Pellicvlaria koleroga. This fungus occurs in great abun- 
dance, especially in the lower altitudes in Porto Rico. In destructiveness 
and general appearance it gives an impression somewhat like that of pear 
blight with many branches killed and the dead leaves matted and hang- 
ing by their fungous attachments. The fungus forms thin skin-like 
membranes over the lower leaf surfaces and has thread-like growths 
leading down the petiole and adjacent branches. In habit it strongly 
resembles Hypochnua ochrohucua Noack as it occiu*s on apples in the 
Carolina mountains, and the writer long has had the suspicion that the 
two fungi are related. 

Hemileia vdstatrix. This destructive fungus, though not seen in Porto 
Rico, is worthy of mention on that account. There is a report that it 
was imported into the island, almost immediately recognized, and due 
to the vigilance of th^ experiment station officials was so thoroughly 
eradicated that not a specimen has since been collected. The following 
quotation from a letter from Mr. May, in charge of the Porto Rican 
Experiment Station, is worthy of record. 

"When the station was first established in Porto Rico we were carry- 
ing on some experiments in the Carmelita cofifee plantation, five hours by 
horseback above Ponce, imder charge of J. W. Van LeenhoiBF. In 19(^ 
or 1903, I do not remember which, it was before I came to the station, 
Van Leenhoff got some little coffee trees from a Dutch warship that 
brought them from Java. After he planted them out he noticed that 
they had what appeared to be Hemileia vcistatrix. Mr. Van Leenhoff 
had been a coffee planter in Java and was pretty sure of the fungus from 
such investigation as he could make. The matter was commimicated to 
Washington and L. A. Clinton, of Connecticut, was sent down to inves- 
tigate the trouble. In the meantime Van Leenhoff took every precau- 
tion, destro3dng all the plants and all material that might have in any 
way been connected with them. Clinton spent some weeks at the Car- 



1917J STBVBNS: PORTO RICAN PLANT DISEASES 131 

melita but oould find no traces of the fungus and as none has appeared 
since, Van Leenho£f doubtless made a 'dean up.' Since that time great 
care has been exercised with all coffees brought from foreign ooimtries." 

StUbeUa flavida. The characteristic circular leaf spot caused by this 
fungus is common in the higher altitudes, but is never fo\md in low re- 
gions. The fungus is of imusual scientific interest on account of its 
problematic relationships. It is by no means limited to coffee but is 
found on numerous hosts. 

Sugar Cane. Lepiosphceria Sacchari, This fimgus is quite commonly 
present as a destructive leaf spot. 

Palm. Graphida Phoenicis. This fimgus, which is of uncertain re- 
lationship and is common as a minor pest in northern greenhouses, is 
found in the open on several species of palms in Porto Rico. It has been 
noted particularly upon the date palm and the hat palm. The hat pahn 
is a very profitable plant, a single leaf being worth about ten cents. Fre- 
quently trees arc seen with all the leaves closely covered with Graphiola 
and lines of diseased tissue reaching long distances through the petioles. 
The financial damage is done to the young, as yet imfolded leaves, the 
fungus penetrating them and rendering them worthless. 

Melicia furcaia. This is present sometimes to such extent as to largely 
cover the leaves with its black coating. It has not been observed on cul- 
tivated palms but occurs in great abundance on wild Thrinax ponceana 
on plants of marketable size. As yet, however, there seems to have 
bepji no attempt to make a commercial enterprise of shipping the bcau- 
tifiil young palms which spring up spontaneously in such profusion in 
Porto Rico. 

Auer$waldia palmicola. This was noted only a few times, but in those 
instances affected nearly evcr>' leaf and leaf-segment on the tree. 

Bread Fruit. Oredo Artocarpi, The inmiense leaves of the bread- 
fruit harbor numennis fungi. The crop, if it can l)c called such, is not 
of high value, and this r\tst, though interesting, is not of much economic 
signific4ince. 

Corn. PhyUachora graminis. Mention liaj< Iwen ina<le of this in 
Phytopathology by Miss Nora Dalby. The disease was \%nde-spread in 
Porto Rico and must Irnve l)een to considtTuble exti»nt injurious. 

Bean. I>imerium grammodes. This striking fungus which occupies 
and covers the veins of the affected jmrts of the leaf with i\^ conspicuous 
black perithecia is common on several grnera of h^gtuncs, among them 
cultivate<i beans. 

GuAVA. Meliola Pauiii. The Mark s|>ots of this fungiu< an» almost 
universally pn»sent where\Tr the host is foimtl. Then* is but liitli*. if 
any injiuy. 



132 PHYTOPATHOLOGY [VOL. 7 

Aschersonia, What is taken to be one of this genus sometimes occurs 
profusely on the lower surfaces of guava leaves, giving them a livid scar- 
let color, conspicuous to a considerable distance. The fimgus appears 
to be growing upon a scale insect, probably Alerodes citri. 

Cephaleurus tnrescens. This algal parasite is of special interest. The 
spots show well from both below and above the leaf, the leaf tissue being 
killed. This alga, also widely known as the cause of a serious tea dis- 
ease, is present parasitically on a large numl)er of Porto Rican plants. 

GoNDULE. Uromyces dolicholi. This universally present leguminous 
plant is almost always rusted to a slight degree, sometimes badly rusted. 

Mango. Meliola Mangiferce, Meliola is very common and wide- 
spread but apparently not injurious. Gloeosporium mangiferct is often 
abundant and injurioiu^, especially upon the fruits of the finer varieties 
of the mango. The effect in general is much like that of the bitter rot 
on apple. 

Sweet Potato. Coleosporium Ipomcece, Rust is common on this and 
other Ipomoeas, but iLsually not t^) serious extent. In one field at Pres- 
ton's Ranche near Nagualxi, infection was general and serious. Each 
sorus was also parasitized by a Fusarium-like fimgus, rendering it white. 

Grape. Physopella vitis. This is a rust of cultivated grape. Three 
collections were made in Porto Rico but all from the same vines, namely, 
at Patillo Springs. The rust was pn»,sent in quantity suflScient to make 
it injurious. The writer knows of only a few grape vines in Porto Rico. 
If there were more \'\nv» perhaps there would have been more collec- 
tions of this rust. 

Peantt. Vramyces arachidis. Only one collection of this rust was 
made. Indec^d, the peanut plant is not very common in Porto Rico. 

Canxa. Pxicciniii Canruz. The rust on Canna is common on both 
wide and cultivated Cannas in all parts of Porto Rico; on nearly evcr\' 
one of the host plants. Sometimes the rust is so abundant as to appear 
fairly destructive. 

I. NO A Lai'rina. Microstroma sp. This host, an important leguminous 
coffee shade tn»e, is frec|uently nmrh infej^ted ^^ith an undescribed Micro- 
stroma which ca\L**es large witches br(M>ms. 

Pitiiecolobium Saman. MicroHtrama sp. This le^(uminous tree is 
being intro<hic<Hi into Porto Rico through the (efforts of the experiment 
station, and in the sihmI Ih»(L< and propagating lyoiU it is frequently heavily 
infest4Ml with an ap|wrc»Jitly un<le-»<cril>ed sp<H*ies of Microstroma. 

Pasi»alum. MyriftgctutsfHtra .**]). Th(» Pa.»*pahmis of yard and pa*- 
tUH' <ift4*n lH»ar this vcr>- intc»n»sting fungiu*. Infertion is usually gen- 
eral throughout thr plant, that is, if one part is infected e^ich leaf is likely 
to Ik* invad(*d. 



1917] STEVENS: PORTO RICAN PLANT DISEASES 133 

Melia. Psendoperonospora sp. Two collections were made, in 
widely separated parts of the island, of this fungus. The damage is 
probably slight. The four fungi last mentioned will be described fully 
by Dr. Lamkey. 

Ficus. Kuehneola Fid, This rust was very conspicuous and pres- 
ent on a large number of species of this genus. Certain large trees at 
the proper period of the year were repeatedly covered with the rust and 
often small shoots a foot or so high would have each leaf completely 
rusted. 

Cotton. Kriehneola Gossypii. Very little cotton is raised in Porto 
Rico. This rust was foimd in considerable abundance in one field, though 
probably not doing much damage. 

Manihot. Uromyces Janiphce. Only one collection of this rust was 
made in Porto Rico, though the host is very common there under culti- 
vation, and the rust has been looked for repeatedly. . 

Sooty Molds. The sooty molds familiar to Northern pathologists 
on the orange and CamelUa and to lesser degree on many greenhouse 
plants, aboimd in Porto Rico. There seems to be no speciaUzation to 
hosts and they grow indiscriminately upon all hosts. If it be a large 
plant as a mango tree that is primarily infected, the fungus, spread 
doubtless by rain, is found growing upon every kind of plant beneath 
the tree. Very Uttle evil eflFect is noticeable other than the imsightly 
condition produced. The statement is frequently seen that these sooty 
molds exist upon insects or insect secretions. Such organic matter cer- 
tainly favors them and increases their luxuriance, but the sooty molds 
are not entirely dependent upon insects and insect products and may 
aboimd without them. 

While many of the Porto Rican sooty molds are much like, perhaps 
quite like, the sooty mold of the orange, other sooty molds diverge more 
or less from this in character, yet show similarity enough among them- 
selves to allow them to be classed in the same group. 

The writer has so far refrained from using latin names for these fungi. 
The orange and camellia sooty molds are best known under the generic 
name Meliola, and the generic conception of Meliola was broad enough to 
receive them imtil about 1892. Gaillard's monograph of MeUola then 
showed that these forms clearly differ greatly from the typical Meliolas 
in essential details, and he excluded from Meliola the tropical sooty 
molds. Today any student of Meliola would, I think, agree with him. 
Meliola with its capitate and mucronate hyphopodia, its characteristic 
mjrcelium, perithecia, asci and spores constitutes a well-defined genus 
from which the sooty molds with their bead-like mycelimn, peculiarly 
shaped pycnidia and perithecia diflFer widely. The fact that they should 



134 PHYTOPATHOLOGT [VOL. 7 

be excluded from Meliola is clear. Jiist where they should be placed is, 
however, not so clear. They comprise a rather well-defined group which 
in Porto Rico certainly consists of a large number of species on many 
hosts. This group perhaps coincides in limits with what Sacoardo in his 
earlier volumes calls the sub-family Capnodiese and which he in his 
foxuleenth voltune calls a tribe. This tribe is not recognised by Lindau 
in the Naturlichen Pflanzenfamilien/but is included in the Perisporiacea. 
Clements gives the Capnodiacese family rank. Amaud in 1911 in his 
monograph '^Contribution a Tetude des Fumagines" Ann. Ek^. Nat. 
Agr. Montpellier, places them for convenience in the ''Spheriaoees dic- 
tyosporecs." Many writers today place the better-known of these forms 
of the habit of the old Meliola Citri, Meliola CameUcB, and so forth, 
in the genus Capnodium. Thus we have C. HeUatumf C. Mangtferum, C. 
Coffe<Bf C. brasiliense, C. footie. Others place these forms in the genera 
Pleosphseria, Antcnnaria, Apiosporiimi, and so on. It is not the pres- 
ent purpose of the writer to attempt to determine the generic limits 
here or the status of these species, but rather to call attention to the 
rich mass of material occurring in the tropics, which may well be called 
the Sooty Molds and in the main belong to the Capnodies of Sacoardo. 
Illinois U.niversity 

Urbana, Illinois 



PYCNIAL STAGES OF IMPORTANT FOREST TREE RUSTS 

James R. Weir and Ernest E. Hubert 

With Two Fiqubes in the Text 

The discovery on September 29, 1916, at Darby, and on October 8, 
/916, at Bonner, Montana, of abundant exudations of pycnospores on 
swellings of Pinus panderosa (fig. 1) and Pinus contorta caused by Cronar- 
Hum Comandrce Pk. somewhat alters the impression that the pycnia of the 
caulicolous species of forest tree rusts appear only during the spring or 
early summer months. This \musual appearance of pycnospores seems 
to be of sufficient importance in the life history of this rust to be re- 
ported at this time together with further facts concerning the pycnial 
stages of Cronartium coleosporoides (D. & H.) Arthur,^ Cronartium Comp- 
tonicBy^ Arthur and Cronartium cerebrum (Pk.) H. & L. Spaulding* in his ac- 
coimts of the white pine blister rust {Cronartium ribicola Fisher) states that 
the pycnial stage may be found early in the spring or at almost any season 
in late summer or fall, he having foimd them on the hosts in November 
within a month after placing in the greenhouse. The collections of 
Cronartium Comandroe on Pinus ponderosa and P. contorta bearing the 
pycnial stage were of the spindle-shaped tjrpe of swellings and bore in the 
central portion cankerous corrugations of the current season's (May, 
1916) aecial eruptions. The pycnial drops appeared on the freshly 
swollen areas at either end of the spindle-shaped hjrpertrophies bordering 
the ruptured areas. This conforms to observations made on a collection 
of the pycnial drops made near Bonner, Montana, on May 22, 1916, 
from lesions of Cronartium ComandrcR on Pinus ponderosa. The pycnial 
exudations, consisting of a clear, sticky, sweet liquid with a large num- 
ber of minutely pyriform spores in suspension, appear as large or small 
drops issuing from minute blister-Uke swellings in the epidermis of the 
infected tissues. Measurements of the pycnospores of the various col- 
lections made agree closely with those made by Boyce,* (50) 3 to 4 m by 

• Weir, J. R. and Hubert, E. E. Recent cultures of forest tree rusts. Phyto- 
path. 7: 106-109. 1917. 

• Spaulding, Perley. The blister rust of white pine. U. S. Dept. Agr. Bur. 
Plant Ind. Bui. 206: 27-28. 1911. 

. The white pine blister rust. U. S. Dept. Agr. Farmer's Bui. 742: 12. 

1906. 

• Boyce, J. S. Pycnia of Cronartium pyriforme. Phytopath. 6:446-447. D. 
1916. 



136 Phytopathology [Vol, 7 

3 to 7 M (3 by 4). They are characteristically pyriform, of a pale turtle 
gre<'n color^ issuing from minute openings in the epidermis and are pro- 
duced from 8ul)epidermal pycnial stromata of irregular outline. Boyoe 
states that the pycnospores are hyaline. An examination of both i«io- 
lated and massed spores indicates that they are colored, thoiigh faintly. 
The pycnial stages of Cronariium coleosporaides and Cranariium Comp- 
lonicB have, up to the present, remained unknown. Mention of the dis- 
cover}' of the stage has been made in a previous report* but details were 
not given at tliat time. In the period from April 4 to 15, 1916, abimdant 
pycnial exudations containing pycnospores were obtained from galls of 
Crofiartium coleosporaides (fig. 2) on Pinus ponderosa and P. cantoria. 
These pycnial dmps were found in the field and were also forced in the 
lalK>ratory at a much earlier date than produced in nature.* Out of a 
total of 32 galls, 28 proiluced pycnia by the forcing process, several of 
these* lat^r producing aecia. The pycnia of Cronartium coleosporaides on 
galls develop similarly to those of Cronariium Comandras with one marked 
diff(»n»nce, that is, their appearance on old galls and legions. The pycno- 
spores of Cronariium Camandrce apparently develop but onoe on the same 
tissue prc'ceding the appearance of the aeciospores. The production of 
aecia kills the infected tissues which are included in the aecial ruptures. 
The tissues lK)rdering this area are invade<l by the mycelium of the 
fungus, produce swellings, and give rise to pycnospores, either in early 
spring or in late simimer and fall, whenever sufficient time has elapsed 
from the last prcxluction of aecia. In the cases recorded the pycnospores 
appt^ired in the same season following the pnxluction of aecia, with only 
five months intervening, but not from the identical area from which the 
pycnia were pr<Hluced. In Cronariium coleosporaides the pycnospores 
an* pr(Kluce<l on ol<l galls previously ruptured as well as on unruptured 
infert<»<l tis^nies. A description of the pycnia of Cronariium coleosporoideM 
on galls follows: 

Pyrnial iitroma in irroi^ularly Hhapini aroAi«, more or less scattered or anasto- 
moflinK. raulirolouM, subepitlemial, forming minute, blister-like swelliDgs when 
mature <m unruptured infecte<i tiMuofl and iiwuinK from cracks in the bark of old 
le^ionfl; exuding a dear, ffueet. stieky fluid in which the pycnosporee are suspended 
forming dropfi of a ca<imium yellow to orange color when first appearing, l»ecomins 
clear aM the Hpore maj«ti KettleM to the lower end of drop, and orange to brick-red 
ufxm drying. PyrnoxporeH hyaline, mostly spherical, occasionally ellipsoid or 
olM»vttte i,V) 1.5 to U.O M by 1.5 to 3.7 /i (2.5 by 2.5). 



*i<idg<'v%a>. HnlMTt. Color ^t:indlird•« and color nomenclature. PI. 32. 1912. 
• Phyt<.path 7: Un't 10l». 11U7. 
' The -aine. 



1917] Weir and Hubert: Pycnial Stages of Rusts 139 

from the field bore remnants of the pycnial exudations and at the same 
time were producing aecia in abimdance. The pycnial drops when fresh 
have a slightly darker yel'ow color than those of Cronartium coleosparoidea, 
and like the latter appear in the bark crevices of old galls as well as in 
minute blister-like swellings on the yoimger unruptured tissues of in- 
fected areas. When old and dried the pycnial exudations are difficult of 
detection on the surface of the infected tissues and have a brick-red color. 

From observations made on Cronartium coleosporoides on galls both 
in the laboratory forcing experiments and in the field, it is determined 
that the aecia follow the pycnia in the same season, usualy from eight to 
sixteen days apart but not appearing upon the identical areas. The 
galls shown in figure 1 were collected at Coeur d'Alene April 1, 1916, 
and were placed in test-tubes with water on April 3. From April 4 to 9 
abundant pycnial drops were produced. From April 11 to 14 the galls 
began to show evidence of aecial eruptions and from April 16 to 17 aecia 
appeared. With a longer time-interval between the two stages this is 
what has been observed to occur in the field. Spaulding^ has observed 
in the case of Cronartium ribicola that the pycnia precede the aecia by a 
short period. 

A very interesting fungus frequently foimd during the past season in 
connection with the pycnial exudations and also foimd accompanying 
the aecial stage of the caulicolous rust is a species of Tuberculina which 
may be referred to T. maxima Rostrup.* This fungus was found at- 
tacking the pycnial and aecial stages of Cronartium Comandrce occurring 
on PiniAS ponderosa and P. contorta, the pycnial and aecial stages of Cro- 
nartium coleoaporoidea on galls of PiniLS ponderosa and P. contorta, and the 
pycnial and aecial stages of Cronartium cerebrum on Pinua bankeiana. 
This species of Tuberculina attacks the stromatal layer as well as the 
fruiting bodies and erupts in powdery, Hlac to nigrosin masses through the 
epidermis of the host tree. This fiuigus is considered by Tubeuf • to be of 
some economic importance although Lechmere^® does not concur in this 
conclusion. The writers have not found it occurring in sufficient abun- 
dance to place any importance upon its economic possibilities. 

Office of Investigations in Forest Pathology 
Bureau of Plant Industry 
Missoula, Montana 

» U. 8. Dept. Agr., Bur. Plant Ind. Bui. 206: 27-28. 1911. 

• Tubeuf, C. von. Ueber Tuberculina maxima, einen Parasiten des Weymouth- 
skiefem-Blasenrostes. Biol. Abt. f. Land- u. Forstwirthschaft. 2: 169. 1901. 

* Tubeuf, C. von. Recent observations on the blister rust of Weymouth pine. 
Naturw. Ztochr. Forst.-u. Landw. 12: 484-491. 1914. 

^* Leohmere, E. Tuberculina maxima, a parasite on the blister rust fungus of 
the Weymouth pine. Naturw. Ztschr. Forst.- u. Landw. 12: 491-498. 1914. 



REVIEWS 

Edible and Poisonous Mushrooms. By W. A. MurriU, Afisistant Director 

of the New York Botanical Garden. Handbook, IGmo., pp. 71, 

large colore^l chart, figs. 47. Published by the Garden. Price $2. 

This work is primarily of interest to users of mushrooms. Tlie chart 

contains very good illustrations of 30 species of edible mushrooms, and 

of 17 species of poisonous ones. A few of these are of interest to the 

forest pathologist, Ix^cause they frequently attack the wood of living trees. 

Geo. G. Hedgcock 

PHYTOPATHOLOGIC'AL NOTES 

Sew hosts for Razoumofskya americana and R. ocddenlalis abieiina, 
Rdzoumofskya americana Nutt, has l)een previously reported on PinuM 
coniorta, P. banksiana, P. jwnderosa, and P. jeffreyi. On April 12, 1915, 
a specimen was received from J. K. Haefner of the Sifiki>'OU National 
Forest, Oregon, on Pinus attenuata. On Septeml)er 5, 1916, the writer 
collected l>oth staminate and pistillate plants on Pinus aUenuaia in the 
Oregon Mountains, Siskiyou Forest. This indicates that the species may 
1h» exi)ecte<l to occur on any of the yellow pines. (See writer's note. 
Phytopath. 6: 414. 1916.) 

Razoumofskya occi4ientalij< nhietina (Kngelm.) (V)ville, the large form on 
Abies. ha.»< Ihh^ii rei>orted on Abi4's concoloTy A, grandis^ and A, magnificat 
During a trip on the Oater National Forest, Oregon, in Septeml)er, 1916, 
the writer <*ollertcHl iM>th staminate and pi.stillate plants on Abies nobilis 
and .4. amabilis. 

James K. Weir 

Lighttiing injury to kale. In a previou.s article (Phytopath. S: IM. 
191')) the writer, jointly with (SillH^rt, reiK)rt<»<l ol)8erv'ation8 upon light- 
iiiiit; killing of |N)tat<H\«< and <*ottoii. As sliown, the plants in the stricken 
zone die j)roniptly over a somewhat eireular area usually fnmi one to 
three nnU in diiiineter. Further evidence* of this sort of injur}* in Wis- 

* Ilo«lKt*'><4c. (>. (f. N(»t("* on florne dineimiM of trees in our national foreau. V. 
Phytopath. 6: I7«». I'M.V 

Wi«T, J. K. .MiMtlctfM* injury to conifi*rH in the northwest. U. S. Dept. Afr. 
Bui. :WM): 33. 1910. 



142 Phytopathology [Vol. 7 



of the storm were rather small and all had the appearance of having beeo 
struck by some strong force and flattened to the ground, and the three 
plants which seem to be inside the circle and have survived were ahnost 
completely covered with earth. The rest of the plants in the circle had 
a powder-burned appearance and all shrivelled up and disappeared within 
a week or ten days." The area as shown in the figure was roui^y 
circular, about twenty to twenty-five feet in diameter. This accords 
closely in all respects with the effect4s of the lightning strokes as we have 
observed them in Wisconsin potato fields. 

It is to be hoped that others may record, as they have opportunity, 
evidence of such injuries imtil we have a fuller imderstanding of these 
matters. From the e\adence at hand, similar injuries may be expected 
with sugar and garden beets, and possibly carrots, with the varioiis mem- 
bers of the cabbage-kale groups of vegetables, turnips, radiahee, and so 
forth, and probably with the allies of the potato, such as tomato and egg 
plants. Special attention may also well be given to possible li^^tning 
injury of legumes in view of Sitensky's observations. (See Abstract, 
SSeitschr. Pflkr. 8: 148, 1898), which have come to my attention since 
our former article. He reports a lighting stroke in a Bohemian alfalfa 
field when the plants were in blossom. The next day the plants were 
wilted down in a circular area about 5 meters across. 

It is noteworthy that no case is recorded of like injury with any of the 
Gramineae, although it would seem that, since great areas are occupied 
by the grains and grasses in the northern states, lightning must often 
strike in such fields. When more evidence is at hand conoeming the 
varying liability of such plants to injury in nature it will pave the way 
to some very interesting experimental work to determine the reasons 
why such variations occur. These may conceivably be associated with 
differences in the character or habit of aerial parts, with the character or 
distribution of the root systems, or with the relative electrical conductivity 
of the different plant tissues. 

L. R. Jones 

Puccinia glumarum. In May, 1915, the occurrence of Pucdnia glu-^ 
marum (Schmidt) Rriks. and Henn. was reported for the first time in the 
Tnited States. It is so well known in Kurope and certain Asiatic countries 
thiit it 8 discover^' at ho many widely distant points in the western states 
led to considerable speculation as to time and method of introduction into 
America. Although we are Htill lacking definite information on these 
points, it is now definitely kn<mii that an examination of herbarium 
s|XM*imen8 at the New York liotanic (iunlens indicates the fact that P. 
glumarum was collected in this country as long ago as June, 1892, when 



1917] Phytopathological Notes 14S 

C. V. Piper reported it as P. rubigo-vera on Elymus americanus and a 
month later as P. rvbigo-vera on Bromus hookerianusy and distributed it 
under numbers 41 and 206. These specimens were found at Seattle and 
Everett, Washington, respectively. 

Other American collections of Puccinia glumarunij made prior to 1915^ 
were by E. T. and E. Bartholomew in August, 1913, at Billings, Mont., 
on Hordeum jubatum under number 4369; E. Bartholomew on Hcrdeum 
jubatum at Rock River, Wyo., in August, 1911, under nmnbers 1063 
and 3763, and by A. O. Garrett in 1907 and 1909 in Utah and distributed 
as P. rubig(M)era imder numbers 138, 191, and 192. 

It would thus appear that Puccinia glumarum has been present in 
America at least twenty-five years and possibly longer. 

H. B. Humphrey 

Newton B, Pierce, The death is annoimced on October 13, 1916, at 
the age of sixty years, of Mr. Newton B. Pierce, formerly pathologist in 
the Bureau of Plant Industry. 

Mr. Pierce in his early manhood was engaged in the lumber business, 
in partnership with his brother at Ludington, Mich. He was from a boy 
interested in natural history and spent a great deal of his time in the 
woods. At first he turned his attention to economic entomology, and 
very early developed into an excellent entomological artist. He was 
sp)ecially gifted in the field of draughtsmanship,* particulary in the 
delineation of plants and insects. Desiring to advance his knowledge 
along entomological lines he went to Harvard and took up some special 
work in entomology. Conditions were not favorable for the best work, 
and he relinquished his entomological studies, and, after casting about, 
decided to take up work in plant pathology under Dr. Volney Spaulding, 
of the University of Michigan. Largely through Dr. Spaulding's influ- 
ence, Mr. Pierce became intensely interested in plant pathological studies. 
He developed into a keen observer and a thorough-going investigator. 

In these early days there was comparatively little pathological work 
carried on in this country, and those engaged in it were few in number. 
The pathological work of the government had only just been inaugurated. 

About 1887 or 1888 there appeared in CaUfomia a serious grape disease, 
which spread rapidly and caused immense damage to the vine industry 
of that state. Early in 1889 the disease had become so virulent that the 
Section of Vegetable Pathology in the U. S. Department of Agriculture 
decided to undertake an investigation of the trouble. In casting about 
for someone to take up this work Professor Spaulding of Michigan was 
communicated with. He reconunended Mr. Pierce, and Mr. Pierce was 
app>ointed. Mr. Pierce proceeded at once to Santa Ana, CaUf., and made 



144 Phytopathology (Vol. 7 

that place his headquarters. He began at once a careful field study of 
the disease. After six or eight months of field studies he decided that 
he wanted to go abroad in order to get a line on the diseases of the grape 
in the south of France and in Italy. He went abroad at his own expense, 
and was away six or eight months. Upon his return he renewed his 
investigation of the grape diseases, and eight or nine months later pub* 
lished his valuable report on the California vine disease. Mr. Pierce 
continued grape investigations and took up other lines of work. 

Gradually the laboratory at Santa Ana grew into one of the most 
important branches of the plant pathological work of the government. 
The name was changed to the Pacific Coast Laboratory, and Mr. Pierce 
was put in charge. He remained in charge of this work until December 
31, 1906, when he resigned. 

During Mr. Pierce's work on the Coast he conducted important in\'e0ti- 
gations in the California vine disease, leaf curl of the peach, walnut bli|^t, 
and the diseases of the grape. 

Mr. Pierce was a man of quiet and unassuming habits. He was pre* 
eminently an investigator, and preferred to work alone. A careful study 
of the record of his accomplishments on the Pacific Coast will show that 
he was an indefatigable and earnest student. 

B. T. Galloway 

Pathological greenkoxue. On the basis of the presentation in Pryto* 
PATHOLOGY for February, 1916, of the need for controlled greenhouse 
conditions in Imtanical research (Potter, Alden A. The control of experi- 
mental conditions in ph>'topathological research, p. 81) funds have been 
secured for carrying out these ideas in connection with the investigations 
of the Bureau of Plant Industr\' on the cereal rusts, and it is hoped to 
have at Ic^st one unit of this apparatus in operation in Washington within 
the present year. 

Cereal rtui nurvey. An extensive barberry and cereal rust field survey 
is projecte<l for the coming spring and summer by the Office of Cereal 
Investigations, Bureau of Plant Industry. 

PernonaU, Dr. J. L. Wcimer, formerly assistant in the Department of 
Botany of Purdue l*niversity, I^fayette, Indiana, has been appointed 
scientific assistant in the Bureau of Plant Industr>', effective February 14, 
to take up work on the diseases of sweet potatoes and other truck crops. 

Mr. Moses Irvine, assistant in the Department of Botany and Plant 
Patholog\\ Tniversity of Minnesota, has recently Ixren appointed assistant 
in Plant Patholog>' in the Kansas Agricultural College, Manhattan, Kan. 



REPORT OF THE EIGHTH ANNUAL MEETING OF THE 
AMERICAN PHYTOPATHOLOGICAL SOCIETY 

The eighth annual meeting of the Society was held in Barnard College, Columbia 
University, New York City, N. Y., December 27-30, 1916, in conjunction with the 
American Association for the Advancement of Science. 

About ninety members were present and a program of eighty-three papers was 
presented, the abstracts of which appeared in the last number of Phttopathologt. 
Twenty-four new members were elected, making a total of three himdred and 
sixty-seven. 

Joint sessions were held with Section G of the American Association for the 
Advancement of Science and also with the Botanical Society of America. 

The following officers were elected: 

Presidentf Dr. Mel. T. Cook, Agricultural Experiment Station, New Bnmswick, 
N.J. 

Vice-PrenderUf Dr. Charles Brooks, U. S. Department of Agriculture, Wash- 
ington, D. C. 

Councilor for three years t Prof. H. S. Jackson, Purdue University Agricultural 
Experiment Station, Lafayette, Ind. 

One of the Chief Editors of Phytopathology for three years, Dr. G. P. Clinton, 
Agricultural Experiment Station, New Haven, Conn. 

AssociiUe Editors, J. B. Rorer, Port-of-Spain, Trinidad; Prof. H. P. Barss, Ore- 
gon Agricultural College, Corvallis, Ore. ; Dr. Geo. M. Reed, University of Missouri, 
Columbia, Mo.; and Dr. H. A. Edson, U. S. Department of Agriculture, Wash- 
ington, D. C. * 

The Society decided to hold its next annual meeting at Pittsburgh, Pa., in con- 
junction with the American Association for the Advancement of Science, Deoeniber 
28, 1917, to January 2, 1918. 

AMENDMENT TO THE CONSTITUTION 

Article II, Section 1, line 1, after the word "include" the word sustaining was 
inserted. 

Article III, Section 3, line 1, after the word "become" a sustainxhg life member 
by paying one hundred dollars in ten conseciUive annual payments was substituted for 
"a life member upon the payment of fifty dollars." 

BEPORT8 OF COMMITTEES 

The Committee on Common Names, consisting of F. C. Stewart, G. P. Clinton, 
F. L. Stevens, E. C. Stakman, and W. A. Orton, presented the following report and 
recommendations: 

Carrying out the instructions of the Society at the Columbus meeting, the Com- 
mittee sent copies of the partial list of conmion names which it had prepared to 
about 200 memoers of the oocietv for their criticisms. In consequence of the sug- 
gestions received the Committee has made some changes in the list and 30 names have 
been stricken from the list. The revised list contains the names of 17 host plants 
(alfalfa to cabbage) and 92 diseases. The adoption of this list is recommended. 

The Committee reconmiends further that this work on common names be con- 
tinued under the following plan: 



146 Phytopathology [Vol. 7 

• 

(1) The American Phytopathological Society shall officially adopt a list of 
common names of plant diseases. 

(2) There shall t>e a oermanent standing committee of the Society, called the 
Committee on Common Names of Plant Diseases, consisting of five membera, one 
memlier being elected by the Council each year to serve five years. The Cammittee 
shall elect its own officers. The meml)crs of the present Committee (1916) shall 
retire in the order of the length of service of each. A vacancy on this Committee 
shall be filled temporarily by appointment of the President of the Society, the ap> 
pointee to serve until the next annual meeting, at which time the Council shall 
elect a meml)er to complete the unfinished term. 

(3) This Committee shall prepare and present to the Society for official action 
at the regular annual meeting a list of common names of plant diseases, and at each 
succeeding annual meeting a supplementary list of names may bo presented. At 
least six weeks l)efore the annual meeting the Committee shall submit a preliminary 
list of names to all nieml)er8 of the Society for suggestions and criticiam in writing. 
At the l)eginning of the annual meeting the revised list shall be conapicuousiy 
posted to invite further HUggentions and criticisms. The list as finally revised by 
the Commit tei» shall In* presented to the Society at the same annual meeting for 
final adoption. The list of names officially adopted at each annual meeting shall 
l¥» printed in Phytopathouhjy in the n^port of the meeting of the Society. The 
official list may lx» amended undrr the same procedun*. 

I'lKin motion the report was arcepte<l an<l the recommendations adopted. Later, 
in connection with a diHcu.HMion of the propo.sed list of common names which the 
Committee ha<i prepan»<l, a motion to reron.Hider the action in regard to the report 
of the (^ommittfH* wa^^ adopted, and a moti<m waM made and carried that the (*ora- 
mittet* be in»<tnirte<l to submit to the entire membership of the Society by mail the 
list of common nafncM which it approve<l and to re<]ueHt a vote for or against each 
name propose<l, a three-fourths majority of the total membership being necessary 
for adoption of any name. \ motion was also adopted authorising the Committee 
on (\»mmon NamoM to change the above plans to make them accord with the 
alNive motion. 

('. \^. Kdgerton was ap|M>intcMl tm the C<»mniittee in place of O. P. Clinton, whoee 
term expiriMl. Since the close of the meeting F. C. Stewart and F. L. Stevens have 
resigne<l and the PreHident has ap|M)inted in their places (i. H. L>'man and J. B. 8. 
Norton. 

The (*tfmmittt'e ttn Wnt^ and Means, consisting of L. H. Jones, C. L. Shear, C. W. 
Kdgerton, H. S. Jackson, and J. T. Barrett, di<l not report, the Chairman being 
al>f«ent. 

The Committee **ri liiUliography, consisting of L. U. Jones. C L. Shear, and R. A. 
Harper, mafli'no fonnal re^mrt. C. L. Shear stated that the (Committee had been 
unable, after two years' effort, to wcure the fifty subscribers necessary for publica* 
tion of the propos4*<i card in<lex to phytopathological literature. It had been the 
exfMTtation of the Conunitte<* that a large profHirtion of the agricultural colleges and 
expf*rinM*nt stations would subsrribe for the index, but only ten such sulMcriptioofl 
hail lH*4*n obtaintsl. The informal report was accepted and the Committee 
disrhargfHl. 

Tht Cnmmittee nn the Schirrinit: (%tUection of Fungi, consisting of C. L. Shear, 
3. ('. Arthur, and \. (i. Johnson, made a report of pn»gresfl to the effect that the 
(*urat<ir of the Herbarium had offfred to take whatever steps were feasible to ae- 
romplir«h th«* pur|M>se desirc^l by the S<N<iety. It is hop<Kl to |>erfect the details and 
havr th»" matter satisfactorily atten<le«l to during the prosent year. 

Thr Cirmmittte on InMitutional Stamiardisation, c<msisting of H. S. Reed, H. H. 
Whi'txd. an<l H H. Fulton, premMittMl no re|>ort and re<pi(*st<Ml that it be discharfed. 
Thr r»'<|U»*st was approve<l by the Society. 



1917] New York Meeting 147 

The Committee on Summer Meetings, consisting of Paul Murphy, E. C. Stakman, 
and Donald Reddick, presented no report, the Chairman being absent. 

The Committee on Pure Culture Supply Laboratory, consisting of C. L. Shear, L. 
R. Jones, and G. P. Clinton, made a report of progress, and stated that an item had 
been introduced in the appropriation bill for the Bureau of Plant Industry for the 
next fiscal year to cover the inauguration of this work. Whatever is accomplished 
in this direction during the year will depend upon the fate of this appropriation. 

tbeasurer's report 
Receipts: 

Balance from 1915 $655.64 

Dues of — 

268 regular members for 1916 $804.00 

72 sustaining life members 720 .00 

9 members for 1915 27.00 

1 sustaining life member 100.00 

Overpayment 3 members 9.00 1,660.00 

Exchange from 8 members. 1 .22 

Interest 15.64 

Excess transfer from Society funds 5.00 $2,337.50 

Expenditures: 

Approp'riation to Phytopathology 1915, and 1916 400.00 

Clerical work (inc. $14.80 for 1915) 73.43 

Printing abstracts, stationery, etc 185.07 

Secretary's traveling expenses to attend Columbus 

meeting ^ 44.28 

Mimeograph work for F. C. Stewart 15 .00 

Supplies 7.75 

Exchange on checks .40 

Excess dues from 3 members 9 .00 

Rebate for No. 1, Vol. V, exhausted .50 

Sinking fund for Phytopathology 501 .58 

Telegrams 1 .55 

Transfer to Phytopathology acct. members 969.00 2,207.56 



Balance $129.94 

FINANCIAL STATEMENT OF BUSINESS MANAGER OF PHYTOPATHOLOGY 

Receipts: 

Balance from 1915 $47.91 

Advertising guarantee 1915 150 .00 

Subscriptions and sales Phytopathology 620.38 

Annual dues transferred account — 

9 members for 1915 $ 18.00 

268 regular members, 1916 536.00 

72 sustaining members (1 excess) 360.00 

1 sustaining member in full 50.00 

1 member who paid $10 5.00 969.00 



148 Phytopathology |Vol. 7 

Sales Phytopatholoot direct 18. 10 

Neiberg subscription (sent to W. A W.) 3.25 

Extra illustrations in PHYTOPATHOLoaY, O'Gara and 

Hotaon 11 .28 

Annual appropriation from American Phytopathological 

Society for 1916 200.00 

Interest on deposits .84 

Interest on mortgage, 6 months 15.00 $2,035 75 

Expenditures: 

Cooke portrait S26.00 

Separates from Phytopathglooy 41 .05 

Stationery, express, postage (Dr. Reddick) 35.00 

Phoenix files .57 

Illustration of horse-chestnut 10.00 

Readjustment of dues one member paid to publishers . . 3.00 

Readjustment Neiberg subscription, paid to treasurer. . 3.25 

Insurance on stored stock 5.40 

Manufacture of Phytopathology: 

No. 6, Vol. V, balance from 1915 $65.80 

No. 1, Vol. VI 432 82 

No. 2, Vol. VI 348.52 

No. 3, Vol. VI 338.78 

No. 4, Vol. VI 260 92 

No. 5, Vol. VI 165 82 

No. 6, Vol. VI, $147.30, pending 000 00 1.612.66 

Williams A Wilkinn mii«cellaneou8 bills for postage, etc. 78.98 

riericalwork 70.43 

Reimbursement American Phytopathological Society 

account over-transfer 5.00 1,892 24 

Balance $143.52 

These accounts were referred to an auditing committee, consisting of A. D. 
Selby. R. Kent Beattie. and K. C. Stakman. The Committee reported that they 
had examine<l the arrounts and found them correct, and the reports were adopted. 

RKHOLl'TIO.VH ADOPTED 

A Committee, conHixting of II. .\. KdHon. .\. I). Selby, and John L. Sheldon. 
was ap|H>intfil by the Society to draft resolutionH in reganl to the deaths of two 
members, \V. \. Mnrtin an<l Vungyen Young, and alno of Professor T. J. Burrill. 
The following rem»hition» were pre.«M»nt«»<l: 

"HtfiUvfd, That whereaM in th<* death of W. .\. .Martin, of lloulton. Maine, and 
VuriKyfii Young, of Shanghai. China, the American Phytopathological Society has 
btMMi <b'prive<l of t>»o of itn menib«*rH. the Society reconU itM sincere regret at the 
taking of theMc gentlemen. 

"That whcrea-* in the death of Profe?*Mor T. J. Burrill. of the Cniversity of Illi- 
nois, uho (ir<«t (ictnoii**trat<Hi the exintenci* of bacterial di.'^eaMes of plants, there has 
bci-n rrninv***! .m eminent lea<ler in botanical and phytopathological research, the 
Anteriran Phytopathological Society i'XpreK?«e?* itM nincere regret at the departure 
of tliM eminent Kcholar and teacher, anci records itM appreciation of the service 
renderwi our science by his researches. 



1917] New York Meeting 149 

"That these resolutions be filed with the records of the Society and printed in 
Phytopathology." 

The following resolution was also passed by the Society: 

"Resolvedj That the Society express its deep appreciation and gratitude to the 
local Committee and the members of the Department of Botany of Columbia Uni- 
versity for the excellent facilities provided and for the many courtesies extended 
during the meeting. 

MISCELLANEOUS BUSINESS 

Upon motion the Society voted to appropriate two hundred dollars from any 
available funds for use in the support of Phytopathology for 1917. 

In response to a request from the Botanical Society of America to nominate a 
member of the American Phytopathological Society for the editorial board of the 
Botanical Society, Dr. A. G. Johnson was reconmiended by the Council. The 
Society approved of the action of the Council. 

The Board of Editors made the following recommendations in regard to Phyto- 
pathology, and these were approved by the Council : 

(1) That no article be accepted which is written in simplified spelling, but that 
in the case of words which have two or more forms in good usage strict uniformity 
is not required, but the shorter and simpler forms are to be preferred. 

(2) That Phytopathology be issued monthly and include five hundred or more 
pages during the year, the price of the Journal to members, including dues, to be 
four dollars and to subscribers five dollars per year, the increase in price to begin 
January 1, 1918. 

(3) Space of one-half page or more at the end of long articles is to be used for the 
publication of briefer articles or notes in order to avoid wasting space. 

(4) It is recommended to members of the Society that they refrain from pub- 
lishing original matter in extension publications, weekly news letters, and other 
similar publications which are not usually preserved and permanently filed, also 
that such references be omitted from the list of literature. 

(5) Recommended that authors of phytopathological papers which are pub- 
lished in proceedings of academies, horticultural societies, and other publications of 
limited distribution, prepare abstracts covering the original matter for publication 
in Phytopathology. 

Professor J. B. S. Norton presented a plan for ''a standard chart for per cent es- 
timates" in regard to injury and conditions of diseased plants. Upon motion this 
plan was referred to a Committee, consisting of L. R. Jones, V. B. Stewart, and 
H. B. Humphrey, for consideration and report to the Society at its next meeting. 

Dr. E. W. Allen, Editor of the Experiment Station Record, in response to the 
resolution adopted by the Society at its last meeting requesting that titles of papers 
abstracted in the Record be published in full in the original language, stated that 
after full consideration of the matter it did not appear practicable to adopt the 
proposed change. 

Dr. Donald Reddick, Editor of Phytopathology, presented a verbal report 
calling attention to some of the matters discussed by the Board as reported above. 

U]>on motion the Society directed the Secretary to publish during the year a new 
membership list. 

The Secretary called attention to the need of prompt notice of change of address 
of members, in order to avoid inconvenience and loss of copies of the Journal, and 
unnecessary expense in correspondence. C. L. Shear, 

Secretary 'Treasurer 



REPORT OF MEETING OF THE PACIFIC DIVISION OF TUB 
AMERICAN PHYTOPATHOLOGICAL SOCIETY 

A meeting of the Pacific Division was held at the University of Caiifomia, Berke- 
ley, December 28 and 29, 1916. President J. T. Barrett, of the CitruB EzperimeBi 
Station, Riverside, California, presided at the sessions, while Ralph E. Smith, of 
Berkeley, California, acted as secretary in the absence of W. T. Home, of Berkeley 
who is spending a leave of absence in Cuba. At the business session of the Society 
the following officers were elected for the coming year: 

President f H. P. Barss, Corvallis, Oregon. 

Vice President, James McM urphy, Leland Stanford Junior University, PkJo Alto» 
California. 

Secretary-Treasurer, W. T. Home, Berkeley, California. 

The following papers were presented: 
Apple rosette. M. A. Willis 

No abstract. 
^11 Alternaria blight of tomatoes in California. Bruce Douolas 

No alMtract. 
Sour rot of lemons. Clayton O. Smith 

No alMtract. 
Stem-end decay of Valencia oranges in transit. Clatton O. Smith 

No abstract. 
Some effects of sulphur on soils. H. S. Reed 

Sulphur in the form of elemental sulphur, sulphides, or sulphates is widely used 
as a fungicid«*. Much of thiH material finds its way eventually into the soil. Itm 
eflfert as a soil constituent is thrn*fon* pertinent. 

Under anaerobic conditions microorganisms may reduce sulphates to sulphites 
or 8uIphi<ieH. l>oth of which are toxic to vegetation. Oxidation processes may cob* 
vert sulphides and elemental sulphur to sulphates. The process is largely, if not en* 
tirely. due to biological agencies. If the oxidation process is incomplete sulphite* 
may \n* formed. 

The hannful effects of sulphur are mon> common in soil deficient in organic mat- 
ter, or in MoilH having an acid reaction. 
Black-heart dinea^e of the apricot. IIelkn Czar.vecki 
StudifJi on Monilia. Kditii Philliph 

No alwtract. 
MinctUnncoiu obnervations. Jamea .NfcMrRPiiT 

No nl»Htract. 
Thr t j/w rimrntal incfstigation of alleged smelter smoke injury in CalattroM County, 

i'tllxittrfiUl. W. W. TUOMAS 

N«> al»j»tr:irt. 
l*Uth\itc%fnt\* rtlated to Phytophthora. J. T. Bakrett 

Kor Mime tiiiif three MtrainH, |M>rlui(M diMtinct species, of a fungus, whoee asexual 
stAg«*»« rcTM-iiiblf vi-ry rloHely thow of l^ythiacyntis citrophthora Smith dk Smith, have 
bet^n uricifr oliservation. Thest* stmins differ mainly from the latter funfue in that 



1917] Berkeley Meeting of Pacific Division 151 

they produce in culture oospores while the perfect stage has not 3ret been reported 
from any culture of P. citrophthora isolated from any variety or species of Citrus. 

Of the three strains mentioned, one was isolated from decaying apples in March 
1908 in Illinois; one from bark of a young apricot tree in March 1916 in California 
and the third from bark of an avocado tree by H. S. Fawcett in May 1914. 

A comparison of the three forms with four species of Ph3rtophthora has revealed 
a very close similarity of the oogonia, oospores, and antheridia to those of P. cactorum 
(Cohn& Leb.) Schroeter, while their asexual spores, (sporangia and conidia) differ 
mainly in the manner of separating from the hyphae. 

This marked similarity of their sexual organs to those of P. caciarumf and of 
Iheir sporangia to those of Pythiacystia citrophthora would seem to indicate a close 
relationship of the two genera Pythiacystis and Phytophthora. 
VaricUiona in Colletotrichum glcBoaporioidea. O. F. Burger 

Cultures of Colletotrichum glceosporioides were isolated from different Citrus spe- 
cies in California. They have been grown on six different media and each strain re- 
sponds differently to the media. The size of the spore, depends in part upon the 
medium used. A hundred spores of each strain were measured and it was found 
that the mean spore-length of most of the strains, when grown on green bean pods, 
is 15 microns. Other strains were found, however, which have a mean spore-length 
of 12 and 17 microns respectively. 

The cultures can be classified according to their mycelial characters, when grown 
on artificial media. Class A. Mycelium dark, olive color, giving a fluffy growth with 
but scant spore production. Class B. Mycelium dark, appressed but abundant 
spore production. Class C. .White mycelium and abundant spore production. 
Sexuality in Cunninghamella. O. F. Burger 

Pure cultures were made from single spore heads of Cunninghamella hertholletia 
and during the entire work no zygospores were formed in the culture tubes. But 
when two strains, whose gametes were compatible are contrasted in an agar plate 
zygospores are produced at a point where the cultures meet. 

A sexual reaction did not occur with Blakeslee's Mucor V, plus and minus, or 
his plus and minus strains of Cunninghamella echinulaia. The strains of C. her- 
thoUetiae which acted as neutrals with these two fungi formed normal zygospores 
when contrasted among themselves. 

The peculiarity in their method of conjugation is, that there were marked differ- 
ences in their ability to conjugate with certain strains. Strain A will cnjugate 
with strains B and C and strains B and C will also conjugate and form normal zy- 
gospores. Cunninghamella bertholletias is therefore a pseudo-he terothallic mucor. 
Curly (op of the sugar heel. Ralph E. Smith 

No abstract. 

One session was devoted to a discussion of the so-called non-parasitic or physio- 
logical plant diseases, attention being paid to a number of obscure troubles which 
are of particular importance in the Far West. A discussion also took place concern- 
ing possible means of making the Society more useful and securing a representative 
attendance from the different states at its meetings. The acting secretary was in- 
structed to take up the latter subject with members in the territory covered by the 
Division to see what can be done along this line. 

W. T. HORNE, 

Secretary 'Treasurer 



LITERATURE ON AMERICAN PLANT DISEASES' 

Compiled bt Eunice R. Oberlt, Librarian, Bureau op Plant Industrt and 

Florence P. Smith, Assistant 

December, 1916, to January, 1917 

Alaska Afiicultttral Ezperlmant Stations. Plant diseases. Alaska A^r. Ezpt. 

StS8. Rpt. 1915: 39-41. 1916. 
Allard, Harry Ardell. A specific mosaic disease in Nicotiana viscosum dialiiiei 

from the mosaic disease of tobacco. Jour. Afcr. Research 7, no. 11:481-486, 

pi. 35. December 11, 1916. 
Avema Sacci, Rosarlo. Molostias cryptoKamicas do cafdeiro. Bol. Agr. [Sic 

Paulo) 17, no. 10: 790-840, fig. 157-285. Outubro, 1916. 
Baker, Carl Fuller. Additional notes on Philippine plant diseases. Phil. Agr. 

and Forester 6, no. 3: 73-78. July, 1916. 
Bancroft, C. Keith. Report on the South American leaf disease of the Para nil^ 

ber tree. Jour. Bd. Agr. Brit. Guiana 10, no. 1 : 13-33. October, 1016. 
Funicladium macronpcrum; die back. 
Boyce, J. S. Pyrnia of Cronartium pyriformc. Phytopathology 6, no. 6: 446-447. 

December, 1916. 
On PinuM ponder ima. 
Brandes, E. W. Report of the plant pathologist. Porto Rico Agr. Expt. Sta. 

Rpt. 1916: 34 35. 1916. 
Kxperiments in the control of a banana disease; miscellaneous experiments. 
Brooks, Charles, and Cooley, Jacquelin Smith. Temperature relations of apple* 

rot fungi. Jour. Agr. Research 8, no. 4: 139-164, 25 fig., 3 pi. January 23, 

1917. 
Ckivers, Arthur Houston. .\n epidemic of nist on mint. Mycologia 9| no. L: 41- 

42. Januar>', 1917. 
/'iirntnio Menthtr Pcrs. 
Cook, MeMlle Thurston, and Wilson, Guy West. The influence of the^tannin 

content of the host plant on Endothia parasitica and related species. New 

Jomey Agr. Fbcpt. Sta. Bui. 291. 47 p. 1916. 
Short<T article with same title published in Bot. Gas., November, 1915. 

Not4*d in previous lif«t. 
Dodge, Bernard OgiMe, and Adams, James Fowler. Notes relating to the Gymno- 

nfMirangi.i on Myrira and (\imptonia. .Mycologia 9, no. 1:23-29, 1 fig., 3 pi. 

Jiiiiuarv. 1017. 



1 I'hM list aim* to iDclu'l** tb« i»u)ilu-atioo« of North an*! South Amoriea. th« WttI ladia Mnadn. 9m4 
laias'ls rootrol»»l b> tho Uait«ii 8t*tM. aa<l mrtielM by Amariraa WTit«n apitoMiag in foralp 

All author* art urg*d to rodpcrat* ia makinc iho liat i-onpWta b> Madiat thoir ■tiiaiiitM wad bjr 
iBc rorr«> tiooaaal a-l-iitioaa. ao-i ••pocialU h\ ralltai attoatioa to m«ritoriou« artirlct pnhliillil 
of r«cul*' lournala ll«i»nBU or corT«aioaii«ar« ahouM t»« a*MrMM«i to Mmm E. R. Ulicrly, UbtSffteB. 
HuTMu of Plant In luairy. U. 8. IHpt. Apir., Waahiagtoa. D. C. 



1917] Literature on American Plant Diseases 153 

Blliott, John A. The sweet potato ''soil rot'' or ''pox'' organism. Science n. s. 
U, no. 1142:7(»-710. November 17, 1916. 
Cyaiospora batata gen. no v., sp. nov. 
Fawcett, George L. A Porto Rican disease of bananas. Porto Hioo Agr. Expt. 
Sta. Rpt. 1916: 36^1. 1916. 
Closely resembles Panama disease. 
Fawcett, Howard S. Citrus scab. Phytopathology 6, no. 6: 442-445. December, 
1916. 
Discussion of article by Grossenbacher. 

A Pythiacystis on avocado trees. Phytopathology 6, no. 6: 433-435. De- 
cember, 1916. 

Fromme, Fred Denton, and Thomas, H. E. The root-rot disease of the apple in 
Virginia. Science n. s. 46, no. 1152: 93. January 26, 1917. 
Xylaria sp. 

Germano de Souza, Raul. O Tylenchus acuto-acudatus ('i ) nos cafezaes de Indaia- 
tuba. Bol. Agr. [Sfto Paulo] 17, no. 9: 726-736, 7 fig. Setembro, 1916. 

Gile, Philip Lindsey. Chlorosis *of pineapples induced by manganese and car- 
bonate of lime. Science n. s. 44, no. 1146: 855-857. December 15, 1916. 

Gfissow, Hans Theodor. Canada's white pine possessions are threatened with ex- 
termination. An authoritative discussion of whit« pine blister rust. Canad. 
Forestry Jour. 18, no. 1 : 900-906, illus. January, 1917. 

Leaf roll in tomatoes? Phytopathology 6, no. 6:447. December, 1916. 

Hartley, Carl, and Pierce, Roy Gifford. The control of damping-off of coniferous 

seedlings. U. S. Dept. Agr. Bui. 453, 32 p., 1 fig., 2 pi. 1917. 

Pythium debaryanum; Fusarium monxliforme; Corticium vagum var, Solani. 
Heald, Frederick De Forest. Some new facts concerning wheat smut. Proc. 

Washington State Grain Growers, Shippers and Millers Assoc. 10th Ann. Meet- 
ing, 1916: 38-45, 2 fig. 1916. 
Huard, Victor Am6d6e. Les principales espdces d'insectes nuisibles et de maladies 

v^g^tales. [Quebec Dept. Agr.] Bui. 23, 75 p., 78 fig. 1916. 
Hubert, Ernest B. Celluloid cylinders for inoculation chambers. Phytopathology 

6, no. 6: 447-450, 1 fig. December, 1916. 
Jehle, Robert Andrew. Means of identifying citrus canker. Quart. Bui. State 

Plant Bd. Florida 1, no. 1: 2-10, 12 pi. (partly col.). October, 1916. 
Johnson, James. Enfermedades del tabaco y manera de combatirlas. Parte V. 

Hacienda 12, no. 4: 124-126, illus. Enero, 1917. 
Johnston, John Robert. Enfermedad de la raiz de la cafia de azticar. Hacienda 

12, no. 4: 117-118, iUus. Enero, 1917. 
To be continued. 

Marasmius on sugar cane. Mycologia 8, no. 2: 115. March, 1916. 

Comparison of M. stenophyllus and M. 8<icchari. 

Lewis, A. C. Cotton wilt in Georgia. Georgia State Bd. Ent. Bui. 40, 18 p., 8 

pi. 1915. 
Varieties of wilt resistant cotton, p. 8 ff. 
McClintock, James A. Is cucumber mosaic carried by seed'i Science n. s. 44, no. 

1144:786-787. December 1, 1916. 

Peanut mosaic. Science n. s. 46, no. 1150: 47-48. January 12, 1917. 

Sclerotinia libertiana on snap beans. Phytopathology 6, no. 6: 436-441, 

2 fig. December, 1916. 

McCobbin, W. A. The white pine blister rust: does the fungus winter on the cur- 
rant? Science n. s. 46, no. 1152: 87. January 26, 1917. 



154 Phytopatholoot [Voi- 7 

Martin, WillUm H. Influence of Bordeaux mixture on the rates of trampirmtion 
from abeciflcd leaves and from potted plants. Jour. Agr. Research 7, no 12: 
52^-548. December 18, 1916. 
Literature cited, p. 547-548. 
Maatey, L. M. The hard rot disease of gladiolus. New York Cornell Agr. Expi, 
Sta. Bui. 380: 149-181, flg. 38-14, pi. 15^16. 1916. 
Bibliography, p. 180-181. 
StpUnia Gladioli, 
Mandlola, Nemeslo, and Bspino, Rafael B. Some phycomycetous diaeaaea of cul- 
tivated plants in the Philippines. Phil. Agr. and Forester. I, no. 3: 65-71, 
illus. July. 1916. 
Bibliography, p. 71. 

Phytophthora diseases; Pythium Ekbaryanum. 
Mix, A. J. Cork, drouth spot and related diseases of the apple. New York State 
Agr. Expt. Sta. Bui. 426: 473-522, 12 pi. 1916. 

Nonparasitic. 
' Sun-scald of fruit trees, a type of winter injury. New York Cornell A^. 
Expt. Sta. Bui. 382: 233-284, fig. 60^1, pi. 18-19. 1916. 
Literature cited, p. 283-284. 

Probably a winter injury caused by direct freesing to death of the tiaaue. 
Morse, Warner Jackson. Studies upon the blackleg disease of the potato, with 
special reference to the relationship of the causal organisms. Jour. Agr. Re- 
search 8, no. 3: 79-126. January 15, 1917. 
Literature cited, p. 124-126. 
Hanllu* atronepticun Van Hall. 
Nowell, William. Fungoid and bacterial diseases. West Indian Bui. If, no. 2: 
133-143, 146 147. 1915. 
Listed under host and locality. 
See also p. 121-122. 
Fungous and bacterial diMoases. West Indian Bui. 16, no. 1: 17-25, 



1916. 

Listed under host and locality. 
See also p. 2. 

Hosellinia root diMMifles in the I^esser .Antilles. West Indian Bui. li, no. 

1:31 71. 12 fig. on 4 pi. 1916. 
Keferenc«»H, p. (H) 71. 
Orton, Clayton Roberts. Phytophthora infestans on tomatoes in .\ustralia. Phy- 
topathology 6, no. 6: 447. Drci'mln^r, 1916. 
Osner, George A. I^>af smut of timothy. New York Cornell Agr. Kxpt. Sta. BuL 
,3S!: is:> 230, fig. 4:> .W, pi. 17. 1916. 
Bihli«»graphy, p. 22«'> 2.10. 
f ' •» / 1 higii ntritrform if . 
Paul, B. H. Th«* pine blinUT niMt. (\»nwrv. Com. State New York BuL 15, 18 p., 

illiiM.. 1 foM map. [1917.1 
Seaver, Fred Jay. Sonu* p:i|N>rH pn>(M*iit4;d during convocation week. Mycolofpa 
9, no, 1:42 -U*. Jaiiuiiry. 1917. 

Joint fW'Minii of Hot. Sor. an<l Phytopath. Soc, P>iday, I>ecember 28, 1916, 
in connection with .\nirr. .\.Hf«i)c. .\dv. S4m. 
Smith, Erwln Frink. .Mrrhani^ni of tumor growth in crowngall. Jour. Agr. He- 
m-arch 8, no. r»: 1(W> 1S(>. pi. 4 <m. January 29, 1917. 
Literature cited, p. is^lW. 

|PnYTOPATHoi/)<iV, foF Fehruafv, 1917 (7: \~M, PI. I) wan iiisued Fob- 
nmr\' 7, HUT. I 



PHYTOPATHOLOGY 

VOLUME VII NUMBER 3 

JUNE, 1917 



STUDIES ON BACTERIUM SOLANACEARUM' 

E. E. Stanford and F. A. Wolf 
With One Figure in the Text 

Studies on the wilt diseases caused by Bad, solanacearum have been 
in progress at the North Carolina Agricultural Experiment Station since 
1903. A recent bulletin (4) dealing primarily with remedial and pallia- 
tive measures for tobacco wilt contains the results of certain of these in- 
vestigations. In the present paper are presented data bearing (1) on 
the distribution withiil North Carolina of the disease on tobacco {Nicotiana 
iabacum) and tomato (Lycopersicon escuUntum), (2) on cultural studies 
to determine the identity of the strains from the several hosts and (3) 
on the results of cross inoculations. 

distribution of BACT. solanacearum within north CAROLINA 

Tobacco wilt has probably been present within the state for at east 
twenty-five years, but occurs in only a small proportion of the lands de- 
voted to tobacco culture. The disease was first definitely recognized 
in the southern portion of Granville county in 1902. Records indicate 
that the disease has yearly continued to spread so that it now occurs in 
eleven counties, namely: Granville, Durham, Vance, Wake, Franklin, 
Ashe, Guilford, Greene, Davidson, Chatham and Yadkin. 

The losses in the first four of these counties are confined to the southern 
portions of Granville and Vance and the northern portions of the adjacent 
counties of Durham and Wake. In this area the disease is so generally 
destructive that the growing of tobacco has been abandoned on many 
farms. The disease is confined, however, to relatively small areas in 
the seven remaining counties. 

* Acknowledgment is hereby made to the several members of the Department 
of Botany and Plant Pathology of North Carolina Agricultural College and Experi- 
ment Station, who, since the inception of these investigations, have aided in the 
work. 



1S6 Phytopatholooy [Vou 7 

It is tt striking fart that collections of Imcterial wilt of tomato which 
have been vcr>' Rcncrally made throughout the State show that the diaeaap 
on tomatoes orcura in thirty-nine counties of the state. It is realised, 
of course, that the disease on Itoth tobacco and tomat^x^ may not have 
been reported from all localities in which it may occur, yet the fact remsiiu 
that the disease on the two host« is not coextensive. No a<lequatc exfdana- 



Piii. 1. Map op North Caholika Shiiwino the Known Dihtubltion or 

BArTERIVM HOLASArEAKl'H ON" ToSACCO ASO-OS ToMATO ' 

tion is ut hnnd (o iiccount for this, in xiew of the fact that reriproeal inoni- 
latioat nre ho caHJiy i-fTocted and that the strains of Bad. iioiaTiactarum 
from IiiIhicco and toniattx-s arv. identical as shown by the cultural atudim 
of scvend investifiiitorx and ronfimwd by studies to l»e presented later 
in this [uipiT. 

It nuKht Ik> ad<lc<l, that no <luta have accumulat^l relative to the di»- 
tribulitm of tliis purHHite on otht-r solanat-eous hotts and that the tliseaa» 
on peanut (ATtickin hypog(ra) has Ixfn ol>serve<l in one locality only. 

nXTIHAL HTrniES 

In view of the fact that in wrtain sections. Bad. Kilanacearum ts not 
present on ull of the hosln which un- known to l>e subject to attack, a aludy 
by means of artiliml cultun-s w:is nmde to iletermine the identity of 
the stniinK from the more comnKin hosts. Several investigatots, anioiiK 
wbnni iii:iy Is- nientionetl Smith ( '> an<l 0) and Honing (6)' have ptvnouiJy 
r(']M>rlvd cxU'iiMve .stu<li<-s on Hact. solaniteearum in artificial culture and 
n-giinl t) rgHniMii from (be s«'viTid hosts as identical. Nevcrthplesn. 

t Hi-ri-n-nri-H III rill- imMii'iiliiniH of lloninii. HunK<-r. und I'yrdk mi* given in Vol* 
uiiK- :l 'if .><iiiil>i'i' tlrK'iirin in Hi-liilion to I'tiinl Diwhwh. Tho tulhora haw not 
■rfii l)ir>>^ i>iililii'Bti»iii>. I>iil only ilii' alMtnirtH lavrti \>y I>r. Smith. BiMiocr«phitw 
of Hart. ...^l.,.l,■■.,r..n. on p. -.'Is iWi iind 1*70-271. 



1917] Stanford and Wolf: Bacterium solanacearum 167 

parallel cultures of the organism isolated from tobacco, potato, (Solanum 
tuberosum) tomato, eggplant (Solanum mslongena), peanut, ragweed 
{Ambrosia artemisiifolia) and Edipta alba have been made. These isola- 
tions were made from various parts of the hosts and from plants from several 
localities within the state. In general, the cultural variations which 
appeared between the strains from the different hosts were no greater 
than those from strains all of which came from the same host. Since, 
however, certain additional facts are brought to light, a brief account 
of the growth in culture is pertinent and is herewith given. 

Colonies on agar plates usually become visible within thirty-six to forty- 
eight hours at 28°C. At a temperature 4 to 5° lower, they may be scarcely 
noticeable at the end of seventy-two hours. They are at first white, 
wet-shining and opalescent, circular in outline, slightly raised and with 
smooth margin. Colonies become 3 to 5 mm. in diameter in five to six 
days. They soon become distinctly opalescent-blue by transmitted light, 
when the plates are held some distance from a poorly Ughted reflecting 
surface. When the colonies are viewed with the blue sky for a back- 
ground, they are distinctly brown with faint concentric rings. Later, 
they become very markedly brown by reflected light. The pigmentation 
originates at the center of the colony, spreads toward the margin and is 
diffused somewhat into the agar. The color is more intense at the cen- 
ter of the colony. Subsurface colonies are globose or lenticular, much 
smaller than the surface colonies and become brown much sooner than 
do the surface colonies. 

The growth on agar slants develops slowly, is filiform at first and usually 
spreading at the bottom of the slant. It is shghtly elevated and the mar- 
IB^ is entire or wavy. Colors and pigmentation develop similar to those 
in plate colonies with considerable variation in time of appearance and 
intensity of pigmentation which may vary from scarcely perceptible to 
brownish black. When Witte's peptone is used, a deeper pigmentation 
develops than when Difco peptone is employed. When the colonies 
become blackened, the organism is no longer viable. It appears to re- | 
tain its vitaUty for about four and one-half months on agar but rapidly ' 
loses its virulence on this medium. 

The appearance of colonies on Utmus lactose agar slants is similar to 
those on nutrient agar. The Utmus is at length sUghtly reduced. Pig- 
mentation is first noticeable in three to four weeks and a brown stain soon 
becomes diffused throughout the agar and masks its color. Portions of 
the substratiun which are not brown become sky-blue by diffuse Ught 
and reddish plum-colored by transmitted Ught. 

The appearance of this organism in bouillon cultures is somewhat 
variable. A rather uniform clouding develops within twenty-four hours 



158 PHYTOPATHOLOCiY (VoL. 7 

which l)erome8 so intenflely opaque within a week as to make it impo»- 
nihle to see through a l)Ouillon tulx; when the tul)e is placed immeclistely 
in front of an object. Numerous pseudogloeae may appear forming 
flocculent particles on the surface. No pellicle nor ring is formed, but 
a thin, opalescent scum appears on the surface. A dirty white, viMom 
precipitate develops within a week or two. Within four to six weeks, 
this precipitate will have l)ecome dense and the supernatant l)ouiIlon 
will have liecome cl(»ar at which time the organism Ls no longer \'iable. 
Various degrees of pigmentation may occur, l>eing more intense with 
Witte's than with Difco peptone. Tul)es of the l>ouillon made with the 
fonner l>ecome hn)wnish black on long standing. 

(>n potato plugs, the growth is spreading, thin or slightly raised, white 
or flc^sh-i'olorefl at first l)Ut rapidly In^comes bn)wn, often pitch-black. 
The surrounding licjuid U'coines clouded and bn)wn. The organism is 
short -live<l on this n)edium and conuiionly loses its vitality within a 
wec»k. The vinil(»n<'e of linct. siflanaccfirum on artificial me<lia is liest 
retained on |X)tat() phigs. but transfers must Ik* made at inter\'als of aliout 
two davs. 

When gn)wn on milk, there is no peptonization nor precipitation of 
ca.«ein. A slight visci<lity and the odor of putn»faction are developed 
and the medium at length In^comes bn>wn and alkaline. 

The organism (*auses n partial clarification of litmus milk with a ck^p- 
ening of th<» blur color which apfx^ars n*ddLsh by transmitted light. A 
slight dirty white i)n»cipitate is fonned, which lK»(*i>mes brown on loiiK 
standing. The ba<*teria may n»main viable* for five months on this me<lium. 

The surface coloni<»s on gelatin are small, circular, white and wet-shin- 
ing. Submerge<i colonies an* glolMist* and yellowi.sh to brownish, (irowth 
aU»ng the line of the stab on gelatin is white, later l)ecoming bn)wn, fila- 
mentous and lH*st at the surfacr of the medium. No liquefaction cMM'urK. 

TIm'H* is no evident gn)wth on Crohn's .solution in four weeks. C>n 
I'schinsky's soluti<»n, growth ranges fnun none to feeble with slight 
clouding. 

Ill (lrxtn>s«» bn»th. a copious gn»wth develops in the opi»n arm, extc^nd- 
ing (»iily to thr bas4' of the* <*Ios4mI ann. .\n abundant, rather viseoiis 
|)rf('if)itatr ap|M>ars. Th<> nHMlium at Irngtii lK*comc*s bn)wn in the o\H*n 
ann and i^ strongly alkalinr with no evolution of gits. 

< ultural <*harartrrs on s;i<*charos<* bn>th an* similar to those* on tlextrnwe 
with a l«»s> marked tend«*nrv to the development of a bmwn color. 

(Irn\%th i*« fe<*ble on la<ioM* brcith with little .s<m I i mentation and little 
or ni» bniwii eolur i?^ devel<»|MMl, even after s<»ven w<»<»ks. The acidity of 
aril! broth is dimiiiishe<{ l>ut neutral broths an* not rendered alkalin. 
<>n niannit. the growth eharaeters an* similar to thos4» on lactos<\ .\ ver>* 



1917] Stanford and Wolf: Bacterium solanacearum 159 

copious growth ensues in glycerin broth with a marked development of 
brown color. Growth on maltose is similar to that on dextrose. Nitrates 
and ammonia are formed in moderate amount in nitrate solutions. 

Growth is much delayed and diminished in hydrochloric acid +25 
Fuller's scale, and is entirely inhibited at +30. No growth occurs in 
double strength bouillon rendered +33 acid by the addition of expressed 
tomato fruit juice. Smith (6) reports growth in +33 acid of beef juice. 
The optimiun reaction lies between +10 and +15. ^ 

Growth is slight or none in bouillon --5 with sodium hydroxid. No 
growth occurred in —10 sodium hydroxid. The organism is little re- 
tentive of vitality on culture media. Milk appears to be the best medium 
for long continued growth on Bad, solanacearum. The organism may 
remain viable for two months in sterilized distilled water. No evidence 
of diastatic activity was found when the organism was grown on potato 
plugs. 

A considerable number of special media have been prepared, among 
which are soil extract, casein agar, Hey den's Nahrstoff agar, potato agar, 
potato leaf agar, and tomato leaf agar. No growth of diagnostic signifi- 
cance developed on any of these media. 

Bacterium solanacearum is very short-lived in mixed cultures. Honing 
(6) noted a marked antibiosis between the wilt organism and B. mesen- 
tericus as well as other species plated from wilted tobacco. In our studies 
also, various bacteria have been found to replace Bad, solanacearum in 
decaying, wilted plants. Five strains of yellow chromogens isolated 
from diseased tomatoes, tobacco and peanuts were found in the fall of 
1915 to exhibit marked antagonism to the wilt organism. In inter- 
secting streaks on agar plates, the chromogens tended to crowd out the 
parasite. The presence of B, mesentericus and other soil inhabitants 
appear never to be so antagonistic, however, as to eliminate Bad, solanace- 
arum from infested soils. 

Thus far attempts to isolate the parasite directly from infested soils 
have been unsuccessful. This is due in part at least to the fact that 
Bad, solanacearum is inhibited by other soil inhabitants which develop 
on the plates. Honing (6) however, succeeded in isolating it on plates 
from dilution cultures of well water. 

cross-inoculation experiments 

Bacterium solanacearum has previously been shown to attack mem- 
bers of eight widely separated families, Urticacese, Leguminosae, Tropaeo- 
lacese, Euphorbiaeeae, Verbenaceae, Solanaceae, PedeUaceae and Compositse. 

The organism was first described by Erwin F. Smith (5) in 1896 as 



160 Phytopathology [Vol, 7 

the cauae of a wilt disease of tomato, eggplant and potato and he succesa- 
fully inoculated Solanum nigrum, Datura stramonium, D. mdelUndeM, 
D. foMuosa, D, cornucopia^ Physalis crasnfolia, P. philaddphiea and 
Petunia (hybiid). 

Several investigators, among whom are Hunger (6), Stevens and Sackett 
(7) and Uyeda (6) have reported a wilt disease of tobacco. Honing (6) 
in 1910 first reported this organism as the cause of disease in plants out- 
side of the fk)lanacea*. He found it in Pouzolzia sp., Phyaalia angulata^ 
Indigofera arreeta, Arachis hypogceOy Mucuna sp., Acalypha boehmeroideM^ 
Ageratum conywides, SpUanthes acmella, Pluchea indica, Blumea baUami' 
fera, Synedrella nodiflora and Tectona grandia. He also successfully inocu- 
lated several ornamental varieties of Nicotiana, Capsicum annuum and 
Sesamum orientate, 

A wilt disease upon peanut was sul)sequently reported from North 
Carolina (2) and later studies (3) in this state added two composites. 
Ambrosia artemisiifolia and Eclipta altni, to the list of naturally infected 
hosts. 

A wilt of nasturtium (Tropetolum maju^) caused by Bad. sotanacearum 
was reported from Maryland by Br>'an (1). She succeeded in inoculating 
also the common cultivated Agc^ratum and Verbena. 

The artificial inoculation ex|x^riments conducted at the North Carolina 
Kxperinu*nt Station prior to 1913 were confined primarily to solanaceous 
plants. When in the summer of 1912, it was found that peanuts are 
subject to attack by Bact, solanacearum, this host was successfully inocu- 
lated with strains fn>m tobacco, peppers and peanuts. The strains from 
peanuts wen* also found to l)e pathogenic to tobacco. 

During the season of 1914, Bact. solanacearum was isolated from di»> 
ease<l ragi)^'ee<ls (Ambrosia artemisiifolia) and subsequently found to be 
prcKluctive of wilt on tobacco, tomato, potato, Eclipta alba and ganlen 
nasturtium (TropuK^lum). The recipr(H*aI inoculations upon ragweed 
with strains fn>m tobacco, tomato, potato and Eclipta aU>a were rather 
unsucc(*ssful. No systemic invasion n^sulting in death, but merely a 
local o<*clusion and blackening of xyl<»m elements occurred in inoculated 
plants. 

In tin* fall of 1915, strains isolatiNi from wilted Eclipta atba were auc- 
c(*Ksfully inocuhit<'<l into tomatoes, potatoes, tobacco, garden nasturtiunui 
and Eclipta allnt, A nit her more comprehensive series of inoculations 
on rultivatcd an<i wild s|)4*cies was in.stitut4*d in 191G, the results of which 
an» hcn»in brit^Hv sum!nanze<l. 

Mrthtti of vHticultittifU. The strain of Bact. yolatmcearum emplo^Td in 
niakiiig the initial inixulations wa.s (»btaincd by the pounxl plate method, 
fnim wilted t4>barro plants from Cn'^Mlmoor. North Carolina. As sooo 



1917] Stanford and Wolf: Bacterium solanacearum 161 

as the organism had developed on these poured plates, transfers were 
made to potato plugs. Rep)eated transfers at intervals of one to three 
days were made on this medium. The pigmentation on old cultures on 
agar and on potato plugs was regarded as sufficiently characteristic to 
estabhsh the identity of the wilt organism. Inoculum from one- to three- 
days-old cultures on potato plugs was used in all of the inoculations. 
Inoculations were made by pricking the plants near the tips of the branches 
and inserting the inoculum. A niunber of check plants, either iminjured 
or pricked with a sterilized needle were used in the case of each species 
tested. Since it was known that Bad. solancLcearum loses its virulence 
even though repeated transfers are made, no attempt was made to use 
the original strain from tobacco in all of the inoculations. Instead, isola- 
tions from certain of the inoculated species were used in continuing the 
series of inoculations. Some differences in virulence appeared in strains 
which had passed through different hosts but no such marked decrease 
occurred as when the organism is repeatedly transferred on culture media. 

In general, young, vigorously growing plants were used in these tests, 
although in some cases, rather matiu*e plants were employed. The cul- 
tivated species were grown either in the greenhouse or in small experi- 
mental plats at West Raleigh, North Carolina and the weeds grew in 
waste places where they could be kept under observation for the neces- 
sary length of time. In general, as soon as inoculated plants showed 
s3anptoms of disease, they were examined microscopicaUy to determine 
the presence of bacteria within the tissues at points remote from the point 
of inoculation. The organism was then reisolated by the poured plate 
method, and its identity established by the characteristic growth on agar 
and potato plugs. As supplementary evidence, the reisolated organism- 
was inoculated into tomatoes or tobacco. 

The accompanying diagram of the plan of these cross-inoculation experi- 
ments has been so arranged as to show at once the source of the inoculum, 
the result of the inoculation and the number of plants inoculated. 

ResuUs. When comparison is made with the host species previously 
enumerated, it will be seen from this tabulation of the results of cross 
inoculations that the following plants 'have heretofore been unreported 
as subject to attack by Bad, solanacearum: Stizolobium niveum, Tropceo- 
lum lobbianumy T, peregrinum, Croton glandulosus var. s&ptentrionalia, 
Impatiens batsamina, Verbena erinoides, Lycopersicon cerasiforme, L. 
pyriformey Browallia demissa, Physalis alkekengij Schizanthus pinnatus, 
Salpiglossis sinuaia and Martynia proboscidea. Twelve of these species 
belong to families representatives of which had hitherto been known to 
be subject to attack and one species, Impaiiens balsaminay belongs to 
an additional family. 



162 PinTOPATHOLOOY [VoL. 7 

I "-si* 

"■ B ■• • 

? 3 S J 







i 7 



--5 5 

, Jil: 

3 « t : p I i 

2 S^ 5 • k ? 

i J «c - fc " 1 







P ^ 






!.mj 



1917] Stanford and Wolf: Bacterium solanacearum 163 

It may also be noted from the tabulation that no infection resulted in 
Stizolobium niveum and Physalis alkekengi when inoculated with the or- 
ganism isolated from wilted Impatiens balsamina. Further, no demon- 
strable infection resulted in the case of Petunia (hybrid), Datura cornu- 
copia, D, fastv4)8a, and Physalis alkekengi when the isolations were made 
from wilted Browallia demissa. Smith (6) had previously shown the 
first three of these forms to be subject to attack. Since Stizolobium niveum 
wilted when Datura tatula was the source of the inoculum and Physalis 
alkekengi, when wilted Verbena erinoides was employed, it is indicated 
that virulence is influenced by the host plant. 

In the following species, Uttle or no external injury resulted from inocu- 
lation, but the vascular tissues were found to be invaded: Euphorbia 
nutans, Solanum carolinense, Physalis angulata, Impatiens sultani, Bid^is 
bipinnata and Erigeron canadensis. 

Inoculated plants of Ambrosia artemisiifolia and Eclipta alba wilted 
thus confirming previous studies (3). 

In general, it can be said that the external symptoms and pathologi- 
cal histology of the plants which were artificially inoculated in these studies 
differed in no essential particular from those of other species which have 
previously been reported as hosts for Bact. solanacearum. The 8p)ecies 
of Tropseolum, Lycopersicon, BrowalUa and Eclipta tested are to be 
regarded as very susceptible, whereas, Stizolobium niveum and Physalis 
alkekengi appear to be very resistant. That Stizolobium niveum is highly 
resistant is shown by the fact that in a field test at Creedmoor, North 
Carolina, no demonstrable infection develop)ed in any of the plants grown 
in wilt-infested soil. It is interesting to note that when young ragweed 
plants grown in the greenhouse were inoculated, they quickly succumbed 
to wilt, while numerous individuals grown out of doors when inoculated 
with the same strain showed no external symptoms of disease. Little 
external evidence of disease developed in rather mature plants of Croton 
but young plants were easily wilted. In the case of Impatiens balsamina, 
the foliage became slightly wilted, some distortion of the stems occurred 
and adventitious roots were formed. The discoloration of the vasculaV 
bundles of the stems showed through the cortical tissues as brown streaks. 
This species was found to wilt slowly when inoculation was effected by 
potting plants in infested soil. The discoloration of the vascular system 
is externally visible in wilted stems of Eclipta alba and the leaves become 
characteristically crisp and blackened. 

The economic bearing of these additional weed and cultivated host 
plants for Bact. solanacearum upon the problem of wilt control is at once 
apparent when it is indicated that certain of these forms, namely; Erigeron 
canadensis, Ambrosia artemisiifolia. Euphorbia nutans, Croton glandulosus. 



164 Phytopathology [Vol. 7 

and Solanum carolinense are widespread in cultivated fields in the State. 
Edipta alba is often found in ill-drained lands. Datura tatuia and Bidenti 
bipinnala are not uncommon weeds about farm buildings and lots. The 
Lycopersicons and Martynia probascidea are locally rather common in 
gardens. The Tropsolmns, Verbena, Impatiens, Browallia, Schixanthus, 
Salpiglossis and Physali^ alkekengi are more or less commonly grown as 
ornamental plants. The results with velvet beans (Stizolobium niveum) 
which is related to Mucuna mentioned by Honing (6) are significant 
since this crop is becoming of considerable importance in the South. At 
least, it cannot l)o recommended that velvet l)ean8 Ix" grown in a rotation 
s\'8tem in soils infested with Bad. aolanacearum. 

SUMMARY 

1. A wilt of tobacco caused bv Bad, Holanacearum has been observed 
in North Carolina in eleven counties and a tomato wilt caused bv the 
same organism has U^^^n noted in thirty-nine counties. 

2. Pn»viou8 cultural studies on the idcntitv of Bad. solanacearum from 
various hosts are (Confirmed since the variations which appeare<l in the 
strains from tobacco, (Nitato, tomato, eggplant, fx^anut, ragweed and 
Ediftta alba were no gn»atcr than in strains all of which came from the 
same host. 

3. A new family of phanerogams, Balsaminac(*ip, has been addcnl tii 
the nuinlxT previoiu<ly reportcil to contain host six'cic'S of Bad. solana- 
cearum. MemlM*rs of nine families arc now known to Ih' subject t4) attack 
by this organism. Thirt(M*n additiomil si>ecies of plants, classifieil as 
follows showe<l wcll-<h'fincd wilting or serious injur>': 

Ii4*ginHinosa* Sticolobium nm^um 

Tn)j)aH)lacea» Trofxrolum lobbumum, T. lyeregrinum 

Kuphorbiaceu* Croion glandulosus var. neptenirionali^ 

Balsa in ina(*ca> ImfHitietM balsamina 

VcrlH*nu<M*a» \'t'rhi'nn vrifundeH 

Soluna(M»a» Lycofpertfmm crrasiformr, L. pyriformr, Brovnil* 

I in (i4'mis8a, Physalis alkekengi, SdiisanlhuJt 
pinnntuii, Salpiglossis siniiata 

VriM'iiivviv .Martynia prttl}Osci(U'a. 

No outward si^n** of disease (|rvcl(»|M <1 in the vnsv of six other s|M»cie3* 
in whirh the org:uii*<tii nuiltiplied rapidly within the vascular |)ortioas. 
Fivf 4»f these sfNMMes an* previously unre|K)rt«'d, mmicly: 

Kuphorbiacea* Euphorbia nutans 

Solaiuieea' Stdanum carolimnse 

Hals^iiiiinaeea' Im/nitiens sulidini 

( *on 1 1 ¥ »-« i t a' B idens bipin nata , Erigeron ca tuidensiM. 



1917] Stanford and Wolf: Bacterium solanacbarum 165 

literature cited 

1. Bryan, Mary K. A nasturtium wilt caused by Bacterium solanacearum. 

Jour. Agr. Research 6: 451-157, pis. 63-64, figs. 3. 1915. 

2. Fulton, H. R., and Winston, J. R. A disease of the peanut caused by Bac- 

terium solanacearum. Nofth Carolina Agr. Exp. Sta. Ann. Rept. 86 and 
87: 4a-47, figs. 4. 1913-14. 

3. Fulton, H. R. and Stanford, E. E. Two wilt hosts of Bacterium solanacearum, 

Phytopath. 6: 108. 1916. 

4. Garner, W. W., Wolf, F. A., and Moss, E. G. Control of tobacco wilt in the 

flue-cured district. United States Bur. Plant Ind. Bui. (In press.) 

5. Smith, Erwin F. A bacterial disease of the tomato, eggplant, and Irish potato, 

(Bacillus solanacearum n. sp.) U. S. Dept. Agr., Div. Veg. Phys. and 
Path. Bui. 12: 1-28, ph. 2. 1896. 

6. Smith, Erwin F. Bacteria in relation to plant diseases. 8: p. 309, pU. 47, figs. 

155. 1914. Carnegie Institute of Washington, D. C. Publ. 27. 

7. Stevens, F. L. and Sackett, W. G. The Granville tobacco wilt. North Caro- 

lina Agr. Exp. Sta. Bui. 188: 81-96, figs. 16. 1903. 



SPARASSIS KADICATA, AX rXDKSCKIBKD FUN(;US ON THK 

HOOTS OF CONIFERS 

j a m k h u. \v k i r 
With Fivk Fic;!kks in tiik Tkxt 

In August. 1912, the writer collected s(»vt»nil siMTiinens of a sp<M'i<'> <>f 
Sjwirjissis growing on th(» nnits of various (•onif(»rs in the Priest River 
Valley, Maho. Lloyd, to whom sjMM'iniens wen» sent, pronounced il an 
inuh»scrilKMl sjx'cies. Cotton of the Pathological Laboratory* at Kew wlio 
was a<lvis4M| hy Lloyd of th<» writ<*r's six'ciniens stated that the plant 
w:ts unknown to him. Since collecting the first s|H»cimens. the writer 
luis studied the |)lant in several regions of the Northwest and finds tlutt 
of the many jx^culiarities of the s|KM'ies the most surprising diM*ovt»r>" 
is its evi<lent parasitism on the nM)ts of conif<Ts. Although this fact was* 
noted in MM 2. it was not until the plant was carefully studied in ix> n-b- 
tion to its S4»V(Tal ho>ts that this ph:ise in its life historv eouhl Ih* snti*- 
factorilv determined. 

nKS<'HIPTIO\ OF THK KrNCiT.S 

Since the fungus d<M»s not agn»<» with any known inemlnT of the genu^. 
it is described as new. 

Sparassis radicata n. sp. 

Fruiting stnictun* larg(^ 12 to 22 cm. ))road. 10 to 1(> cm. high. dilat«-<i 
aUive. compact. Heshy. tough, whitish, cn^amy yeUow with age. I>ninclif«|; 
hninches numerous, hori/^ontal or vertical, anastomosing, sometimes fonn* 
ing lahyrinth-like cavities. nion» often comiKictly arnmgiMl. ver>* thin, fan- 
shafMMl with wavy, sometimes din-ply IoImmI margins, ocnt.'iioniilly striat«»<i. 
aiiiphigcnou*^ or unilateral, de|M*nding on the fMKsition of the l>nin<*h. 
Malk. H'lrrotioid. tuU'rculate, firm, solid, sometimes hnincheil, 21) ^{l> mi. 
long. .'» s rm. hroail: s|)on*«i, ..">()< nmgc 2.S 4.0 X 2.S-r>..') ^, standard ^ir.9* 
'.iV .' '».l ^. oviiid. hyaline. 

7*v/*» UH-nUtij, Pri<»st River. Idaho 

Ihilntni. Living kmiI-^ in c'oiiiferous tn'4'^'. 

litiHtj* . nn*Kon. Idaho. \Va.*«hington. Montana, and British (\»luml*ia. 

T\tlH- tniit*rt'il. In the nffin* of Inv("«tigatio!w in Forest PatholiH^y, 
liun-riu fif Plant Industry. Mis.s^nila, Mont. 



1917] Weir: Sparassis radicata 167 

general morphology and taxonomy of the genus sparassis 

The genus Sparassis was established by Fries* and placed in the Cla- 
variaceae because of its frondose habit, fleshy consistency, and the be- 
lief that the spores were produced on all surfaces of the sporophores. It 
has recently been shown by Cotton^ that the hymenium of Sparassis is 
not amphigenous but that the flattened branches with the exception of 
those in the center of the sporophore, are unilateral. On the basis of the 
flattened sporophore and the inferior hymenium Cotton suggests that 
Sparassis should be removed from the Clavariaceae and placed in the 
Thelephoracea*. He points out that in the Merisma section of the genus 
Thelephora are species with upright, partly unilateral sporophores either 
terrestrial or growing on wood which in many respects have the charac- 
ters of Sparassis. In points of smoothness of the hymenium he further 
suggests that Sparassis is alHed to Stereum but since the relationship 
to Stereum is not very close sees no reason why the genus Sparassis should 
not be transferred to the Thelephoracese without reference to any par- 
ticular genus. Sparassis would then be distinguished as a genus of the 
Thelephoracese having fleshy, flattened, horizontal or vertical anastomos- 
ing branches with unilateral structures. The same view is entertained 
by Lloyd' who thinks the definition as laid down by Fries *' fertile on 
both sides ^* should be corrected. Whether or not this view should be 
adopted in view of the fact that there is considerable irregularity in the 
formation of a unilateral sporophore is doubtful. In young sporophores 
of Sparassis crispa (Wulf.) Fr. examined by the writer, also of Sparassis 
radicata^ the hymenium is by no means confined to the lowermost portion 
of the flattened branches but is found more or less uniformly over all free 
surfaces. This is particularly true, as Cotton points out, for those 
branches in the center of the sporophore but with a more pronounced 
unilateral structure toward the periphery. The hymenium of Sparassis 
radicata is formed very rapidly on the reverse side of the peripheral lobes 
when changed from their origninal position. A few specimens with un- 
usually vertical lobes showed an amphigenous hymenium throughout 
making it seem probable that the lobes only become unilateral when they 
develop in a position allowing the influence of gravity to be more active 
on one side than another. There are, however, very few unilateral fungi, 
if any, that, under proper conditions of growth, will not when reversed 
develop the hymenium on the upper side. 

' Fries. Systema mycol., I, p. 462. 

• Cotton, A. D. On the structure and systematic position of Sparassis. Trans. 
British Myc. Soc. 1911: 336-339. 

» Lloyd, C. G. Letter No. 61, note 400. 



168 Phytopatholoot [Vol 

Until QiH'Ict* nn<l PatouilInnl* iiotni the affiiiiticx of Sparassis with ci 
tiiiii ifroiips in l)ii' Thc-lt-pliomrcii' Imt iippamilly without ilcfinilr knot 
i-djEi' of ilic liyiiirnial ilfvclopiiiciit in llic (jt'iiiis. Somi-wliat later Mai 
M-iuinilcit Spitrassis fniiii tin- < 'lavariiH-i'u' making it the ty|>p «f a «pw 
family, tlic SiMirassiili>ii>. AllhoUKli Muirc's (-lassifii-alion wiis udoptini 
l^itsy,' rritioal work on thi* licvi-loiinicnl of the hyincniiim. ixTmanpn 



"Iftlk :iltKrlin) Ui rhr root* 



nf ih.. .iMihl.-ral -ini.-l.in- <,f ih.- l,raiu-li<.. niul.-r vari.ni^ fa.-l..r^ ..f rh.w 

aitil -.. lortli i- wry i.iu.l. ii.-.-l.-.i Ui,,r.- tli- .■ImiiKi- .-li.aiM U' a.-r.-pf 

l.l..y.l La- mail., ll..- xiKU.-rnm t,. tli.. wnt.., lli:,t rli.. u.-iiii- Sp^.ra- 

f:tll- naliirally iiili> Iw.. M-.-ljnii-.: tii-l >', r<,v,,„, ii|„.|| „ „i,.ir ».f ;, n.-l 

' l^i.-[.i Kl..r:. [i.vr..|<.Ki<|ii'- 'i>- l;i KriM.'.. I'urj*. Ivvs. 

' I': ill^r.l \j~ llviix'i yW'l.'. .i'Kiir..]- I'urU IS.S7. 

■ \I:,.r. ItirK-r. Iir- .-> l..l..Bi.|ii. - .r l,.\..Mm,ii.|i.,> -ur 1.-. H«-i.l..rnv.-f.tf ,. A 
iu-\.- :,<t Hull S.M' iinr, tr:iii.r. 18: -, I'.Nrj. 

' I...t-> V..rir.p' iil-r l-.tuiii«li.- Si:,i ,. (pmliLilnr. t. Jrna. lUttV 



1917] Weir: Sparassis radicata 169 

nature especially near the base of the branches and is very closely re- 
lated to Clavaria, and a second section consisting of species with thin 
lobes such as S. spathulata in the United States, S. laminosa of Europe, 
and S. radicata which has thinner lobes than either of the former. This 
seems to be a very logical arrangement. He further suggests^ that Spa- 
rassis laminosd and S. spathulata are probably indentical. Their sporo- 
phores are certainly very similar. 

THE ROOT STALK OF SPARASSIS RADICATA 

Sparassis radicata (fig. 1) differs chiefly from Sparassis crispa(WuU.) Fr. 
{S. ramosa Schaff.) which is reputed common in the eastern United States 
and in Europe, S. laminosa Fr. of Europe, and S. spathulata Schw. (Ste- 
reum spathulatum Schw.) (sparassis Herbstii Pk.) of America in the thin- 
ness of its lobes and by its very pronounced perennial sclerotioid root- 
stalk from which the sporophore develops annually (fig. 2). Since the 
rootstalk is usually attached to the deeper lateral roots of its host, it is 
often of a surprising length especially if a thick deposit of forest litter has 
accumulated around the base of the tree. Specimens have been found 
50 cm. in length but the average is from 20 to 31 cm. No record exists 
of such a rootstalk for any other species. Sparassis crispa has a rooting 
base but it is not known to be perennial. It is possible that this phase 
of development is common to the other two species but has been over- 
looked. Sometimes the underground stalk is divided into two secondary 
ones each supporting a sporophore (fig. 2). The spongy character of the 
upper portion of the rootstalk soon merges into a very hard, compact 
mass and at the point of attachment to the root has very much the ap- 
pearance of true cellular structure with the component filaments arranged 
longitudinally. The periphery of the stalk at the surface of the ground 
is composed of hyphae very much modified into a hard encrusting layer 
and may sometimes have a resinous appearance. The mycelium at the 
base of the stalk usually cements the earth into a hard stone-like body 
often of large dimensions. The fungus has not been found growing in 
the soil unattached to woody material. It is doubtful if it ever does so 
occur. All specimens so far collected were found at the base of trees. 

The structure of the rootstalk is not that of a true sclerotium although 
it functions as such, is permanent and produces new sporophores from 
year to year. The stubs of old sporophores are plainly evident on the 
old root stalk (fig. 3) and as high as ten have been found on a single speci- 
men. It was expected that the rootstalk would have great power of re- 
generation. This was tested on July 3, 1915 by cutting off a half-grown 

« Lloyd, C. G. Letter No. 44, note 51, 1913. 



1917] Weir: Sparassis radicata 171 

fruiting end, showing not only the evident polarity'' of the rootstalk but 
that it is a reserve structure of considerable reproductive power. 

The formation of sclerotioid bodies from which their fructifications are 
developed is common to a number of Polypores. Chief among these 
noted in western United States are Polyporus berkeleyi,^^ P. umbeUatuSf^^ P. 
frondoBus^ and Lentinus sp., parasitic on the roots of conifers and probably 
unnamed. The latter species has a true sclerotium." Lloyd^* lists the fol- 
lowing species growing from sclerotia-like structures and separates them 
as a distinct group of the section Ovinus of Polyporus: Polyporus tuber- 
aster (Japan, China, and Europe), P. Goetzii (Africa), P. Sapurema (Bra- 
zil), and P. Mylittce (AustraUa). Three other species also with sclerotia 
but not included in this section are P. bdsilapidiodes (AustraUa), P. sacer 
(Africa), and P. rhinocerotis (Malay). 

The formation of sclerotioid bodies seems to be common to the Cla- 
variacese. Some of the large species of Clavaria are observed to spring 
from large globose masses which when sectioned exhibit a very compact 
structure and are known to last over for more than one year. This has 
been observed by the writer for Clavaria aurea, C. amethystina and C. 
formosa. The members of the interesting genus Typhula always, so far 
as observed, produce sclerotia from which the sporophore is produced. 
In view of the fact that the sclerotia-forming habit seems to be more or 
less common to the Clavariacese, together with the fleshy consistency of 
the sporophores, flattened or cylindrical anastomosing branches, large 
size of many species, amphigenous hymenium, constant in most genera, 
irregular in others, it seems that this family is very well defined. The 
removal of the genus Sparassis to the Thelephoraceae, which possesses few 
or none of these characters, would be, it seems, an unnatural arrangement. 

* Weir, James R. tFntersuchungen tiber die Gattung Coprinus. Flora n.s. 108: 
301-305. 1911. 

*• Weir, James R. Some observations on Polyporus berkeleyi. Phjrtopath. 3: 
101-103, pi. 9. 1913. 

Later observed by Lloyd, Letter No. 60, note 391, 1915; and Letter No. 59, note 
306, 1915; and by Overholts, The Polyporace® of the Middle Western United States. 
Washington University Studies 3: 23, pi. 2. 1915. 

" Lloyd, C. G. Letter No. 58, note 277, 1915; and Overholts in The Polypora- 
ceae of the Middle Western United States. Washington University Studies. 3: 24, 
pi. 2. 1915. 

" Fetch, T. The pseudo-sclerotia of Lentinus similis and L. infundibuliformis. 
Ann. Roy. Bot. Gard. Peradeniya 6: 1-18, pi. 1. 1915. 

" Lloyd, C. G. Synopsis of the Section Ovinus of Polyporus. 74-76. Oct. 1911. 
Cincinnati, Ohio. 



172 Phytopathology [Vol. 7 

the disease caused by sparassis radicata 

The observation that possibly some members of the genus Sparassis 
are parasitic on the roots of forest trees has been made by others. In a 
letter to the writer, dated January 7, 1916, Doctor Cotton writes: "Spa- 
rams crispa has been found frequently, and from its intimate connectioo 
with the roots of Pinus and other conifers we are strongly inclined to sus- 
pect that it is parasitic/' 

Kirchmayr/^ it appears, was the first to entertain the suspicion that 
Sparassis had symbiotic or parasitic tendencies. Working with Spara$$iM 
crispa, he found that the stalk of this species penetrated deep into the 
earth at the base of the tree (Fohre). Boring into the roots from which 
the fungus appeared to have sprung, he found that after passing througli 
a sone of healthy wood the auger encountered diseased wood. TUs wood 
was of a brown color, gave out a strong odor of turpentine, and was very 
soft so that the auger readily pushed through it. Two trees when cut 
showed that the brown rot extended up into the heartwood of the trunk 
for a distance of two meters. The decayed wood could be nibbed into a 
fine powder and gave out an odor of turpentine. The decay resembled 
that produceii by Polyporus sidphureuSf the checks extending veitaeally 
and |)aralleling the annual rings. The checks were lined wiUi a fine my- 
celial layer which was encrusted with granules of calcium oxalate. Larfee 
peicres of the cubical checkoil wockI could Ix^ removed from the hollow in 
the heart wo(m1. The heart w(mx1 in the larger roots was also dec a jred, 
while the sapwocxl was infiltrated with pitch {"verkieni'*). The decayed 
wcHxl largely dissolved in anmionia prcxiucing a thick brown liquid whidi 
on neutralisation held a brown deposit in suspension. 

The author was unable to demonstrate the relation of the mycdium of 
Sparannis crinpa with that in the disi^as^^l w(xxl. He calls attention to 
the fact that the shrinkage of the wo<n1 in the fonn of cubes with surfaces 
covennl with a fine white mycelial layer, bn>wn color, odor of turpentine, 
and ability to Ix' niblMMl into a fine powder an* chanicteristic of the decay 
pnnhi^Ml by PolyfHfrun HchweiniUii, In the writer's experience the rot 
of l^olyfHtruA HchuTinitzii may not always Im» acrompanied by the pnxluc- 
tion of s|)<>n>phon's until a long timo after the wcxhI Ls well advances! in 
diTay. Sinre din^t ronn«M'tion of thr mycelium of the base of the sptiro- 
phon' with that of the d(M*ay('<l winhI was not disc*emible, it seems quite 
pn»b:ibl(* thut i\w invrstigator hii^ made an inc(»mH*t diagnosis. 

A ran*ful examination bv the writer of six tn»es, the nx>ts of which lx»re 
the fructifiration of SfHintssis nuUcntn has not n»vealiNl, with one excvfv 

** Kirrhiiinyr. (Mmt «li*ti pHruNitiKiiiUH v<»ii Poly|>c>rui« frondoflus Kr. umi S|MirMi- 
•u ranioiia .^luifT liodwifciii M: XW .'MT. 1914. 



1917] Weir: Spakassis radicata 175 

with a thick, mycelial mat from which the rootstalk takes its origin. The 
greatest decay occurs at the point where the rootstalk is attached and 
is at first confined principally to the sapwood. Small roots originating 
from larger ones to which the rootstalk is attached are usually decayed 
throughout. The early decay of the heartwood in the larger roots is 
probably prevented by the large amount of pitch which they contain. 
Eventually the heartwood is invaded but is pot broken down uniformly. 
Elongated pits filled with a white mycelium are formed in different parts 
of the wood, often anastomosing in such a manner as to leave long pieces 
of partially decayed or solid wood which may be very readily removed 
(fig. 5). Sunken areas on these pieces correspond to similar pits on 
pieces which have become wholly disorganized. These elongated pits are 
often bounded by a white mycelium arranged in the form of a network. 
The tissue in the heartwood is brittle but can not be rubbed into a fine 
powder as described by Kirchmayr for wood attacked by Sparassis crispa. 
The rot of the heartwood is always of a darker color than that of the 
sapwood. In Douglas fir it is brown; in spruce, of a more yellowish color. 
Away from the seat of first infection the mycelium may advance into the 
innermost heartwood causing the formation of a pitchy zone next to the 
sapwood. The diseased wood may be drawn out of such roots in strips 
leaving a hollow cylinder. The cambium and outer bast are always, how- 
ever, permeated by the mycelium in the characteristic fan-shaped masses. 
The action of the mycelium in the resin ducts of the bast causes a flow 
of pitch which may cement the soil to the root in stone-like masses. 

The fact that the fungus can maintain its activity in the cambium in 
roots deep in compact, mineral soil is very unusual. Some of the root 
fimgi which attack primarily the heartwood may follow the roots to a 
considerable depth, and Annillaria mellea and Fomes annosus habitually 
attack the cambium to a considerable distance in the mineral soil, but in 
the experience of the writer no other species has developed this ability 
to as great an extent as Sparassis radicaia. The decay is apparently 
confined to the roots proper, never having been traced beyond the sur- 
face of the soil. In case of an excessive accumulation of forest debris 
around the base of the tree the decay may extend higher up on the lateral 
roots than is ordinarily the case when this accumulation of materials 
does not occur. 

Only two species of fungi are definitely known to parasitise the roots 
of coniferous trees in the temperate zone, viz, Fomes annosus and ArmiU 
laria mellea, Rhizina inflata}^ may possibly be grouped here but in north- 
western United States seems to be confined principally to seedlings. 

^* Weir, James R. Observations on Rhizina inflata. Jour. Agr. Research 4: 
93-05. 1915. 



176 Phytopathology (Vol. 7 

There arc a number of fungi which attack the roots of forest trees, are 
not strongly parasitic and do not cause a rapid browning of the foliaiEe 
and rapid death. Their action is confine<l mainly to the heartwood of 
the roots and the base of the trunk. The most common of these is Poly- 
porus schweinitzii. Other species which are either wholly confined to 
the roots and bases of trees or extend into the roots from infection through 
wounds on the trunk are Trametes Piniy Echinodoniium iindoriuni^ Poly- 
parus sulphureuSy Porta trei'ni, and so forth. In the light of the pres- 
ent status of the study it can not Ix? stated just how rapidly Spara^unn 
radic€Ua causes the death of its host. It has not l)een found on repro<hir- 
tion or young trees. The plant is not abundant but sufficient data have 
been assemble<l to show that it may l)e placed in the same g^roup with 
Armillaria mellea and Fomen annoaus. 

To date only four trees, two Douglas firs (Pseiuiotsuga taxifolia), cme 
white pine {Pinua monticoUi), and one spruce {Picea engelmanni) have 
iKH'n found to have succuhiIkhI to the action of the fungus. The conclu- 
sion that the <l(»ath of th(^sc» tn»es was causc*d by SjHira^Hts rndicala was 
arrive<l at l)ecau.He of the absence of any other fungus or factor which has 
heretofore l)een accre<lite<l as causing the death of trees. Several un- 
healthy trees with the fungas on their roots have l)een studied, but the 
common n>ot fungi wen^ prt^^nt making a cornH*t diagnosis impossible. 
The fungus has in ev(»r\' ciis<», however, Uvn found to cause the death of 
the living parts in the nK)ts to which it wjis attachcnl. 

HOSTS AND DISTRIBUTION OF THE FUNGUS 

Sparanms radicata is ver>' widely distributed in the Northwest, hav- 
ing lH»on found by the writer in British Columbia, Washington, On^gon. 
Idaho, and Montana. Sparasais crispa as report^nl from C^alifomia is 
ver>' probably bascMi on this species. 

The fungus has been found attacking the r(K)ts of the following conifers: 
PnewUAifuga taxi folia, Picea engelnuinni, Pinujt moniicola^ and Ijorix (Kri- 
dentalis. Its cK'currenc<» on the nK)ts of broa<l-leaf species has not U^en 
note<i by the writer. Kirchmayr cites instances of the occurrence of 
Sparannttis rrM/xj on oak an<l l)eech and other bn)ad-leaf species. 

SUMMARY 

The large s|)ecies of Sparassis in the wwtern Tnited States is found to 
diffiT in a numlK*r of <ietails from Sptira^sis laminosa, »S. crispa, and N. 
ttpathuUitn, and is clt^scrilMHl as new under the name Sparansis radicata. 

The fungus is chiefly <iistinguish(Hl by its thin lol^es and an unusu- 



1917] Weir: Sparassis radicata 177 

ally large perennial rootstalk which is of the nature of a sclerotium and 
from which new sporophores are developed from year to year. 

The most important feature in the life history of the species is its para- 
sitism on the roots of conifers. The myceUum attacks the bast of the 
roots and later the wood, producing a yellow or brown, carbonizing rot. 

Office of Investagations in Forest Pathology 
Bureau of Plant Industry 
Missoula, Montana 



SOME CHANGES PRODUCED IN STRAWBERRY FRUITO 

BY RHIZOPUS NIGRICANS 

N K I L E. Stevens a \ d L o x A. H a w k i n a* 

INTRODrCTION 

Tho rot rauscMl hy Rhizopun nigricans EhrenI). in fttrawl)ern' fniitu 
(Fragnriii sp.) and |K)tatc) tuJ)ors {Solanum (uberosum) has l)Ocn i«tu<iie<l 
l)V the writers. In \Hy{\\ tlu»s<» cimk'h as w(»ll as in others' the rot caiu«eti bv 
this funfai-*< in characteriziMl l>y the rapid softening of the affecte<l tiwuf« 
aeeonipanied hy the loss of a Iarfi:e amount of juice. The morpholofQcal 
chan^^s pro<hi(*ed in the straw!)err>' by Rhizopu.s nigricans have alreaily 
Ix^en inv(*sti^ated. It was to (»Y>tain sonu* information on the bi<>-<*heini- 
ral rhanf^'s brought al)out in the strawU^rry fruit by this funinu* that 
tlie presc»nt study was und(»rtaken. In this work the effect of Hhizopu* 
nigricans on the su^ar. a<*id, ix^ntosiin, and crude fat content and the 
fXTct'iitage of dry matter of the strawU^rry was studied. 

METHODS 

The U»rries uwd in this study wert» all of the variety Missionary, itniwn 
at Vienna, Virinnia. and picked lK»twe<»n May 2() and June 5, \9U\, The 
methcNis for disinfecting an<l .*<amplinK us<'d suc(*essfully by one of the 
writers in studit^ of fM'ach (3) and (M)tato (5) rots were found inapplicable 
to this work. The outer layers of (vlls of the strawlierry were s<i injuretl 
by antis<>ptics. such jis mercuric chlorid an<l alcohol, as to n»nder n*suUj> 
of doubtful value. es|M*ci:illy as it had already Inhmi <ienionstnit4Mi that 
under normal moistun* conditions the mynOium of the funfni^ |Cn»W!i 
chicflv in the outer n'll la vers (S). The textun* of the Htrawl»errv. «f 
coursi'. pn»vents |>ortions of the siiine U'rry U'inK u.*«<mI for incN'ulation 
and r(»ntn»l. The* error dut* to variations in individual fruits inav lie 
.«om<*what greater than where iMirtions of the same fniits can lie t^mifian'il. 

' In th«* t\(MTiiiiriitf (If.NrriUMl in thifi paiMT the rultiirul work wan lionr by St«^ 
vi*nH. '\\\o jiiiiHir utithnr it* rf.«p<inHi)>lf* fi*r tli«* rhciniral work. Th^ wrtCem an> 
inili-htcil t<» Mr A A. HilfV of iIh* uttwv nf DniK-IMant. Poiflonoun-Pltiiit. Phymolo. 
Kiral. ami FiTnirntatinn InvrntifcationH for nHHiHtnnnf in the chemical work. 

' 'I ht' litiTaturc r«>fi'rrinK to thr cfTcrt of lihiznpus uigricann <in various fruit« 
haa \fvti l>ri4'tly rrvicwrtl in another pa|)cr tmon to U* piil>liiihf*d. Stcvena, Neil K. 
and Wilrox. H. li . Uhixopuri rot of fitrawU'rri<'H in traniiit. l*. 8. D. A. Bui. 531. 



1917] Stevens and Hawkins: Rhizopus nigricans 179 

After some preliminary experiments the following method was found 
satisfactory and was followed throughout the work: Berries as nearly 
uniform in size as possible were picked when nearly ripe, i.e., when about 
half of the berry showed a bright red color. They were picked early in 
the morning while still cool and covered with dew. The calyxes were 
removed and the fruit washed several times in sterilized, distilled water. 
They were then placed in wide-mouthed flasks which had been plugged 
with cotton and sterilized. Three or four berries were usually placed in 
each flask. The berries were inoculated with spores and myceUum from 
pure culture, a strain of Rhizopus nigricans isolated from strawberries 
shipped from Florida during February, 1916, being used for inoculation. 

The method usually followed in preparing the samples of fruit for analy- 
sis was to grind the berries in a mortar and then wash the pulp quantita- 
tively into the proper container. The flasks with the berries in them 
were weighed immediately before the fruit was prepared for anal3rsis 
and the washed and dried flasks were weighed again after'the berries and 
juice had been removed. The wet weight of the fruit could thus be cal- 
culated. All determinations were related to wet weight of the sound 
or rotten fruit. The methods for the determination of the sugars, pen- 
tosans, and dry matter were similar to those followed in the studies of 
peach brown-rot (3) and the rots of potato (6). 

The acid content was determined by grinding a sample of fruit, usually 
about 20 grams, in a mortar, then allowing it to stand three days in a 
flask with 150 cc. water to which a Uttle toluol had been added. The acid 
was titrated with n/10 sodium hydroxid in this flask using litmus solution 
as an indicator. The end-^point in these titrations was not as exact as 
might be desired because the pigments of the strawberry which were pres- 
ent in the solution made it impossible to detect slight changes in color. 
However, the determinations are all comparative and the differences in 
acid content in the sound and rotten berries are large. The crude fat 
determinations were made by extracting the dried and ground samples 
of fruit with water-free ether, which was then evaporated and the 
residue dried and weighed.' A number of samples of freshly picked sound 
berries were analyzed to obtain some idea of the variation in the con- 
tent of the compounds determined between the individual samples. The 
results of these analyses are shown in table 1. 

From table 1 it may be seen that there is some variation in the content 
of the compounds determined, especially the acids and sugars. The 

' Wiley, H. W., ed. Official and provisional methods of analysis. Association 
of Official Agricultural Chemists. As compiled by the conmiittee on revision of 
methods. U. S. Dept. Agr., Bur. Chem. Bui. 107 (rev.), 272 p., 13 fig. 1908. Re- 
printed, 1912. 



180 



Phytopathology 



(Vol.7 



TABLE 1 



Showing the content of sugars, pentosans, acids, crude fats, and dry maUer infreski^ 

picked strawberries. Three separate samples used in the 

determination of each substance 



PBBCBIfTAOB 
WCT WBIOBT 


AOD AS CC. 

KOBMAL ACID 

rBB 100 OBAMB 

WBT WBIQHT 


RBDUCINO 

SUOABII AB PBB- 

CBNTAOB WBT 

wxioirr 


BrCROBB AS 
PBBCBNTAOB 
WCT WCIORT 


CBUDC rATB AS 
rCBCCNTAaB 
WBT WCIOBT 


OCT MATTSC 

AC rscaurTACS 

WCT WCMBT 


0.57 
0.59 
56 


2 59 

2.10 
2.15 


2.89 
3 67 
4.03 


1 37 

1 69 
1 65 


27 
0.29 
0.34 


7 97 
8.17 

8 15 



variation in pentosan content is slight. There is a considerable amount 
of sugar and the acid content is rather high. The l)errie8 of course weir 
not ripe when picked and analyzed but wen* at al>out the stage of ma- 
turity at which they are har\'e8ted in some sections of the South where 
this variety is ^own commercially. A comparison of the results of the«e 
determinations and the data obtained from the analysis of the sound 
strawlH»rries which were analvzed three, 8(»ven, or fourteen da>'8 after 
har\'esting gives some data on the (*hanges which take place in picked 
strawl)erries during ripening. 

In table 2 is shown the pentosan, acid, sugar, and crude fat content 
and the percentage of total dr>' matter in the sound and rotted samplen 
of fruit at different times after harvesting. The analyses are also of some 
interest in showing the amount of the various sul>stances in the straw- 
lK»rr>' fruit. (Considerable work hjis, of cours<». already been done on 
this subject by various investigators. A review of much of this work 
is given by Wehmer (9, p. 284-285). In table 2 the rc9ult« given are 
averages of at least three determinations of the various compounds on 
as many separate samples. 

TABLE 2 

Comparatire pentosan, arid, sugar, and crutie fat content and the amount of totai dry 

matter in sound and rotten strauberries 





rCWTOBAMB 

4B rBKCRNT- 

AOB WCT 

WBKiirr 
51 51 

1 

:js .TJ 


ATiD ro^rtBjrr 

AH CC KOBMAL 
ACID, rcB 100 

oMfi. 09 rBrrr 

li ' li 

1 i :2 

1 9H 1 H9 
7r> 1 4'.» 
73 1 .V> 


BBOrclMQ 

•lUABB 

AB rBRCBNTAUB 

WBT WB|(«HT 


BrCBOBB 

AS rBaCBMTAQB 

WBT WBIUHT 


CBCDC FAT 

ooirrcirr 
AC rcccnrrAOC 

WCT WCtUMT 


OCT MATTBC IC 
•nLAWCKCCT 

AC rccrciTTACS 

W«T WCMVf 


w 


1 95 1 :Ci 
44 ■ 13 


li li 
1- ' 1- 


36 
34 


P 


P 


P 


3 

1 
14 


1 w» fki 

Jf) ' 


40 
31 


7 19 
««3 


«19 
5M 



1917] Stevens and Hawkins: Rhizopus nigricans 181 

From the results shown in table 2 it seems that the pentosan content 
is no lower in the rotten fruit three days after inoculation than in the 
corresponding sound samples. There is, however, a decrease in the 
pentosans as calculated on a wet-weight basis after the fimgus has acted 
fourteen days. It seems probable then that the fungus utiUzed a por- 
tion of the pentosans. It is interesting to note that there is a somewhat 
similar decrease in the percentage of dry weight in the inoculated berries 
in two weeks so that if the pentosans were calculated on the basis of dry 
weight at the time of analysis the percentage of the furfurol yielding sub- 
stances in the sound and rotten fruit would be approximately the same. 

The effect of the fungus upon the acids seems to be to reduce the acids 
slightly, as the acid content after the first three days is somewhat lower 
in the rotted samples than in the corresponding sound ones. The acid 
content of the soimd berries decreased rapidly until at the end of seven 
days it was only about half that of the rotted berries, and a similar ratio 
k evident seven days later. From a comparison of the acid content of 
the soimd berries in table 2 with that of the freshly picked berries shown 
in table 1 it is evident that there is a gradual decrease in the acidity the 
longer the berries are allowed to stand and that this decrease is much 
more rapid in the first week. That this decrease was not due to a neutrali- 
zation of the acid by ammonia either in the sound or rotten fruit was 
shown by the negative results obtained from several series of ammonia 
determinations by Folin's method. The acid is apparently used up by 
the berry in its metaboUsm, probably in respiration. That the decrease 
in acidity in the sound fruit was greater than that in the rotted berries 
seems to indicate that the mechanism for the utilization of this acid 
is destroyed or its action vihibited by the fungus. The fungus apparently 
uses little of the acid. 

The sugar content of the rotted berries is always lower than that of 
the sound fruit of the same series of samples. A comparison of the per- 
centage of sugars in the sound fruit, as given in tables 1 and 2, shows that 
the sugar content rapidly decreases after the strawberry is harvested. 
The sugars as well as the acids are apparently used by the strawberries 
in respiration or in other metaboUc processes. The much more rapid 
decrease in sugar content of the inoculated fruit is evidence that the fun- 
gus uses the sugars. 

The percentage of ether soluble material in the soimd and rotted ber- 
ries, considered in the tables as crude fats, does not undergo any decided 
decrease when the berry is rotted. 

The percentage of dry matter in the rotted berries is less than in the 
sound fruit. 

As has been mentioned above, this strawberry rot is characterized by 



182 



Phytopathology 



(Vol. 7 



a rapid softening of the tissue, the loss of water, and apparently a itenend 
collapse of the l^rry. It was considered of interest in this connectioD 
to determine the amount of sugar and acid present in the juice which 
escapes from the inoculated l)erries as compared to that in the juice of 
healthy berries picked at the same time and maintained under the same 
conditions of moisture and temperature. For this experiment the two 
samples of I)errie8 were picked, washed in - sterilized water, and placed 
in liter flasks. The l)erries in the one flask were inoculated with Rhiio- 
pus in the usual way. while those* in the other flask were maintained is 
controls. The flasks weiv filled to the wime height and were allowed to 
stand in the lal)oratory for three days. The juice was then poured off 
the inoculated fniit and the lx»rrics of the control sample were froipn 
with carl)on dioxid, and the juicv expn^sstnl with a fniit press. The migar 
and the acid content of the samples of juice from Iwth lots of berries were 
determined according to the usual method. The results are shown in 
table 3. 

TABLE 3 
Sugar and acid contrut of juice from nound and rotted utrawberrieM 





nf-iiAK (rzmcr.sr\u%) 




ATIDITT INTBMIi 


i or iioBMAi. Mem 


Juice frtMn kmiimI (niit Juice fruni ruCUtd fruit 


Juice frtMn 
•ound fruit 


Jui»trom 
rotlifti irmt 


Rfvlucinc ■UfAT 


SucnM* ' K«Hluctnc sucAr 


Sucrraw 


2.66 


2 9S 


0.62 


0.14 


191 


208 



DifTunion tension in Atmonphon^a. 



jncB rmoM 
•ocMD mcrr 



604 
8.37 



iricB 



1 037 
12.50 



From tabh* 3 it is appan^nt that the acidity of the juice from the di»- 
c:i.s4m| lK*rri(*s is .nlightly higher than that of the juice from the sound oneti, 
while th<* ."iugar content is considerably lower. In table 2 it is shown 
that the sugar content of the dis<*a.^Mi fniit thnv days after inoculation 
\va> <l<'cn'iL»*<M| consi(h»ral>ly Ih*Iow that of the control samples. This 
may. of coursi', account for jmrt of the diffen»nce. Howex'er, the suirar 
rimtent of till' ino<ulated InTries after thnn* clays is a little over half that 
of the >4iun<i fruit, while the sugar content of the juice that leaks out of 
tlie rotted fruit i> alMMit one-eighth that of the jui<*e expressed from s<iund 
Urrie**. Th<* utilixation of th«' ^ugar by the fungus, then, can lianlly 
.'irrniiiit eiitiri'Iy for tli«' lower sugar <*onteiit of the juic<* from the inucnilated 
li«*rri«*> and much of the sugar must still n'lnain in the infected fruit. 



1917] Stevens and Hawkins: Rhizopus nigricans 183 

Other materials than sugars and acids are, of course, present in the 
strawberry juice. In order to obtain some idea of the amount of substance 
in this watery extract, freezing point determinations were made on the 
two samples of juice. These determinations were made with a Beckmann 
freezing point apparatus in the usual way. The depression of the freez- 
ing point (A) of these juices below that of distilled water and the calculated 
diffusion tension (7, p. 30-31) or osmotic pressure of which these juices 
are capable are shown below: 

The freezing point of the juice from the rotted berries is considerably 
lower than that of the juice from the sound fruit. As calculated by this 
method the solution from the rotted berries has, obviously, a higher dif- 
fusion tension than that from the sound fruit. The juice from the rotted 
berries then is a more concentrated solution of some substance or sub- 
stances than is the juice from the sound fruit. From these experiments 
with the juice from the sound and rotted fruit it is evident that the 
juice which escapes from the rotted berries contains at least a part of the 
soluble matter that is present in the cell sap of the berry before it is attacked 
by the fungus. 

DISCUSSION 

The effect of the fungus upon the various constituents of the straw- 
berry as shown in the foregoing pages is much the same as has been shown 
for other fungi and other host plants in similar studies. Most fungi 
apparently utilize the sugars in their hosts when growing parasitically. 
This has been shown by one of the writers in the case of the brown-rot 
disease of the peach (3) and some of the Fusarium rots of potatoes (6). 

That the fungi sometimes lower the pentosan content of their host 
when living parasitically has also been shown (4, 6). Rhizopus nigricans 
apparently does not utilize the acids of the strawberry to any extent. 
Some fungi are apparently able to use the acids in their host plant while 
others are not, probably depending on the ability of the fungus to assimi- 
late the specific organic acids that are present in the host. Behrens 
(1, p. 700-706) has shown that the acids in apples can be used by fungi. 
Sclerotinia, however, apparently had little effect on the acids in the 
peach fruit (3). 

In considering these results it should be remembered that at the time 
of the first analysis, i.e., three days from the time of inoculation, leak 
had progressed to an advanced stage. That is, the berries were flattened 
and a large amount of juice had escaped. At this time, as shown by table 
2, only relatively slight changes have taken place in the amounts of the 
various constituents for which analysis was made. There is apparently 
no difference in the pentosan content between the rotted berries and 



184 Phytopathology (Vol. 7 

sound berries of the same af^, and the difference in the amount of acid 
present is very slight. Some reduction in the amount of sugar, liolh 
sucrose and reducing sugar, has of course occurred but as the sugar was 
probably chiefly contained in the cell sap this change offers no due a« 
to the cause of leaking. 

The bio-chemical studies have, then, served to confirm the conrlusioo 
derived fruni the hu^tological study that the changes, detectable by the 
methods followed, which have taken place in the cells of the strawljerry 
at the time leak occurs are relatively slight. The histological study 
showed that the cell walls of the 8trawl)erry are seldom pierced by thr 
fungous hyphae and that the protoplasm of the cells is only slightly alterpd 
in appearanc(\ the nuclei in particular retaining their normal appearaner 
until the c<»lls are crushed. 

In a<*counting for the losj< of juice which occurs in strawberries attacked 
by Hhizopuji nigricann the only tenable hypothesis seems to Yye that thr 
fungus so affects the protoplasm of the cells, perhaps by secreting soaie 
toxin, that it is no longer capable of functioning as a semi-permeable 
membrane. In this connection it is interesting to note that (lortener and 
Blak<»sl<H» (2) have n»cently demonstrated the presence of a substance in 
Khizopus which is extn»mc»ly toxic to rabbits. Whether the proti>pla«iD 
of thi» strawl)erry is kille<i at once by the fungus or whether it is anr** 
thetized an<l rendenni permeable to the material dissolve<l in the cell 
sap is an op<»n (|uestion. Further investigations on this subject mrp 
planned. 

BiRKAr OF Pla.nt Indistry 
Washimjton, I). (\ 

LITKHATrUK (UTKD 

1. Hkhkk.ns. Joiiawkh. IVitrnf^o lur Konntnis dor (HMtfaulniii. CVntM. liakt . 

AUi. 2. i: 7(«)-7(m. IKIW. 
'J. (lOKTENKK. K. A., and Hlakkslkk. .\. F. (>lMu*rviitiontt on the toxin of Khiiop^M 

nifcriranH. .\ni«>r. Jour. PhvKiol. 94: XA-lVu. 1014. 

3. liAmxiNs. L. A. SoriK* rfTfrtH of th<* l»rown-rot fiinguii on the r(»mpo«ition of 

thr jx'arh. Afiirr. Jour. liot. 2: 71 SI. HH.'i. 

4. — Th<* utihiati<in of r«'rtain p<*iitoH4'H and roni|M>undN of pcntoum hy (tlo 

H'lla rinfculata. Ainrr. Jour. Ii«»t. 2: :C'> .'iSS. 191.V 

5. Thr dim*a»M* of |Mitat4N'H known an "Irak." Jour. \gr. Uciioarrh S: fU7 

t\. -- I'ifTiM't of rrrtain K|M'<*ic^ of KuMariuni on tht* rompodition of thr p«»tAto 

ixi\n'T. J«Mir. Aicr. Kf-MNinh 6: lH.VP.m. lUHi. 
7. LiviN(«M<i\. H K Th«' nMf of ditTuHJon and o!«nioli(* pn*fuiurr in pUnta. 149 p 

('hir.'iKo. hit>ho|craphy. p. '2. llNKi. 
H Sti.\kn^. Nkii. K. I'athotoKical hiHto|o|cy of HtrawlM'rriotf affected by 

of liotr>ti« and Khiz<ipui4. Jour. Agr. HriM^arrh 6: 361-306. 1916. 
\t. \\i:iiyKit. <*\Ki. I)i«* Pflanz(*ni«tofTv .... \KVt p. Jrna. 1911. 



WITCHES-BROOMS ON HICKORY TREES 

F. C. Stbwabt 
With One Figure in the Text 

In Ontario county, New York, trees of the shell-bark hickory, Carya 
ovaia, occasionally bear witches-brooms apparently caused by the fungus 
Microatrama juglandis (Bereng.) Sacc. During winter, while the trees 
are bare, the "brooms" are readily detected at a considerable distance. 
They are typical witches-brooms consisting of compact clusters of short, 
upright branches. They are of all sizes up to about two-thirds of a meter 
in diameter in the bare state and, of course, considerably larger when 
in foliage. As many as thirty "brooms" of various sizes have been ob- 
served on a single large tree. 

The leaves on the "brooms" are yellowish green above, and white and 
mealy with Microstroma spores on the under surface. Usually, they are 
smaller than normal and much curled. In mid-summer they blacken 
on the margins, then wither and fall prematurely. The fallen leaves are 
not replaced by new ones as happens with the cherry witches-brooms 
caused by Exaascus cerasi. The branch bearing the "broom" is, usually, 
considerably enlarged at the point of attachment of the "broom" and 
often dead beyond the point of attachment. 

The constant occurrence of Microstroma juglandis on the leaves leads 
to the belief that this fungus is the cause of the "brooms." Almost every 
leaf on every "broom" shows the fungus over its entire under surface 
while the leaves on all other parts of the tree may be wholly free from 
Microstroma. The presence of the fungus becomes evident as soon as 
the leaves unfold in the spring. This condition of affairs is not rare. It 
has been observed during seven consecutive seasons on a large number 
of "brooms" on nine separate trees in three localities — Geneva, Canandai- 
gua and Victor. 

On the other hand, Microstroma jiiglandis has long been known as a 
parasite on the leaves of walnut and hickory and is widely distributed 
in Europe and America; yet its association with witches-brooms has not 
been previously recorded. In fact, the writer has been imable to find any 
published account of witches-brooms on hickory trees. The writer, him- 
self, has occasionally observed M, juglandis on the leaves of hickory trees 
which bore no witches-brooms. At Geneva, in 1916, this was of com- 



[917] Stewart: Witches-Brooms in Carya 187 

)f the leaflets were attacked by Microstroma. On an adjacent branch 
-here was a larger "broom" every leaf of which was covered with Micro- 
itroma, but none of the other leaves on the tree were affected. A later 
examination, made on July 2, revealed no change in the "broom" except 
hat the margins of the affected leaflets had begun to blacken. Further 
>bservations were impossible owing to the accidental destruction of the 
^oung "broom." 
New York Agricultural Experiment Station 
Geneva, New York 



A NEW LEAF-SPOT DISEASE OF CHERRIES 

Bert A. Rudolph 
With Three Figures in the Text 

In August , 1913, a conspicuous loaf-spot disease of sweet cherries was 
ol)ser\'ed by the writer near San Jose, California, and specimens have 
lM*en received from the principal cherr>' growing sections between Red- 
lands, California, and Cor\'allis, Oregon. No mention of it has been 
found in any of the literature examined. Descriptions were sent to F. C. 
Stewart, Ceneva, New York; Howard S. Heed, BIacksbui|s, Virfinia; 
M. B. Waite, Washington, I). C., and Donald Reddick, Ithaca» New 
York, and all expn\sse<i doubt as to its occurrence in their localities. It 
is lH»lieve<l to Ik; jx^culiar to the Pacific coast. 

IVa<i, definite, circular spots from one to al)OUt 14 mm. in diameter 
ap|K*ar on the leaves. The dea<l areas are a pronounced reddish brown 
or chestnut to mahogany color, and are .sharply differentiated from the 
living ti.Hsue, exten<ling from epidennis to epidermis and commonly marked 
with a delicate, (*(>n(*entric zonation consisting of narrow lines and liarker 
bands. St»vcTal spots may coalesce* to fonn one large one. 

i )n the upper surfa<*e of the leaf may nearly alwa^'s l)e found a minute. 
whitish gray pustule lo(*ated in the <*enter of the s|M>t, and about which 
the zones an* concvntric. The pastules an' upliftcnl bits of epidermal leaf 
ti.NSue, and a minute inM*ct of the family Chalcididae has regularly lieen 
found in tliein. 

Within the s|M>t then* may U» a definite, centnd. circular portion which 
i> lighter than the n*main<ler. This inner an*a sometimes reaches mm. 
in diameter and is ochra<vus to f(*rnigineus (Saccanlo's Chromotaxia^ 
or it ni:iy U* entin*ly absent. The darker portion is ciLstaneiis to badius. 
Th«* pw«tul«». if pn'H»iit. is Ineated in the eentiT of the inner, lighter area. 
if •*ueh an nrvii nreurs. The nnd(*r sid(* of the s|M)t pn*sents a slightly 
dilTtTtht <'n|nr frmn the up|MT. The inner lighter an*a is isaliellinus, antl 
thi' retii.'iiiiiiiK |M»rtinii Irttfricius. iK'ing lighter than the com*s|H»ntiing 
ana nn the up|MT surfaer. 

Tlif «l«Md ti^^^ue n'niaiii*<i intact within tlu* leaf. 

Soiiiftiiiir^ ihf s|M>t-« *ipn'ad niit in an irretrular, Mimewhat indefinite. 
nn»*:iif-liki' fa*«hiori i tig. 1;. 



1917] Rudolph: Leaf-Spot Disease of Cherry 191 

The details of subsequent inoculations are recorded in the writer's 
thesis, deposited in the library of the University of California. In all, 
over two hundred inoculations were made on the following varieties of 
cherries; Royal Ann, Richmond, Morello, Black Tartarian, seedling sweet 
cherry and California Wild Cherry (Prumis ilicifolia Walp.). During 
the winters of 1913 and 1914 experiments were confined to the leaves of 
seedlings. In the spring of 1914, however, large numbers of inoculations 
were made upon the various named varieties. The method of inocula- 
tion was the same as that described earlier. Checks were made on one 
side of the mid-rib and inoculations with a flamed needle on the opposite. 
Not more than ten of all the inoculations made in this manner were nega- 
tive. In most of the inoculations no bell-glasses were used, and the spots 
developed quickly, although less rapidly than where covered. About 
twenty other inoculations were made in lots of two to five by laying bits 
of the fungus in agar on the leaves without puncturing or injuring them in 
any manner. All these were negative. The greater part of this work 
was done in a greenhouse without heat. 

The fungus is particularly active when inoculated in the leaves of Cali- 
fornia Wild Cherry. About three dozen inoculations were made on this 
plant, and not more than five proved unsuccessful. Frequently arti- 
ficially inoculated leaves were so badly affected as to be shed from the 
tree. This was especiaUy conunon when the trees were kept under bell- 
glasses. The spots produced differ greatly in color from those on the 
leaves of sweet cherries. There is usually a circular, inner area in each 
spot which is avellaneus on the upper side and isabelUnus on the lower. 
The remaining or outer portion of the spot is isabelUnus, and the lower 
side latericius. At times the spots may be a deep brown color, especially 
when formed more slowly. 

Microtome sections made of the freshly produced spots stained with 
Congo red and methylene blue show best the action of the fungus. The 
parasite is intercellular. The chloroplasts of the cells lying just beyond 
the tips of the advancing mycelium are first affected and cannot be dis- 
tinguished. The cells collapse and disintegrate rapidly as the fungous 
threads come in contact with them. 

All inoculations in the bark and wood of normal cherry twigs were nega- 
tive. Over two dozen inoculations were made on stems up to 2.5 cm. in 
diameter. The bark was first sponged with alcohol. Slant cuts were 
made with a flamed scalpel and the infectious material placed beneath 
the flap, or inoculations were made by puncturing the bark through the 
spore-bearing material. Both types of inoculations were either left ex- 
posed or wrapped with thoroughly boiled linen strips or bound in absor- 
bent cotton. Checks were also made in the same way. The wounds 
healed normally, the plants apparently being unaffected by the fungus. 



102 



Phytopathology 



(Vol. 7 



When inoculated in the leaves of other plants the results are often as 
pronounced as in the cherr}' leaves. The leaves were first sponfced with 
alcohol and the inoculations and checks were made in the usual man- 
ner. The results obtained are shown in table 1. 



TABLE 1 



ResuiU of inoculations of leaves of various hosts with a species of Allernaria fi 

cherry leaves 



HOST 




mtmvvn 


OBMtBTAnolM 


Apple (Pynis Malus L.) 

Winesap 

Newtown Pippin 

Box Elder (Acer negundo L.) 

Hungarian prune (Prunui4 domestica L.) 

Wickson plum (Prunus triflora Roxb.), 
(P. Simonii Carr.) hybrid 

Orange (Citrus nobilis Ix>ur.) 

King Mandarin 

Loquat (Kriobotr>'a japonica Lindl.)... 

Potato fSolanum tulierosum L.) 

Avocado (Persea gratissima (iaertn.).. 

Watermelon (Citrullus vulgaris 
Schrad.) 

Pearh (Prunus pc'rsica S. A Z.) Oaw- 
fcird p<»ai'h 


20 
25 
50 
18 

•6 

20 
21 
30 

10 
40 


All positive 
All positive 
All positive 
All positive 

All positive 

Doubtful 
Negative 
Negative 
All positive 

All positive 

Positive 


Jjirge reddish spota 
Large reddish «poU 
Large brown spoU 
Small brown spoU. 
Developed slowly 

Small brown spoU. 
Developed slowly 

Spots liarely Urfsr 

than on therheeki 
Spots no larger than 

on the checks 
Spots no larger than 

on the checks 
Large reddish brown 

spotii 

Black spots. Devel* 
oped slowly 

Irregular gray* 
brown spots 



In ^*m*nil it wiis found that the funj^is prcxluctMl its optimum ftrowth 
in the If'uf tissue* when tlu* atniosphon* W!is moist and warm and sunliKbt 
at a niiiiiriiuin. The men* shading of an infected leaf with a piece of 
pajMT was found to fH'nnit the prcMJue'tion of largtT spots in a nhorter time 
than whrn* the leavers were exi)os<»d to direct Kunlif2:ht. The fungus is 
a typi(*al wound panu^ite. all incx'ulations on uninjured leaves ha\*iiig 
failiMl. Whrn a young leaf w:is incK'ulated lH»fon» Innng fully developed 
a shot-bolf I'fTtTt M)mrtim(v n'sulted on its exiuinsion. 

The fungus gn»w vigorously on the conunon culture media, and its 
more imfMirtant characteristirs an* as follows: 



1917] Rudolph: Leaf^pot Disease op Cherry 193 

On non-nutrient agar. Growth rapid, mostly confined to the surface 
of the medium which is not discolored. A small amount of long, aerial, 
dry, silky, gray-white myceUum is produced. Spores thinly scattered 
over the surface of the medium. 

On nutrient agar (containing meat extract, peptone and salt.) Growth 
vigorous, a copious aerial, downy mycelium is developed consisting of 
long, branched, silky, gray hyphae. Spores commonly produced in 
greatest numbers in concentric zones which are dark green at first becom- 
ing sooty black with age. The spores are oUvaceus under the microscope. 
The agar is cleared of any cloudiness by the fungus as it develops. 

On steamed rice. Growth vigorous. A snow-white, aerial, downy 
myceUum first develops which darkens to a dirty, greenish gray with age. 
A flesh-colored peUicle is produced upon the surface of the medium darken- 
ing with ^e to black. The rice grains gradually become colored a Ught 
yellow. Spores are produced close to the surface of the pellicle and be- 
neath the longer aerial hyphae. They are pale oUvaceus imder the 
microscope. 

On bread and prune juice (Duggar's Fungous Diseases of Plants, p. 24). 
Growth vigorous. A copious, downy, aerial mycelium is produced which 
is dull white at first becoming a dirty greenish gray with age. Patches 
of older parts of the aerial mycelium are often yellowish. A cream colored 
peUicle is formed on the surface of the medium becoming black with age. 
Spores develop close to the peUicle beneath the longer, aerial hyphae. 
They are dark oUvaceus imder the microscope. The medium becomes 
darker as the fungus develops upon it. 

On steamed potato slants. Growth vigorous. A white, downy, aerial 
myceUimi is first produced becoming a dirty greenish gray with age. A 
peUicle is formed upon the surface of the slant and may be flesh colored 
or greenish, becoming black with age. FinaUy the aerial myceUum usually 
collapses, and only a black, shining peUicle is observed. After growth 
has entirely ceased the plugs no longer react for starch with iodine but 
give a good test for reducing sugar with FehUng's solution. 

On beet agar. Growth vigorous. An aerial, downy myceUum is first 
produced which is gray-white becoming greenish and finally black with 
age. Cultures have a sooty, granular surface punctuated with whitish 
hyphae in scanty tufts and occurring singly. The aerial myceUum may 
or may not be somewhat zonate. Spores are inclined to be smaller and 
decidedly darker than those found on other media, being oUvaceus to 
fuUgineus imder the microscope. 

On steamed cherry twigs. Growth vigorous. A copious, downy, aerial, 
white myceUum is first produced which becomes a dirty greenish gray 
to black with age, giving the cut siufaces a sooty appearance. The bark 



194 Phytopathology [Vol. 7 

ifl Hpareoly covered. Spores are proiluced in abundance close to the nit 
surfacen of the twif^. The}' are somewhat smaller than thoee on vmriouf 
other media and are dark olivaceus to fuligineus under the microscope. 

On nat^el oranges (Sterilized by washing the surface with mercuric 
chloride solution). When inoculate<l in moist chambers at the navel 
end a black rot of the rag or pulp cells results which is identical with that 
produced by Altemaria Citri Pierce (fig. 2). At the point of inoculatioii 
an aerial mycelium develops which Ls pulvinate and gray-white at firat, 
becoming a dirty greenish gray with age. The rind discolors becoming 
olivaceus in a gradually increasing area around the fungus colony. Se\'eral 
months after inoculation the aerial mycelium, having overrun the oranf^, 
bleaches out and ultimately l)ecomes a l)eautiful pink. The whole fruit 
gradually settles down with a soft, moLst rot. 

On + 5 nutrient agar agar. This medium remains liquid due to the high 
acid content. The i.solated colonies of ai'rial mycelium are whitbth at 
first l)eroming s<M)ty black with age and rounded or hemispherical. On 
titrating the incdiuin thn*e ww'ks after planting it wiis found to have lieen 
re<luc€»d to -f 4. The color was changed from a light amlKT to a <leep 
l)rown (fuligineas). This destruction of acid by the fungus was oliserved 
on various other media. The average of four titrations was alwa>'s taken. 

In genertil it was ol)s<Tved that tlu* color, shape and size of the spores 
pnMluce<i on various me<lia may var>' slightly, but the most important 
characteristics n*niain the same. 

The fungim l)ears a striking similarity to Altemaria Citri Pierce and e\Tn 
a closer n^lation-^hip to an Altemaria found on watermelon leaves. Purr 
cultun»s of the thn»<» fungi wen* obtained by the single-spore methoii. 
In drop rultun^s of 4-2 nutrient broth the fungi may \h* said to l>e ich^ntird 
morphologically. Possibly the spon*s of A. Citri are slightly rougher than 
those* of the other two, but this difTerenc(* was not found to \)o amslsmi. 
The thn*<* fungi <'antiot Im* difTen*ntiate<i on nutri(*nt and non-nutrim 
agar, and tlu* nits (inxhu'cd by them in navel orang(*s an* identical. 

The cherry .Xltcniaria cannot Ih» distinguished from the wateniH*lo' 
.Mterniiria on -f-'> nutrient agar, but is di.stinguished from A, (^htri c: 
this medium. The latter jmMhK'es colonies which an* circular, whiti^ 
at tir>t. iNM-oiiiing gray with age. They an* also flat or depn*ss<H| wi 
erater-like e<*nters which an* darker in color (gri.sc*us-oIiva«»us). 

The cherry .Mternaria is distinguishtMi fn»m the oth€*r two Altenia 
when inoculated on <*herrv leaves only by the size of the spots and t 
rajudity uith wliitli they an* produ<*e<l. The watermelon Altenia 
priM|im»s the >nialle>t >|M)ts. and they lievelop nion* slowly, but the tl 
fen'MH' is very slight. Over four <lozeii ino<*ulations wen* made with 
(Vri and the watermelon .Mternaria. 




1917] 



Rudolph: Leaf-Spot Disease op Cherry 



195 



The cherry Altemaria was distinguished from the other two by its ac- 
tion on watermelon leaves (var. Cuban Queen), being the least virulent 
of the three fungi. Sixteen inoculations each were made with the cherry 
Altemaria and A . Ciiri on separate plants. Twenty-four inoculations were 
made with the watermelon Altemaria on a third plant. The black spots 
produced were identical, but the watermelon Altemaria spread to the stem, 
killing the plant, while the cherry Altemaria confined itself to the leaves. 
A. Citri formed sUghtly larger spots than the cherry Altemaria but also 
confined itself to the leaves. 

The cherry Altemaria may be further distinguished from the other 
two in the matter of spore germination. Fresh spores of the cherry Alter- 




FiG. 3. Sporophores and Spores of Alternaria Cithi var. Cerasi 
From drop culture of 4- 2 beef broth with peptone. X 500 

naria will germinate in neutral, +1, and +2 broth in less than twenty- 
four hours, but in +7, and +8 broth germination rarely takes place in 
less than a week. It will grow and produce spores in +8 nutrient broth. 
Spores of the watermelon Alternaria will germinate in +8 broth and grow 
feebly, but the fungus has rarely been observed to produce spores in this 
medium. Spores of neither will germinate in +9 broth. A, Citri will 
grow and produce spores in +6 broth, but spores will not germinate in 
+7 broth. Spores of both the cherry and watermelon Alternarias ger- 
minate in +7 and +8 broth with the greatest difficulty, the germ-tubes 
developing in an abnormal manner and resemble the budding of yeast. 
Ordinarily the germ tubes are straight with but few septa, but in broths 
of high acidity, the opposite is the rule. 



196 Phytopathology (Vol. 7 

The cherry Altemaria cannot be distinii^ished from the others by 
fcprmination testo in alkali solutions. All germinate readily in tap water 
containing 8 per cent normal alkali (sodium hydroxid), but in —10 tap 
water germination may not take place for a week. None of the three 
fungi will germinate in — 11 tap water. 

On steamed rice the watermelon Altemaria colors the rice ipiuns a 
riightly lighter shade of yellow than does the cherry Altemaria, while 
A. Citn colors them all shades of yellow to laterieious. In other respect* 
the fungi arc identical on this medium. 

On +5 nutrient agar the growth and acid destmction by the cherry 
Altemaria was identical with that of the watermelon Altemaria. A 
Citri within the same time only reduced the acid content 0.6 per cent 
instea<l of 1 per cent. 

Tlie longevity of the cherr>' Altemaria is largely dependent upon the 
presence of moi.sture. However, sports ov(»r fourteen months old pro- 
ducer! on steamed cherr\' twigs, which drie<l out soon after the planting 
of the fungus on them, wen* found to l>e viable, although germination 
rarely Vnyk [)laoe in less than a we<»k in neutml or +1 broth. 

The various (»xix»riments enumerated show the three fungi to lie very 
closelv n»Iated. The nanie of the watennelon Altemaria is not known, 
but it is not lx*lieved to Ix* .4. cucurbitce Ia'X. which is also parasitic on 
melon vines. The spon»s of A. ciicurbita' arc* descril)ed as longer and 
narn)wer -mostly (>() to i\H by 8 to 9 /i — while the spores of this particular 
Altemari^i an* only U) to 47 by 0.8 to 15/4. 

The ch<»rrv .\ltemaria is not In'lieved to Ih» the same as Altemaria Certun 
Potebniii found at Kharkov, Russia, the si>on's of that fungus l)eing dc^ 
cide<lly larger and pnMluced in v(4vety patclu*s on dr\' margins of leaves, 
a(H*ording to Saccardo. 

Believing this fungus to U' hitherto undesrrilMMl. and being of the opinion 
that its rIoM' relationship to A. Citri Piera* entith's it to l)e elassificMi as 
a variety of that s|M»('ies the writ(»r suggi*sts the name Altemaria (^itri 
Pierce, variety Cvrasi with the following technical description. 

Altemaria Citri Pierre var. Cerasi nov. var. 

PrcN luring <lead >iMits on leaves of swe<'t cherr\'. Sjxits 2 to 14 mm. 
in diameter, n'dtlish brown or chestnut above and lighter below, often 
faintly zonat(% soni(*times with a distinct, lighter <*olore<l central area and 
UMially ^ta^tinK from an uxm^vX injury, sometimes extending outward in 
an indefinite nio?^ii<'. 

\ wound pani>ite only, :ls shown by artificial infections, capable of 
pnxluring s|M)ts on leaves of numerous plants. Distinguished from A, 
Citri PiiTn* with difficult v. 



1917] Rudolph: Leaf-Spot Disease of Cherry 197 

Mycelium, in leaves of sweet cherries, sub-epidermal, of slender, sep- 
tate, hyaline hyphae, 1 to 3 m in diameter. Aerial mycelium very rarely 
produced and then only in the presence of unusual humidity and opti- 
mum temperature, hjrphae 3.4 to 4.8 n wide, gray-white to pale oUvaceus, 
long, silky, branched, septate; conidia, not observed in field, occasionally 
produced in presence of unusual humidity and optimum temperature — 
then close to the lower surface of the leaf, never on long, aerial hyphae, 
clavate fusiform or elUptical at maturity, 16.3 to 57.8 by 6.8 to 15.3 /*, muri- 
form, translucent, oUvaceus-brown, slightly verrucose or smooth, becoming 
constricted at the septa with age, transverse septa commonly parallel, 
3.3 to 9.9 fjL apart, with short, smooth, hyaline-subhyaline isthmus which 
is usually 3.4 by 3.4 /x; several catenulate, in cultures 2 to 7 in simple or 
branched series, somewhat variable in size, form and color, germination 
from any cell, produced abundantly on various cultiu^ media. Conidio- 
phores, short, in cultures 1.7 to 153 /* by 1.7 to 6.8 m, olivaceus-subhyaline, 
erect, in general narrower than the vegetative hyphae. 

Bureau of Plant Industry 
Washington, D. C. 




BLISTKU SPOT OF APPLES AND ITS RELATION TO A 

DISEASE OF APPLE BARK 

Dean H. R o b e^ 

With Three Ficjureh in the Text 

In the present pufXT is descrilx'd a (ILseaHe of apples (fruits) which hit 
\KH*n under investigation through two {^rowing seasons. A brief report 
has already l)een published by the writer^ but so far no other mentioa df 
it luis l)een found in the literature. There is fqven also a descriptaoil cf a 
dis(*aseof apple bark which seems to l)e causally rt^ated to the fruit 
The ex|)eriinental pr(K)f is not yet complete but considerable 
that the relation actually exists has l>een obtained and will be found 
marized in the s<»c()nd part of the papt»r. 

BLISTKK SPOT OF APPLEH 

Occurrence ntul general apiHtarance of the disease 

The blister-s|)<>t dis<*:i.se was first noticed on July 6, 1915, on Noifoft 
Pcauty (dwarf) as roughly (*ircular or sometimes irregularly lol)ed shallow 
blisters, varying in color from light brown to black, and in siie from 1 lo 
r> mm. in diameter (average aUmt 2 mm.) by 0.2 mm. in depth. Searrh 
through the experiment station orchard at Mountain (irove, Miiwtmri. 
thru .showed similar .s|K)ts on Melon, Ishewold, and Hawley. In 1916 
s(>ots wen' first found aUxit the mid<lle of June on Blue Peamiain, Higfnn- 
Iwitham, Yellow Transparent, Ii<'noni, Melon, Hock Pippin, I^Ansingburg. 
Karly Hi|M*. Victuals and Drink. Isham, Ishewold, Hawley. Norfolk 
Hcauty, Hr<l Astrachan, White Pippin (wrongly given as Yellow Xewt4»n 
ui the rc|N>rt mentioned earlier).* Kloiidyke, Duling, ami Jonathan. AHow- 
in^ for the fact that .su<*h varieties as Yellow Tran.^^pan'nt and Ke<l .VMra- 
rliari wen' goiu' when afTe<*ted apples wen* di.scovere<l in 191o. this list 
'Hhow> the diseasi' much mon* prevalent in the station orclianl in 19IH 
tliaii m P.M.'). Little is known of its distribution. .\ppU»s showing typi- 

' The writiT v%i>lirH to HrkiKiwIcd^c hi** iii«l('l>t4'<hirf(«4 to Mr. IlHTold Swartimt and 
.\Iij»?» n«';itrir«' W liifc. uithoiit u ho*ti> <:in'ful :iii(l i*rtiri«*fit hflp thr work hrrr rr- 
|»«irt«Mi roiiM rio* have iMM'ti :l^^oIl)pli^h4■<l m [\\v tunc HVailjihlr. 

' Ho>M'. I)«';iii II llliHti-r >in»t of :ippl««'» ;i!i?*tr:irt . Phytopath. 6: II0 Krh 
P»|ti. 



200 Phytopathology [Vol. 7 

appearance dcscrilxHl above (fig. i, B). On white or yellow apples such 
as Yellow Transparent the spots are surrounded by a narrow greenish 
ring; the same ring is found on Benoni and Duling, which are red when 
ripe, but the spots on Red Astrachan show a red ring. 

The disease is not a serious one in the way that bitter rot is serious. 
Nevertheless, susceptible varieties often have the whole crop so seriously 
blemished as to be unfit for packing in any but the lower commercial 
grades. P'ortunately such severe injur>' seems to be confined to varieties 
of minor commercial importance. 

Cause of the disease 

The disease is caused by an organism l)elonging to the genus Piieudo- 
monas. It does not seem to have been descrilx^d previously and the 
following name is propo8e<l and a description appended: 

Pseudomonas papulans n. sp. 

Morphological characteristicji. The organism Ls a rod, motile by one 
to six polar flagella. Fiagolla occur at lx)th poles and were demonstrated 
by means of Ixx'ffliT^s flngclla stain, using stains on Pseudomonas fiuart^ 
cens as check. (Px. fluorescena fumisheil by the American Museum of 
Natunil History', New York). Staine<l from twenty-four-hours-old 
agar cultun's the organism shows as a short ro<l with rounded ends, meas- 
uring 0.9 to 2.3 M lofif^. by about 0.() ^i in diameter. It occiu« singly and 
ver>' often in pairs. No si>ores or caj)sul(»s have lx»en \lemon8trat4*d. It 
stains n*adily with carbol fuchsin, gentian violet, and methylene blue. 
It is not acid fast and it den's not .stain bv (iram. 

Cultural characterii<tia<. The following account is base<l on a study of 
25 stniins of the organL^m isolatc<l from (1) naturally infectetl sp«»ls. 
(2; artificial infections, and (3) infect ioas pnxluced with the n«iM>late<i 
organism. Culture's wen* coinpanMl with li. coli and B. amyUnporus (fur- 
nished I IV the .\iucrican Mummhii of Natural Hi.stor\', New York). 

Thr organism does not form gas from |)eptonized Inmillon containinn 
dcxtniM*. sn(M*haros4\ nialtos<'. hu'tose. glycerin, or maiHiit, and it d<M»!* 
not rl<Mi<l the cl<KS(*d rnd of th<' fcrmrntation tuU* in any case. (tn>wth 
sto|h« short in thr neck of the tulM*. indicating an obligate aerolM.\ The 
oric:int>tii clouds lM*<*f bouillon -h H). slightly in twenty-four hours, and 
nHMJiTatrly in forty-«'ight hours. It li(|U(*fics gelatin slowly at 20^1 \. 
li(|uefa<*tion not U^ing complete* in test-tuiN* cultun^s until after twel\*e 
to fourtn'ii w<H*ks. Some >t rains form a soft (*oagulum in plain milk. 
S4»ine no roaguluni at all. but all of thiMu clear it in alnmt twenty ila\'ii. 
The organism blues litmu> milk throughout <luring the first six day». 



1917] Rose: Blister Spot of Apples 201 

with the formation usually of a soft coagulum, and then gradually decolor- 
izes it from above, with the production of a dark blue* color thr9Ugh- 
out after sixteen to twenty days. On plain agar it produces a filiform, 
slightly convex, whitish growth. On potato cylinders it produces, after 
forty-eight hours, a whitish, filiform, irregularly spreading growth, which 
after seven days shows a sUght browning, accompanied by a sUght darken- 
ing of the mediimi. The optimuip temperature seems to lie between 25® 
to 28*^C., though fairly good growth takes place at 20*^C. It does not 
grow at 37°C. The thermal death-point has not been determined. On 
dpxtrose agar and glycerin agar the organism produces a light green fluores- 
cence as also in Uschinsky's and asparagin solutions, but it does not grow 
in Cohn's solution. A test with six strains showed that the organism 
grows in bouillon over chloroform and tolerates hydrochloric acid up to 
+ 15 on Fuller's scale, and sodimn hydroxide to —5. The optimmn re- 
action for growth seems to be about +10. 

The organism is sensitive to sunUght. Petri dishes one-half covered 
with black paper and exposed to sunlight, on August 3, on a bag of crushed 
ice showed, for six strains, an average of 98 per cent killed after an exposure 
of ten minutes. Six strains inoculated into test-tubes containing different 
amounts of sodium chloride showed growth in all up to and including 
4 per cent. Using the method described by Edson and Carpenter* it 
was found that the organism, produces alkaU in plain milk during the first 
ten days, then increasing amounts of acid up to forty days. On peptonized 
bouillon containing two per cent of various sugars and alcohols it produces 
acid from dextrose and saccharose, alkaU from lactose, and maltose, and 
neither acid nor alkali from glycerin or mannit. 

Quick tests for differential purposes; bluing of litmus milk followed by 
decolorization from bottom upward accompanied by slow digestion and 
the formation usually of a soft coagulum; fluorescence and luxuriant rugose 
growth on glycerin agar; fluorescence on neutral gelatine but none on gela- 
tine + 10. 

Isolation of the organism. The organism was easily isolated from affected 
apples by the method of poured agar plates. Spotfe were merely given 
a good washing with steriUzed, distilled water, sometimes preceded by a 
brief rubbing with a finger dipped in alcohol. The diseased material was 
then scraped off with a sterilized scalpel and dropped directly into melted 
agar. The colonies appeared in from thirty-six to forty-eight hours, 
usually in pure culture. They were thin, smooth, circular, glistening, 

• Saccardo, P. A. Chromotaxia seu Nomenclator Colorum. 1-22. 2 pi. Pata 
vii, 1894. 

* Edson, H. A. and Carpenter, C. VV. Micro-organisms of maple sap. Vermont 
Agr. Exp. Sta. Bui. 167: 321-610. 1912. 



2()2 Phytopathology [Vol. 7 

whitish by n^flerted liRht, bluish by transinitted liRht, and 0.1 to l.U 
mm. in diameter. Not all the affected varieties were used in thia work 
but no difficulty was experienced in obtaining pure cultures from thoete 
that were usetl. 

Inoculation, l^in^ sul>-cultures from single colonies, the disease hah 
l>een repro<luced on six varieties of apples. In this work 123 apples were 
use<l, 60 of which were che<*ks. All of them were treated cm the trees 
and were bagfced after treatment. The incubation period averaised about 
fourteen days, thouf^h some apples failed to show signs of the disease 
until the end of eif^hteen to twenty-five days. Some strains of the orfcanisin 
were infectious on all the varieti(»s teste<l, others on only one or two. 
Further work is nc<*essar>' to clear up this situation. 

Inoculations wen* made in thret^ different ways, using twenty-four to 
fort y-t»ight -hours-old iKuiillon cultun»s: 

1. By spniying uninjunnl apples with th<' bouillon culture. No info^ 
tion n*sulted. 

2. By spraying apples whi(*li had first Innm pricked with a flamed needle. 
Seventy-two |kt cent infection resulted on Yellow Transparent, Jonmthan, 
Melon, Hawley. and White Pippin. No signs of infection appeared on 
I^*noni. 

3. By hy|KMlennic inje<*tion just under the epidermis. Eighty per 
e<>nt infection resulted on Benoni, Hawley, Jonathan, Melon, and White 
Pippin. 

Ino(*ulations with n*isolat4Ml (uiltun's by hyixKiermic injection on ^liite 
I^ppin, Jonathan, and Melon wen> also successful. The organism isolated 
from infections agn>ed in all characteristic's, morphological and eultural, 
with the one us(mI for ino<*ulation. Checks to correspond with the three 
methods of inoiHilation descrilM'd al>ove nnnaineii healthy throughout 
tlu* s(*ason. 

KorcSII-HARK OK SC'CKFY-HAKK (WNKEK OP APPLBS 

DeAcriptitm of the f{ij<ease 

What might U* called tlu* ({uiescent st:tge of the scurfy-lmrk disease 
<M*rurs :us patches of n>ughen<Ml scaly bark which simiewhat respmhie 
blotch ranker {PhyUostictti suUtnrin K. and Kj. but differ fmm it in show- 
ing no blotrh pycnidia and usually no regularity of cracking up and down 
or arri»NS X\\v limb (fig. 2. .1). Thes<* roughened |):itch(*s var>' gn*atly m 
M/e fn»ni tliosi' covering only a few sipiare centimeters to thost* covering 
till* wliolf Hjdt' nf a limb for a meter or in<»re. Thev an* usuallv f(»und i»n 
thf iiurth ^ide of a limb and with few exceptions an* bordenNi by a pimpltMl 



1917] Rose: Blister Spot of Apples 205 

scaling off of small patches without the formation of a definite spongy 
layer. Sometimes the diy, brown vestiges of such a layer can be foimd, 
sometimes not. Possibly in such cases it develops slowly and progres- 
sively from one point to another, loosening the bark only a little at a 
time and drying down almost immediately. 

No detailed studies of the diseased tissues have been made. A pre- 
liminary survey of both free-hand and microtome sections shows the pres- 
ence of peculiar spots or pustules like those described by Hewitt* in his 
work with a new disease of apple bark in Arkansas and by the writer* 
in work with what is almost certainly the same disease, known at this 
Station for over ten years under the name of pimple canker. It remains 
to be proved, however, whether this disease is a phase of or in any way 
lielated to the true scurfy bark canker. The most that can be said at 
fvesent is that they show considerable morphological similarity and are 
often though not always associated on the same tree. 

Besides the deep-peeling type of scurfy-bark canker there sometimes 
occurs a "shallow-peeling*' type, in which only the epidermis is loosened. 
A spongy layer is formed here also, but it is thinner and more evanescent 
tiian in the deep-peeling type. 

Occurrence of the disease 

The disease occure on such standard varieties as Ben Davis, Jonathan, 
Logan, White Winter Pearmain, Beach, Stayman W'inesap, Munson, 
and Marsh, but much more severely on certain dw^arf varieties. 

The writer has found the disease in numerous orchards in southern 
Missouri and has received specimens of it from perhaps a dozen localities 
scattered over the state. No information is at hand as to is occurrence 
in other states, unless the trouble investigated by Hewitt in Arkansas be 
considered a phase of it. Affected trees are not quickly killed as in the 
case of Illinois canker — caused by Numviularia discreta — but there is no 
doubt that the peeling off of fresh layers of bark every spring is definitely 
injurious to the tree, aside from the opportunity given for entrance of 
canker fungi and various bark insects. 

Cause of the disease 

The disease seems to be caused by the same organism as that of the 
fruit spot. Poured agar plates, using material from (1) the deep lying 

* Hewitt, J. Lee. An unknown apple disease. Arkansas Exp. Sta. Bui. 122: 
481-491. 1912. 

• Rose, Dean H. Report of the Pathologist. Missouri State Fruit Exp. Sta. 
Rept. 1913-14 (Bui. 24): 30. 1914. 



206 Phytopathology f\*OL. 7 

spoDfor layer, (2) the pimply ridge at the edge of roughened areas, (3) 
areas exposed naturally the preceding season when the loosened layer 
peeled off, (4) the spongy layer under loosened epidermis, gave pra<rtically 
'pure cultures of an organism very similar, morphologically, to the blister- 
spot organism. Extensive cultural studies show, however, that instead 
of one organism there are two different ones or possibly two closely related 
but distinct varieties. One of them, represented by five strains, shows 
great similarity in morphological and cultural characteristics to the bliiH 
ter-spot organism; the other, represented by fifteen strains, resembles 
the blister-spot organism morphologically but differs from it in cultural 
characteristics. It liquefies gelatin rather rapidly, it produces a green 
fluorescence on nutrient agar and it begins to clear litmus milk inside of 
twenty-four to thirty-six hours. The first and second of these are not 
characteristic of the blLster-spot organism, while the last is characteristic 
only of three strains. 

Inoculations 

Inoculation of bark with the rapidly liquefying bark organism produced 
swollen spots 1 to 2 mm. high and covering an area of roughly 1 sq. cm. 
(fig. 3, C). At these swellings the typical signs of the disease were re- 
produced, in miniature, and an organism was recovered which agreed 
in cultural and mor|)hol(>giral characteristics with the one use<l for inocula- 
tion. The check.s showed only a slight swelling. Typical blister spots 
on the fruit wen* pnxiuced by inoculating Jonathan and Melon apples 
with l)oth bark organisms and these in turn were recovere<l fr«>m the 
lesions pr<Hluce<l. While such evidence is strongly suggestive it is not 
final pnK)f, an<l nion* work is nec<\ssar>' l)ef()re the true relation U»tween 
th« fruit di.s<»jLS<» and the bark di.*^»jis<» can Ih» dis«rovenHl. 

In table 1 arc? shown the results of compamtive tests made with the 
blLster-s|>ot organism and the rapidly li(|U(*fying bark organism. 

A similar comi)arison lM*tw<H*n the bark and* the blister-spot organL^n 
on the onr hand an<l pHcudomorum fluorescent on the other .show s<i many 
<liffrrrnei»s that the two fonner must Ik» considrn»d entin»lv distinct fn>m 
the latter. 

Further work on these <iLs<':i.ses should include (Da continuation of 
cultunil studi(*s of the blister-s|H)t organism and the two bark organbuiut. 
(2; (To>s-incMnihitions from bark to fniit and from fniit to l>ark, uii a 
study of the time and nxxle of infection and (4) a study of the microscopi- 
cal eli:iraeteri>tirs of health v and <lis<»as«Ml tissues. 



I 



1917] 



Rose: Blister Spot op Apples 



207 



TABLE 1 
Comparison of the blister-spot organism and the bark organism 



Agar plates. . 

Agar slant. . . 
+ 10 bouillon 

Gelatin stab . 



Neutral gelatin stab., 



Litmus milk 



Sterile milk. 



Glycerin agar. 



Uschinsky's solution. 



Nitrate reduction 

Indol test 

Ammonia test 



Resistance to sunlight. 



Flagella. 



BLr8TKB-«POT OBOAKISM* 



Whitish colonies, slightly 
bluish in transmitted 
light ; medium not 
greened 

Growth rather slow, no 
fluorescence 

Clouding and pellicle; one 
strain showed faint green 
fluorescence in 2 weeks 

Liquefaction slow, begins 
in 2-3 days. Complete 
in 12-14 weeks. No fluo- 
rescence 

Liquefaction slow. Slight 
fluorescence 

Alkaline reaction for 10 
days, then slow increase 
in acidity up to 40 days. 
Medium cleared in 2-3 
weeks; final color blue 
throughout. Banded 

appearance produced by 
3 strains 

Clearing begins in from 7- 
10 days, complete in 17- 
20 days 

Growth vigorous, elevated, 
contoured to rugose. 
Moderate fluorescence 



Clouding moderate; bluish 
green fluorescence. Pel- 
licle of pseudo-zoogleae- 
like fragments 

None 

No indol in 20 days 

Ammonia produced 



Average of 98 per cent 
killed after 10 minutes 
exposure 

Bipolar; one to several 



BABK OBOAmSIC* 



Whitish colonies, slightly 
bluish in transmitted 
light; medium slightly 
greened 

Growth rather slow, fluo- 
rescence marked 

Clouding; green fluores- 
cence after 1 week; four 
strains showed pellicle 

Liquefaction more rapid, 
begins in 24 hours, com- 
plete in 2 months. Slight 
fluorescence after 1 week 

Liquefaction more rapid. 
Marked fluorescence 

Slight alkaline reaction at 
top in 2 days, acid reaction 
below. Acidity increases 
as digestion proceeds. 
Banded appearance re- 
sulting in clearing in 3-4 
weeks. Final color green- 
ish blue above, buff below 

Clearing begins in 36 hours, 
complete in 3-4 weeks. 
Green fluorescence 

Growth vigorous, elevated, 
contoured to rugose. 
Fluorescence more 
marked than for blister- 
spot organism 

Same as for blister-spot 
organism except fluores- 
cence more marked with 
some strains 

None 

Indol present in 10 days 

More ammonia produced 
than by the blister-spot 
organism 

Average of 50 per cent 
killed after 10 minutes 
exposure 

Bipolar; one to several 



^ Under this heading are included also the slow liqueflers from bark. 
* Under this heading are included only the rapid liqueflers from bark. 



208 Phytopathology (Vol. 7 



METHODS AND MKDIA 

As standanls for methods liiid for the making of media the writer has 
followed directions given in Krwin V. Smith's Raeteria in Relation to 
Plant Diseases, Vol. I, and ICyre's Ha<*teriolo|dnil Teehnie, 2nd Kd.. 
except where noted otherwise in the t(»xt. 

Sl'MMAKY 

1. In tlie foregoing i)a|K»r is d(\scrilHMl a l)aeterial disease of applf>. 
no mention of w)ii<*h has Ihm'Ii foim<i in phytopathological literatunv 

2. By isohition, niltural, and inoculation work, it is proved that thbi 
dis<»ase is <'aused l)V a motile organism, which H(jueties gelatin slowly, 
and lK»longs to the grccn-fiuorescent group of l)acteria. 

'A. H<*caus4' of the Mister spots produc'(Ml by this orgsmism on the Mir- 
fa<*e of apples, the naiiH* Pscmlofunntis pdjnthins is profKwed. 

•I. Description is also given of a rough-hark or scurfy hark canki-r 
from which has Im^cii isolated an organism also U'longing to the gn-«*n- 
fluoH'Scent grou)). 

.">. Kvidence is present I'd that then* are really two varieties of the hark 
organism, one of whirh has all of the cultural rharact eristics of the hlister- 
sfxit organism, including s|(»w Ii(iuefa<*tion of gelatin, while the c»ther dif- 
fers fn»m it in S4'veral import .iiit particulars, including rather nipid li«|Uf>- 
facti(»n of gelatin. 

(>. Inoculation of healthy apple hark with two strains of the nipi<ily 
lifiuefying hark organism pHxluccd small lesions which showe<i the typi- 
cal <'racking Ioom* of diM*:iM'> from healthy hark, and in sevend e:is*'s thf 
lumpy apjM'arance characteri>ti<* of the early stages of the scurfy -tiark 
canker. 

7. .\n organism agrei-ing in cultural react ion> with the one umhI fur 
inoculati<»n has Imi'Ii re<*overed from thesi* le>ions. 

S. Typical hli>ter s|)ot> have Ihh'Ii produced hv inoculation of Imth 
tyjM's of hark organism> into healthy apples. From th<^» s|)ot,s the or- 
gani>ms u>ed for inoculation havi* U-eii recov<»nMi. 

\K \ preliminary <Mimparative >tudy of the cultural chaniet<Tist ii-^ oi 
the Mi«»ter->pnt organi*»m ami the two h.ark organisms suggi^ts tluit fhf 
difference iM-twei-n them are difTeren<-e> of degn-e nit her than of kind 
That i^. that .all thre<* are iM»«»sihly men-ly varieties of one s|n»cic»s. Mon* 
work i-* nec4'*.sary. however. U^fore this <|ue^tion ni n lati<inship can U* 

M'ttlrd. 

Mis-^oi HI Statk KiiMr l*!xPKHiMK\r Sr\rio\ 

M«>l\rAlN <IUoVK. Ml^S4U KI 



THE PATHOGENIC ACTION OF RHIZOCTONIA ON 

POTATO 

H. T. GOssow 

With One Figure in the Text 

It appears that satisfactory evidence has been lacking clearly demon- 
strating the pathogenic action of Rhizoctonia (Cortidum vagum B. & C.) 
on various host plants, particularly the potato. 

The attention which the well known disease has received in the new 
world and more recently in the old, left, in my opinion and in that of 
quite a number of other investigators, several important points unex- 
plained. Every pathologist fully recognized the symptoms of this dis- 
ease which have come to be regarded as typical Rhizoctonia infection. 
The unmistakable folding of the leaves of the growing plant, together 
with the brown stem lesions so frequentlj*^ described, in other instances, 
or in addition perhaps, the formation of aerial tubers and peculiar small- 
ness of subterranean tubers, are now well known as general symptoms 
resulting from an attack of Rhizoctonia. 

Indeed, the folding of the leaves associated with this disease differs 
greatly from the curling of the leaves of plants affected with leaf roll, 
particularly noticeable is this difference when examining the lower leaves 
of an affected plant. Where, however, doubt existed, the presence of 
stem lesions was looked upon as final proof of a Rhizoctonia infection. 

I must confess, however, that the often surprising scarcity and appar- 
ent superficiality of these lesions, nay, often enough their entire absence 
in what was otherwise unmistakably a plant infected with Rhizoctonia 
and not with leaf roll, frequently caused me surprise and certainly failed 
to readily convince the farmers on the occasion of field demonstrations 
of the correctness of the diagnosis — which at times I shared much against 
my own belief. 

For some time I have endeavored to discover the true pathogenic action 
of this fungus on the host plant. My colleague, Drayton,* demonstrated 
to my satisfaction the profuse permeation of the tissues of and surround- 
ing the lesions, but even that failed to convince me entirely of the cause 
of the characteristic symptoms, which statement is not intended to infer 

^Drayton, F. L. The Rhizoctonia lesions on potato stems. Phytopath. 6: 59. 
1915. 



210 Phytopathology [Vol. 7 

that I (louhtcHl Rhizoctonia to l^e associated with the same. But from 
what evidence was available, the actual injuries caused by the stem le- 
sions ^-ere so infinitesimal that it was felt the true injury is done elsewhere, 
and what we did observe was the result of such unlocate<l but far more 
serious injury. 

A careful stud}' of diseased plants in the field revealed at first little or 
no additional clues. Lesions were sometimes present where the lea\*es 
were folded, the tubers were covered with more or less numerous lumpy 
funfcous nuisses, indeed the roots often showed the well known pseudo- 
sclerotia. Pot experiments showed the presence of sclerotia on rootlets 
more abundantly th^m was the case in the fiel<l, and yet while abundiuit 
superficial and lesser amount^s of intracellular h>^hae of Rhizoctonia were 
found on microscopical examination, the evidence of an all round general 
soundness of the underground parts examined still left the seat of the 
injury undetermine<l. 

On careful examination of the root system of a plant clearly affected 
with Rhizoi*tonia and no other disease, that had lx*en pulled up from loose 
sandy soil, or had l)een lifted with care by means of a fork or spa<le. one 
factor at last attracted my att<»ntion, which later led to interestin^c oliser- 
vations. This was the almost entire al)sence of the fine fibrous rootlets. 
so common in sound plants. Surc»ly such rootlets must have been presu 
ent ori^nally? When examininfc thereafter plants in various stagi*s of 
infection one could obstTve a corresponding absence or presence of finer 
nH)tlets ucconiing to the amount of disease present. Of course, in thi* 
detennination can* is net»essiir>', but after some experience one cannot but 
recogniz<» the existing n^lation of nK)tlets to deja"ee of disease. 

What if the fungus a<*ted upon the rootsS of the growing plant similar 
to the way in which it (1<h's on the r(M)ts of Rhizoctonia-infecte<l tulM^m 
sprouted in a closed sten<ier <lish? The disastrous effects of the fungu'^ 
at the early stages of growth arc sometimes so pronounce<l as to kill off 
growth liltogether; this is a H*ell known fact. 

Ia'X us iM'ar in mind that in a potato field we find many stages of severity 
of Hhiz(M*tonia infection, from total **mi.ssc»s'* to one, two or more shoots 
clearly afIe<-t<Ml uj) to the cas4» wlu^n* the plant Invars plenty of aerial tulier* 
and nuMHTous littU* |M)tat(M\s underground fnnn which the popular namr 
**littlr jMitato (lis<»ji.*<<»" has sprung. .Verial tul)ers have l)een commonly 
ji.H>ori:iteii with Hhizoiioiii:!. tlu'V are jxTluqw exclu-sively manufacture«l 
from in.itrrial produteil l»y the heaves, a <*oinpanitively slow proresw, but 
alua>> iii(ii(*:itiim iiiipainMl nnit function in plants where they may br 
c<ni>i«h'nM| abiioriiial. .Verial tuU^rs natunillv mav occur from anv 

• • • 

raii.M* (MittiiiK otT or intrrnipting nN>t function. Imt only when such inter- 
nipti(>n> an* gradual. We have, then'forr. no aerial tulN*rs in the black 



1917] Gtjssow: Rhizoctonia on Potato 213 

but the roots infected with sclerotia remain in the ground, since they are 
not pulled up by the digger or are at any rate returned to the ground. With 
the diminishing food supply in these roots, sclerotia develop ready for 
subsequent attacks. This observation also accounts largely for the soil 
contamination and the persistence of the organism iQ land once infected. 
It also indirectly suggests a new means of control, viz., the prevention of 
infection by cultural methods or the application of fertiUzers producing 
vigorous plants in the first instance and aiding in the production of a 
generous supply of new feeding roots. 
Central Experimental Farms 
Ottawa, Canada 



212 Phytopathology [Vol. 7 



leg disease, whore the cutting oflF of supplien is rather sudden. .\II th 
symptoms are the lof^ieal results of the al)sence of the abundant fee<linc 
n>ots. Roots are present in all growing plants, otherwise the planbt 
would have died ; small and fine roots are less in evidence in affecte<I plant.*< 
while a generous supply exists in healthy strong plants. 

De<iuctions — however logical they may l)e — still are h\iM)theses and 
hypotheses are not facts, but the accompanying plate will pmvi<ie 
some foundation for the observations n'corded and may stimulate 
wider n»s<»arches on this point than hiive l)een made so far. I am satu*- 
fied fnnn the obs<»r\'ations made, that the destniction — often ver>' gradual 
— but very jx^rsistent all the same, of all or many of the feeding rootj* of 
the potato plant a<*c()unts for every one of the symptoms associatcNl with 
this dis<»as4». The l(»sioiis which have so often lH»<'n recorde<i are evident I v 
not of MTious conscHiuence, as indicated by their general superficiality and 
fn»(|uent (»ntire al)s<»ncc. In some instan<Ts iiidcHMl these k^icms an* not 
due U> Hhizortonia at all, but to Aciinomya's scabiej< (liissow, whirh I 
hoiM» to sliow in anothrr pa|M»r, when they afford easy resting pl:i(*es in 
the unprotecte<l su|HTficial cells for the mycelial m:iss4^ of I{hiz<N*tonia 
sh(»wn in .Mr. Drayton's photo-mi<Tographs, :is well as for the [)c*rnie:ition 
of the hyphae into the interior, which, as must have Imh^ii noticvd. is not 
accompanied by any prominent injurious action ufMm the ctIIs invadtnl. 
A stu<ly of Mr. Drayton's slidf»s clearly confirms this observaticm :is well 
as the photographs ma<l<' fn»m them which an* ac<rssible to our readers. 

The i)athogeni(* a<'ti<»n is as follows: We an* aware of the very pntfu**** 
growth (»f mycelium of Hhizo(*tonia. particularly in the dark, :u< al>«» of 
the pHNluction of enormous <{uantities of ps^'udo-scltTotia on nMit> and 
tuU'rs. Whethrr thr sclcrotia an* lt»ft over in the soil from pnM*edinK 
(Mitato cn)ps or c»ther host plants, or whrther they have Uvn intnMiu<*«*«i 
by untn^attMl infc(*t4Ml s4»<mI potat(M*s — (and what **farmers' nm'* [M»tatm*s 
an* not infected?) <I(m»s not matter much. Th«» ti|)s of the fn-sh nnitlft^ 
niHiU fall a victim to tlu* invading myc<'lium. the nN>t cap iH'ing undoubt«Hlly 
the nio*«t vulnerable |M»iiit and s<»on the short nM)ts have lN*<*n d«*>triiye4i. 
the niyeelium meanwhile reaehes older rootlets, whieh it mueh niorv 
ran*lv de>tro\>. though that hiis occurn'd. l)ut when* the mvcelium fn- 

• • • 

(luently prtHJueo re^^ting niyrelial mas.^<^s from which invading hyphae 
iv^ue aInio>t >iniullaiieously with new nnitlets whieh an* pnMlui*«t| bv 
the pl.mt in i\^ elTort to ree«*tab!i>^h its resources. This pnNH^s got-^ i»n 
fc!r:idually and >lowly or more ra))idly de|x*nding naturally \i\Mm the vigor 
of the plant. I'iiially the |NT*«i>tent efforts of the fungtis n*sult in deen-ik'^ 
uig Mf-NN. Ml ftii'^tratinL; the growth of the t ulnars. lN>cau.s<* of lack of Um^i 
su|>phe'^ from the roots. :nu\ eventually in the production of m*rial tuliers. 
.Meanulule harve>t-time ha> arrive<l, what tuln-rs an» there, are har\*este«l. 



1917] G^ssow: Rhizoctonia on Potato 213 

but the roots infected with sclerotia remain in the ground, since they are 
not pulled up by the digger or are at any rate returned to the ground. With 
the diminishing food supply in these roots, sclerotia develop ready for 
subsequent attacks. This observation also accounts largely for the soil 
contamination and the persistence of the organism iQ land once infected. 
It also indirectly suggests a new means of control, viz., the prevention of 
infection by cultural methods or the appUcation of fertilizers producing 
vigorous plants in the first instance and aiding in the production of a 
generous supply of new feeding roots. 
Central Experimental Farms 
Ottawa, Canada 



SYNTHETIC' C ULTURE MEDIA FOR WOOD-DESTROYINT. 

FUNC.r 

Ernbst J. PiEPER, C. J. Humphrey and S. F. Acrbb 

Wood-destroying funfd grow readily on many of the ordinarj' culture 
media which have as their principal ingredients malt extract or plant 
decoctions and meat extracts, usually hardened with agar-agar or gelatin. 
As an example of such media, a malt extract preparation of the following 
formula has proved very satisfactory for gt»neral culture work: 

Extract of 1 pound lean }k>cP in distilled water 1000 cc. 

Malt extract 25 grmmfl 

Agar-agar 20 grama 

This hiis found a wide us*» in Europe and luis \)een emplo^Td for much 
of the routine work in the piithological section of the Forest PhmIucUi 
I>iilK>rator>'. In certain lines of investigation, however, such as the test- 
ing of the toxicity of chemical sul)st.iinc<»s, and in compiirative Xe»Xs on 
the physiological U'havior of w(M>d-<Ic^troying fungi, this medium ht^ 
the s<Tious disa< I vantage's of lx*ing chemically complex and variable. 
Its composition and constitution <lepend upon the nature of the meat 
and malt extract, the method of preparation and the duration of stan<iing. 
and physically it may 1k» variably <'oIloidal. Tlie |M)ssibility of chemi- 
cal or physical combination of c<»rtain pr(»serv'atives with the highly com- 
plex organic cotn|M>unds and also the coagidation of the latter by elec- 
trolytes an* of cxtn»me importance also in toxicity work. 

In the pn*s(*nt work an attempt was made to prt^pan^^ a synthetic mcHiium 
which wouhl support a growth of wcMxUiestroying fungi at least as gurwl 
as that on the malt extmct agar, and which at the same time would lie 
cf>miM>se<l of as simple constituent'^ as |K»ssiblc. The medium could 
then U» <iuplicat<Ml at any time, by any inv<»stigator. pn)viile<l the ch<»mi- 
cals UM»d wen» of the same standani of purity. 

For .satisfactory growth of w(HM|-<l<»st roving fungi a culture miMiium 
mii*<t have, in addition to certain simple inorganic salts, the n€H*e9««ar>' 
coin|Mitind.^ to furnish lM)th nitrogen aiul carlwin in a f<*rm n^dily available 
to the fungii**. .Vmmonium stilts, nitrates and a.^paragin or its salts have 



1 



Thf pr«'M<rit p:ip(*r it* otH> of four pr('|):in*d l>y the junior authoc (l*ieprr» to 
parti:il fultilhiH'tit of r«M|uirftiiriitM for th«' d«'Kn'<* of I)<»('tor of I'hilofMiphy in thr 
liuvrrMty tif W i.Hr«»njtin. 

' l.:tt«'r t«*f<t^ in thiH l:il)or:itory indicati* th:it In'^f in (»f littlr or no advanta|[r. 
in m:in> c:im*m it luiiiirHhat rcturdH thf growth of W(KNl-<i«*i4t roving fungi. 



1917] . PiEPER, Humphrey and Agree: Synthetic Media 216 

frequently been used in synthetic media as a source of nitrogen, while 
various carbohydrates have been used as a source of carbon. 

The first step in this work was to select a nutrient solution of inorganic 
salts with di-ammonium phosphate as the source of nitrogen. This solu- 
tion was used as the basis for testing the nutrient value of various carbo- 
hydrates and consisted of the following: 

Di-potassium phosphate (KSHPO4) 4 grams 

Di-ammonium phosphate ( (NH4)2HP04). • 2 grams 

Magnesium sulphate (MgS04.7H30) 2 grams 

Agar-agar (powdered) 15 grams 

Distilled water 1000 cc. 

Varying concentrations of the following carbohydrates, usually 20 or 
40 grains in a liter of the nutrient solution, were used: Lactose, maltose, 
cane-sugar, galactose, glucose and glucosamin. Growth of the fungus*^ 
was compared with that on malt extract agar as a standard. 

The organism grew fairly well in every case. Cane-sugar and glucose, 
however, gave the most favorable indications, the growth on the cane- 
sugar being slightly more favorable. Since, however, the growth might 
be changed by using other nitrogen sources in addition to di-ammonium 
phosphate, it was decided to continue the use of both sugars in further 
work. 

The next step was to obtain a nitrogen source more available to the 
fungus than di-ammonium phosphate, so the following substances were 
tested by adding 2 and 4 grams, respectively, to a liter of the nutrient 
solution containing forty grams of cane-sugar: Asparagin, sodium aspara- 
ginate, ammonium asparaginate, caffein, guanidin carbonate, glycin, 
leucin, creatinin and betain. With 0.2 and 0.4 per cent of caffein and guani- 
din carbonate, respectively, no growth of the fungus occurred, but in all 
the other cases a fairly good development was secured. The best growth 
was, without doubt, obtained with asparagin and its sodium and ammoni- 
um salts. The fact that asparagin alone might be a source of available 
carbon for fungi was considered, but experiments showed that practically 
negative results were obtained in the absence of a sugar. 

Glucose was next substituted for cane-sugar while using asparagin and 
di-ammonium phosphate as a source of nitrogen. The character and 
rate of growth was the same as that obtained with cane-sugar. It has 
been shown* that not all fungi contain an enzyme which will hydrolyze 
cane-sugar, hence the substitution of glucose would presumably be an 
advantage, and cane-sugar was therefore discarded. 

* Fames annosus was used in all the preliminary tests. 

* Boeseken, J., and Waterman, H. Akad. We tense h. Amsterdam, 20: 548. 1911. 
Abstract in Bot. Gaz. 69: 413. 1915. 



216 PinTOPATHOLOGY (VoL. 7 

On the ha^is of th««o cxix^rimcnta a culture medium of the following 
composition was selected for further test: 



Ctlucose (CJiijOi), powdered 40.00 

Di-potassium phoHphate (KjHPOi) 4.00 Krams 

Ajtparagin (C«Ht()|Xj) 4.00 gnuns 

Di -ammonium phosphate ( (NH4)iHP04) 2.00 grmim 

Mafcnesium sulphate (MgS04.7HsO) 2.00 Krams 

( *alcium carlMmate (('aCO|) 0. 25 {(rmm 

Calcium chloride (CaClj) 0. 10 gram 

Afcar-agar (powdered) 15.00 grmms 

Distilled water 1000.00 cc. 

It is evident that thb< medium Is synthetic except for the agar-agar^ 
which is used lis a sohdifyinfc agent. Its nutritive properties for four im- 
portant wckmIh lest roving fungi wen* determined. As a comparison, simi- 
lar t<*sts were made on another medium differing only in the 8ul)«titution 
of Witte's |)eptone for jusparagin and di-ammonium phosphate. Although 
this latter medium is not strictly synthetic, still a definite grade and purity 
of the {)eptone can 1k» obtained from a reliable source. For many pur- 
pos4's such a medium might Im* found of considerable advantagt% as has 
Imhmi shown by t<*sts on Fotnes (trirwsn:< and Fomen pinicola rt»|X)rte<l later. 

In pn»paring the synthetic me<lium, the mixtun* was heatcnl in a 1.^ 
liter fljisk in a watiT bath to prevent charring. It was then pounnl into 
test-tulK»s lis quickly as iHJSsible, and well stirred during the operation 
to avoid losing any precipitate that was formed. The tul)es were then 
pluggcMJ with cotton and sterilizcil in live steam (1(K)®(\) without pressure 
for thirty minutes on thrcH* succi'ssive <lays. A very slight pnn'ipitation 
was f(nmd in the lM)ttom of the tulx^s after .*<terilizat ion. This was pn>l>- 
ably a mixture of cal(*ium and magnesium phosphat4*s and car)N>nat4^. 
\> small amounts of calcium salts s<H»m to incn»a.M» the vigor of the gmwth, 
it is advi.sable to n^tain this s<Mliment by thoroughly shaking the tulM^si 
U'ftjre (xmring into jx^tri disln^s. 

The WitteV |><>ptone me<liuiii wjis pn»pan»d in the .**ame manner :is tlie 
synthetic* and wa> <M»m|K)s<Ml of the following sul)stanc*f»s: 

(iliiroHi* •( MiiiOci. piiwdcrrd 40 (M) fniinis 

I)i-pf>taHHiuiii plio«4phati> (KilllH),) 4 00 grama 

Witti-M |M>ptoiii* 4 00 grams 

Mafcix'Miiiii Hulph:it<> MkS< >4.7li;< >) 2 00 grams 

< 'ulciufii rarlHin:it(> (':i( '( >] i 25 gram 

< ':ilriurii rhl«»ritl«' (*:i<'l: 10 gram 

VK^tr-aicnr {Hiwdcrcd ■ 15 00 grams 

Dintitlrd H.itor 1000 (K) cc. 

' ( 'iill<»i<ial ;*ilirii* :i*'n\ ha** Imi'Ii ummI hy Horiif* wnrkrrs ill plai*e uf agar-agar and 
might U> «if advaritaKf here l»ut the writrrM huvr not eX|M*rimented with it. 



1917] PiEPER, Humphrey and Agree: Synthetic Media 217 

The malt extract medium used for comparison was made as previously 
indicated. It was tubed and sterilized in the same manner as the others. 

All these media were tested with four wood-destroying fungi. The 
tables give the growth of these at 25*^0. over varying periods up to twenty- 
eight days. 

From the results it is seen that the synthetic culture medium which 
produced the best results gives a good growth and compares favorably 
with the malt-extract medium. Perhaps by continued cultivation the 
fungi may gradually become adapted to the new medium, giving then 
better results than were obtained in this investigation. 

The Witters peptone medium is especially good for the growth of Forties 
pinicola and Fomes annosus. With Lenzites sepiaria, and especially with 
Siereum frustulosuniy it gave less favorable results than the other two. 

By additional work it may be possible to improve the synthetic medium 
further so that it will give a better and more uniform growth than here 
described. Such a medium would be very valuable both for toxicity 
work and general physiological experimentation with wood-destroying 
fungi. 

In addition to the media for which the formulae are given in the pres- 
ent paper sixteen other preparations were tried. The proportions given 
are for 1000 cc. distilled water and 1.5 per cent agar. None of these were 
as satisfactory as those reported above. 

1. Cane sugar, 40 grams; ammonium asparaginate, 4 grams; magne- 
sium sulfate, 2 grams. 

Gave thick but slow growth for Fomes pinicola; wMi Fomes annosus 
gave thin growth, covering the plate in two weeks. 

2. Fraenkel and Voges' Solution.^ 
Gave verv poor growth. 

3. Fermi's Culture-Fluid. « 

Gave poor thin growth; plate not covered in three weeks. 

4. Uschinsky's Solution.® 

Gave poor thin growth; plate not covered in thre(i weeks. 

5. Modified Uschinsky's Solution.* 
Gave very poor growth. 

6. Hasselbring's Solution.^ 

7. Cane sugar, 40 grams; glycerin, 40 grams; asparagin, 4 grams; mag- 
nesium sulfate, 2 grams; di-potassium phosphate, 4 grams; di-ammonium 
phosphate, 4 grams. 

Gave best growth for Fomes annosus; thin growth for Fomes pinicola; 
thick but slow growth for Fomes applanatuSy Lenzites sepiaria and Siereum 
jrustulosum. 

* See E. F. Smith, Bacteria in relation to plant diseases, Vol. I, p. 197, 1905. 
"* Glucose, 1 gram; ammonium nitrate, 1 gram; di-potassium phosphate, 0.5 gram; 
magnesium sulfate, 0.25 gram. 



218 



Phttopatholoot 



(Vol. 7 



TABLE 1 
Radial growth in millimeUrs of Pome* annas tu in pariouM media at iS^C, 



MEDIUM 


NUMBBB or 
rBTBt-DIUI 


BADIAL OBOWTB OT rCMmVB W 
MXLLMMWtmwm 




7d«JB 


lOd^ys 


M dAf* 


Synthetic < 

Peptone . < 

Malt-<»xtract | 


1 

r 

2 
2' 

3 
3' 


21-23 
23-24 

23-24 
24-26 

•24-25 
»V-28 


30-34 
31-35 

35^37 
33^39 

29-34 
30-35 


40-12* 
40-i8* 

43-44* 

40-42* 

40-43* 
41-45* 



Character of growth: 

Synthetic. Slightly more fliifTy and slightly leas dense than on mmlt- 

extract, although the color was the same. 
Peptone. Alx)ut the same as on synthetic medium but not quite as denat. 

Malt-extract. Dense, creamy, fluffy growth. 
The growth of Fomen annosus on synthetic medium and peptone medium was 
tested for acidity with litmus and found to give a slight acid reaction after fourteen 
days growth. 

•Surface of medium entirely covered. 

TABLK 3 
Radial growlh in milUmrtrrs of Fomrn pinirola in variotix media at tS*C. 



MBOIL'M 



I 
pEmi-Diaa 



RADIAL OHOWm OT Pt'NUt'S IH MnXIMBTBBS 

14 fUys ! ?1 dar* 



limyn 



10 <Uy» 



Synthetic 



1 
1' 



24-28 
24-2t5 



2 21-22 



l*rpt«iiie 



•>' 






2<>-32 
27-a3 



33-35 
30-35 



Surface 
covered 

Surface 
ctivrred 



31-32 Surface 

covere<l , 
Surface ■ 
cnvennl 



31-32 



Mnlt-4»\tr:irt 



3 



JfV 27 ! 32-:« I Surface 

coveriMl 
32-.'M : Surface 



2.7 27 



covered 



Character of growth: 

Synth*' tii'. Thill iirid Htriatni. rotor i«:tme as on malt -extract medium 

iVptoiiv Wry fluffy and juMt .hm di*niH' ns on malt -extract medium 

.Mttlt-fxtrart. White. denHe. fluffy growth. 



1917] PiEPER, Humphrey and Agree: Synthetic Media 



219 



table 3 

Radial ffrowth in millimetera of Lemites sepiaria in variotts media at $S^C. 



MKDXUIC 


NUM- 

BBBOF 

PBTBI- 

DI8B 


RADIAL GROWTH OF FUNGXTS IK mU.imTBBS 




7 days 


10 days 


14 daya 


21 days 


28 daya 


* 


1 


21-22 


30-31 


33-37 


Surface 




Synthetic 


1' 


22-23 


'31-32 


37-38 


covered 
Surface 




k 










covered 




* 


2 


17-20 


2&-30 


34-35 


37-39 


Surface 


Peptone - 


2' 


16-20 


29-31 


35-36 


36-39 


covered 
Surface 


b 












covered 


* 


3 


17-18 


27-n30 


33-35 


Surface 




Malt-extract - 


3' 


17-20 


29-30 


36-38 


covered 
Surface 




k 










covered 





Character of growth: 

' Synthetic. Margin of growth thin with much sub-growth; more fluffy 

towards center than on malt-extract; color not as dark as 
on malt-extract medium. 
Peptone. Growth poor in appearance; color same as on malt-extract 

medium. 
Malt-extract. Fairly dense; dirty brown color. 

table 4 
Radial growth in millimeters of Stereum frustidosum in various media cU B5^C, 



MEDIUM 


NUM- 
BER OF 
PETRI- 

DISH 


RADIAL GROWTH Ol 


' FUNGUS IN MILLIMETERS 




7 days 


10 days 


14 days 


21 days 


28 days 


» 


1 


9-12 


14r-16 


29-33 


Surface 




Sjmthetic • 


V 


10-11 


15-19 


28-34 


covered 
Surface 




k 










covered 




Peptone < 


2 


4r-5 


5-6 


&-9 


9-10 


10-11 


2' 


7-« 


9-11 


10-13 


12-13 


13-14 


» 


3 


11-16 


21-22 


26-28 


30-36 


Surface 


Malt-extract i 


3' 


13-14 


22-23 


27-29 


36-37 


covered 
Surface 


k 










• 


covered 



Character of growth: 

Synthetic. Very fluffy, dense and creamy; slightly more brown in color 

than on malt-extract medium. 
Peptone. Poor growth; deep orange-brown color. 

Malt-extract. Fluffy growth; slight yellow tint. 



220 Phytopathology |Vol. 7 

8. DifTrrs from No. 7 in substitution of 40 gmnis Kalactogo for th«* 
vnm* suj[;ar. 

(lavi* inurh slowcT growth than No. 7; platr not (\\uiv covitcmI in thnt- 

WiM'ks. 

S), Differs from No. 7 in substitution of 40 ^ranis lactose for th«- ran*- 
sUKur. 

( lavr slow growth, not as rocmI as No. 8; platr not cov(T<hI in thn*** \v«i*kv 

10. Canr sug:ir, 40 ^^rains; glycin, 4 ^ranis.; (li-])otassiuni phosphate. 
4 j^rams; nia^n<^iuni sulfati', 2 Rraujs. 

(lave frmyi] jjjrowth; almost as rapid as on nialtn'xtract agar, but ap|x-ar- 
anr<' not as j^ood as on No. 1. 

11. DifTrrs from No. 10 in substitution of 4 grams rrratinin for th«- 
glyrin. 

(•a VI' fair growth: platr covircd in thriM* wrcks. 

12. DitTiTs from No. 10 in thf sul)stitution of 4 grams, caflfrin for th«- 
glyrin. 

No growth in thn-t* wrrks. 

Mi. l)iffrr> from No. 10 in th«' Mib«^tit\ition of 4 grams guani<lin rar- 
l>onatr for thr glyciii. 

(lavr no growth in three weeks. 

14. Cant' sugar. 20 grams; glucosamin, 4 grams; (li-]><»tassiuni phi**- 
phate. 4 grams; magn« vjum sulfate. 2 grams. 

Fairly good growth, but less deii^r than nn maItHxtra<'t agar; plate 
<M)vere<l in two wim k*^. 

lo. (Ilueosr, 2.") grams; d and l-leuein, 4gram>; tli-|M»tassium phos]>hat«*, 
4 grams; magnesiinn sulfate. 2 grams. 

Platr eovrn-d in twn wrrks but growth thiiuur than on No. 10. 

Hi. Laeto>e. 'A2 gran'>; brtain. 4 grams ;di-iM)tassium phosphatr. I Kni!ii«»; 
inagin simn sulfate. 2 grams. 

(Irowth fair; plate not cpiite eovered in thn^e weeks. 

LirKKATlKK 

.\s praeti<-;dl\ all of th<' literature dealing with synthetie eultun* ni(Nii:i. 
a> far a> tlu* wrifi'r- have invest igati'd, ha^^ n^ferenee to its ada|)tabilit\ 
to tlu' growth of baet«Tia or mohls and as thex' organisms ap|):in*ntl\ 
H'aet to the media in a diffennt manner than the wtMKl-4h»>t roving llyni**- 
nomyi-etes ufN>n which thi'^ stu<ly was eondu<*ted no l»ibliograp)i\ i^* 
ap|M'ndtMl. 

I\\ K>in;\iin\> IN rouKsi l*ArnnLn(;v. HiHKAr OK Plant Inoimhy 
In ( uui'KHMioN Wirn thk ToiiKsr Piionrrrs Labokatoky. 
Maoismn. \Vim onsin 



PHYTOPATHOLOGICAL NOTES 

Apple scab on the twigs. Does the apple scab {Venturia pomi (Fr.) 
Wint.) pass the winter on the twigs, which thus become a source of in- 
fection? This is a question frequently presented to the American plant 
pathologists. The presence of the organism in the twigs has been re- 
ported by a number of workers, but the first satisfactory^ data bearing 
on the 'probabilities of this being a source of infection wei-e presented by 
Morse and Darrow in 1913.^ They gav(? a very satisfactory review of 
the literature of the subject, which will therefore be omitted in this 
discussion. 

In the latter part of April, 1916, the attention of the writers was called 
to a nimiber of diseased apple twigs from Freehold, Monmouth County, 
New Jersey. A careful examination showed that the organism was 
Venturia poniiy and that the conidia which were present in great numbers 
were viable. 

The twigs showed an abundance of infection for several inches and the 
bark was split, thus giving them a very ragged appearance. Directly, 
beneath the ruptured bark were dense masses of stromatic growth, which 
protruded through the openings and produced an abundance of conidio- 
spores, which were short and irregular and rested on still shorter, in fact 
almost equilateral, irregular basal cells. The spores were typical and 
agreed in shape and size with those obtained from other sources, and 
grew readily in culture. We are unable to say whether these spores were 
formed in the fall of 1915 or the spring of 1916, but it is very evident 
that the organism survived the winter in the twigs. 

The writers did not have an opi)ortunity to examine the trees, but 
Mr. W. B. Duryee, Jr., the County Farm Demonstrator who sent the 
twigs to the Station, reported the disease in abundance. The twigs sub- 
mitted to us carried an abundance of the organism, and the infection 
extended from the tip back some 12 to 15 inches, but was most severe 
near the tip. 

Many of our New Jersey apple growers cultivate their orchards so 

* Morse, W. J. Spraying experiments and studies on certain apple diseases in 
1913. Maine Agr. Exp. Sta. Bui. 223. 1914. 

Morse, W. J. Spraying experiments and apple diseases. Maine Agr. Exp. Sta. 
Bui. 252. 1916. 

Morse, W. J. and Darrow, W. H. Is apple scab on young shoots a source of spring 
infection? Phytopath. 3: 266-269. 1913. 



222 PnYTOPATiioLoaY [Vol, 7 

thoroughly that fallen leaves an» vm' scarce* in the spring of the y«-ar. 
However, thc^> same orchards will some times pro<luce an abundance 
of «lis4»ase<l fruit. Although we fully realize* that a s<»vere inffTtion may 
rt»sult from a small source, we have for some time lK»en inclimHl to Ix^lieve 
that there must Ik» some source of infection other than the asco>|M>n'!» 
foniUMl on the leaves of the prec<*iling year. 

Mkl. T. Cook aSd C\ A. Schwarze 

On Uiciug an ether freezing microtome in warm atui damp ire/ither. MoMt 
|M*rsoiis who use an ether fn^'zing microtome may rememU*r that during 
the warm and humid davs of midsummer and earlv fall then* is likelv to 
Ik* coiisitlt*ral)lc ditiiculty in freezing material, wlu*n at otlitT tinle^ littlf 
or no difficulty i> cx|M*rienc(>d. During the very damp and rainy day^ 
of f»arly sumnuT (P.)H») much difficulty of this sort was ex|N*rienc<Ml in 
the I^il>orat(»ry of Fon'st Pathology, Providence, K. I. At times it was 
absolutely imiM>ssible to frcM^ze the pn*paration. This IcmI to sonn* «*x- 
IM*rimenting on the part of Mr. N. <). Howard. CollalKirator. ami the 
writer, whit-h liniilly n'sulted in oven*<»ming tin* main difficulty in a vcr>* 
simple and effi<*ient maimer. The a|>paratus <*:)nsisted m<*n*ly of a widt^ 
mouthe<l. eight- or ten-ounce l>ottle containing anhydr(»us calcium chloride. 

which was in.^MTted )N'twe(*n the pn'ssure tatik and tlu* atomizer. Thbi 

• 

lM>ttlt* was connect<Ml so that tlu* air from tlu* tank pri-vsed thn»ugh a glasei 
IuIn* in the stop|M*r to the hott >m of the botth*. and tliencM* up thn>ugh 
the mass of cah'ium chloride to another gla.ss tiilH* whi(*li conncct4Hl with 
the atomizer bv means of a rubiNT tuU*. 

The calcium <*lil(»ri<le w:is broken into small piec(\s and |»acked intii 
the Uittle. but not .so tightly :is to pn*vent the long glass inlet tuU* U-inie 
worke<l down through tlu* mass as the stop|)er w:is ins<*rt4*d. The nil»- 
Iht stopiMT was tied .s<»cun*ly in place so as to pn*vent its lM»ing blown 
out by an i'Xc«*s.h of air pressure. 

.-\fter a few (Livs of oc<*:i>i(»nal u.s4* the calcium chloride usuallv ^h4»u<*«i 
sign> of (leliqueMvme through absoiption of moi.stun* from the air. Wlten 
thi.s deli(|uesn'nce lN*came rather pn»nounc4*d, tli<* <'alciinn cliloride %ia> 
planMJ in a small "fry-pan" and heated until it wits again entirely dry .tnti 
hard, .\fter it had c<K>h*<l sufficiently to handle it was bn»k(*n up into 
small pi(M*(*s and put back in the Inittle whih* still warm. Tlie same 
cah'ium ehloride. which cost l»ut a few <*ents when |Mirchas(H|. |i:ls non 
N-eii in Use for nion* than six months. When the fnn*zing microtome 
\\a.s Us4*i| M'veral time> each day the <'alcium chloride hail t4> Ih' t|rit*ii 
al'out every wi*ek or t**n davs. 

.\lt hough the apparatus df*MTilNMl may Ih* consiflert*<l lis a soniewh:it 
erude affair, it has worktMl verv effiri(*ntlv for mon* than six m«inths and 



1917] Phytopathological Notes 223 

has given no indication that its efficiency would not continue indefinitely. 
Without doubt a more finished apparatus of still greater efficiency would 
result from using a regulation chemical dehydrating apparatus. 

Although this method of manipulation usually prevents the formation 
of snow on the imder side of the freezing disk — ^which delays freezing — 
it does not always prevent it. Recent experiments by Mr. Howard 
show that this difficulty can be prevented entirely by placing several 
small lumps of anhydrous calcium chloride in the ether bottle, or, better, 
in the ether can itself as soon as it is opened, and letting it stand for half 
a day or a day before using. This withdraws the small amount of water 
in the ether, which apparently is partly responsible for the formation of 
the snow. 

In using ether for freezing sections we have always found it necessary 
to filter the ether before it reaches the atomizer and also to avoid using 
rubber in contact with it. The ether intake tube in oiu* microtome has 
an inside diameter of less than 2 mm., and filtering is very easily accom- 
plished by thrusting a small wad of cotton into the end of the tube. This 
wad of cotton also is extremely useful in regulating the supply of ether 
going to the atomizer, as, with a Uttle experience, the supply can be in- 
creased or decreased almost at will by using respectively a loose wad of 
cotton or a compact one. Of course the cotton used for filtering should 
be renewed whenever it shows any tendency to become clogged. 

This note is offered for pubUcation with the thought that other workers 
who have had similar difficulties in freezing material with ether might 
like to know that such difficulties can be overcome so easily. 

J. Franklin Collins 

Note on Xyhria polymorpha and X. digitata. The recent article by 
Fromme and Thomas^ on a root-rot disease of the apple in Virginia, in 
which the causal organism is provisionally referred to some species of 
Xylaria, may be further substantiated by the following observations. 

In 1906, near Scottsburg, Indiana, the writer collected mature speci- 
mens of Xylaria polymorpha from diseased areas in living roots of a four- 
years-old apple tree of the variety Winesap. The following year this 
tree died and was pulled up. The conidial stage of the fimgus was after- 
wards noted on the diseased roots. On October 5, 1908, in the same or- 
chard Xylaria digitata was collected from the roots of a six-years-old pear 
tree which had died from some unknown cause. In the writer's herbarium 
are two other collections of Xylaria digitata, made at Priest River, Idaho, 
from decayed areas in living roots of Populus trichocarpa and Crataegus 

1 Science n. s. 46: 93. 1917. 



224 Phytopathology (Vol, 7 

douglam. The roots of the former wen* partially deca^'ed, but not in 
the same part, by Fomea applanatuSf ami those of the latter by a species 
of Follies* ix*culiar to this trcK*. 

Jamek K. Weir 

Puccinia triticina Erikss, Leaf -rust of winter wheat causes damage in 
Kansas, It is j^encTally e<)nsi<lenMl that the leaf-nist of wheat due to 
Puccinia triticina Krikss. is not s<»rious enoiigh to cause any appreciable 
damaf^e to the erop, at h>ast publieations indicate that an attack of leaf- 
rust in May or June does not produce* any marked effect on the yield. 

()l>w*r\'ations by the \\Titer th<' past season showcnl that the Ieaf-ni5t 
in some fields in Kansas was verv abimdant, an<l that its occurrence wa.* 
not confim^l to the folia^ce but that the "necks" of the wheat wen» xngor- 
ouslv attacke<l bv this rust. Careful o!)serv'ations and examinatioa«« of 
«mch fields showed that no othir factors could have lM»en res|)oaHible for 
the p<H)r cjuality of the ^rain and the rc<luced yield. The yield of one 
variety in partic\ilar, a pure line winter wheat ^own in Kansas and 
called P 7(M), was re<hic<Ml 8K jxr cait, acconlinR to yiehl data fumishe<l 
by th<» Deimrtnii nt of AKnnnnny. The fields showing the effect nwirt 
were thosi' whi<-h had bi'^'n planted lat<*. It is thought that this is par- 
tially resjxmsible for the lar^c percent ag*' of leaf-rust. 

The iMTcentaKe of infection on the "necks" of the wheat, as e;^iniat<*d 

•by the newly adoi)ted scale for estimating nist iMTcentafC^^s of the Officf 

of Cereal Investigations, I)e|mrtment of ARriculture, was 10 to 25 per 

cent, while the folia^* of thf alM»ve-mentionc»<l variety Renendly showwl 

KM) JXT cent of infection. 

It is iM'lievi'd bv the writer that the leaf-nist of winter wheat in Kansas 
can under favorable conditions ca\Ls<* con.sidenible damage and that t<Mi 
little stress has In^en Riven in literature to the imi>ortance of this rust. 

L. K. Mku*hers 

Earhj (liacwery of white ptne blister rust in the Vnitni States, Then* 
has nHM*ntly come to the atU'ntion of the writer the fact that a siM»cinien 
<if white pin«* blister ru>t was c(»llceted nii white pine iPinus strobus Linn, i 
by Mr. Samui'lN. Haxt«T of Philadelphia, in April, HM^o. at a nurs«*r>' n^-ar 
Philadflphia. A s«-arch of the (>orresi)ondence in thr files of the rnited 
Stat«-*« I>4*partmrnt of AKri<'ultiin* cnrrolnirates this statement. 

The »»p<rinMn whi<'h wa> sent t4i the TnitiHl States |)<*|mrtm«*nt of 
AKrirultun- w;i> r»'f«TnM| to th** Mycoloj^ist, Mrs. F. W. Patters<in. f«»r 

I \\v\f. J:iiii«- \{ Nfiti'H nti \%M<HlHli>itrii>iiiK fiiiifei which ftrow on Uith romfrmui 
and 'Iff nlii'Mi- xrw^ I. Phyi<i|):itli. 4: J72. VA\. 



1917] Phytopatuological Notes 225 

examination, and pronounced "a Peridermium which causes what is called 
a pine-blister rust." 

A search in February, 1917, in the pathological collections of the Bureau 
of Plant Industry failed to reveal the specimen. The letter from Dr. L. O. 
Howard, dated April 22, 1905, referring the specimen to Dr. A. F. Woods, 
has the notation on it, * White Pine, Peridermium on'* in the handwriting 
of the Mycologist. 

Since there is no reason to believe that the determination was incor- 
rect, and since but a single species of Peridermium has ever been reported 
as causing a blister rust on white pine, this specimen was in all probablity 
Peridermium strobi Klebahn, the pine stage of Cronartium rihicola Fisher. 
This record, then, antedates the finding by Stewart of the Cronartiiun 
stage on currants at Geneva, New York, in 1906, and the hitherto earliest 
record in this country of the Peridermium stage on pine discovered in 
New York on June 8, 1909, and reported by Spaulding in 1909. 

Roy G. Pierce 

Needle rust on Pinus resinosa. In June, 1916, the writer saw at Sharon 
Vermont, a very striking case of needle rust in a plantation of 10,000 
trees of Pinus resinosa about 4| feet in height. Up to about 3 feet the 
yellow spore bodies, although small, were so abimdant on the 1915 needles 
as to be readily discernible 15 to 20 feet away, single needles bearing as 
many as 20 pustules. Hedgcock has identified the rust as belonging 
to the two species, Coleosporium solidaginis (Schw.) Thimi. and C. deHca- 
tulum (Long) Hedge. & Long. The alternate hosts were abundant in 
the plantation as well as beyond it. This seems to be a case of healthy 
trees being brought to that locality and infected by the fitngi which were 
already present on the herbaceous hosts. Because of the abundance 
of the rust the writer thought it might be a serious matter to such small 
trees. A second visit made in September, however, showed that the 
needles were a healthy green color except for small dead spots where the 
rust pustules were produced. It is possible that the damage may later 
become more evident and this point will be determined. 

Perley Spaulding 

Notes on the distrihution of the bacterial disease of western wheairgrass} 
Until recently the writer had not observed the bacterial disease of western 

* O'Gara, P. J. A paper read before the meeting of the American Phytopathologi- 
cal Society, Columbus, Ohio, December 28, 1915. 

Abstract published in Phytopathology 6: 98-99. 1916. 
Science n. s. 42: 616-617. 1915. 
Phytopath. 6:341-349. 1916. 



336 Phitopathology [Vol. 7 

wheat-grass, Agropyrmi smithii Rydlt., causoil by Aplatwbacter Agropt/ri 
O'Oara, 4iut!<kic of two cMunties within the atato of Utah. The disease 
has been recently found, however, occurring on wetrtem wheat-grass in 
throe widely wparated districts of Montana, namely, Lewis and (,'lark, 
Broadwater, and IXht Loilge counties. 

Ab noted in previous papers, this disease is most characteristic in that 
the yellow bacterial oose is fuuml to cover the glumes of the inflorescence 
and appears also in droplets of considerable slie on the outride of the 
^umes and un the sheaths. It also causes Minu> dwar6ng of the plants 
aa well aa a Ix'nding of the stem alwve the last int^-mode. When the 
inflorescence is infected gemiinable see<ls arc not produced. 

The fact that this disease has l>een found in widely separated distrieta 
would indicate that it may be found wherever western wheat-grass grows. 
The writer would appreciate u note from anyiine finding this disea.'<e, as 
he is interested in establishing the ext^'nt of is distribution. 

P. J. O'Gara 

Thr occurrence of Cotletotrichum aolania^um O'Gara on eggplant. A note 
cunreming this species of C'olletotrichum was publinhetl as an almtrsct 
in Phytopiithologj-.' Later ii description of the orgiminni appeare<l in 



Myi-<iloi;i:( ■ At tht- time of pliblishiiiK my i-urliiT nutts there was M>me 
dimbl a- t.i \h>- |i:ir:i-iti-ni of thi- m-w -pc<'ii-s. Ciiltun-s wm- exchangiil 

MiCiini (' .r A .li.»-:iM' i.f iln- iiiKltricn 111 rill hiiiiii- nf Irii-li piitAUi rnuard by ■ 
Ii<-» ^|.ii... ..t l'Ml|.-i..lii,'|iillti l'livrr>|):itli 4: tl» III I'll). 

'•>(;, r, ]• .r \.» .fi,.,!... .,rr..|l.ir..tri.l,i,..i:.[i.l ni..r>in. Myr..l.>Ki» T: :to -II. 



1917] Phytopathological Notes 227 

with Dr. J. J. Taubenhaus, then at the Delaware Agriculture College, 
who concluded that the organism is a species of CoUetotrichum and that 
it has parasitic tendencies (oral communication). 

During the summer of 1916 the writer had occasion to observe a field 
of eggplants in which fully ninety per cent of the plants showed wilt. 
At first it was supposed that the wilt was due to a Fusarium, noting only 
the general appearance of the field. A careful examination of the plants, 
however, indicated that Fusariiun was not present but that the roots 
and stems were badly infected with the above-named organism. Interior 
portions of infected roots and stems were taken under sterile conditions 
and placed in culture tubes, where the organism fruited characteristically. 
No other organism appeared in the cultures where the proper precautions 
were taken. Even in mixed cultures, Fusariimi did not appear. 

When the organism was studied as a root and stem parasite of the 
potato, it was not suspected of being a serious wilt fungus, but in the case 
of the eggplant it has been found to product a wilt disease similar to that 
•produced by Fusarium. During the early growth of the plants no trouble 
was noted, but about the time some of the earlier fruits began to mature, 
the infected plants wilted. This condition shortly prevailed throughout 
the entire field, producing an almost total loss. 

The field in which these eggplants were grown had supported a stand 
of potatoes the previous year and it was in this field of potatoes that the 
writer first found the above-named organism. From specimens collected 
in this field the original description was made. 

This note is published in order to give notice of the economic character 
of this species of CoUetotrichum. 

' P. J. O'Gara 

Personals. Mr. K. E. Quantz, formerly assistant plant pathologist at 
the Virginia Experiment Station, has become plant pathologist to the 
Brazilian Government, with headquarters at Rio de Janeiro. 

Mr. H. E. Thomas has resigned his position as instructor in plant 
pathology at the Virginia Polytechnic Institute to accept an appointment 
as assistant pathologist at the Federal Experiment Station at Mayaguez, 
Porto Rico. 

Mr. Fred R. Jones, formerly a graduate student at the University of 
Wisconsin, has been appointed to the position of pathologist in charge of 
forage crop disease investigations. Bureau of Plant Industry', beginning 
April 14, 1917. 

Mr. Gustav A. Meckstroth, a student at Pennsylvania State College, 
has accepted an appointment as scientific assistant in plant pathologj', 
Office of Cotton, Truck and Forage Crop Disease Investigations, Depart- 
ment of Agriculture, beginning May 1, 1917. 



LITERATURE ON PLANT DISEASES* 

Compiled bt Eunick R. Obbrlt, Librarian, Burbau op Plant Industry, amb 

Florkncb p. Smith, Absibtant 

February to March, 1917 

Arthur, Joseph Charles. Uredinales of Porto Rico bsBod on collections by H. H. 

^lietiel and E. W. Olive. Mycolofda 9: 55-104. F. 1917. 
Bloletti, Frederic Theodore and Bonnet, Leon. Little-leaf of the vine. Jour. Agr. 

Research 8: 381-398, 2 fig., pi. 89 02. Mr. 6, 1917. 

"A disease of the vine, vyinfc in seriousness with oidium and phylloxera." 

Cause unknown. 
Blsby, G. R. The short -cycled Uromyces of North America. (Abstraei.) Phjrto- 

pathology 7: 74. F. 1917. 
Blake, Msurice A., Cook, MelvUle Thurston, and Schwsrze, Carl Alois. Studies on 

peach yellows and little |>carh. (Abstract.) Phytopatholoay T: 76-77. F. 

1917. 
Block, W. S., and Ruth, W. A. Control of apple scab by bleaching powder. (Ab> 

stract.) Phytopathology 7: 76. F. 1917. 
Brooks, Charles, and Cooley, Jscquelln Smith. Jonathan spot. (Abstract.) Phy- 
topathology 7: 76. F. 1917. 
Tom|)eraturc relations of apple rot fungi. (Abstract.) Phjrto- 

pathology 7: 76. F. 1917. 
Brown, Nellie Adaless. A bacterial stem and leaf disease of lettuce. (Abstract.) 

Phytopathology 7: 63. F. 1917. 
Boiler, Arthur Henry Reglnsld. Black rust of wheat. Bui. Misc. Inform. Kew, 

1917: 4K. F. 1917. 
I'>ononiir 1<his due to m'hoat rust in North America. 
Bnrkholder, W. H. Bean diseases in New York 8tate in 1916. (Abstract.) Phyto* 

pathology 7: 61. F. 1917. 
Dry rcN>t rot, Futiarium sp.; blight, BacUrium Pfuueoli. 
Butler, Ormond Rourke. How to control the snapdragon rust. 

FhiriHts* Kx. 4S: 353. F. 17. 1917. 
Dusting with sulphur. 
Bysri, Luther Psrrls. A nomatrMle diHcase of the dasheen and its control by hoi 

wat<*r tn'tttmcnt. (.Mwtrart.) Phytopathology 7: 66. F. 1917. 
Tylenchtui triliri on whrat. Phytopathology 7: 56-57. F. 1917. 




' fWfttnntnc with this numbrr. it i* intrndvtl that this liat thmll includ* all r«f «f««MB l» Um 
luf« ol plant lii t'mar*. bbtb Amn-lrmn and f«»f«lgn All forriga mrinekf publiabad MBO* Jmumtt I. tflft 
• hirh itnif t-.i our Bttrtiti'in. «ill hr rntrrcii. wi that th« imirs may hm ulttmAlvly 
from tlut (lat* 

Ail aut>tor« ar«> "rfirl Ut loi'iprratr in makinc thv lt*t C(im(»l«.# by ft«ndittc Ibair 
ibC r«>rrrviftn« aiiit aiMitmn*. atwl r«|imall> by rallinc ait4*titi<>n to mrht4>n<iua 
nf rvBular |ii-irnaU iip|irifit« <»r r<irTM*|M»fMlFtirfl* •liuulil tie aililrrMd lu Miaa K. R 
BiirvAU i4 IMabt loduMo. l*. .*< I>*p« Agrx , WMhit^ton. I). C. 




1917] Literature on Plant Diseases 229 

Carsner, Eubanks. Do the bacteria of angular leaf spot of cucumber overwinter 

on the seed? (Abstract.) Phytopathology 7: 61-62. F. 1917. 
Chivers, Arthur Houston. The injurious effects of tarvia fumes on vegetation. 
Phytopathology 7: 32-36. F. 1917. 
Bibliographical footnotes. 
CoUey, Reginald Hunter. Discovery of internal telia produced by a species of Cron- 
artium. Jour. Agr. Research 8: 329-332, pi. 88. F. 26, 1917. 
Literature cited, p. 332. 
Cronartium ribicola. 

Mycelium of the white pine blister rust. (Abstract.) Phytopathology 

7: 77. F. 1917. 
Cronartium ribicola. 
Pycnial scars, an important diagnostic character for the white pine blister 



rust. (Abstract.) Phytopathology 7: 77. F. 1917. 
Cromwell, Richard O. Fusarium-blight, or wilt disease, of the soybean. Jour. 

Agr. Research 8: 421-440, 1 fig., pi. 95. Mr. 12, 1917. 
Literature cited, p. 438-439. 
Ftaarium tracheiphilum Smith. 
Cuba. Secretaria de Agricultura, Comerdo y.Trabajo. Comlsion de Sanidad 

Vegetal. La enfermedad del cocotero, y medios para su exterminio. Cuba 

Sec. Agr. Com. y Trab. Com. San. Veg. Circ. 2, 4 p. S. 1916. 
La enfermedad del platano y metodos para combatirla. Cuba Sec. Agr. 

Com. y Trab. Com. San. Veg. Circ. 3, 4 p. S. 1916. 
Dalbey, Nora £. Com disease caused by Phyllachora graminis. Phytopathology 

7: 56-56, 1 fig. F. 1917. 
Damell-Smlth, G. P. A disease of spring flowering bulbs. Agr. Gaz. N. S. Wales 

88: 141-142. F. 1917. 
Davis, W. H., and Johnson, Aaron Guy. The aecial stage of the red clover rust. 

(Abstract.) Phytopathology 7: 75. F. 1917. 
Uromycea fallens (Desm.) Kern. 
Doran, William L. Controlling snapdragon rust. Value of copper and sulphur. 

Florists' Ex. 48: 501. Mr. 8, 1917. 

"Bordeaux has no effect on the rust of snapdragons, and will not control this 

disease." 
Doubt, Sarah L. The response of plants to illuminating gas. Bot. Gas. 63: 209- 

224. 6 fig. Mr. 1917. 
Literature cited, p. 224. 
Durrell, W. L. Notes on curly dwarf symptoms on Irish potatoes. (Abstract.) 

Phytopathology 7: 71. F. 1917. 
Edgerton, Claude Wilbur. A Gnomonia on eggplant. (Abstract.) Phytopathology 

7: 78. F. 1917. 

Perhaps identical with Phyllosticta kortorum. 
Sdson, Howard Austin, and Schreiner, Oswald. A malnutrition disease of the 

Irish potato and its control. (Abstract.) Phytopathology 7: 70-71. F. 1917. 
XUiott, John Asbuiy. A new parasitic slime mold suitable for class work. (Ab- 
stract.) Phytopathology 7: 74. F. 1917. 
^aulwetter, R. C. Dissemination of Bacterium Malvacearum. (Abstract.) Phy- 
topathology 7: 64. F. 1917. 
Dissemination of the angular leafspot of cotton. Jour. Agr. Research 

8: 457-475, fold, chart. Mr. 19, 1917. 
Literature cited, p. 473-475, 
Physiology of bacterium malvacearum. Smith. South Carolina Agr. Elxpt. 

Sta. ^th Ann. Rept. [1916]/16: 49-64. [1916.] 



230 Phytopathology (Vol. 7 

Pronime, Fred Denton, and Thomas, H. S. Spraying and dusting tomatoes. Vtr* 
ginia Agr. Expt. Sta. Bui. 213, 14 p., 3 fig. 1916. 

Fromme, Fred Denton. A Xylaria root-rot of the apple. (Abstract.) Phyto- 
pathology 7: 77. F. 1917. 

Gardener, Max William. Dissemination of the organism of cucumber anthracnoae. 
(Abstract.) Phytopathology 7: 62-63. F. 1917. 

Gilbert, William Williams. Virulence of different strains of Cladosporium eum- 
merinum. (Abstract.) Phytopathology 7: 62. F. 1917. 

Gladwin, F. S. and Reddick, Donald. Sulfuring Concord grapes to prevent pow* 
dory mildew. (Abstract.) Phytopathology 7: 66. F. 1917. 

Great Britain, Board of Agriculture. 8clen>tinia diseases. Jour. Bd. Agr. [Lon* 
don) 2S: 109:>-1008. pi. 1917. 
ScUrotinia sclerotiorum. 

Varieties of imtatooK roMiHtant to wart disease. Jour. B<i. Agr. [London] 

88: 1017. Ja. 1917. 
These varieties are more fully deMrril>ed in Garden 81: 8-9. Ja. 6. 1917. 

Hedgcock, George Grant, and Hunt, N. Rex. An alternate form for Coleosporium 
helianthi. (Abstract. > Phytopathf»logy 7: 67-68. F. 1917. 

Noten on some .H|H»cies of (.\>Ieosi>orium. (Abstract.) Phyto- 
pathology 7: VtS. V. 1917. 

The Peridermium l>elonging to Coleosporium ipomopv. (Abstract.' 

Phytopathology 7: 67. F. 1917. 

\ IVri<lermium U'longing to Colecwporium terebinthinace*. (.\b- 

Htraet.) Phyt<»pathology 7: 67. F. 1917. 

- Some new hosts for Colcos|N>rium inconspicuum. (Abstract.) 

Phytopathology 7: 6H m. F. 1917. 

Some new hosts for Coleosporium solidaginis. (Abstract.) Phyto* 



path<»l<»gy 7: tlS. F. 1917. 
Hedgcock, George Grant, and Long, William Henry. The aecial stage of C<»K 
s|H)rium elephantop<uiis. (.Xhstract.) Phytopathology 7: 66-67. F. 1917. 
Periderm turn came u m . 
Hlggins, Bascombe Britt. A dis4*aM> of |N»ean catkins. Phytopathology 7: 

2 fig. F. 1917. 
Hongerford, Charles W. Pureinia graminis an wheat kernels and its relation to 

sulHM'quent inff*ction. (Abstract.) Phytopathology 7: 73. F. 1917. 
Jackson, Herbert Spencer. A six*eies of (*hrysomyxa new to North America. ;.\1>- 
HtriMt.i Phyt<»pathology 7: 7«. F. 1917. 
t >n Picra engelmannii. 
Jagger, Ivan C. Tw<i transmissible mosuie diseaM*a of cucumbers. (Abstract ; 

PhytiipHtholufcy 7: 61. V. 1917. 
Jeffrey, J. W. MyHterimis vine «lis4*aM'. .Mo. Hul. Stati* Com. Hort. (Califomim) 
6: 4in 117. N. P.Mr, 

"It ilitfN Hot :ip|K*ar that w thontiigh examination of this malady has ercr 
Ihm'Ii iii.-idf, hut exp«'rts have determined that the cause is not Phylloxera. Aha- 
hi-ifii di-i-:i>f. fungus nr biM'teria." 
Jehle, Robert Andrew. < 'h:ira<'terii*tirs of eitrus ranker and of the causal orgma* 
f«iii i^Mi:irt Mul StHt<- IM:int Ii«l. Floriila 1: 'J4 'SI. illus. Ja. 1917. 
P*t 'tdiifuitu'i* ritri. 

Citru" I nrikiT irive!(tiKati4»MS at thr Klorifla tnipiral lalmratory. (Abstract > 
Pli>t«.p.itho|Mj:v 7: .> :»9. F. 1917. 
Johnson, Aaron Guy, ami Coerper, Florence M. .\ baeterial blight of soy beaa. 
(Abstrart ) Phytopathiihtgy 7: t>5. F. 1917. 



1917] Literature on Plant Diseasi^ 231 

Johnson, Aaron Guy, and Hungerford, Charles W. Scolecotrichum graminis on 
timothy, orchard grass, and other grasses. (Abstract.) Phytopathology 7: 
69. F. 1917. 

Johnson, M. O. The spraying of yellow pineapple plants on manganese soils with 
iron snlphate solutions. Hawaii Agr. Expt. Sta. Press Bui. 51, 11 p., 4 fig. 
D. 13. 1916. 

Johnston, John Robert. Enfermedad de la rafz de la cafia de azticar. Pt. II. Ha- 
cienda 12: 146-147. F. 1917. 

History and cause of the rind disease of sugar cane. Jour. Bd. Comm. Agr. 

Porto Rico 1: 17-46. pi. 1. 1917. 
Bibliography, p. 43-45. 
Melanconiufn sacchari, 

Jones, Fred Reuel. The Pseudopeziza leaf spot diseases of alfalfa and red clover. 
(Abstract.) Phytopathology 7: 70. F. 1917. 

Jones, Lewis Ralph, and Bailey, Ernest. Frost necrosis of potato tubers. (Ab- 
stract.) Phytopathology 7: 71-72. F. 1917. 

Johnson, Aaron Guy, and Reddy, C. S. Bacteria of barley blight seed-borne. 

(Abstract.) Phytopathology 7: 69. F. 1917. 

Keitt, George Wannamaker. Peach scab and its control. U. S. Dept. Agr. Bui. 
395, 66 p., 6 fig., 6 pi. (1 col.). 1917. 
Literature cited, p. 64r-66. 
Cladosporium carpophilum Thtim. 

Second progress report on investigations of leaf spot of cherries and plums 

in Wisconsin. (Abstract.) Phytopathology 7: 75-76. F. 1917. 

Elrout, W. S. Bacterial diseases of celery. (Abstract.) Phytopathology 7: 64. 
F. 1917. 
Crown rot, Bacterium and Fusarium; crown rot wilt; bacterial heart wilt. 

Wintering of Septoria petroselina var. Apii. (Abstract.) Phytopathology 

7: 65. F. 1917. 

Lathrop, Elbert C. The generation of aldehydes by Fusarium cubense. Phy- 
topathology 7: 14r-16. F. 1917. 
Lee, H. Atherton. A new bacterial citrus disease. Jour. Agr. Research 9: 1-8, 
pi. A, 1-2. Ap. 2, 1917. 
Bacterium citrarefcicienSy sp. nov. 
Long, Wilham Henry. Five undescribed species of Ravenelja. Bot. Gaz. 61: 417- • 
424. My. 1916. 

Ravenelia roemeriancBf sp. nov.; R. morongiae, sp. nov., R. thornberiana, 
sp. nov., R. reticulata, sp. nov., R. anntdataf sp. nov. 

Investigations of the rotting of slash in Arkansas. U. S. Dept. Agr. Bui. 

496, 14 p. 1917. 

Oak slash: — Stereum rameale, S, umbrinum, S, versiforme, S. fasciatum 
Shortleaf-pine slash: — Polystictus abietinus, Lenzites sepiaria. 

None of the main fungi concerned in rotting either the oak or the pine slash 
in Arkansas produce heart rots in living trees. 

A preliminary report on the occurrence of western red-rot in Pinus ponde- 



rosa. U. S. Dept. Agr. Bui. 490, 8 p. 1917. 
McClintock, James A. Economic hosts of Sclerotinia libertiana in tidewater Vir- 
ginia. (Abstract.) Phytopathology 7: 60. F. 1917. 

Lima bean mosaic. (Abstract.) Phytopathology 7: 60-61. F. 1917. 

Peanut-wilt caused by Sclerotium rolfsii. Jour. Agr. Research 8: 441-448, 

pi. 96-97. Mr. 19, 1917. 



232 Phytopathology (Vol. 7 

McClliitock, Jamei A. Will SponKospora subtcrranea prove serious in VirgiBiA* 
(Abstract.) Phytopathology 7: 72. F. 1917. 

McCnbbin, W. A. Doen Cronartium ribicola wintor on the currant' PhjrtoiMitbol- 
o|0' 7: 17-31. 1 fig. F. 1917. 
Bibliography, p. 31. 

\Vhit<^ pine blister rust on currants. Canad. Hort. 40: 34, 1 fig. F. 1917. 

Mackle. D. B. Observations on the distribution of citrus canker. Philippiat 
Agr. Uev. 9: 278-281, pi. 4. 1916. 

Martin, William H. A sclerotium disease of peppers. (Abstract.) PhyiopatholoflQr 
7: M. F. 1917. 

Sclerotium bat alt cola. 

Msi4, Pierre Marie. Chlorose toxique du mais, la s6cr6tion interne ei la rW stance 
natun^llc df*8 v^g^'taux sup^ricurs aux intoxications et aux maladies paraai- 
tain>M. (Nmipt. Hcnd. Soc. Biol. [Paris] 79: 1059-10($6. D. 1916. 

Melchers, Leo Edward, and Dale, E. E. Black spot of popper. (Abstract.) Phy- 
topathology 7: 03. F. 1917. 
Alternaria sp. 

Melhus, Irving E. Notes on nxmiac symptoms of Irish potatoes. Phyiopniholofcy 
7: 71. F. 1917. 

and Diehl, William. The development of the aecial stage of Nigredo on red 

clover. (.\bRtra4t.i I*hytopathology 7: 70. F. 1917. 

Merrill, J. H. Further data cm the relation between aphids and fire blight (Bacil- 
lus amylovorus (Bur.) Trcv.). Jour. t>on. Knt. 10: 45-46. pi. 2, F. 1917. 

Murphy, Paul A. The economic importance of mosaic of |>otato. Phytopathology 
7: 72 73. F. 1917. 

Seed |M>tato certification in Nova Scotia. (Abstract.) Phytopnthology 

7: 72. F. 1917. 

llorton, John Bitting Smith. Host limitations of Spctoria Lycopersici. (Abstract. ) 
Phytopathology 7: 65. F. 1917. ' 

Ilowell, William. Summary of notes on fungi and plant diseases. Agr. News. 
{Barbados) 16: 14. Ja. 13. 1917. 

Olive, Edgar William, and Whetzel, Herbert Hice. Kndophyllum-like rusU of 
Porto Uico. Amer. Jour. Bot. 4: 44 .'>2. 3 pi. Ja. 1917. 

Botryttrhiga Hipftocratctr \Vheti4*l Ar Olive, sp. nov.; EndophyUum eircum- 
itrrifdum (Schw.) \yhetn*l A Olive, comb, nov.; Endophyllum W^ddiw (Earle) 
Whetiel A Olive, comb, nov.; Endophyllum decoloratum (Schw.) Whetsel A 
Olive, comb, nov.; Endophyllum Stocky tar phettr (Henn.) Whetsel 4 OliTe. 
c<in»b. nov.; EndophylloitleM portoricenifiit Whelwl A Olive, sp. nov. 

Osner, George A. Pn^Iiminary not4*s on a m*w leaf spot of cucumbers. (Abstract. ) 
Phytopathology 7: 62. F. 1917. 

Patten, Charles G. < >rigin and development of hardy, blight-resisting pears. Minn. 
Hort 46: 97 Uf2. Mr. 1917. 

Pennington, Leigh Hunt. Boleti Hnd niycorhisa u|M>n f«»n*8t trees and an unusual 
iii>ri>rliiia upon white oak. (.\l>tttr:irt. ) Phytopathology 7: 74. F. 1917. 

Pierce, Roy Gifford. Albany c(»nfen*n(e on white |>ine blister rust. Phytopathol- 
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Potter, Alden A., and Melchers, Leo Edwsrd. Kcological observations on I'siilago 
Z. :». Ph>inp;»tholngy 7: TH 74. F. 1917. 

Rand, Frederick Vernon. U-afiipot-rot of pmid lilien raumMl by Ilelicosponum 
n>tiiph:uruni. Jour Agr. It«M-arch 8: 219 2:i2. pi. 67 70. F. 5. 1917. 



1917] Literature on Plant Diseases 233 

Ruikiii, WiUiam Howard. The control of white pine blister rust in small areas. 
(Abstract.) Phytopathology 7: 58. F. 1917. 

The penetration of foreign substances introduced into trees. Phytopathol- 
ogy 7: 5^13, 1 fig. F. 1917. 

Ravn, Frederik K^^lpln. Jens Ludwig Jensen (1836-1904). Phytopathology 7: 
1-4, port. F. 1917. 

Reed, George Matthew. Phytopathological survey of the trees and shrubs of Pros- 
pect Park and the Botanic garden (Brooklyn). I. Report of the first season's 
work. Brooklyn Bot. Gard. Rec. 6: 14-20. Ja. 1917. 

Rhoads, Arthur S. Some new or little known hosts for wood-destroying fungi. 
Phytopathology 7: 46-48. F. 1917. 

Rosenbaum, Joseph. Studies of the genus Phytophthora. Jour. Agr. Research 
8: 233-276, 13 fig., pi. 71-77. F. 12, 1917. 
Literature cited, p. 273-276. 

and ShapofvaloY, Michael. Strains of Rhizoctonia. (Abstract.) Phyto- 
pathology 7: 74-75. F. 1917. 

Sackett, Walter O. A bacterial disease of the Wragg cherry. Jour. Bact. 2: 79- 

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Schneider, Albert. Further note on a parasitic Saccharomycete of the tomato. 
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Nematospora Lycopersici n. sp. 
Selby, Augustus Dawson. The blight situation as afifecting the pear and apple in 
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Bacillus amylavorus. 

Report on plant diseases in Ohio for the year 1914. 48th Ann. Meeting 

Ohio State Hort. Soc. 1916: 83-97. [1915.] 

Report on plant diseases in Ohio for 1915. 49th Ann. Meeting Ohio State 



Hort. Soc. 1916: 16-21. [1916.] 

Shear, Cornelius Lott, Stevens, Neil Everett, and Tiller, Ruby J. Endothia parasi- 
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1917. 
Literature cited, p. 77-82. 

Smith, Clayton Orville. Sour rot of lemon in California. Phytopathology 7: 
37-41, 2 fig. F. 1917. 

Spalford, W. J. Some diseases of wheat crops and their treatments. Jour. Dept. 
Agr. So. Aust. 20: 531-548. F. 1917. 

Spaulding, Perley. Evidence of the over wintering of Cronartium ribicola. (Ab- 
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Notes on Cronartium comptonise III. Phytopathology 7: 49-51. F. 1917. 

Stakman, Elvin Charles, and Piemeisel, Frank Joseph. A new strain of Puccinia 
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Stevens, Frank Lincoln, Ruth, W. A., Peltier, George Leo, and Malloch, J. R. Ob- 
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Bacillus amylovorus. 

Stevens, Neil Everett. A method for studying the humidity relations of fungi in 
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Literature cited, p. 432. 
Storage rot fungi. 



234 Phytopathology (Vol. 7 

Sterent, Neil Everett. The influence of certain climatic factors on the deveUif>- 
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Literature cited, p. 31-32. 

The influence of temperature on the growth of Endothia parasitica. Amer. 

Jour. Bot. 4: 112-118. 1 fig. F. 1917. 

Stewart, Vem Booham. Dusting and spraying nursery stock. New York (^umrll 
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and Reddick, Donald. Bean mosaic. (Abstract.) Phytopathology T: 

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Phytopathology 7: 59 60. F. 1917. 
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J. Ritiema lion, director. 
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Htract.) Phytopathology 7: 60. F. 1917. 
Walker, J. C. Studies up<m the anthracnose of the onion, (.\bstract.i Phyto- 
pathology 7: 59. F. 1917. 
Washburn, Frederic Leonard. Work on the white pine blister rust in Minoeeota. 

St:it«> Knt. .Minni'Hota ('in*. 40. 19 p.. 6 fig.. 1 rol. pi. 1916. 
Cntunrtium nhicola Fim'hcr «»r I'rriilrrmium i*trohi Kleb. 
Weir, James Robert. S<inii' HuggrtttioriH on thr control of mistletoe in the national 

forrfttH f»f the nnrthMcHt. ForcMtry l^uart. 14, no. 4: 567 577. December. 1916. 
Wolf, Frederick Adolf. .\ Miunnh diHc:iM> chummI by (*hoiinophora cucurbit a rum. 

Jniir Agr. |{. ^.•:l^h 8: .'U** :V2S. pi s.-^ s7. F. Jti. 1«»17. 



iPii^ nn*MH«»L'M.K f«»r .Vpril. 11M7 i7: Vi l.Vl. PI. II) wan iraucHi Apnl 5. 
P.M7 



PHYTOPATHOLOGY 

VOLUME VII NUMBER 4 

AUGUST, 1917 

THE CUPRAMMONIUM WASHES 
Their Preparation, Biological Properties, and Application 

O. Butler 
With Plates III to X 

A number of cuprammoniums have been recommended as fungicides, 
but, despite the fact that they form, or it would be more accurate to say, 
could be made to form, clear solutions and leave, on drying, inconspicu- 
ous spots on the foliage, no single one has sufficiently met the desiderata 
of practice to become generally employed. Practice demands that a 
fungicide be non-toxic to the sprayed plant at the strength at' which it is 
most efficient and effective, but the cuprammoniums have the reputa- 
tion of being unduly toxic and of not being as effective though more 
efficient than Bordeaux mixtures. 

The toxicity of the cuprammoniums has been ascribed to soluble cop- 
per (Millardet^ being notably a proponent of this view), to excess am- 
monia, and to ammonium sulphate. The prevailing opinion regarding 
the ineffectiveness of the cuprammoniums is based on their behavior 
relatively to Bordeaux mixtures which, in fact, is comparing solutions 
weak in copper with mixtures considerably stronger. Hawkins,* for 
instance, compared a cuprammonium containing 0.053 per cent copper 
with Bordeaux mixture containing 0.18 to 0.25 per cent copper. The 
question may, therefore, be asked, are any or is any one of the cuprammon- 
iums worthy of being retained amongst the fungicides? In order to satis- 
factorily answer this question it will be necessary to study: (1) The com- 
position and preparation of the different washes. (2) The relative 
toxicity of the different washes, and the conditions affecting the same. 

* Millardet, A., and Gayon, U. Les divers proc6d68 de traitement du mildiou 
par les composes cuivreux. Journ. Art. prat. 1: 729. 1887. 

• Hawkins, L. A. Grape -spraying experiments in Michigan in 1909. U. S. 
Dept. Agr. Circ. 65. 1909. 



236 -Phytopathology [Vol. 7 

(3) The relative efficiency and effectiveness of the cuprammoDiumft. 
This we will now proceed to do. 

I. CHEMISTRY AND METHODS OF PREPARATION OF THE CUPRAMMON'U-MS 

In the preparation of the cuprammonium washes met with in practice 
either animoniiim hydroxid or ammonium carbonate are employerl an 
the solvent, the solute being, in the case of the former solvent, either 
copper tuminf^s, i.e., metallic copper, copper sulphate^ the basic <*<»pper 
carlwnatc malachite (CuCOj. Cu(()H)x), or the basic copper carlK>DAt« 
of Burgunily mixture (2 CuCX),. 3 ('u(()H),)» and in the case of the latter 
the copper salts mentioned, together with basic copper sulphate and cu- 
pranunonium sulphate (CuS()4. 4 NHj. HjO). With the exception of 
the copper sulphatisammonia wash which Ls a cuprammonium sulphate, 
all the other waslu»s preparwl with ammonium hydroxid produce cupnuu- 
moniums of very similar, if not identic composition and fonii a well 
charact<»riz(Hl group; similarly the wjisIh^ prepared with aimncmium 
carl)onato an* also compositionally so ne^irly alike as to form a well lie- 
fincnl gn)up. The* fonner ar(» cuprammonium hydrati^s, the latter cupram- 
monium carlN)nat<^. Since (^uprammoiiium sulphate was the first in- 
tnxluced of the cuj)ramm<)nium washes and the cuprammonium hydrates 
were introduccHl prior to the cupranunonium carlMmates, it will lie possible 
lK>th to n*tain a group distribution and consider the M^veral fungicid<<9( in 
chn>nological ord("ir. 

,4. Cuprammonium Kulphate wafihen 

CopiHT sulphnlv and ammonia. The copfx^r sulphate and ainmunia 
wash (ejiu c^lc^stcO was the first iiitnKluc(Kl of the cuprammonium fungi- 
cidfw and still n^nuiins. taking the world at large, the l)ost known. It 15 
tlu* most easily pn<^|)anxl and at the same time the most unstable, even 
when sufficient amnumium hydroxid Ls (iinployini to give a clear h>Iii- 
tion. The fungicide was intHNluccnl by AudoynaucH in 18S5, but the 
original fonnula which is as follows: 



Cupriciiulphntr 1 

Aiiitiumiuiii hydroxiti ^p. gr. 9() 769* by volume 

WiiXt'T to 100 



* li4Mifi)r(l. Dukf of. uimI Pick«*nnf(. S. l*. Wotmrn Kxperimental Fruit Fi 
H«pt U: S4i. IIMO 

' Aij«loyiiniiii. A. Ia* miUlioti c*t Im roinp<iA<'t< cupriqucs. Progrteagr. el nt. 

IKK'. 

* Kfiuivnii-nt of animoniiim hydrntr up. gr. 92, 1 part by volume called for in cht 
origpiml foriiiula. 



1917] 



Butler: The Cuprammonium Washes 



237 



proved injurious to vegetation and has suffered ftiore or less marked 
modifications at the hands of subsequent writers as will be seen from a 
perusal of table 1. 

TABLE 1 

Strength oj copper sulphate and ammonia wash and ratio cupric sulphate: ammonium 

hydroxid recommended by different authors 





CUfRIC SULPHATK 


STRBKOTH IN CUPRIC SULPHATB 


AMMONIUM HTDROZID 
SP. OR. 0.90 


per cent 


■ 


0.26 


1:1.50 


0.50 


1:0.76 


0.50 


1:1.06 


0.50 


1:1.70 


0.50 


1:1.14 


1.00 


1:0.73 


1.00 


1:1.06 


1.00 


1:1.46 



The formulae given in table 1 do not necessarily represent the composi- 
tion of the fungicide when put in service, however, for we find authors 
recommending that it be allowed to stand after being made for a few 
hours, half a day or even several days* so that the excess of ammonium 
hydroxid may pass off. Nor do the formulae permit, except in one in- 
stance, i.e., in the case of the wash containing 1 per cent cupric sulphate 
and a ratio cupric sulphate-ammonium hydroxid of 1: 1.46, of the fung - 
cide being applied as a perfectly clear solution which is essential if tlie 
copper is to be deposited on the sprayed foliage in the proper physical 
and chemical states. Millardet^ long ago pointed out tliat Audoynaud's 
formula was in this respect defective and increased the amount of am- 
monium hydroxid so as to give a ratio of 1:1.53 instead of 1:0.769. 
The ratio cupric sulphate ammonimn hydroxid required to give a clear 
1 per cent solution (and Millardet's figures are correct) has to be greatly 
increased in order to prevent a precipitate forming when washes contain- 
ing less than 1 per cent cupric sulphate are employed. The Duke of 
Bedford and Pickering* have shown that the amount of ammonium hy- 
droxid required increases very considerably with the dilution and the 
data presented in table 2 confirms this view. But while the data given 
in the table show a very considerable increase in the amount of ammonium 

* Viala, P. Les maladies de la vigne, ed. 3, p. 143. 1893. 

^ Millardet, A., and David, E. Essais comparatifs de divers proc^ds de traite- 
ment du mildiou. Compte-rendu Congr^ nationale viticole, Bordeaux. Appendix, 
60. 1886. 

• Woburn Exp. Fruit Farm Rept. 11: 18. 1910. 



238 



Phytopathology 



(Vol. 7 



TABLE 2 
Amount of ammonium hydrorid required }o give clear nolutionM of copper MtUpkmie 
and ammonia of different ntrengthn in cupric sulphate together unth the corrt»pomd-' 
ing ration cupric sulphate: ammonium hydroxide and percentages of ammonia 



VrRKNUTH IN 



per rtnl 

I 

'> 

2 

1 



AMOI'Nr AMMONlim 

■TDSOXID MBQt'lKBD TO 

flIVB rUBAR ftOLUTIONi 



per cent 

15 
1 
8 
7 



II4TIO 



CUPKIC •rLTMATB 
AMMONII M HTDMOXIO 



1:15 
1:20 
1:4 
1:7 



IK NHa tn»m-Anri 

OMLT 



386 
2.SS 
251 
179 



'The* data given under the heading amount of ammonium or ammonium rarliunjit^. 
as thecaacmay Iw, required to give a clear 8olution indicatea the amount of the Milt 
required to give a clear solution for a ixTicMl of time of not leiM than two houm in 
a closed veatM*!. 

hydroxid n»lativo to tho copper, it also brings out equally clearly that 
the al)solute amount of anunonia* in solution decreases as the conr(*nt ra- 
tion of the copfMT is lowennl. It may also )>e well to add that onitiK 
to the extn^mc; volatility of ammcmium hydroxid the fi^reit given in the 
table will have to Ih» inrnMistMl at temp<Tatures much alnive 20**(\ :uk1 
conversi»ly may 1k» somewhat <h»rnjas(Ml for tomiKTatures l)elow 2iY*i\ 

The rop|NT sulphate and ammonia wash may l)e most conveniently 
prepare<l by adding the ammonium hydn>xid nH)uiro<l to a strong si>lu* 
tion of copfMT sulphate and diluting imnuHliately after the pnH*ipitat« 
first fonn<»tl has dissolvtui, though the wash may Ih» satisfactorily pn»- 
pannl even when the n^lative dilution of the salts varies f^ithin wxilc 
limits. It is g(*4ierally considi^n^l that the copper and anunonia wash 
(and the other cupranunoniums) are In^st pn^panni with soft water Mncp 
the solutions tin*. d(H*ompos4Ml by hard water. The amount of copper 
pnH'i(utate<i wliftn hani water b( usimI is, however, entirely m^Ugible in 
practi(*<» lis nuiy Ih» judgcMl frofu table 3.** * 

TABI.K 3 
Am4>unt of cttpiHT itrrripitated from thi mpfur »ulphnte and amm4ntia womK hy ir«i.'rrt 

iff difftrt ut dtgntM of htirdttrMx 



IM>I tt'K or WATRR 



H%iibMiciM or I 

MrTHH- OKllRKU , 



corrva 
raBrirrr»Ti» 



(*ily «if liord«>.*iu\ 
(!nvoii ykvW 



-.Yi 
92 



OOONt 

ocMm 



*The ii'Tiu afiiitionia in \imh\ to denote Nil, unlefut the context indicatm tlie 
connotation Ml .Oil 

'* Mdlardrt. A . and tiayon. V. Id** divert* prtWuirii de traitement du mtlcfaou 
par Ira comfHMM'i* ruivreux. Journ. .\gr. prat. 1: 7.Ti. 1KK7. 



1917] Butler: The Cuprammonium Washes 239 

When ammonium hydroxid is slowly added to a strong solution of 
cupric sulphate a precipitate of basic cupric sulphate (CUSO4. 2 Cu(OH)i) 
is thrown down which dissolves in an excess of the reagent forming a 
deep blue solution, the copper being then in the form CUSO4. 3 NHj. 2 
HjO" or, according to the more commonly accepted view CUSO4. 4 NHs. 
H2O a salt which decomposes readily on volatilization of ammonia or on 
dilution, the copper' being precipitated as a basic sulphate. When the 
fungicide dries upon foUage the copper is deposited as a basic sulphate 
mixed with a Uttle ammonium sulphate in the ratio of 1:0.35; in other 
words only a very small amount of the latter salt can be present even 
when a 1 per cent solution is sprayed on foliage as will be clearly seen 
from a study of the reactions involved which are as follows:" 

(1) 3 CUSO4 5 H2O + 4 NH4 OH = CUSO4. 2 Cu(0H)2 + 2 (NH4)2S04 
+ 15 HjO. 

(2) CuSO.. 2 Cu(OH), + 2 (NHOjSO, + ;„ "' "T = 3 (CuSO*. 4 

in excess 

NHs.HjO) + 9 HtO. 

(3) 3 (CUSO4. 4 NH3.H,0) + H2O = CUSO4. 2 Cu(0H)2 + 2 (NH4) 
SO4 + 8 NH, 

B, Cuprammonium hydrate washes 

A cuprammonimn hydrate is formed when metallic copper, cupric 
oxide, cupric hydrate, malachite, or the basic cupric carbonate of Bur- 
gundy mixture are dissolved in ammonium hydroxid, and washes have 
been used in practice prepared from copper and all the copper salts men- 
tioned with the exceptions of cupric oxid and hydrate. All the cupram- 
monium hydroxid washes decompose on dilution or on volatilization of 
ammonia with formation of cupric hydrate, the copper also being de- 
posited in this form when the fungicides dry spontaneously on foliage. 
The cuprammonium hydrate washes are more stable than cuprammonium 
sulphate. 

Copper and ammonia wash. The copper and ammonia wash, or 
Schweizer's reagent, was first introduced as a fungicide by Bellot des 
Miniferes in 1887" but despite the fact that the results he obtained are 
said to have been highly satisfactory it is practically unknown in the 
literature. 

For the preparation of the copper and ammonia wash a very large 
amount of ammonium hydroxid is required and the copper must be acted 

" Bedford, Duke of, and Pickering, S. U. Woburn Experimental Fruit Farm 
Kept. 11: 17. 1910. 

** Chester, F. D. The copper fungicides. Journ. Myc. 6: 23. 1891. 

" Bellot des Mini^res, H. Ammoniure de cuivre et parasites de la vigne. 1887. 



240 Phytopathology (Vol. 7 

on in thc^ firesenco of air or traces of aniinoniuni salti). Bellot de» Mm- 
i^res employed the fonner method and prepared a stock solution whirh 
was diluted at time of use so as to contain 0.25 to 0.75 per cent metallic 
copper, i.e., the copper equivalent of a 1 to 3 per cent Bordeaux mix- 
ture. The stock solution was made as follows: 



Copper turnings 1 

Ammonia, up. gr. 0.9 .' 119 by volume 

A stock solution prepare<l in the manner indicated can l)e dilutc<l with 
water to 0.0^^17 per cent copper without a precipitate forming within a 
pericxl of two hours. At this dilution, however, the solution c<mt2iins 
0.97 pcT cent ammonia which, as a glance at table 4 will show, is much 
higher than in the other cuprammoniums of (H]uivalent stn^ngth in i-oi^ 
per. The fact coupled with the difficulties incident to the prep^iration 
of the st<K»k solution hjis sc»riously militate<i against the emplojnnent of the 
fungicide »n practice, the advantage's incident to its iLHt\ i.e., an ailht*!*ivi*- 
ness wpial to the copper sulphate and ammonia wash'* and U»sser injuri- 
ousness to the grape,** l)eing not sufficiently comp<»nsator>' to outwf*i|^h 
the dmwbacks. 

TABI.K 4 

Amount of ammonia riquiud to ffiir t Irar solutions of the ruprammttnium ir«i«A/« 

irhrn containing 0J)!M7 ftrr cent mrtallic copjter 

NAMC or ruNoiriDr. 



( *op|MT-nmnioniii 

(\)|i|M>r ((ulphiit<'«nnim(iniA 

(*np|M*r xiilphato- iinirnoniuni rHrl>onat4* 

Malnrhite-amnionia 

Hiirgimdy niixture-ammc»nia 

Malafhitr-ntiimonium rarbonatr . 

Hiiricuiiily niixtun*-aninioniuni carhonati* 



4MOr»T NHi BB4Jt »«• 
TO OIYB % iLBkB 




ptr cent 




e 9772 




179 




OI9 




GMM 




• ,ViO 




047 




aiH 



Hunjundy mixture and ammonia. This the ftarlii»st copjier carkNinate 
and ammonia wash employe<l in practi(*e wt&s intnNluce<l by Patrigi^in 
in 1KS7** and coiL*<i.»*ts simply in dissolving th<' ba»*ic coppcT carlNmate 
of Burgundy mixtun* din'i'tly in the mothcT li(iuor by moans of am- 
monium hydn)xi<i. The w:ish Ls us<h| to some extent in practice and 

'• Fo*\. (1. ("ourr* roriiplct dr Vitirultiin* ed. 4. 577. 
" 1 1»^\. <1. TXw iMiiiu*. p. .'>7H. 

^* I'ntrigroii. (t. Nouvraux pHN'^l^ di> tr»it4*m(*nt dii mildiou. Journ. m^- 
prat. 1; s-sj. ish7. 



1917] 



Butler: The Cuprammonixjm Washes 



241 



is known in the United States under the name of modified eau celeste. 
The formula originally proposed was as follows: 

parte 

Copper sulphate 1 

Sodium carbonate 1.5 

Ammonia sp. gr. 0.9 0.769 by volume 

Water to *. 100 " 

Patrigeon's formula has not suffered any marked modifications at the 
hands of the various authors who mention it as will be seen from table 5. 

TABLE 5 

Strength of Burgundy mixture-ammonia and corresponding ratios copper sulphate 
sodium carbonatCf and copper suLphaie ammonium hydroxid recommended by dif- 
ferent authors 



BTRENQTH IN CX7PRIC SULPHATE 


COPPER SULPHATE 

RATIO 

SODIUM CARBONATE 


COPPER SULPHATE 

RATIO 

AMMONIUM HTDROXID 


per cent 






0.25 


1:1.20 




:0.83 


0.30 


1:1.25 




:0.83 


0.50 


1:1.25 




:0.83 


0.50 


1:1.25 




1.04 


1.0 


1:1 




:0.73 


1.1 


1:1.25 




:0.78 



The amount of ammonia called for in the various formulae for the 
preparation of modified eau celeste is never sufficient to give clear solu- 
tions. The basic carbonate of copper of Burgundy mixture, separated 
from the mother liquor by decantation is, however, readily soluble in 
ammonium hydroxid, as may be gathered from table 6. 

TABLE 6 

Amount of ammonium hydroxid required to give clear solutions of modified eau cileste 



STRENGTH IN COPPER SULPHATE 


AMOUNT OP AMMONIUM HTDROXID 

REQUIRED TO GIVE CLEAR 

SOLUTION 


STRENGTH OF SOLUTION IN NH| 


per cent 


per cent 


per cent 


1.00 


4 


1.029 


0.50 


3 


0.772 


0.25 


2.5 


0.642 


0.10 


1.4 


0.360 



Burgundy mixture dissolves in ammonimn hydroxid, forming cupram- 
monimn hydrate and is not a mixture as Chester^^ believed of cupram- 

" Chester, F. D. Report of the Mycologist. Delaware Agr. Exp. Sta. Rept. 
4:68. 1891. 



242 Phytopathology (Vol. 7 

monium hydrate and carbonate. Modified eau o^leste does not fcive 
jw. to malachite on decomposing thus indicating absence of cupram- 
monium carlx>nate. When the wash dries upon sprayed foliage the cop- 
per is deposited as an hydrate, mixe<l with some sodium sulphate and 
bicarl>onate unless the copper carlx)nate is separated from the mother 
lic]uor and levigated l>efore l)eing di«<solved as is sometimes recommended. 

Copper carbonate and ammonia. The copper carbonate and ammonia 
wash, or ammoniacal copper carl)onate was introduced by Gasline'' and 
in American fungicide literature is the cupranunonium most commonly 
met. with. 

Malachite dLssolvos in ammonium hydroxid forming a solution which, 
according to the Duke of Be<lfonl and Pickering,'* consists mainly of 
cupranunonium cariM)nate, while (-hester*® Lh of the opinion that Inrth 
cupranunonium carbonate and hydrate are forme<l. As, however, the 
malachite ammonia wiish dcM^s not deposit malachite on standing. I 
incline* to the view that the copper is pres4»nt solely as cuprammonium 
hv<inite. 

Malnchit<» (iissolv(\s sparingly in anunoniurn hydroxi<l, the total amount 
entering into solution lK»ing l(»ss in a strong than a weak concentrati<in 
of ammonia. P<»iuiy** for instance, found that a 42.()8 per cent ammonium 
hvdn).xid dLssolviHl. imt gram weight of ammonia, 0.01329 grams of nHv 
tallic co|)ixT while !ind<»r similar conditions a 21.38 percent solution din- 
soIvchI 0.3132 grams and a 3.20 |K>r cent solution 1.063 grams metallic 
i'opiMT n*sjH»<»tiv(»ly. The.s<» results, unfortunately for practice, can not 
Im> obtaine<l by dis.Holviiig a given (plant ity of malacliite in the suitable 
corr<*s|)on<ling strength of ammonium hydn)xid. In order to obtain the 
maxinnun s<»lvent action it Ls nec<»ssar>' to us<» a ver>' large excesw of mala- 
chite, **even five fold or more" which int roduc(*s ob vioas difRculties t hat 
can not Im» tununl cxct»pt in a v(Ty empirical an<l unsatwfactorj' manner. 

The malachite-anunonia wjish was, {is I have aln*ady indicat<*<l, pn>- 
|M>MMi by (fiistine whos4» formula w:is jis follows: 



Mnlarhitr . . M 

.Viiiiiiniiia Kp i^r. n.lN) ... 76U 

Watrr to .100 

Th(* alK>v<* fonnula hit** Imkmi iiiorr or U'ss m<Nlifi(Hl at the hands of 
subMH|U(*nt writers, as will W\ .»<4»<»n from table 7. 

'* (iaMtiiK'. i\. Ijiiploi <lij f*:irlM»ii:it4* aiitiiioiiianil di* cuivre contfc* Ip pm>ni>* 
P|Hira I*r«»([ agr i-t vit. 8: 1SS7. 

»\\i»lMirii K\p Fruit I ami \U\>x 11: JI !«»I(I 

• I III* ««arii«'. p ♦">>*. 

■> rititix (' I. 'I'ljf p-«paratiiin nf :tninii»iiiaral miIiiIioii of ropprr carlmiuilr. 
Dc'laman- Aier l.xp ."^la Mill 22: .'> iyi:{. 



1917] 



Butler: The Cuprammonium Washes 



243 



TABLE 7 

Strength of malachite^ammonia wash and corresponding ratioh malachite: ammonium 

hydroxid recommended by different authors 



STRKNGTH IN MALACHITE 


MALACHITE 


BATIO 

AMMONIUM HTDROXID 


per cent 




0.045 




22.2 


0.046 




5.5 


0.060 




12.8 


0.075 




11.3 


0.078 




:10 


0.078 




:13.2 


0.086 




:10 


0.093 




:8.7 


0.093 




:5.5 


0.097 




:10 


0.097 




:13.2 


0.100 




:1.23 


0.100 




:11 


0.125 




:8 


0.200 




:8 



Neither in the original formula nor any of the subsequent ones that 
have come to my knowledge is the ratio malachite-ammonium hydroxid 
such as to insure complete dissolution of the copper salt. In order to 
dissolve the malachite completely, at least within a reasonable time, the 
ratio must be increased to 1 : 30. It is therefore clear that, as usually 
prepared, the wash either contains less copper than the formulae call 
for, or if the undissolved malachite is incorporated in the wash then the 
copper will be placed on the plants partly in the form of malachite and 
partly as a copper hydrate. In order to obviate these difficulties I have 
employed a stock solution prepared as follows: 

parte 

Malachite t ? 1 

Ammonia sp. gr. 90 30 by volume 

Water 20 by volume 

In preparing the stock solution water must be used as otherwise the 
solution would prove unstable, decomposing %vith formation of cupric 
oxid. A stock solution containing as little as five parts water may be 
prepared and probably more water than the formula calls for could be 
used, though it will be perfectly obvious that there is no object in making 
a stock solution unduly dilute. In fact, ceteris paribus highly concen- 
trated solutions are to be preferred. 

The stock solution as above prepared is quite stable and may be diluted 
very considerably without decomposing, but contains more ammonia than 



244 



Phytopathology 



(Vol. 7 



TABLE 8 

Amount of ammonium hydroxid required to ffive cleat nolulions oj maiarhiU* 

ammonium hydroxid 



•TIIKKOTH IN TEBMi OF 

corpftM arLniATB 



prr rent 
1 

5 
25 
10 



AMOUNT AMMONIUM HTOKOXIS 

MBQUIRBO TO UtVK CLBAB 

•OLUTION 



ce. 

26 5 
13 '25 
6 {\2 
2 65 



•TBBNOTV or •OLTTION IN NHf 



6 82 

3 41 
1 70 
0.6S2 



mcNiified eau celeste for (Hjual p<»rcoiitttg«s of copper (Cu) as may l>e Hsen 
by comparing tahlo 8 with table (>. Then^ is, therefore, no just ifieat ion. 
since sodium sulpliate and biearlM)nate are not injurioii:^ at the conrcm* 
trations at which the wjtsh may l)e employed in practice, in the preference 
aocordi^d the malachite-anunonia wash, as the (*opper (M*curs in the same 
fonn in Inith. The difTen»nce in favor of modifi(Ml iiau c^Uwte is n<it only 
markcMi. however, in the fonniihu> I have us<»d, but Is also favorable to 
the latter wh(»n w<» comparer \\u\ formulm^ of authors. Taking the ejc- 
tn»nM^ met with we find tlie n«ults shown in table 9 wliich an* even 
mon^ favonible to modified eau c^U^ste than in the case of my fonnulae. 
And when we consider the (^ost of the unit copper employiHl (exclasive 
of lalK)r) in nuHlifi(Hl eau c^l(*ste and malachite-ammfuiia we obtain a 
ratio of 1:3 wliich is so siKnifi(*ant as to n^iuin^ no comment. 

TABLK 9 

Extrrmr jterrrutagrtt of ammnuin nut with in thr Utrmidae of author* for the ffrefiaro-' 
tiou of numiifitd rait n'lrHtt * A ) and mat ac hit i -ammonia \H\ renpertirtty 



•TRrMiTM Of HOLI^ION IN 

TKBMM or rorrcH 
■I Lrn «TC 



per ttnt 
J.") 



1 1 



nTKKM 


iTH 


OF 


MiLi-ri«».M 


iM 


NH* 




A 






\ 




B 




prr rrnt 










ptremni 




051 






: 




554 




(»73 










141 




joi; 










707 




CI JIM 










2 S2S 





t'. t'liprntntnitnium cnr^Httuitf wnshrs 

< 'upniiniiKiiiiuni carlNiiiatc \\:i^h(•^ an* foriiuNl when cupric sulphate, 
ni:il:i<*)iiti*. rupraniiiifinMim >ulph:it<* '('uSn4. -| Nils. H3O) and the Imisic 
cupn«' *:irlM»iiai<* nf HurKuiidv tnixtun' an* ilirv-olvnl in runmoniuni car- 
ImukiIi MMf< t); MI4. NH,<'n, . Till- \\a>h«-^ an» ver>' sUble. the 
nMi>t «t:tii|i- III till* riipraiiiiit«>iiiuni fun^icidi*^. only decom|M)sinK slowly 



1917] 



Butler: The Cuprammonium Washes 



245 



on long standing with formation of malachite. When the washes diy 
on sprayed foliage the copper is deposited as a carbonate. 

Cuprammonium suiphcUe-amm^mium carbonate. This wash was in- 
troduced by the United States Department of Agriculture in 1890** 
under the name of mixture number 5 but has never been used to any ex- 
tent in practice as it was not found to possess a lesser toxicity than other 
cuprammoniums and is not economical to prepare. The formula origi- 
nally proposed was as follows: 

porta 

Ammoniated copper sulphate (Cuprammonium sulphate) 0.21 

Ammoniiun carbonate 0. 12 

Water to 100 

Malachite-ammonium carbonate. This fungicide was introduced by 
Chester** in 1891 as a substitute for the malachite-ammonia wash, but 
despite manifest advantages has been but Uttle used in practice. Ches- 
ter's formula is as follows: 

parts 

Malachite 0.052-0.058 

Anmionium carbonate 0.27 -0.31 

Water to 100 

The original formula has been modified to some extent by subsequent 
writers as i^ shown in table 10. 

table 10 

Strength oj malachite-ammonium carbonate wash and corresponding ratios malachite: 

ammonium carbonate recommended by different authors 





MALACHITK 


STRSNOTH IN 1IA.LACHITE 


AMMONIXTll CARBONATK 


percent 




0.039 


1:6 


0.046 


1:5.3 


0.052 


1:5.19 


0.058 


1:5.34 


0.066 


1:3.3 


0.093 


1:5.3 



Malachite dissolves fairly readily in ammonium carbonate, carbon 
dioxid and a little ammonia being evolved during the reaction, but the 
reaction is not sufficiently rapid nor the conditions under which it takes 
place such as to permit the preparation of the fungicide as required. A 
stock solution is necessary and may be conveniently prepared as follows: 

« United States Department of Agriculture Rept. 1890: 402. 
» Delaware Agr. Exp. Sta. Rept. 4: 71. 1891. 



246 



Phytopathology 



[Vol. 7 



Malachite 1 

Ammonium carbonate (hard)** 3 

Water 30 

Place the malachite in a suitable non-metal vessel, add the amnionium 
carbonate in small pieces, and then the water. Warm gently and mb 
soon as effervescence bepns remove from flame and stir. Let Ktand a 
few minutes, place back on flame and continue as before until on wann* 
ing fi^ntly no further effervescence takes place. The vessel should thiro 
be closed and set aside until the malachite has completely disHolved, 
should it not already have done so. The stock solution prepared as aljove 
will withstand marked dilution without a further addition of anunonium 
earl)onate I>eing require<l at least within the ranfi^e of concentration in 
coppcT that I liave used, as will lx» seen from table 11. 





TABLE 11 




Amount of ammonium carbonate {hard) required to give clear ttolutionn of malarhitf 




ammonium carbonate 


n'RKNOTM IM 


AMOt'NT AMMOMCM 

(-\HBONATE NKgriHKb 

TO ur\'K A (LJCAM 

IM»LrTION 


HALAcnrrK 


STRCffOTII or IMILC- 


MAi.4rHnrB 


AMMONIt'M C'AKBONAnC 


TioM m NH* 


prr rtmt 


prr ctnt 




^tretmi 


.V) 


1 5 


1:3 


476 


JO 


f) 


1:3 


19U 


10 


3 


1:3 


oas 


o:> 


15 


1:3 


047 



Copper Hulphaie and ammonium carbonate. The coppt;r sulphate and 
anunonium car)K)nate wash known in Anu^rican literature as Johnson'^ 
mixtun; has lHM»n but little uschI in pnictic(» an<l Is but ran»ly mentione^i 
by writers on the funfci<'idi*s. The wiu<h was first dtwcrilKid in 18!U by 
J(>hns<»ir* who profKiMHl the following formula for its preparation: 



(NjpJMT Htllphfld' 

Ariiiiioniuin riirlK»iiiiti> (hard) 
(ir Ariifiioriiiiin rnrlNtrmtr 'Htift ) 
WfttiT to . . . 






1 





21) 





23 


1(10 





'* Aiiiiiiofiiiiiii rarUtiiatc diM^oiii^MiW!* (»ri cxpoHurc tf> nir ami in prrparinfc th<* M«K*k 
iu>ltitii>n th«' atiiiiunt of thr Halt ii^mmI will have (o U> incroamHl unirm it ia in prr- 
f«M tly hard tranNlurrnt platrH. \\ hrn romplft<>ly df'<*oniiM»m>d ammonium rarlKinjite 
ocriirH lis an o|Ktc|uc ihiwiIit and wh<*n in thin romlition the amount railed for in 

tli«- fi*niitl]a ^h(lllld U* dollhlrd. 

" Jnliiit^oii, S \V Noll' l»y ihf Dirertor. ConniM'tirut A^r. Kxp. Sla. Kept. 
1890:113 iy«l. 



1917] 



Butler: The Cuprammonixtm Washes 



247 



Johnson's mixture is, next to the copper sulphate and ammonia wash 
(eau celeste), the most easily prepared of all the cuprammoniums. When 
anmioniimi carbonate is added to a strong solution of cupric sulphate a 
precipitate is first formed accompanied by effervescence due to the lib- 
eration of carbon dioxid which on a further addition of ammoniimi car- 
bonate promptly and completely dissolves even in the cold. 

Johnson's mixture forms very stable solutions and, as a glance at table 
12 will show, is for equivalent of copper compositionally identical with 
malachite-ammonium carbonate. 

TABLE 12 

Amount of ammanitan carbonate hard and soft required to give clear solutions of John' 
son's mixture and corresponding ratios cupric sulphate: ammonium carbonate 



■TBXNOTH IN 


AMOUMT AMMONIUM CABBONATE 

BSQUIBND TO OIVB A CLBAR 

■oxjUTIom 


CUPRIC SULPHATE 


STRENGTH 
or SOLUTION 

IN NHt^ 


PHATB 




AMMONIUM CARBONATE^ 




Hard 


Soft 




P€reerU 


percent 


percent 




percent 


1.00 


1.56 


2.40 


1:1.56 


0.495 


0.50 


0.78 


1.20 


1:1.56 


0.247 


0.20 


0.31 


0.48 


1:1.56 


0.099 


0.10 


0.15 

• 


0.24 


1:1.56 


0.049 



^ Refers to solutions prepared with undecomposed ammonium carbonate. 

Burgundy mixture-amnumium carbonate. Burgundy mixture may bo 
readily dissolved in ammonium carbonate 3delding a cuprammonium 
very similar to those obtained with malachite, copper sulphate, or cupram- 
moniiun sulphate as will be seen by a glance at table 13. 

TABLE 13 

Amount of ammonium carbonate required to give clear solution of Burgundy mixture- 
ammonium carbofKUe and corresponding ratios Burgundy mixture: ammonium car- 
boncUe 



BTRENOTH IN COPPER 
SULPHATE 


AMOUNT AMMONIUM 

CARBONATE (HARD) 

REQUIRED TO OnTE A 

CLEAB SOLUTION 


BUBGUNDT MDCTUBB 

BATIO 

AMMONIUM CARBONATE 


STBENGTH OP SOLU- 
TION IN NHs 


percent 


percent 




percent 


1.00 


1.20 


1:1.20 


0.380 


0.50 


0.60 


1:1.20 


0.190 


0.25 


0.30 


1:1.20 


0.095 


0.10 


0.12 


1:1.20 


0.038 



The data given in table 13 are for a Burgundy mixture in which the 
ratio copper sulphate sodium carbonate (crys.) was 1: 1.84, and the pre- 
cipitate was separated from the mother liquor before dissolving in the 



248 Phytopatholoot [Vol. 7 

ammonium carbonate. In practice, however, the precipitate would not 
need to be separated from the mother liquor, since the salts therein con- 
tained are not injurious^ at the concentrations at which the wash may 
be employed in practice. 

As a result of our study of the properties and preparation of the cupram- 
moniiun washes we may conclude: 

1. The cuprammonium carbonate washes are the most stable and for 
strengths in metallic copper of 0.14 per cent or less require less ammonia 
to give clear solutionis than the washes prepared with ammonium hydroxid. 

2. The copper salts dissolved in ammonium carbonate 3rield washes 
in which the active principle, i.e., the copper is in the form of a carbonate. 

3. Metallic copper, malachite, and the basic carbonate of Burgundy 
mixture form cuprainnionium hydrates when dissolved in ammonium 
hydroxid modifie<i eau c^K^e requiring pvir equivalent of copper the 
least amount of solvent. 

4. Cupric sulphate forms with ammonium hydroxid a cupraiiunonium 
sulphate which Is the least stable of the cuprammonium fungici<ics. 
though less anunoiiia b< required to give a clear solution than in the case 
of the niprammoniiun hydrates. 

II. RELATIVK TOXICITY OF THE CUPRAlfMO.VIUM WASHES 

The cuprammonium washes may l)e toxic to the sprayed plant: {D 
Between the time of application and time of drying; (2) after dr>nng 
owing to dissolution of the contained copper on weathering; or (3) the 
injur>- pnxluced, if any, may l)e the result of the additive effect of 1 and 
2. Thon^ lin'i no other possibilities. 

A. Effect of the cuprammoniuffm on planta between the time of applicaiian 

and the time of drying 

It will Ix) at once evident that if the cuprammoniums nuule with ammoo- 
iuiii hy<in>xid owe their toxicity to the presence of anunonia, the toxic 
action, owing to the rapid dis.sipalion of ammonia in the interim lietwec^ 
time of application when its con(*ent ration will Ina highest and time of 
d<*>i(vation when its conci^ntnition H-ill \)o zero, must and can only take 
phi«*<* during the ilrying of the .^pray. Ammonium carbonate bt lev 
vol.'itilc than junmoniuni hydroxid, but nevertheless decomposes readily 
on rx|H»sure to air and has vani.shc<l when the wiishes of which it is a com- 
ponent have dritni u|K)n the foliage, hen<*<* injur>' due to the presence of 
ainin«iiii:i in ainn ionium ciu'lMmate can also only In^ produced in the 



1917] 



Butler: The Cuprammonium Washes 



249 





















o 
o 



00 

o 



Si 



M 
O 

•-a 



f S 

O) 

6 



9 
O 

1a 

S 

Pk4 



§ 



k^ 



OC^O«0'^1^00 



00 

■ 

o 


SC 'H d »-( 1-1 


• 


1^1 ®S®i§:::2*=*= 



o 



^1 «'S"?Jc5S°'= 



9 

o 

i 






1^1 0'Tt40Tt<Tt<»000 



oo 


ri 


o 


t^ 


to 


o 


CO 


Tt* 


o 


o 


^ 




1-H 




CO 


f-H 


C^l 






o 






















r§ 




5 


CO 


CM 


CO 


^ 


o 


o 


o 





















1^ 



1,1 ??S?58§S®=" 



9 

o 

a 

Pk4 



s 

o 



^^ oo«oo«oxoo 



o 


K"g OTt<0005000 

K.8 ^ ^ 


• 

o 





^ 



"5 io»o»oa>i^<poo 

C ^^ CO CO ^ 



3 

O 

a 
S 






|g OCOOOCOiOOO 



o 




00500b-000 

1— » 


o 


r§ 


XOSi-HCOOCOOO 



3S 



^1 t2 g ^ =; §5 S 



o o 



> u 
OS 



-^ >>^ >>^ >.^ >. 

;3030303C 



fa 

5 

>> 
& 

Pi 

> 



I 

a 

o 
O 

• 

08 
> 

QO 

3 I. 

o -^ 



o 

0!) 



> 



03 

s 

o 



QQ 



I 

o 



OS 



eg 



CO 



0) 

c3 



o 

c3 



d 

08 



§0) 

U 

S ^ -^ 

« ^ ;3 



4^ 



o 

CO 0) 

.s ^ a 

i « § 

3 a (4 

O '^ "^ 

^j ^ o 

00 *> -^ 

1 ^ ^ 

.5 1^ o 

*- CO Z3 
>> 03 
08 

^ OS 
o8 0) 

IT- cr's 






o 
"a 

a 



g 



03 
X 
4^ 

d 08 

1^ 



o 



00 



00 

3 
O 



3-S ^ 



03 
> 

03 



O. 03 






H 

08 .O 



3 
O 



00 

00 3 

g ^ 

- & 

08 

00 

P :S 



00 M^ 

2 G 

^ o 

O -D 

ii > 

X c3 

c3 -C 

^ o 

C -^ 

<^ 3 

" I 

.^^ 00 

o ^ 

H *- 

^ 03 



3 t^ O 

-5S O 6iD 
5 " 3 

^ 'S 

** o8 • 

sis 

i -"^ 

_2 o o 
-r 03 00 

Ih O 
CO Q. 

2 w r: 

a oj ^ 

^ no 08 

3 o ^ 

-o 0« >> 

S ^ s 

^ 03 
0) B^ O 

^ °° fl! 

^|| 

>>•- Si 

S '•-' 

O h 



o 



00 



a «» 



-^ 2 3 

± =3 3 



250 Phytopathology [Vol. 7 

* 
interim between time of application and time of drying. If the toxic 

action is due, on the other hand, to noluble copper or ammonium sulphate 
whenever this Halt occurs, then the injury resulting may be produced dur- 
ing the time of drying and also at such sul)sequent times as the fungicide 
is wetted by meteoric water. The rate at which the cuprammoaiums 
dry upon sprayed foliage will, it may therefore be presumed, have a very 
marked effect on the degree of injury produced. And in fact experimental 
evidence fully confirms the presumption as is shown in table 14 and plates 
III and IV. 

The data presented in the above table show how significant was Audoy- 
naud's reconmiendation that the copper sulphate and ammonia wash 
be applic<l during dr>% wann weather and fully justifies Bourcart*.^'^ 
statement that scorching '*is especially to he feared when eau c^Ie:<te i^ 
applied during moist weather and, coni^c<}uently, when it dries slowly on 
the leaves;** but that on the other hand ''when the spray is applied <lur- 
ing the hot days of summer, this fault disappears entirely, and eau c*elf^te 
possesses nothing but advantages.*' The data presented in the table 
show conclusively that slow drying is much more injurious than quirk 
drying, the difference l)eing ver>' striking indeed in the ca**e of malachite- 
ammonia and malachite-ammonium carbonate containing 0.28 per cent 
and 0.14 per cent copper. 

While the data prosente<l in table 14 show that whenever a cuprain- 
monium is toxic it is invariably more injurious when drieil slowly im^ 
spective of the plant spmyetl, it does not give us any ver>' definite infor- 
mation regarding the cause of the deleteriousness of these washes. The 
data do not supiN)rt conclusively either the view that aimnonia is the 
toxic agent, or the view that the toxicity is due to soluble copper since 
were but one of tlu»sc^ conijKments tin* sole cause of the injur>' protluccti a 
certain proportionality would exist differing only in degree in different 
plants lM!tw(H'n a given strength of the toxic Kul»stance and the resulting 
mjur>', but a considenition of table 14 shows that no such relation exists 
in cither c]is4*. On the other han<l, the data clearly show that ammonium 
sulphate do«rs not |K)ssi*ss luiy niark<Mlly injurious properties. Neither 
an* the malachite wa*<hes shown to In' K^s injurious than those maiie 
fn»in cupric sulphate and auuiionia. a fact worthy of S4*rious consiiiera- 
tion in view of the* general abandonment of the latUT cm account of sup- 
fjosiil gr«iter toxicity. 

Hut siiKM* nu individual coin]Minent of the cupranimoniuni wa*«h«*s is 
apiMin-ntly inr x# the mn^r of the toxie action pnKluce<l in the inteival 
lx*twe( n thf- applieatjnn of th«> fungirid«> and its desiiraticm it will U* 

• liourrnrt. K I^-h iiiii1:m!i»'< «!«f plant h. .'JTii. Pnrirt. W^U). 



1917) Bdtlbb: The Cuprahhoniuh Washes 251 

necessary for us to study their behavior when applied separately in order 
to interpret the data ^ven in table 14, and to the action of soluble copper 
we may well devote attention first. 

The only suitable copper salt to use in studyii^ the effect of soluble 
copper when applied in the form of & spray is cupric sulphate and since 
the acid radicals of the copper salts are not in themselves injurious*" the 
toxicity of cupric sulphate may be considered as due to the copper. Sol- 
uble copper is, as is well known, extremely toxic to vegetation and we 
would, therefore, expect that the injury produced by an application of 
cupric sulphate would be the greater the slower the spray dried on the 
foliage, and the data presented in table 15, fully confirm this expectation, 
and the illustration shown in plate V is no less emphatic. 

TABLE IS 

Effect of quiek and tlow drying on the loxieity of cupric tulphate eijtreued in per cent 
of injury 



> The beading, used also ia plate viii, means that the percentage strength of the 
solution ie given in terms of milligrams iastead of fractions of a gram. 

The data presented in table 15 and shown graphically in plate VIII 
indicate that the tomato, Oxalis, bean and cauliflower are much more 
sensitive to soluble copper than either the Coleus or the Pelargonium. 
The tomato, bean, Oxalis and cauliflower respond in a somewhat simitar 
mamier to soluble copper, the curves for quick and slow drjii^ being 

" Bedord, Duke of, and Pickering, S. U. Woburn Experimental Fruit Fann 
Kept. 11: 1910. 

Clark, J. F. Oa the toxic properties of some copper compouods with special 
refereoce to bordeaux mixture. Bot. Gaz. 33: 39. 1902. 

Hawkins, L. A. The influence of calcium, magneBium and potaaalum nitrates 
upon the toxicity of certain heavy metals towards fungus spores. Physiological 
Researches 1: S7. 1913-16. 



252 



Phytopathology 



[Vol. 7 



ver>' nearly parallel at the higher concentrations. In the case of the cauli- 
flower which is very sensitive to soluble copper the curves are nearly 
proximate, while in the case of the tomato, which is much more tolerant, 
they are distant. The curves for the Oxalis and bean are very similar 
in character, and resemble those of the tomato, though the bean is more 
sensitive to soluble copper than the Oxalis and the Oxalis less resistant 
than the tc^mato. In the most highly resistant plants studied, the Pelaricrv 
nium and C'oleus, the curves show marked similarity, the to:;icity on slow 
dr>'ing increa«<ing a little more rapidly in the former than in the latter. 
It will also be noticed that while in the more resistant plants ((*o!eua« 
Pelargonium) the toxicity is practically proportional to the concentratioo 
in the less resistant plants proportionality ceases to exist as scMin as the 
threshold of toxicity is appn ached, the decrease l>eing much more rapid 
than the data for the higher cxincentrations would lead one to anticipate. 
The practical importance of these facts will escape no one. 

TABI.F 16 
Effect of hIow nrui quick druiug on the toxicity of ammtmi um hti<iroTid ■/». gr. 90, 

eTjrreiitted in fnr cent of injury 



\ ANIKTT mtV 



HOW 
DNIKD 



nTHt NUTH (»r AOLrTION IN N Hi 



lU 21) I 5 14 i 4 II 6.^7 2 (A I.2H 

l^'T iwr ! |«rr I prr . iht jtrr 

wilt ct'Ui ' <i*i»! I rent , o'lit r««iit 

1 I 



102 
frnt 



51 






Tomnto 
CiiiiliflowtT 



'(^uirkly 
.Slowly 
Quirk ly 
Slowlv 
(^uirkly 
Slowly 
(^Uiirkly 
Slow I V 



per 



inr ^ per \ prr per , per 



cent • cent rent , cent . ctnt ! rwnt 



IS 

7ti 



I 

VA) ! 
7.'» 



29 
50 



X\ i I 21 i 

2:< I Iti 

17 :i:> 



10 

I 25 

I '^^ 

; 4ii 



< 

5 



per 

CtHl 
I 

s 
12 
34 

O 

a 



93$ 
rrflkl 



fw%S 



5 

22 



U 



. 10 



Thr t<»xi<*ity of :iiiiiiH»niuiii hy(ln>xid h:is Ih»<mi ronsi<len»d higli by all 
writers who have h<»ld the t<»nct that the toxi<*ity of the copp<»r ami am- 
monia wastu's was due to th«* amiiionium hydroxid though MillanlH 
|)oure«|, he tells us. stnmg aiiimonium hydroxid on the foliagf^ of the grafie 
without pHMlucing injur>'. a result >tn>ngly (Mintradicting the prevailing 
vi(*w. and the data pn>ent<sl in table Ki are not on analysis favorabh* to it. 

A glanrc at the table revrals that like the cuprannnoniums and ruphc 
sulphate* aniinoniuin hydroxid even though highly volatile is nmch UMkn* 
t4»\ir when dri«»<l slowly and the illustnition given in plate VI sh*»ws 
verv "^trikinglv what marked differences mav Ik* obtaineit. The tfata 
al*4» sh<»w that, of all the plants us4<l, the tomato is the most sensitive 



1917] 



Butler: The Cuprammonium Washes 



253 



to ammonium hydroxid while the Coleus, bean and cauliflower follow in 
increasing order of resistance. Now if ammonium hydroxid is primarily 
the cause of the toxicity of the cuprammoniums of which it is a compo- 
nent part the relative resistance of the plants when sprayed with the 
copper sulphate and ammonia wash or the malachite-ammonia wash 
should remain imchanged. In reality we find that when the former is 
employed the sensitiveness of the plants is in decreasing order as follows: 
Tomato, bean, Coleus;** and when the latter is used that it is as follows: 
Tomato, Coleus, bean. The evidence is therefore clear that anunoniiun 
hydroxid is not the primary cause of the toxicity of the cuprammoniums. 
The toxicity of ammonium hydroxid is of course due to the ammonia 
(NH3) it contains and it would therefore be expected that ammonium 
carbonate which has been used in the preparation of cuprammonium 
washes would also prove injurious since while less volatile and alkaline 
than the former it nevertheless decomposes rapidly on exposure to the 
air with liberation of ammonia and carbon dioxid. And in fact experi- 
mentation shows ammonium carbonate to be much more toxic than 
usually supposed as will appear from a consideration of table 17. 

TABLE 17 

Effect of slow and quick drying on the toxicity of ammonium carbonate, expressed in 

per cent of injury 



▼ ABIETT U8XD 



Coleus "j 

Tomato < 

Cauliflower 

Bean 



STRENGTH OP SOLUTION IN NHj 



HOW 
DRISD 


1.90 


0.05 


0.47 


0.23 




percent 


percent 


percent 


percent 




per cent 


per cent 


per cent 


per cent 


Quickly 


40 


2 








Slowly 


100 


81 








Quickly 


40 


15 


5 





Slowly 


100 


70 


50 


20 


Quickly 


75 


29 


10 


7 


Slowly 


92 


42 


13 


6 


Quickly 




1 








Slowly 




8 









The data presented in table 17 and more strikingly illustrated in the 
graphs (plates IX and X) show that within the limits of toxicity ammonium 
carbonate is much more injurious per equivalent of ammonia than am- 
monium hydroxid and it is rather diflicult to understand how it could 
ever have come to be considered less noxious than the former. As would 
be expected from the nature of the salt, the toxicity of ammonium car- 



*<» The cauliflower was not used in the experiments on the toxicity of the cupram- 
moniums. 



264 Phytopathology [Vol.7 

bonate when dried slowly is much more marked than when it is dried 
quickly. The illustration (plate VII, fig. 1), will show what striking 
effects may be obtained. 

The data show that of all the plants studied the tomato is the most 
sensitive to ammoniimi carbonate, the susceptibility of the other plants 
being in order of increasing resistance as follows: Coleus, cauliflower, 
bean. Similarly in the case of ammonium hydroxid, the relative 
susceptibility of the plants is in increasing order as follows: Tomato, 
Coleus, bean, cauliflower. The relative toxicity of ammonium hydroxid 
and ammonium carbonate is clearly shown in plates IX and X. An in- 
spection of the graphs on these plates shows that the toxicity of am- 
monium carbonate, whether dried quickly or slowly, increases much more 
rapidly with the concentration than does the toxicity of ammonium 
hydroxid, the curves for the former indicating proportionality between 
concentration and toxicity while those for the latter resemble those given 
by copper sulphate. A consideration of plate IX shows that ammonium 
carbonate is more toxic to the bean and cauliflower irrespective of the 
rate at which dried than ammonium hydroxid. From plate X, on the 
other hand, we gather that in the case of the tomato ammonium carbon- 
ate is less toxic between and 0.95 per cent ammonia than ammonium 
hydroxid when dried quickly, but is invariably more toxic when dried 
slowly; in the case of the Coleus ammonium carbonate dried quickly is 
less toxic between and 1.02 per cent ammonia than ammonium hy- 
droxid and, when dried slowly, less toxic between and 0.51 per cent. 

Ammonium sulphate has been considered by certain writers as the 
toxic agent of the cuprammoniiuns in which it occurs and the copper 
sulphate and ammonia wash has suffered relegation in consequence of 
this view. Pearson,'® however, at an early date impugned this belief 
for he found that the mother liquor of a strong copper sulphate ammonia 
wash caused no injiuy to the grape vine, the strawberry and "various 
other vegetables." A glance at table 18 will show that ammonium sul- 
phate can not possibly be the cause of the toxicity of the cuprammoniums 
in which it occurs, since the amoimt of ammoniiun sulphate formed could 
not exceed 0.53 gram for every gram of cupric sulphate employed. But 
if ammonium sulphate can not be the cause of the toxicity of the copper 
sulphate and ammonia wash or Johnson's mixture, the data presented 
in the table show that it possesses a peculiarity to which we may well 
devote a moment's attention. 

" Pearson, A. N. In Report on the experiments made in 1888 in the treatment 
of the downy mildew and blackrot of the grape vine. U. S. Dept. Agr., Sec. Veg. 
Path. Bui. 10: 18. 1889. 



1917] 



BcTLEs: The Cupiluiuonidh Washes 



BS*et 0/ flew a*d quick ttryitin on tht loneily 

per cent of injury 



$vtpfuiU, erpratttd tn 





■• 


euin 


™>,«n.o,^„.o- 




4p««Dt 


Iperont 


lp««t 


0.1 p««i» 


Col.«. 1 

B..„ / 


Quickly 

Slowly 
Quirkly 
Slowly 
Quickly 
Slowly 


91 
24 
63 
25 
73 
SO 


19 
28 
4 
34 
22 


24 


16 
1 
8 
6 







TooMto 


{ 







Bfftett on tomato, CoUvt and btan of the mIowIj/ dried euprawimonimiu and their eom- 
ponenli <U the $lr^nftht at trhich Ihey occur in the ictuhei, txprtiud in per cent of 



256 Phytopathology (Vol. 7 

Amnionium tmlphute is more toxic when drieci quickly than whrn 
drietl slowly, beha\ing in this respect exiietly the reverse of the other 
components of the cuprammoniums all of which are much more toxic 
when dried slowly. The injur>' pro<luce<l by quick dr>ing may \x* vvry 
markcKl and the illustration, plate VII, fig. 2, will add but emphasis to thf 
striking figures in the table. The explanation of this peculiarity is that 
ammonium sulphate is slightly hygroscopic and when dried quickly with- 
draws water from the leaf which vnlt» and dies, but that when drietl 
slowly equilibrium lx»tween the c(»lls of the e])id(»rmis and the solution is 
r<»ache<l by the time dr\'ing begia**. 

The plant most scTiously injunnl by quick (lr>iug is the (\>leus, then 
follows the lM»an, the tomato Ixing but littl<» more* seriously afTert^l by 
quick dr>'ing than by slow dr>'ing, the data for 1 per cent solutions beinK 
in this respect particularly ia»«tnictive. It would ap|M»ar then»fore that 
the cutirl(»sof the Coleusand b(»an are not reacHly iKTineatiMl by ainni«>- 
niuin sulphate while that of the tomato is easily iM'netnite<l which farts 
are of cdnsidrrable inten'st since slow drj'ing which pVoiM»rly nu^asuroA 
the toxicity of the salt shows that the most readily iH*netrat<Hl» leaf is 
also the most siiscei)tible. 

Having conchuled our study of th(; com])onents of the cuprammoniums 
we are in a [)ositiou to determine the nature of their role in the toxicity 
of tht»s4' washes. In order to simplify our stu<ly I havt» placinl en regard 
in tabh» 19 the iMTcentage injuries pro<luc(Hl on the one hand by the 
M»Vfral cupranunoniums and <»n th<* other the injur>' that wouhi have 
followe<l the us<* of the com]>on<nts at the corresiMinding strengths at 
which they <M*cur in the washes, the* data being in all cases for slow ilr>'ing. 

The data prrM-nttnl in the tnblr confirm in large measure the \ifw of 
Millardet that solubU* copp<T is the cauw* of the injur>' pnHluce<i by the 
cupranmioiiiums though it would also apix*ar that anunonia lH*c«)mes 
toxir when its con(*entration excetKls an amoimt thiit may or may not \^ 
consiiliTably in exci'ss of that normally tolerati^l by the plant amcirniil. 
For instance in the cas<' of the Coleus, malachiti'-ammonium carlK»n:it«» 
containing ().2S7 imt cent copper, is more toxic than the i^quivalt-nt 
strength of S4)lubli' copfHT or ammonia whence it must Im* c<mclu<h*tl that 
the injury is due to coinbim^l action of thr two; and it would appear 
fn»ni thr behavior of this wash at other strengths that the pn's«nri' of 
aimu<»nia has in all ras<*s even when its<'lf not apparently tiixic. increas«il 
the toxicity <;f the copi>er. The malachit4'-amm(mium carUinate wash 
aUo ^hn^l*< evidi nr«' of an a<lditive effect except at the hiwest concentra- 
tion U'^mI. (Ml the other hand. Johns<m*s mixture shows that the t4>xicity 
of snlubl* eiipiM f i^ re<liired by it< presence despite the fact that the c<»n- 
centration of aniiii« nia is verv nearly the sjime as in malachite-amnii>- 



1917] ^ Butler: The Cuprammonium Washes 257 

nium carbonate; but in the case of the copper sulphate and ammonia 
wash the evidence is conflicting. When we come to consider the tomato 
we find that the presence of ammonia reduces the toxicity of soluble 
copper in the case of Johnson's mixture and the copper sulphate and am- 
monia wash, but that in the malachite-ammonia wash its toxicity is 
increased except at the lowest concentration used. In the case of mala- 
chite-ammonium carbonate we have the toxicity of soluble copper in- 
creased at the highest concentration (0.287 per cent copper) not changed 
at 0.143 per cent copper and 0.035 per cent copper and reduced at 0.071 
per cent copper. 

Finally in the case of the bean we find that the presence of ammonia 
has in all cases reduced the toxicity of soluble copper. 

The evidence is therefore in favor of the view that the presence of am- 
monia isL beneficial and not injurious as too commonly supposed though 
it should be noted that while this beneficent action of ammonia is suffi- 
ciently general to be considered established and is independent of the 
rate at which the cuprammoniums decompose, the data nevertheless 
clearly show that cuprammonium sulphate, the most unstable of the 
washes, is also, all things considered, less inj\u*ious than cuprammonium 
hydrate and carbonates which are very stable. Soluble copper must 
therefore be the major cause of the toxicity of the cuprammoniums in 
the interim between application and desiccation. 

B. Effect of the cuprammoniums after they have dried upon the plant and 

are subject to the action of the weather 

After the cuprammoniums have dried upon the plant there will be 
present on the leaf only a copper carbonate or hydrate in the case of the 
washes prepared from malachite, but in the case of those prepared with 
cupric sulphate (copper sulphate and ammonia wash, Johnson's mixture) 
ammonium sulphate not in excess of one-half of the cupric sulphate 
employed will also be present, and in the case of the washes prepared 
from Burgundy mixture we will have besides the copper salt both sodium 
bicarbonate and sodiiun sulphate present, the former to the extent of 
0.41 gram for every gram of cupric sulphate taken, the latter to the ex- 
tent of 0.56 gram for every gram of cupric sulphate used.^^ In two 
instances, therefore, the dissolution of the copper in meteoric waters is 
not affected by the presence of a foreign substance, in two instances the 
foreign substances (sodium sulphate and bicarbonate) are neither toxic 

** The calculations are based on the formula (vide Bedford, Duke of, and Pick- 
ering, S. U. loc. cit., p. 86). 5 CUSO4 5 H2O+8 NajCO,. + 10 HjO = 2 CuCO,, 3 
Cu(OH),-f 6 NaHCO,-f 5 NajSO* + 105 H,0. 



268 Phytopathology [Vol. 7 

at the strengths at which they are found in the washes or solvents of the 
copper salt, and in two instances the action of meteoric waters is heightened 
by the presence of ammonium sulphate which is a solvent of inflolul>le 
copper salts but non-toxic itself at the strength at which it occurs in the 
washes. It is, therefore, clear that the toxicity of the cuprammonium 
washes after they have dried upon the leaf can only be due to the prei^- 
ence of soluble copper. Whence it will only be necessary, in order to 
determine the magnitude of this toxicity, to ascertain the dogrec of 
solubility of the copper in the several cuprammoniums as compared with 
that of a soluble copper salt, and, as already indicated, cupric sulphate 
is the only conunon inorganic salt of copper that satisfies the condition!<i 
under the experimental methods employed. It is desirable in teeing 
the relative solubility of cupric sulphate and of the copper salt of the 
dried cuprammoniums that an organism sensitive to soluble copper be 
employed as indicator. The conidia of Plasmopara viiicola are, as \» 
well known, extremely sensitive to soluble copper*' and are admirably 
adapted to thin purpose and were employed in obtaining the data presented 
in table 2(). The data were obtained by spraying microscopic slides dSUsr 
the manner tlcscrilN'd by Ke<ldick and Wallace'' with the solutions to be 
testeil, allowing them to dr>' spontaneously at room temperature and 
putting in Her\'ice not earlier than twenty-four hours after the fungicides 
had dricMl. In making a test the spores were washcni with distilled water 
into a l)eaker from leavers just freshly gathcre<l. Small drops of water 
with spores in sa^^pt^nsion were taken from the l)eaker, and place<i on the 
slides which were then incubatiHl at or near the optimum temperature 
for iiidirei*t geniiination.'^ Simultaneouf^Iy a witness was always pre- 
pare<i so that the vitiility of the spores could lx» properly judged and no 
exiM^riment was considere<l in which the germination in the witness prove<i 
low. Finally it should l>e noted that the data given in table 20 are the 
mean of five ex|M*riments except in the case of the malachite-ammonia 
wjish with which only two testn wore made. 

Tlu; d:ita show that the presence of anunonium sulphate increases the 
toxicity of a wiu^h. the unit copper in copfXT sulphate and ammonium 
carlM)i)ate U^ing mon; toxic than the unit coppcT in malachito-ammonium 

^ .MillnrtJrt, .\. niid (iiiyon, l'. Traitniifnt du mildiou par Ic m^lAnge dr vulfAtr 
d<» niivrr <»t dt» rhnux. Jourii. agr. prut. 2: 7<X». 1SS.5. 

Wtithrirh. K. IVUt die KinwirkiinK von MotnllHaltcn und Siuren auf die 
KtMinfahigki'it der Sixtrrn einifcrr don ViTbrritetiitcn pjiraiiitiirhcn Filw unarrer 
Kultun>flnn£4>n. //<*it. rnaiiienkr. 2: ir>-:U. Hl-IM. l.Hirj. 

" Hrddirk. I>. and Wulinn*. K. On a InUiratory method of drtermtninK the 
funKit'idal valui* t»f a ^pr:ly niixturr or nolution. S<'ienre n. s. SI: 798. 1910. 

** MflliiiH. I. K. (ii'nninatinn and infrctinn with the funguf of the latr blifcfat 
of p«>tato. WiHconmn Agr. Kxp. Sta. Tech. liul. S7: 'M\. ltU5. 



1917] 



Butler: Thb Cuprammonium Washes 



259 



carbonate. It will be also noticed that the highest toxic value for the 
unit copper occurs in the copper sulphate-ammonia wash, though on 
account of the presence of ammoniimi sulphate it is impossible to tell 
to what extent this high value is due to the presence of this solvent, 
to what -extent to the basic cupric sulphate. Judging from the increased 
toxicity of cupric carbonate in the presence of ammoniiun sulphate it 
would seem that the high toxic value of the unit copper in basic cupric 
sulphate is due to the presence of ammonium sulphate. However this 
may be, the table shows conclusively that the unit copper in the cupram- 
monium carbonate washes has a lower toxic value than in a cuprammonimn 

hydrate or sulphate" wash. 

TABLE ao 

Relative toxicity of the cuprammonium washes and cupric sulphcUe to the spores oj 

Plasmopara viticola 



rUirOICIDB USED 



Malachite-ammonia 

Malachite-ammonium carbonate 

Copper sulphate-ammonia 

Copper sulphate-ammonium carbonate 
Cupric sulphate 



LETHAL STRENGTH 



per cent Cu 

0.0033 
0.0057 
0.0027 
0.0035 
0.0019 



SOLUBILITT or 
COPPER 



Relative nutnbera 

58.13 
33.33 
70.42 
54.34 
100.00 



Knowing the toxicity of cupric sulphate to any given higher plant 
it may be calculated readily from the data given in table 21 at what 
strength the cupranmioniums would have to be used in order to prove 
uninjurious after they had dried on the fbliage and are wetted by meteoric 
water. Taking the plants used in the experiments with cupric sulphate' • 
we arrive at the results shown in table 21, the data for the cupric sul- 
phate being obtained from table 15, either directly or by extrapolation. 

The data presented in the table show the strength at which the several 
cuprammonimns could be applied to foliage without producing injury 
after diying due to dissolution of the copper in meteoric waters. The 
question that we must now consider is whether these strengths are supe- 
rior to or smaller than those at which injury occurs between time of 
application and time of drying. If inferior then the maximum strength 
at which the cuprammonimns can be used will be governed by the sol- 
ubility of the copper after drying; if superior, then the degree of injury 

•* There is no reason for supposing that modified eau c61este or Burgundy mix- 
ture-ammonium carbonate would possess a toxicity materially different from their 
prototypes mentioned in the table. 

» See p. 251. 



260 



Phytopathology 



[Vol. 7 



produretl while dr>nng will limit the strength at which theme funfdcidcs 
niay be useil safely. The data presented in table 22 will permit us to 
answer the question raised. 

The data show that in the case of all four fuiigicides the degree of tol- 
eran(*e of the drie<l fungicides must limit the strength at which thc>' cao 
be aseil. 

TABLK 21 
Calculated tolerance of jAatitn to dried cupramfnoniumn 



ri.JiXT CMPU>TED 



j crPMic 
nrLPHATC 

UHIED 

MUJWLT 

M)N-TOXir 



MAXIMTM STRCNOTH AT WHICH rrraAlllt«>Vtt Hi 
COt'LO BB IHBD 



I 

Malarhite- ' 
nmniunia 



Malachitt«- 
aninioniuni 
carlx>iiat«' i 



C'«»pprr 
Hil|»h»l«>- 
ammonia 



•ulpnal*^ 
ainn>««n«uM 
rartmojai* 



CflllMlS 

T(»iiiat<) 

CaiiliflowiT 

PrlarKoniuni 

OxaliM . . 



prr cent Cu p*r r^nt Cu 

I (K)?.") 0110 

[ (M)?.') (HID 

(NN)7 (N)12() 

(KM 7 ().>».■) 

OOP.) ! (KXTJ 

0070 i) ()\:i'}S 



fur ernt f^u 

(n?2.*> 

02-r) 

(xrji 

int'ii 

(K):i7 

(n.>:{7 



\ptr rent Cu 

- oKm 

I 01<N> 
: (XNr.lO 

(urio 

; 00-3) 
i 0112 



Mr rr<»f *'% 
OI.'iH 

o oi:{H 

IHMJH 

o a\\:i 
miM 
o oi4:> 



TABI.i: 22 
Affiouut of cop lie r toUratrd in thr Atr*Tol ruprammoni urns during and after drv^t^g 



( OLM n 



TDMATO 



• ft«^ 



rcNdu mr. i ii>.d 



(%>p{)«*r tokratril j (\>p|irr |o|rratr«l i ('4*|>prr to|rrat«»l 






Dunne 
dryins 



4ir>ib< 



' jtrr rrut jt^r frnt ■ per rent • ptt rrnl 
Cu ru Cu Cu 



.\!al:irhit<'-aiiiiiionia 



r rrnt 
Cu 



, 01>«W Oi:i.">.S: IKTJ7 ■ Ol.'USi 02S7 O <«t<J 



.Malarhitr-aiiitnoiiiiiiii rarlM>ri-; 



at(* 



' o:{7:i 02:17 ' o ojs7 ' o oxiT \ o oim3 n tiii:»7 



(*i>p|>4-r Miilphatc-ainnionia. 



inr.N • 0112 ' ofki.') i o 0112 1 01.'>2 1 oirjn 



C'np|MT ^ulI>hatf*-aIllInolliuI^ ' I I 

rarlMiiiatf i 02.Vt OU.'i OtWio 



I I 

0145 : O (r2*> U UUI 



(\ Injurtj hij niiihtivr cfftct 

A.*« wr \\:\\'r h*4*ii th(' ru|>r:iiiiinoiuuiiis may pnMluce injur>' cluniig 
ilryiiiju ami aftrr drying dur to di>M)hition of the cMipper in nwtoorio 
^:it«T>. Whni tin* injuria pro<lur<Ml l)y thrs4» sourw^s is sufficiently 
distant, thrir mutual rfTrrt> rnnaiii diMiiirt, but when thev wcur ncarlv 
^inlultaIl('4>tl^ly an injury gn^atrr than that <lut» to the sum of the eflft-rt* 



1917] 



Butler: The Cuprammonium Washes 



261 



of the injury produced during drying and after drying is to be anticipated 
since as SchandeH^ and Barker and Gimingham^^ have pointed out 
soluble copper is more injurious to recently than to remotely injured 
leaves. The data presented in table 22 show clearly that if injury is 
produced during diying, injury will also follow wetting with meteoric 
water. The converse is not, however, necessarily true, since the rate 
of drying markedly affects, as we have seen, the degree of tolerance of 
copper. 

III. PRACTICAL considerations 

If we consider the strength at which the cuprammoniums sffe or have 
been used in practice, we will find that these fimgicides are, or have been, 
as will be seen from table 23, applied at a strength in copper ranging 
from 7.2 to 47 times the lethal concentration for Plasmopara viticola, 

table 23 

Strength at which the cuprammoniums have been most commonly employed in practice 
and lethal concentration of the same for Plasmopara viticola 





a 


B 


A 


PUNOICIDE USED 


Strength at 
which applied 


Lethal 
concentration 


RATIO = 


\lalachitc-aininonia 


per cent Cu 

. 0493 
0.0264 
. 0270 
0254 


per cent Cu 

0.0033 
0.0057 
0.0027 
0.0035 


1: 14.9 


Malachite-ammonium carbonate 

CoDDer sulohate-ammonia 


1:4.63 
1:47.03 


Copper sulphate-ammonium carbonate 


1:7.25 



Now since the cuprammoniums may all be considered equally adhesive, 
as regards resistance to mechanical shock, because they form precipitates 
composed of particles of nearly like size, the concentration at which they 
are applied should bear a definite relation either to their efficiency or 
efifectiveness.'* But an inspection of table 23 will immediately show that 
no relation exists between lethal concentration and strength of applica- 
tion whether we take as our criterion efficiency or effectiveness. The 

" Schander, R. Uber die physiologische Wirkung der Kupfervitriol Kalkbriihe. 
Landw. Jahrb. 33: — . 1904. 

•• Barker, B. T. P. and Gimingham, C. T. The action of Bordeaux mixture on 
plants. Ann. Appl. Biology 1: II et seq. 1914. 

*• The efficiency of a fungicide depends both on the solubility of the copper and 
its toxicity when in solution. Usually, though not necessarily always, solubility 
is a measure of toxicity and conversely. Effectiveness depends on the power of a 
fungicide to withstand weathering, that is, to possess adhesive properties, while 
at the same time yielding sufficient soluble copper to give protection from a specific 
organism or organisms. 



262 



Phytopathology 



(Vol. 7 



formulae in use should therefore be amended so as to give a numerical 
relation between lethal concentration an<l strength of application. 

liCt UH first of all determine the factor required to give maximum 
effectiveness. 

Since we have been unable to assign a value to this factor frr>m the 
data presented in table 24, it will be necessary for us to determine it in- 
directly and this we can do from our knowledge of Bordeaux mixture. 
Acconling to a recent French enquiry*** a 2 per cent Bordeaux mixture is 
ncccssar>' to give adequate protection from Phmnopara viticola in yca» 
favorable to the development of this parasite though in years when in- 
festation is not severe 1 per cent mixtures meet more or less satisfactorily 
the re<|uircmcnts of practice. In the United States, on the other hand, 
both Plasmopara viticola and Phytophthora infeatans may be .satisfac- 
torily held in check by 1 per cent Bortleaux mixtures though 1.2o per 
cent mixtures are ako commonly emplc)y<Hl. We may therefore in all 
propriety take a 1 per cent Bordeaux mixture for our standanl of 
comparison. 

Now Bordeaux mixture 1: 1 is toxic to Ixjth Plasmopara viticola and 
Phytophthora infiHtans*^ at 0.0039 per cent copper which gives us a factor of 
64 as the re<juir(»ment of practict^ for adcKiuaU^ protection. Accepting this 
factor of M for Bonicaux mixture the factors necessary to apply to the 
cupramnumiums, due regard Innng taken of the n^lative (efficiency of the 
unit coppcT, in ordiT to obtain satisfactory' pn)tection would then be as 
indicato<i in table 24. 

TABI.K 21 
Fariarn by which the lethal nmrtntnitiorm oj the aereral cufframmoniumM mu*! he mui- 

tipliiii in onier to obtain adequatt ftrotertion 



rt-KUk'iDC rtiKD 



UCTNAL 
COMt KWTIIATIOM 



lionli'AUx uiixtun* 1:1 

Miilnrhitr-iiinniunia 

Mnlarhit4*-Hiiiiii«)iiiuiii rarU«imtr 

( *t>p|M*r Milphiitc-iiiiiiiiotiiti 

C'oplMT Milphatc'-aiiiiiuiiiiiiiii rnrlNiiiatt' 



n(»9 

(X»33 

ortt7 

0027 
0035 



r4rToa 



64 
53 7 
93 4 
44 I 

56 9 



Fntiii th«' ilata giv(*n in table 24 one (*an n^adily d(*teniune the stn*ngth 
at uhirh the riipraiiunoniuiiis hhould Im* us<*<1 in pradice in order to ul>> 
tiiiii :i pnae<'tion ^*ul^^<tanti^llly (H{uivalent to that given by Bonicaux 
iiiivtun'. :tn<i when the data m» obt^iined :u'e eoiiipanNl i^nth the strengths 

* (':ipiiM. J. Ia'a traitiMiieiitH ilu iiuMiou. Urv. d<* vit. 44:302. 1916. 
•' WiM-niiHin Agr. i:xp. Sta. IVch. Hul. 37: M). 1915. 



1917] 



Butler: The Cuprammonitjm Washes 



263 



employed in practice, as in the following table, we find that the calcu- 
lated strengths are from fom* to twenty times greater than those that 
have been actually used except in the case of the copper sulphate and 
ammonia wash when the agreement is close. But since the cuprammo- 
niums have not afforded, at the strengths used in practice, protection 
commensurate with Bordeaux mixture and we are now in a position to 
understand why they have not, the formulae employed should be emended 
so as to approach the calculated values indicated. But the actual 
strengths employed will be determined by the tolerance of the plant 
sprayed to the fungicide in the interim between appUcation and desicca- 
tion, and to the solubiUty of the dried wash in meteoric waters. We will 
first of all, consider the latter case. 

The dried cupranunoniums must not, of course, yield on being wetted 
more soluble copper than^the sprayed plant will stand. Let us accept 



table 25 



Strengths at which the cuprammoniums are used in practice and strengths at which 
they should he employed in order to give protection equivalent to Bordeaux mixture 



rUNOlCTDK USED 


BTRENQTH USED 
IN PRACTICE 


STRENOTH EQUIVA- 
LENT TO 1 PER 
CENT BORDEAUX 
MIXTURE 


Malachite-ammonia 


per cent Cu 

0.0493 
0.0264 
0.1270 
0.0254 


per cent Cu 
0.1772 


Malachite-ammonium carbonate 


0.5323 


Copper sulphate-ammonia 


0.1190 


Copper sulphate-ammonium carbonate 


0.1991 







for the sake of concreteness, the value for the tomato 0.0075 per cent 
copper. This percentage of metallic copper is yielded by a 0.045 per 
cent copper sulphate and ammonia wash under laboratory conditions 
but the tolerance of the tomato under field conditions may be safely 
placed at 0.125 per cent, since rains even of moderate intensity will carry 
away appreciable amoimts of the fungicide. And since in the other 
cuprammoniums, as we have seen, the copper is less soluble than in the 
copper sulphate and ammonia wash, we may safely use them at the 
same relative concentration which would then give us the following as the 
permissible strengths at which they can be applied without injury from 
soluble copper resulting to a plant tolerating 0.0075 per cent soluble 
copper. As will appear from a consideration of table 26, the calculated 
values for soluble copper tolerated are lower than those obtaining in 
practice for the malachite-anamonia and copper sulphate-ammonia washes 
and higher in the case of the two cuprammonium carbonate washes. 



2G4 



Phytopathology 



[Vol. 7 



The (lata presented in table 26 further show that it is impotwible to 
apply the ouprainnioniums at strenjijth*s equivalent in effectivencsw to 1 
per cent Bordeaux mixture when the plants spraytni will not tolerate niorp 
than 0.(K)75 per cent soluble copper since in onler to obtain equivalence 
the plant sprayed would have to tolerate 0.0158 per cent soluble coppiT. 

We have adniitteil that, under the conditions of practice plants will 
tolerate cupraninioniunis 2.8 times stronger than tolerated under critical 
conditions. It remains now to be seen whether cuprammoniumA <»f this 
strenjrth can l)e applied without injury resulting during dr>nng. The 
data present(Hl in table 27 show that in the cjise of the tomato uxi<ler 
the conditions of quick drying, all the cupranunoniums except tlic mala- 
chitt^junmonia wa.^h can Ix* us(»d at tiie nH|uired concentration, hut that 
under the conditions of slow drying inalachite-ammonia and malachite- 
anunonium carbonate, the latter particularly,* are toxic at a lower con- 
centration than that deinaii(lcd. In tlu^ case of the Coleus we find <|uick 

TAIU.K 2« 

Strt'figthM at which tht rupramtruniiumM may be UKcd withoui an iujurinu^ ntHi»uftt •»/ 
mtluhlr rop/HT forming on wetting with meteoric water, a plant rrnixtant Itt ft mfTS 
f}er cent foluhle eop/nr in ing presupjHtsed 



r\ sou tut. \ nr.n 



•»TH» N«.TH 
TOM M«T> II 



•TRrN««TN ' •• t* 



Nf.'iiarliitf'-HininnTii:! 

Mal:ir|iitc-;tnifii<iiiinin ('Hr)N)iiat«' 

( *op|MT »>ul|>h:it4'-aiiiiii<»ni}i 

i^opfMT huiphati'-aiiiiiioiiiiiin <*:ir)M>ti:it<* 



/Mr rrnt f'u 

(WIT 

mio 



I 



(» ova 

O.Y>l 



drying jH-nuits the us4' in evrry rast' (»f MrongcT s^ilutions than tolenifnl 
in the driisl wa.*<h, whil<» tlio n»vrrs<» is the vh-a* if .slow dr>'ing is p4*nnitte«l. 
In the ca»* <»f the Imviu tin* plant will tolerate' Wronger dr>'ing than dri«tl 
w:i.»*Im»s. In tho ras4» of thr tomato and ( 'oleus the wjislM-s cjin all lie u?«*«i 
at 11.7 tiinrs their toxi<' <'on<M»nt ration to Plasmoimra vHicvia when «lri«*«l 
(|uirkly but in tlir ra>4' of the iH'an thry can In* appli<'<l at only 3.^i tim«-!« 
tln'ir K'thal «*onrrnt ration with safi^ty, no matter how .*ilowly or c|uirkly 
th«' w:ls|m's are driiMJ. It siM-ins, thrn»f<»n», <'lrar that the cuprainmoniunu* 
can n«»t Ik» ron.Md«*nNl a,< efT«»rtive as Hordraux mixtun* for the ctmtnJ 
of pani'^itir organisiiLs whirh «io not n^juin' a <*onct»ntnition in S4»lublo 
cop|M*r gn\atcr tlian that yi<»ldc.d by the latter. We have now t«i C'»n- 
hidiT thf cupraminoniums fn»in the |M»int of view of efficiency. 

TIm' unit ropjxT in the (*upramm<M)iunLs has generally IwH'n con.sidiTetl 
iiion* rtficicnt than the unit ropfxT in Hord<'aux mixtun*. and this opinion 
\^ mhloubt<H||y well grounded wh«*n thr cuprammoniunts which an* \\t:¥> 
ti<*all\' neutral as scMin as dry an* (M^mpan^d with alkaline l^mleaux mix- 



1917] 



Butler: The CuPRABfMONiUM Washes 



265 



tures in which the copper is without action during the time required to 
reach neutrality; but when compared with neutralized or neutral Bor- 
deaux mixture at the lethal strengths to Plasmapara viticola the difference 
in favor of the cuprammoniums is indeed small. In the most efficient 
wash (copper sulphate and ammonia) the unit copper has a value only 
1.44 times that of Bordeaux mixture and in the least efficient (malachite- 
ammonium carbonate) it is 1.46 times less active. But in fimgi resistant 
to copper the unit copper in the cuprammoniums may be manifold that 
of Bordeaux mixture, the highest values being given by the copper sul- 
phate and ammonia wash. For instance in the case of the uredospores 
of Puccinia Antirrhini the efficiency of the unit copper in the copper 
sulphate-ammonia wash is very much greater not to say infinitely greater 
than the unit copper in Bordeaux mixture since it would appear that the 
latter is non toxic at all concentrations.^^ 

TABLE 27 

Amount of copper tolerated in the cuprammonium washes during drying by the tomatot 

Coleus and bean 





TOMATO 


COLBUS 


BBAN 


rUNQlCIOB USBD 


strencth of dried 
wagb tolerated 


StreoKth 
tolerated 


Strencth of dried 
wash tolerated 


Strength 
tolerated 


Strencth of dried 
wash tolerated 


Strength 
tolerated 




Wash dried 
quickly 


Wash dried 
slowly 


Wash dried 
. quickly 


Wash dried 
slowly 


Wash dried 
quickly 


Wash dried 
slowly 


Malachite-ammonia. . . . 
Malachite-ammonium 
carbonate 


per e^nt 
Cu 

0.0386 
0.0668 
0.0317 
0.0410 


per cent 
Cu 

0.0359 
0.1437 
0.0635 
0.127 


per cent 
Cu 

0.0327 
0.0287 
0.0635 
0.0635 


per cent 
Cu 

0.0386 

0.0668 
0.0317 
0.0410 


per cent 
Cu 

0.0718 

0.1437 
0.0635 
0.0635 


per cent 
Cu 

0.0298 

0.0315 
0.0228 
0.0254 


per cent 
Cu 

0.0089 
0.0154 
0.0073 
0.0101 


per cent 
Cu 

0.0301 
0.0229 
0.0203 
0.0279 


per cent 
Cu 

0.0287 
0183 


Copper sulphate-am- 
monia 


0.0152 


Copper sulphate-am- 
monium carbonate. . . 


0.0228 



It is therefore clear that in the control of parasitic endophytes the 
spores of which are highly resistant to soluble copper, the cuprammoniums 
may be of very considerable value provided the plant to be sprayed will 
withstand the concentration demanded. But except in those cases where 
Bordeaux mixture is non toxic to the parasite from which protection is 
sou|2:ht it does not seem to me that the cuprammoniums as a class or any 
one cuprammonimn in particular possess merits sufficient to warrant 

** Doran^ W. L. Controlling snapdragon rust. Value of copper and sulphur. 
Florists' Exchange 48: 501. 1917. 



266 Phttopatholoot [Vol. 7 

their emfdoyment in practice, especially ainoe the quality of inconspio* 
uouaneeB can be obtained quite readily with Bordeaux mixtures 1 : alkalinity 
Bordeaux mixture 1 : alkalinity is no more conspicuous than the copper 
sulphate and ammonia wash when the same amount of copper is applied 
per square meter in both cases but since the latter usually wets the foliage 
better than the former it appears to be less highly colored, due to the 
fact that the copper is spread over a larger surface. Whenever Bordeaux 
mixture 1 : alkalinity does not wet the foliage sufficiently to offer the proper 
degree of inconspicuousness, the wetting power oi the mixture may be 
increased by the addition of an infusion of quillaia (i.e., saponin) or a 
small amount of casein. It is therefore not necessary to resort to a cupram- 
monium when an inconspicuous copper fungicide is required. 



SUMMABT 

1. The cuprammoniums met with in practice belong chemically in 
one or the other of the following groups: (1) cuprainmonium sulphate; 
(2) cuprammoniuni hydrate, and (3) cupraninumium carbonate. 

2. When decomposed by drying cupranunonium sulphate deposits 
the copper as a basic sulphate, cuprammonium hydrate yieldB a copper 
hydrate, and cuprammonium carbonate a copper carbonate. 

3. (^uprammonium sulphate is very unstable; cuprammonium hydrate 
and carl)onatc very stable. 

4. The cuprammoniums are more toxic when slowly than when quickly 
dried. 

5. The toxicity of the cuprammoniums during drying and on weather- 
ing is due to soluble copper. 

6. The copper sulphate and ammonia wash and Johnson's mixture are 
less injurious than the malachite washes. 

7. The cuprammonium washes arc more efficient and effective than 
Bordeaux mixture when large amounts of soluble copper arc required to 
give pn>tcction. 

8. The cuprammonium washes arc less effective than Bordeaux mix- 
ture when hmall amounts of soluble copper suffice to give protecticin hut 
with the exception of the mala(*hite-ammonium carbonate wasli are 
slightly more efficient. 

9. The relative efficiency of the unit copper in the cuprammoniums is 
in decreasing onier as follom-s: Copper sulphate-ammonia, malachite* 
aiiunonia. copper sulphute-ainmonium curlxinate, malachite-ammonium 
carbonate. 

10. Tlie cuprammoniums nmy be used at 11.7 times their lethal con* 



1917] Butler: The Cxtprammonium Washes 267 

centration for Plasmopara viticola on plants not affected by 0.0075 per 
cent soluble copper. 

11. The cuprammoniums are of limited practical applicability and 
should not be used' in lieu of Bordeaux mixture whenever the latter yields 
sufficient soluble copper to give protection. 

New Hampshire Agricultural Experiment Station 
Durham, New Hampshire 

BIBLIOGRAPHY 

AuDOTNAUD. Le mildiou et les composes cupriques. Prog. agr. et vit. 1885. 
Bedford, Duke of, and Pickering, S. U. Woburn Experimental Fruit Farm 

Report, 11: 1-1429. 1910. 
BouRCART, E. Les maladies des plantes, 372-382. 1910. 
Chester, F. D. The copper fungicides, Joum. Myc. 6: 22-24. 1891. 
Gastine, G. Emploi du carbonate ammoniacal de cuivre contre le peronospora. 

Prog. agr. et vit. 8: 114^117. 1887. 
HoLLRUNG, M. Handbuch des chemischen mittel gegen Pflanzenkrankheiten. 

1898. 
Johnson, S. W. Note by the Director. Connecticut Agr. Exp. Sta. Rept. 1890: 118. 

1891. 
LoDEMAN, E. G. The spraying of plants. 1899. 
MoissoN, H. Traits de chimie Min^rale, 5. l905. 
Patrigeon, G. Nouveaux proc6d^ de traitement du . mildiou. Joum. agr. 

prat. 1: 881-882. 1887. 
Penny, C. L. The preparation of ammoniacal solution of copper carbonate. Dela- 
ware Agr. Exp. Sta. Bui. 22. 1893. 
Pickering, S. U. Note on an anmionio-copper sulphate. Journ. Chem. Soc. 

Trans. 48: 336-339. 1883. 
Pickering, S. U. On the basic sulphates of copper. Chemical News 47: 182. 1883 



288 Phytopathology [Vou 7 

DESCRIPTION OF PLATES 

Plate III 

Effect of the malachite-ammonium carbonate waah containing 0.28 per oeat 
Cu on the tomato var. Bonny best. Plants on the left dried quickly, planta on 
the right dried slowly. Photograph taken twenty-four hours after tlie fungicide 
was applied. 

Plate IV 

Kffect of the malachite-ammonia wash containing 0.28 per cent Cu on tlie lomato 
Tar. Bonny l>ost. Plants on the left dried quickly, plants on the right dried tlowlj. 
Photograph taken twenty-four hours after wash was applied. 

Plate V 

Tomato var. lionny liest photographed twenty-four hours after being spr»yed 
with 1 per cent cuprir Mulphate. Plants on the left dried quickly, plants oo the 
right dried slowly. The plants dnod quickly showed slight scorching of ytning 
leaflets at the time of making thf photograph but the injury was not sufficiently 
marked to show in the plate; the plaiitrt dried nlowly were, on the other hand, very 
seriously injurc<l all the leaves UMng with(*rt>d and flaccid. 

Plate VI 

Kffect of ammonium hydn>xid containing 4.11 \H»r cent ammonia on the tomato 
Tar. Bonny best. Plants showing no apparent injury dried quickly, withered plants 
dried slowly. Hiotograph taken twrnty-four hnurs after treatment. 

Platk VII 

Fio. 1. Kffect of ammonium rarUinate containing 0.96 per cent ammonia on the 
Coleus var. (iolden l)edder. Plant on tin* right dried quickly, plant on the left 
dried slowly. The photograph wan taken furtyHMght hours after the salt was 
sprayi*d on the plants. 

Fig '2. Kffect of a '2 |mt c«*nt Holution of aninionium sulphate on the bean var 
Dwarf hortiniltural. Plant on the left dried slowly, plant on the right dried 
quickly. Photograph taken forty^Mght hours after treatment. 

Pi.\tk VIII 

<iraphH t*ho\%iiiK the relative toxicity of f|iiickly iitid mIohIv dri«*<l solutions of 
cuprtr trilph.'ite to the < 'oleiiH. tiHiiato. Ox.mIih. Perl:irKoiiiiiiii. lM»an and cauliflower 

Pl.VM I\ 

(fr:ipli!« -tliiiuiriK rrLitive toxicity of i)iiickly and sIohIv dried m^hitions of amm«>- 
niuiit li\<lrii\iii :irid aniinoriiuiii carl)on:ite to the )N*:iii and cuulitlowrr. 

Pi.\Ti: \ 

(iraph- »lif»uiiik; ril.itive tn\irir\ nf i|tiii-kl\ .iihl •tliiulv 1 1 ned mil utii>ns of ammo- 
nium h\ilri>\til titil :tiiitiioiiiiiiii i\irlH>ii.iti' lti ttio tnni:it«t :iitd <^>Ieus 



rtlYTOPATIIOIXX>Y. VI t 



FHVTOPATHOIJJGV, VII 



PUATK VIII 




HtUOTYM 00. tOiTO*! 



^ASHKS* 



PHYTOPATHOLOGY, VII 



PLATB X 




O. B. d«l. 



BuTUER : Th« Cuprammonium Washes 



HtUOTVPt 00. MtTOM 



1917] Boncquet: Bacillus morulans 271 

from diseased plants or portions of plants, it has not been possible to 
produce curly top by inoculation with cultures of this organism; that the 
same organism has been isolated from the surface of beet seed, the sur- 
face of normal sugar beet leaves and from the soil about the roots of 
sugar beets. Also that certain bodies which seem to represent the same 
organism have been found in great abimdance in curly top sugar beets, 
in the interior of the sieve tubes, accompanying a specific lesion in the 
phloem, and that similar bodies, in varying but much less abundance, were 
found in the same tissue in supposedly normal beets or those with various 
morphological irregularities of the foliage (fig. 1). Whatever may be the 
entire significance of the organism in question, its peculiarly abundant 
occurrence in connection with the sugar beet and its apparent relation to 
curly top have seemed to justify its careful study, and it is the piupose of 
the present article to describe more in detail the characteristics of this 
species, to which the i^une Bacillus monUans has been given.''^^- ..' 

THE DISEASE 

ft 

The disease of sugar beets called curly top is of annual occurrence 
throughout the sugar beet growing regions of Colorado, Utah, Idaho and 
California. The severity of the disease, however, varies greatly from 
year to year. Some years veritable disasters are produced by curly top, 
thousands of acres of sugar beets being totally destroyed after all the ex- 
pense of preparing the ground and planting the crop has been imdergone. 

Symptoms on leaves 

The comparative size of the inner and outer leaves is altered. The in- 
ner leaves are dwarfed, the petiole especially becoming shorter and flatter 
than the normal, while the outer leaves, if already full grown before the 
disease becomes apparent; maintain their natural size and shape and, for 
some time at least, their color, although they may finally turn yellow 
and die prematurely. The first symptom of abnormality plainly visible to 
the eye is a distinct transparency of the finest venations of the youngest 
leaves^ This transparency starts at the base of the leaf blade. Gradu- 
ally the abnormality works higher on the leaf until finally the whole leaf 
is aflfected. The youngest leaves are first to suffer; the older ones (such 
as are not already full grown) show the symptoms as their expansion and 
growth progress. Almost simultaneously with the appearance of the 
transparency of the veins small warty protuberances appear upon the 
veins on the under surface of the leaves, eventually even upon those which 
are of the smallest size visible to the eye (fig. 2) . The margins of the af- 
fected leaves then begin to curl slightly upward so as to expose the lower 



1917] Boncquet: Bacillus morulans 273 

several abnormal bendings; the angle of each bend is slightly swollen and 
if the rootlet is far advanced the swollen region appears to be necrotic 
(fig. 3). When the main root is cut transversely the successive rings of 
vascular tissue appear discolored. On careful examination it will be 
observed that the phloem is the only part of the vascular system which 
suffers severely. This phloem discoloration is observed more or less 
throughout the whole system in the veins as well as in the roots. This, 
however, only becomes apparent to the naked eye when the disease has 
reached its severest aspect. 

Cause of the disease 

It was E. D. Ball* who discovered that the sting of the insect EuteUix 
tenella Baker is a necessary factor in the causation of this disease. His 
observations were confirmed by Shaw,' and very fully tested and confirmed* 
by Smith and Boncquet. The latter, however, together with Hartung,* 
proved a fact which had previously been suspected, that EuteUix teneUa 
is not the fundamental factor in the causation of this disease, but rather 
must be a carrier of a second factor, presumably a parasitic micro-organ* 
ism. This discovery made very important a thorough search for and study 
of all micro-organisms which possibly could be found in connection with 
the disease, and it is with this portion of the study of curly leaf that the 
present article hais to do. 

BACTERIOLOGICAL INVESTIGATIONS 

The methods and detailed results through which the conclusion was 
reached by the writer that Bacillus morulans inhabits constantly and 
specifically plants affected with curly top, as well as occurring in certain 
other situations may first be described. It was decided at the outset to 
make a very thorough and accurate search for any organism which might 
be present in the tissues of plants affected with the disease. The unfav- 
orable or at best imcertain results reported by previous investigators 
along this line led to the belief that the problem would be a diflScult one, 

* Ball, E. D. The beet leaf hopper. Utah Agr. Exp. Sta. Ann. Rept. 16: 16. 
1905. 

The Genus Eutettix. Proc. Davenport Acad. Sci., 12: 41 and 84. 1907. 

The leaf hoppers of the sugar beet and their relation to the "curly leaf" 

conditions. U. S. Dept. Agr. Bur. Ent. Bui. 66, pt. 4. 1909. 

» Shaw, H. B. The curly top of beets. U. S. Dept. Agr. Bur. PI. Ind. Bui. 181. 
1910. 

* Boncquet, P. A. and Hartung, W. J. The comparative effect upon sugar beets 
of Eutettix tenella Baker from wild plants and from curly leaf beets. Phytopath» 
h\ 348-349. 1915. 



274 Phytopathology (Vol. 7 

but at the siiine time a Rtudy of the nature of the disease had led to a wry 
strong feeling that some parasitic micro-organism, of which the* in.*««*ct 
Eutettix tenella was presumably a carrier or secondary host, muKt lie in* 
volveti in this disturbance. Assuming then that the sought-for <>rganL<ni 
would l)e an obscurer one and difficult to demonstrate by onlinar>' cuhund 
or histological methoils, various siXMrial and somewhat elaborate culture 
methods were attempte<l. 

Preparation of media 

The following meilia which seemed most promising fortius purpoM* wen* 
preparcMJ: 

FilUrni hrrt juicr. For thi» purpom* thr plniitH from which the juic«» wan (lf«irnl 
'wcro wiiHhr<l nM thorouKhly uh poHsihle in Hterilisod wntor Aiid then icri>un(i fiiH* in i 
ninit ^rindor. In niont ram^s 1(K) vv. of (liHtillcMi wntor wait a(ldf*<i to rarh 1(1) icmn.t 
of hcrt pulp and t)i«* niasH w»h thon covered and h*ft xtandinK for two houri*. Thr 
rnihhtMl material waM Hii)iHc(]Uently put into clean ch(H'iM*cloth and the juir«* Mpifrfrd 
out in a prcHi*. Thf juice thus o)>tained wa8 fluhitequently dilutc^l twin* it* vuluinr 
with n (t Halt sf>lution. VariouH dcf^recM of dilution have \wvi\ einployni. hn«ifvrr 
from th«' original juice up to alxnit ten t<» one. either in Rait aolution <ir w.itvr In 
mime cas4't< tlic solution was then titrated and hroURht to the neutral p<iint «if phfn>M- 
phthalein with so<lium hydroxid. This juice was now clear, nliichtly hmvin and 
passi'd easily thmufch a common filter pafn'r. After it had iN'cn filtered through 
pafMT it wa> parsed throuKi) h mciliumHh'nse liiTkefeld filter camlle for pur|M»<M-» nf 
sterilization. An apparatus wan e^perially devised for this purjMim*. a fitriii of whirh 
IS des(-rili«>d in antither article in the presi'iit lunnlier of l*hytopath«ilofEy. In onW-r 
to Ih* Mire that rill miitaminatinn had ocrurred durinK the manipulation, the tuU'« 
after tillniK uen* ke|»t in the inrtitiatnr fftr two days at ^tf)''(\ It i*« Udievrd that lhi« 
app:iratii!4 and method is wnrthy of eonf<ideralile employment in the preparatimk «>f 
cultiin* media for use in plant patlmlni^y. 

.1 *f 1*1 If, iitif.mftiihit t >/<M ^. 'rhe?«eMer4' prepared in the following manner Smnd 
healthy l>eet*i Were •<i-le(ted. thoroughly eleancd and immers4*d in iNiilmg water f^r 
three minute^, in \]i\^ ^ay !«terili7.inK the surface hut not heating or chanKinx in .iti\ 
maniiiT thr ti>stie;* dr»per in the lH«>t. They wen' thi'Ii cut into sliren mth a eafr- 
full\ -'rriii/ed knif«' Kaeh ^li^e Was then put into a sterile |N*tri dtsh ini«i whirh 
pri'\ i<>ii-l> lirilinaiN inittient a^ar had tn^en poured. 

/iff' i> .-'.K. '1 I. Ill liuthlred KTams nf lieet leaves were cut into sm:i!l piece « :%r.<l 
ImiiIi-iI fur an hmit in (I ;, htrr nf uater. W ater wai* then athh'd to make up tn I litfr 
aini i< f* -' iiiilifik! !'<>r !»•■ Imiir'*. It H:i<< th«-n tiltereil thri»uith ciitton an<i .*■<■> t'«- •>! 
tfii- l.i«' .\rrii* i.|i|».l til 1 litre i»f Iji'luu'?* I'ft'th. The Ijeliic's hmth haii prr% i- 
«iii-l\ !'•«!. p'lfiirij in I In fiitjiiw mu: May : J icrams of I.iehiK's extract. |n g^ram* i>f 
\\i'*i iMji'-M i!i'l '• k'?-ini- of Mnliinn rhloml wiTf addet] to 1 litre of matrr Thi« 
riM'i.iMi ^^ •- - ii'« ii'ii ;.' \ III iiM-ih/fil tn pheiinlphthalein with iMMiiuni h\iiri>\i>l 
aii'i ."•: .•:-;.•!■: ■! ■!.• 1"«' jui- • \\a«« hritiiclit up In O .'» yn^i cent acidity with 
iii:i!.> I .•! I 111 - in.i fill •!: irti u ix al-n pri*p:ire<| with an increaMMl |iropiirti«>n nf 
!■• « • I \*r ■■• * 



1917] Boncqubt: Bacillus morulans 276 

Artificial media. A protein- and peptone-free medium was composed with the 
supposition that the organism did not attack the higher nitrogen compounds of the 
beet. Therefore several of the amino acids were used as the nitrogen supply. Ala- 
nin, leucin and tyrosin were used. Asparagin, although not an amino acid was also 
considered a possible favorable source of nitrogen for the parasitic organism. All 
these compounds were used in a dilution of 0.5 gram to 1 litre of water. The neces- 
sary minerals were added in the following form and proportion: 

Magnesiimi sulfate 0.2 gram 

Ammonium phosphate 0.5 gram 

Potassium nitrate 0.2 gram 

Calcium hydroxid 5 cc. of a saturated solution 

Ferric chlorid trace 

These artificial media were sterilized in the Arnold sterilizer for fifteen minutes 
upon three consecutive days. Special glycerin and glucose media were also pre- 
pared. For this purpose 1 per cent glycerin was added to a part of the asparagin 
medium. So also 5 per cent glucose was added to another portion. The glucose 
medium was especially used for anaerobic purposes. 

Other media. Ordinary media such as nutrient bouillon, potato glucose bouillon, 
bean pods, milk, litmus whey, nutrient agar and nutrient gelatin were prepared ac- 
cording to the standard methods. 

Methods attempted for separating parasites from the plant 

In order to separate the assumed parasites from the plant and obtain 
them in pure culture the f ollowmg technique was used : 

Surface-disinfected plant parts placed in culture medium. The usual 
method employed in this sort of work consists in soaking the tissue to be 
employed for a given length of time in mercuric chlorid and then washing 
oflf the same with sterilized water before placing the tissue in the culture 
medium. A need of standardizing this method was felt, inasmuch as 
there is no assurance, as it is usually described, whether on the one hand 
the disinfection was sufficiently thorough to kill all smrface organisms or 
whether on the other hand the material was washed sufficiently to remove 
all the mercury and prevent its being carried over into the culture medium. 
The method consists in dry sterilizing a number of cotton-plugged flasks 
of 50 cc. capacity or any other desired size. At the same time larger 
flasks, Ukewise cotton-plugged and filled with distilled water, are made 
sterile in the autoclave: Other requisites are supplies of 95 per cent 
alcohol and 1 to 1000 solution of mercuric chlorid in water. The mate- 
rial from which cultures are desired, after thorough wiping with cotton 
swabs in 95 per cent or absolute alcohol in a photographic tray, is cut 
into convenient sized fragments, but no smaller than necessary. These 
are placed in one of the empty sterilized flasks and covered for a moment 
with the alcohol for the purpose of removing air bubbles. The alcohol is 
immediately poured off again and the flask nearly filled with mercury 



276 Phytopathology (Vol. 7 

• 
solution 80 that all the material will be submerged. This is allowed to 
remain for the desired length of time, depending upon the nature of the 
tissue. The petioles and main veins of sugar beet leaves, especially fairly 
old leaves, will usually stand twenty minutes, but with leaf bladen and 
other more delicate material ten minutes has been found the maximum 
time which can be used without too severe burning. Cut surfaces will 
naturally absorb more of the solution than those protected by the natural 
covering of the plant, and this can be taken into account both in con>id* 
eration of the length of time which the tissue will stand without being 
burned by the mercur}' and also the time neccKsary for washing it out 
again. On this account it is best to cut the tissues as little as powible 
before disinfecting. After the desired time has elapsed a piece of brass 
wire gauze, l)eiit to form a cap over the mouth of the flask, is steriliie<l in 
the flame, placeil in position and the mercur>' poured off. The flask is 
then filled with sterilized water from the large flask and the water of this 
first washing, after having the material well shaken up in it, is poured off 
imme<iiately and more water poured in. Tlie pn>cess of pouring off and 
refilling is then Continued at gradually increaseil inter>'als; the length of 
each must depend ui)on the nature of the material. It was found, how- 
ever, that if the amount of material in the flask is comparatively small in 
proportion to its capacity, which should always l)e the case, six changes 
of water, extending over a |x^rioil of two hours, is amply suflScient in every 
casi\ In this case the first five changes can be made during the first hour 
and the last one at the end of the second hour. If one wishes to practice 
extreme caution the mouth of the flask nmy be flame<l an<i the cf>tton 
stopp<T replaceil after each change of water, but this has not l)een found 
ne<'i*ss:iry so long as the amount of water is sufllicient to thoroughly sub- 
merg(» all th(* material. In our work the wire scret^n is usually left over 
the mouth of the flask and this is freshly flanunl l)efore each change of 
water. Aft4T the pnwess is completed the material is taken out of the 
last watrr with flanH^i forceps, hniken into small pieces if necessar>' an<i 
th<»rou^hly rnish<^i with the same instruments and dropped into the cul- 
tun* licjuid. 

I*i*ct culturta. It was thouglit tliat a gradual adaptation fn>ni the 
plant in which tht* organism is living to the me<iium in which it was at- 
tempti'd to jjmw it nii^lit I k* ntMM»ssary to insure success; therefore t he di:^ 
eiuird tir.Mi«- was so tran>frrnMi us to distiu^h as little as possible the cells 
of tin* l>«i*t. Fnr this puri)os4» glass tuln^s were drawn out to 2 nun. dianu*- 
Xvr. \\XvT >i«Tili/in>E l>y h<'at tht'V wt»n» 2iS4*iit icnlly inserted into the di*- 
e:LMMi ir^ioii** of thr Ui-t to a d«*pth of 1 rm. The tul>e m'as then m*ith- 
drawn. )>ririihn^ with it a |)ortion of the licM't tissue and the tenninal 
part containing tlir tisMiu* \v:l<4 can^fully hniken off withsteriliied forceps 



1917] Boncqubt: Bacillus morulans 277 

and dropped into the medium. In this way both ends of the tissue slightly 
protruded from the glass tube and came into direct contact with the cul- 
ture medium. The slow diffusion of the latter was supposed to secure a 
gradual change of habitat in such a way as not to hinder too severely the 
growth of the parasite. Tissue was thus removed from the petiole, from 
inside the root and from the larger veins of the leaf, after surface sterili- 
zation with a flame or boiling water, afterwards cutting into the interior 
with a steriUzed knife and then introducing the glass tube to take out a 
small core of tissue. 

Results of isolation experiments 

The various special methods described were carried out very carefully. 
The result was that in almost every instance cultures from curly top tis- 
sue in all the various media described, and especially those which con- 
tained glucose, showed a heavy growth after twelve hours of incubation 
at 20°C. This result was practically imiform wherever diseased material 
had been used. Occasionally growth also appeared in cultiu'es from sup- 
posedly normal plants, but in by far the great majority of cases such cul- 
tures remained sterile. This seemed to indicate that the organism was 
not peculiarly difficidt to isolate, judging from its abundant growth on such 
a wide variety of media. Nevertheless a painstaking work was imder- 
taken in order to complete the thorough study which had been planned. 
The anaerobic cultures also proved to be invaded by the same organism. 
Here, however, the growth was less abimdant and extremely slow. Sev- 
eral days elapsed before any colonies were visible. A great deal of effort 
was further spent on work with all kinds of media but always the same 
organism grew abimdantly. Contaminations naturally occurred now and 
then but the fact was most decidedly apparent that the one species an- 
nounced by Smith and Boncquet predominated in the tissues of curly top 
plants to the practical exclusion of all others. The special culture meth- 
ods described above are given in some detail, inasmuch as they may con- 
tain suggestions of value in similar work. Having foimd that this organ- 
ism grew so easily and abundantly upon ordinary media, the use of special 
preparations was abandoned in the attempts to isolate the organism from 
plant tissues and the work was carried on entirely with standard bouillon 
to which 5 per cent glucose had been added. The object of the glucose was 
to promote the growth of the characteristic zoogloeae of this organism, 
rendering its identification in the original tubes easy without plating. By 
occasional plating, as a check on the work, it was soon possible to identify 
this organism very accurately by microscopic examination of tubes which 
showed the characteristic ring formation at the surface of the Uquid. The 



278 



Phytopatholoot 



(Vol, 7 



TABLE 1 
Results of bacterial isolation experiments by cultural methods 

(Tul)eB incubated at 28H!). Disease meant curly top) 



MATSKIAL 


NtJiiBSK or 

TVBBS 


•■irut 


Petioles of curly top beets 


6 


5 tubes developed B. wwrulans 
within two days 


Petioles of normal beets 


6 


Tubes remained clear for a w#rk. 
when they were discarded 


Petioles of diseased l>eets 


9 


8 tubes developed morulans 


A leaf showing curly top symp- 


5 


All developed marulanM 


toms on half of blade and in cor- 






respondinK half of petiole. 






Other side appeared normal. 






This material from affected half 




. 


of petiole with black streaks 






Correspondinfc half of blade 


3 


2 tul)es developed morulanM 


Normal-appearinK half of petiole 


6 


5 tubes developed morulant two 
days Inter than those from 
blackened part 


Norinal-appcHrinK »ide of blade 


3 


No development 


Petiole of a diHcascd center leaf 


4 


3 with mofu/anir. 1 doubtful 


Petioles of good-sized leaves from 


10 


2 tul)es frr>m 1 leaf both with morw 


5 different n(»nnal-appearinf( 




lann; others all clear 


i>eeiM 
Typiejilly diseased leaf with very 


6 


All developed mtrrulans 


slight dark streaks in the jM'tiole 






Badly affected {wtiole of name 


4 


All develope<l morulans 


iM'et. Pieces rut out with 






flamed scalfx'l 






Petioles nf 4 beets from ins4'Ct- 


8 


Tulies from 2 plants remained 


pronf cagt*. No sign of diseaM^ 




clear ; those f mm other 2 lieramr 
slightly cloudy after m-vrral 


• 




days, but no mi^rulana 


PftioIrK <»f 2 slightly dis<»as<'d 


13 


All tul>es apparently r«mtaininK 


Irrivi--*. Pierrs rut (»llt with 




pure cultures of mttrulana 


tl.iMH'ii .Hr:tlpcl 






A >fll«i\\i-h :i>t«T leaf 


o 


Ilemained clear 


Afi «'l«l yillnwirih biM't li'af without 


4 


S<»me fungous growth. No morb- 


•Mirly top. Tissue still s<»u!id 




tans 


!>•'.•» v«'«i i»f ri snrnewliat abnonnal- 





Some growth, but no iiMiriiiij»i« 


:ippi'ir:iig tn-rt but Dot With 






<MirI\ top 







I!i:i!*h\ - ij>pt -iriHt: !r:ivr> <»f aster, 
i I.: *. » t:<7|ii iii'iiii •irihli:i. ti>iiia- 
* ■ * • .»fi !•■• t ut •■ ritnl r.iddith 

I't*i"!i i.t '\pi< ill\ •ii-f:iHiM| livif. 

t.i- -ii -lltli ■ • ;-.!i 



24 ill tubes with fungi and l>artrriA. 

remainder clear. No m«>rW«in« 

I founti 

(i Very abundant growth of mi^^a^t 

intermixf*<l with other organ usn* 



1917] 



Boncqxtet: BACiUiUS morulans 



279 



TABLE l-Continuei 


IIATSRIAL 


NT7MBKB Or 

TUBM 


BK8ULT 


Petiole of slightly diseased leaf 


2 


Both very abundant morulanB 


Blade of same between veins 


2 


Both remained clear 


Typically diseased leaf; scraped 


4 


3 tubes developed morulans, 1 


out interior portions of petiole 




doubtful 


with flamed scalpel after clean- 






ing off epidermis 






A young leaf visibly affected on 


4 


All developed morulans 


one side and very slightly at 






the base of the other side. Tis- 






sue taken from the most dis- 






eased side at base 






Terminal portion of diseased side, 


4 


2 developed mortdans; 2 clear 


less visibly affected 






Slightly affected base of other side 


4 


1 developed morulans; 3 clear 


of same leaf 






Not visibly affected terminal por- 


4 


All remained clear 


tion of last 







Note.— The last four are from the leaf illustrated in Phytopathology 6: 106. 
The most elaborate precautions were taken to secure perfect surface disinfection and 
avoid contamination. These tubes in which gprowth appeared were plated out and 
found to contain pure cultures of morulans. The leaf was perfectly sound, showing 
only a slight roughening of the veins on the affected portion. 

appearance to the eye of this ring, supplemented by microscopic examina- 
tion, finding it to be composed of the characteristic zoogloeae, supple- 
mented by occasional plating, is amply sufficient to identify this organ- 
ism. A number of typical examples of isolation experiments with sugar 
beets are shown in table 1. 

Several himdred illustrations similar to those shown in table 1 might 
be given. The results varied somewhat with the perfection of technique 

TABLE 2 
Bacillus morulans upon sugar beet seed 



MATERIAL 


NUMBBR or 

TUBES 


RESULT 


Beet seed imported from Ger- 


10 


At least 7 developed an abundance 


many, 1 dropped into each bouil- 




of morulanSf mixed with other 


lon tube, with no previous treat- 




organisms 


ment 






Similar seed previously soaked for 


10 


All clear 


twenty minutes in mercuric 






chlorid and washed in sterilized 






water 







280 



Phytopathology 



[Vol. 7 



and in individual cases, but a mass of evidence was collected to indicate 
that this organism exists regularly in the interior of the foliage of migar 
beets where the visible s^^mptoms of curly top occur and that it does not 
develop in cultures from nomud foliage or even the normal-appearing por- 
tions of partially affected leaves; also that it does not occur in the interior 
of beet leaves which may be yellow or sickly from ordinary cauM«. 

Cultures from seed. Many attempts similar to those shown in table 
2 were made to isolate the organism from sugar beet seed. The uniform 
result was that almost every unsteriUzed beet seed dropped into a tube 
of lx)uilIon developed a very luxuriant growth of Bacillus fnarulans, 

TABLE 3 
liacillim tmnulann from noil 



MATCRIAI. 


NruBBR or 

TCBCn 


KaBn.T 


Pinches of soil from alxmt the 

r(H)t8 of a diseased l)eel 
Pinches of soil from about the 

roots of a normal U'ct in insc»ct- 

pnK>f cajje 


4 
4 


Marulana wm abundant in tpverml 

of the tul)e« 
Some morulan9 present in the 

mixed growth resulting 



Culiurenfrom soil. That the organism is present in some soils is indicated 
by tho data preK»nted in table 3. The work was rather crude but cer- 
tainly li. tuorulans was abundant in the soils examined. 

Cultures from unsteriUzed foliage. Cultures made from unsterilised 
leaves of the sugiir In^'t (table 4) show that the organism is common as a 
sapro|)hyte upon the leavt^ of the* plant, but in all cases when leaves simi* 
lar to these w<Te thoroughly disinfcvted no growth was obt^ned. 

TABLE 4 
CuUnrf* from unntfrilizrd foliage 



M\ri HI«L 



I.<-:ivi*«» i»f iiortiial iHTtH 



Ni'MBCR or 
Ti'Bm 



10 



saicxT 



several contained an abundance 
(»f moridanM 



rii>t«'riliz(Hl loavt*^ of many other plants were also tried but the resulting 
grtiUlh \%:i> Ml luixod that no safe rtiiirhisions (*ouhl 1m» drawn. The only 
rertaiii iicvt*Inpiiu>iii< of muruUius (NTiirnMi in tnU's inoculated with pieces 
of r)in>anth('iiuuii h*avi'.<. 

i'ulturtt^ frttm suijtir /w«/ Imns tnth ty/Ms of disease other than curly top. 
Th«- I'art that lM»ilit> n'x-iiihliiiK bacteria have b4M»n s<»en i*ith ihe micro- 
iii*ii|H' in sii^jir Ui't h'av«-> not afTt-t-t^Hl with curly top, Init affected with 



1917] 



Boncquet: Bacillus morulans 



283 



TABLE 5 
Cultures from sugar heel leaves with types of disease other than curly top 



MATERIAL 



Yellowish area of young "black 
edge'* leaf taken from between 
black and green portions. 
Thoroughly disinfected 

Similar to last, but not disinfected 

Similar material, disinfected 
Similar material, disinfected 
Typical "mottled leaf;'' not dis- 
infected. Blade, petiole and 
veins 
Petiole of "black edge" leaf, dis- 
infected 
Petioles of normal appearing leaves 
from healthy plant. Very 
carefully disinfected 
Petiole of decidedly "mottled 
leaf." Inner tissue removed 
with flamed scalpel 



RESULT 



Both gave a strong growth of 
morulans 



Very vigorous and apparently 
nearly pure growth of morulans 

All with morulans 

All with morulans 

All produced morulans in abun- 
dance 

All appear to have pure cultures 

of morulans 
All tubes clear 



Very vigorous growth of morulans 



Further study of the organism, which was uniformly present in diseased beets 

Although the organism was able to grow most abundantly on the com- 
mon culture media, the peculiarity of this growth under all circumstances 
was of such a nature that for some time a continual contamination was 
suspected. Each separate colony seemed always to have two kinds of 
bacteria, very distinct in form. Very active bacteria were always observed 
at the edge of the colonies, while capsultated bacilli were generally ob- 
served in the middle. Therefore, before any further study of the organ- 
ism was taken up, repeated efforts were made to separate these two widely 
distinct forms. For this purpose, the calcium carbonate and the India 
ink method for separating the individual organisms previous to plating 
them were resorted to. 

Calcium carbonate. To 10 grams of calcium carbonate enough water 
was added to form a milky paste. This was subsequently introduced into 
a 200 cc. Erlenmeyer flask and sterilized in the autoclave. After the nec- 
essary cooling several yoimg colonies of the bacteria were introduced into 
the semi-liquid mass and shaken for two hours so as to separate each indi- 
vidual organism from the other. From this paste, several plates were 
poured in the usual manner. They were incubated at 37°C. and closely 
examined as soon as any sign of development occurred. 



284 Phytopatholoot [Vol. 7 

India ink method. For this purpose special Chinese ink, prepare«l by 
Grilbler, (Punkttusche) was used. A 15 per cent nutrient gelatin was 
made and poured into clay-covered petri dishes. Special care was given 
to prevent condensation water from flooding the medium. The GrQbler's 
ink was diluted twenty times with n/6 glucose solution and sterilised in 
the autoclave. In a sterilized, empty petri dish ten drops of the ink were 
put in a row. The first drop was inoculated with a small amount of bac- 
teria from a twelve-hours-old streak culture. The bacteria were thor- 
oughly mixed with the ink of the first drop. Then a loop of this was trans- 
ferred to the second drop and also thoroughly mixed. This transfer was 
repeated in the same way with the remaining drops in the dihh. From 
the tenth drop, with a sterilized drawing pen, a small amount was taken. 
Small (lots were made with the pen on a gelatin plate in such a way that 
the surface pellicule of gelatin remained uninjured. These ink dots were 
left to dry for two minutes then covered with a sterilized cover-glass. A 
small drop of immersion oil was 8ul)sequently applied to the cover-glai« 
and the whole pt^tri dish was i)rought to the microscope for examination. 
Each black p<jint wa.^^ then examine<l \^'ith microscope until one was 
found which containoil one single organism. The organism appeared as a 
translucent dot on a black field. Its development was closely foUom-ed; 
the first division was distinctly noticed after half an hoiu*; it muhiplied 
rapidly; all the individuals were motile; they liquefied the gelatin riightly 
and nioveil alK)ut ver>' briskly in the liquid under the cover-glass. After 
six hours some of the organisms l)ecame sluggish and gradually k)st their 
motion. They incn*a.'*<Ml in size and forme<l a capsule. Repeatedly they 
divide<i in the same capsule, stretching the jelly-like membrane more and 
more. The newly forme<i organisms within the original capsule also en- 
ca|)sulated in their turn (figs. and 7). At the same time the indi\idual8 
on tlic rim of the colony multipliefi and remaine<i mcvtile. The double 
form of the bacillus was in this way clearly explaincMl and pn>ve<l. 

IDKNTITY OF THK OKCANIHM FOUND IN TURLY TOP BEETS 

\ Study of the litcnitim' of the subje<-t shows that the greatest similarity 
to our organism (»f any descrilN'd s|K'ci<»s is presented by that descrilieil by 
.\nhur and Holl(*y^ as liacUrium Dianihi as the cause of a leaf spot of the 
caniatic»n. In its morpholog}'. so far as descrilKxl by these writers, this 
organ i;4iM is v(*r>' similar to ours, the n*semblanc<» lieing nmde pronounced 
by thf (i«-veIopinent <if characteristic z<M)gl(H*a<'. In biological liehavior, 
Imwrver. the iwo or^canisins cannot Im' accurately compared, since the 

* \rttiiir. .) i' :ini| liiillfv. II. L. HiirtrriiMiiN (»f rnriintioriii. Indi»n» .\Kr. Kxp 

St:i lilt I .v.* IVHi. 



1917] Boncquet: Bacillus morulans 285 

work of Arthur and Bolley was carried on at a time when bacteriological 
technique was not standardized upon modem lines. One noticeable dif- 
ference exists in respect to growth upon an acid medium, B. DiarUhi being 
said to grow best under such circumstances, which is not the case with 
our organism. The description of the bacterial organism given by Arthur 
and Golden^ and again by Miss Cimningham^ as the cause of the so-called 
Indiana sugar beet disease, is similarly subject to imcertainty, but if this 
work was accurately done the organism must certainly have been differ- 
ent from ours in that it is said to be a particularly active gas former, which 
feature is totally lacking in our organism. It seems proper to mention 
here, however, the fact that Professor Arthur in a recent personal letter 
states that the accuracy of all this early work performed under his direc- 
tion is open to some doubt on accoimt of the imdeveloped condition of 
bacteriological technique at the time and he expresses the opinion that 
the organisms found by Bolley, Miss Golden and Miss Cunningham were 
very likely identical. 

The organism described in the unpublished work of Schneider* as BaciU 
liLS califomienaiSj which was isolated from curly top beets in California, 
seems again in its morphological characteristics to be entirely similar to 
ours and we feel little doubt that Schneider and the present writer had 
the same organism before them. Schneider found his organism also very 
abundant in sugar beet soils and upon the surface of the plants. He at- 
tributes a stimulative effect to this species, when applied in pure culture 
to sterilized beet seed or to the foliage of yoimg plants. 

The organism described by Dtiggeli* as being abimdantly and often ex- 
clusively present upon the surface of various plants and seeds, seems also 
very similar to ours in form and size, formation of zoogloeae, color, sapro- 
phytic habitat and most biological characters. This was named by Diig- 
geli Bacterium herbicola aureum, but "said to be the same as the BaciUus 
meserUericus aureus, isolated by Winkler from the surface of plum leaves." 
The latter statement confuses the identification. 

DESCRIPTION OF THE ORGANISM 

Summing up the whole situation, we feel justified in describing oiu: 
organism as a new species on account of the incomplete and doubtfully 

* Arthur, J. C. and Golden, K. E. Disease of the sugar beet root. Indiana Agr. 
Exp. Sta. Bui. 39, pt. 3: 54. 1892. 

^ Cunningham, C. A. A bacterial disease of the sugar beet. Bot. Gas. 28: 177- 
192. 1899. 

' Schneider, A. The California beet blight. Spreckels Sugar Co. Exp. Sta. 
Rept. 28: — . 1906. (Unpublished.) 

• Centbl. Bakt. II, 12: 602 and 695; 18: 56 and 198. 1904. 



286 Phytopathology [Vol. 7 

accurate descriptions of those species which more or less rcsemblo it . ami 
the fact that none of them corresponds throughout. 

Bacillus morulans n. sp. 

Morphology 

Vegetative cells. Grovm in Liebig bouillon for sixteen hours at aUiut 
20°C., oval to short rods, single or in pairs. Groim at 37*, shoft rrMb in 
pairs or in short chains. 

Sizi'. Length 1.5 m; breachh 0.1) n: extreme length from 1.5 to 2 m- 

Capsules. Kasilv observed in 1 lOCK) glvcerin iKmillon after twenty- 
four hours and also in milk nuKlia (figs. 6 and 7). 

Motility. Very active on agar and in l>ouillon, when grown at 37' for 
twelve hours. 

FUujella. StaiiuMi by Z<»ttnow*s meth(Hl; four long peritrichial flagella 
(figs. G and 7). 

PU'omorphism. Cocciforius obstTved in glucose Inmillon tulles and 
bloo<l s<»niin nie<iia after thirtv davs. 

Stain. Miisilv with waterv fuchsin, d(H*olorize<l bv CSramV m€*thcNl. 

Cultural features 

(ielatin platv mutral to phenol phthalein, Konn. round to irregular; 
surfa<*(» elevation. Hat to convex contoure<l; internal Mnieturv, refnuiion 
strong, hyalin**, inoruloid; zoogl(K»ae very marke<l; tHlgi*s. entire to undu- 
late: optical characteri.<tics transparent to butynnis; consistency. \'u*ctm.*. 
Kacli colony is surrounded with many .^'condary colonies, appearing a.H 
sniall. «»ily drops of high refra<'tiv<* power. The appearance of so(»gloeaf 
is verv noticeable in the middle of the cohmii'S. 

(it hit in plntfs I ..'t oeid tn phvnolphthalein. The entire nuM» is a xooghM^a, 
IoIn'iI and irregular in outline; the colony is slightly colored; orange-yrl- 
Inw. !in >iirroun«liiiu ro|nni«»s noti(*e<l. 

fnhit'f, stnnk. After five days: gro\\lh, linear; margin, continuoiL«; 
surf.-m- iriji-f, flat i<» eiuivex: li^Jht transmissi<»n. butynius; t*olor. yellow- 
oraii^*-: lu-^trr. ^li-trninj:: cimsi^tency, visi-ous. The water of conik*n«&a- 

tinii ha^ :i yrjinw >4Mliiiieiit . 

ft't iitt. /i.'/». Aft IT twi'iity-twn h«»urs. top gn»wth:si£e. 5 mm., im^ilAr 
('(iiiiciit*'d pulvinate tn capitatr. li^lit orangt* in color; vis(*ous in coiLM^t 
<*in\ . 'ii-tti ^liiiiiim. 

(,..>' / ^ti,ttl . I'ilifnrin tn slinlitly iM*adi'd. .\fter fifteen <lays. liquid 
f.f Ml. ii «.i iiii'diuiii. rratrrifnrm with a vellow s4Miiment. After Iwenlv 
iii>-. li«j»i« fretimi ytratiforiu; yellnw pigment. decreas<M| by alMtenci* of 



288 Phytopathology [Vol. 7 

Agar. The colonies are extremely variable according to the deniQty trf 
growth, the moisture and the t-emperature. 

Milk. Peptonisation of casein in fifteen days at 37®. The re«iclMm w 
alkaUne to Azolitmin. 

LitmuH xvhcy. Remains clear, alkaline reaction. 

Bouillon Uibea. Opacity l)egins after eight hours at 37**, a pellicule 
fonns in twenty-four hours or less. The color of the pellicule antl the 
ring is dull, soft gray ; thick, viscous and conaists of oongkimerate leogloeiir. 
The8e are generally oval, but may l)e linear and all united in ehainii. 

Deposit, forms after two days incubation at 37**. I>epoKit is in the 
lK*ginning slight, and finally yellow. The amount of deposit and the in- 
tensity of the color increases, how<*ver, rapidly. After t*»n days, a de- 
cidedly d(»ep yellow-orange has develofx'd. The de|MK<it is compact and 
viscid on agitation. 

Potato streak. After twenty four hours at 37**. Size, 2 nun.; sharp. 
linear; margin, continuous; color, yellow, honuM*hn)mous ; lust<T, glisten- 
ing; texture, homogencHnis. Xo Hcjuefaction of |)otat<» and no gat 
formation. 

Physical a tut biochemical features 

Heaction. In carl M)hy drat <'-fre<» nuMiia the reaction is alkaline; in carlMH 
hydrate media, the reaction is acid, except in lactos4», where the n*action 
is .slightly alkaline. S«m» table <>. 

\ Urate Liebig broth. After twenty-four hours at 37', stnmgly nNhice^l 
to nitrite. 

ludol. Not pHMiuaMi in p<*ptone solution after ten days. 

Optimum temfnrature. 37**, meju^unnl by the amount of acid pnMiu<'«'d 
in 1 JMT <'ent glu<*os4* after five days. Acidity w:l»* 2.5. 

Thermal death fmint. Six-hours culture in iMmillon; i'A'^i \ in ten minui<*9». 

Carlnth yd rate fermentation. Shown in table ti. 

lirsistanee to mercuric chloritl. Six-hours <*ultun' on iKiuillon agar stn^ak 
killc<l in 1 2:>.(NN) to 1 ;i(MMM) in ten minut<^. 

Ut latter growth in acid and alkalin media. IX*tennin(H| by the ap|M*:ir- 
aiKM* of cloudinos in the tulH>. (Sniws bc^t cm neutral or slightly idkalin 
mrdia. Vwv \h't cent in ari<l appan'ntly stops all gnmih; 7 per ei-nt in 
alk:tlin«': >am('. 

<ffi> piiuhu'tnni. No gas i> pHNJuctMl. Sim* tabic G. 

litlntittu tit frtt oiygtn. AiTobir; facultative anaerobic. 



1917] Boncquet: Bacillus mordlanb 



TABLES 

CarbohydTate /ermentation of BaeiUui morulana 
(Incubation: 37''C., medium neutral to aiolitmin) 



NoTx. — A, acidi B, basic; p, permanent; b, abundantly present; a, absent; x, 
more or less present; *, acid on top and basic in tuho. 

PathogeneaU 

One loop from a twelve-houre-old streak culture on bouillon ^ar intro- 
duced intravenously in a rabbit, caused death within twenty-four hours. 

On Diajithus incamaUi. The young unfolded leaves,' when unrolled and 
covered with an abundant suspension of bacteiia, developed small necrotic 
r^oDS. The necrotic regions are watery and translucent on the edges, 
slightly elongate or irregular in outline, following the venation. The in- 
side of the necrotic r^ons is sUghtly brown. 

UmvBBsnr or Caufoknia 
Bebkelet, Califoknta 



A NEW APPARATUS FOR ASEPTIC ULTRAFILTRATION 

Ralph E. Smith 
With Two Fiquees in the Text 

In various investigations of so-called nonparasitic or phyaological plant 
diseases, as well as in numerous animal diseases in which the pmence 
of an ultramicroscopio organism is suspected, the juices or body fluids of 
affecte<l plants or animals have often be< n subjected to filtrmtion through 
Berkefeld, (^haml)erlan(l and similar filters in order to remove bttcteria 
and other organisms of microscopically visible size. While inocuUtions 
with such filtere<i juice have lxH*n made frequently, and in some cases 
(tobacco mosaic) with i)ositive results, the possibility of dcmonstniting 
the presence of a t)nrasite in the filtered juice \iy its poosiUe growth 
when all other organisms an' excludeil, se<*ms to have received little at- 
tention so far as plant diseases are concerntHl. 

Another object in pnnlucing an aseptically filtered juioe is that of 
obtaining a st^Tile, unheat<Ml plant extract as a culture medium, as men* 
tion(*<l by Mr. B<>nr({uet in another article in this number of Ph>'to- 
path()log>'. In either cast' the juice may l)e varied in concentration or re- 
action, any desinul substance which will pass through the filler may be 
addtnl to it. an<l in many ways ilh4* may hv found in the investigation of 
plant diM>as<* f(»r tisi^ptically filtennl and preserved or ooM-ffteriliaiHl 
jui(M\s. Various devict^ for this purpose^ have l)een described but all 
of them, HO far as the writ<T is aware, an* clums}' and of very doubtful 
efficiency. Those in which the candle and the Uquid to be filtered 
in 11 tulN* <iin*rtly aUive th(* receptacle or outlet for the filtered juice 
esiMM'inlly uiidrsirahle. since the slightest leakagf* may result in contam- 
in.HtiiiK the filtrate with the unfiltenHi juice and thus d<*feating the whcilc* 
objtrt of filtration. HiiblNT stop|)ers an* alwa>'s op4*n to sus|Nci4m. 
ArranK«inentH ju whieh the filtrate is caught in an opi*n or a cutton- 
stopiMii ve>Ml and then iM>ure<i into the* cultun* tul)es in the open air 
are eiTtaiiily far fmm safe. Those in which the liquid is forced thmugh 
the raiiiilf fri»in the iiL-iide outward are obj«H*tionjible on account of the 
quirk eujitii»K ovt r of the inner surfaer with sentiment , which, on the i»ut- 
>ii\r. may Im- iimMly Imishid off. In the ap|)aratus illustrated hen* the 
only )Hi>-.il>ility ni <*ontaiiiination is fri»ni the air and cannot occur fn>m 
th< \ihfUti n tl juicf. Ill 4 it her words, it is abs<ihitely c<-rtain that nothing 



292 Phytopatholoot (Vol. 7 

in the line of tubing from the candle to the upper re s e r vo ir are wrapped 
closely with cotton, extending beyond the ends of the rubber connections 
and for about an inch down over the candle itself. Over these an* put 
again still longer cotton wrappings and finally a layer is put on covering 
the whole line completely from a point two inches bdow the upper end 
of the candle up to the reservoir. The whole region around the fKUip- 
cock is similarly wrapped with several layers of cotton, with a largi* plug 
of the same material in the lower opening and a wrapping over this and 
up arotmd the tube. It is the intention that all the joints shall be air- 
tight and in this apparatus the number of joints and chances of con- 
tamination arc less than in most similar devices. (Compare for example 
the arrangement figured on page 65 of Marshall's Microbiology.) The 
cotton wrappings are added, however, as an extra precaution. 

After the apparatus has been put together and wrapped it b sterilised 
in the autoclave. At the same time a supply of cotton-phigged tf-nt- 
tul>o8 is Rterilized by dr>'' heat. The apparatus is then set up on a taMe 
convenient to a gas burner and some of the juice to be filtered pourrd 
into the l)eaker, taking cure not to allow the cotton at the upper end of 
the candle to touch the li(|ui(l. The water vacuum pump is starteil. 
using as little suction as po8sil)le, and allowed to operate until a supply 
of the filtered juice has l)een collected in the reservw*. If the aurfare 
of the candle iK'comes Uh) much clogged it may be cleaned with a soft 
brush, but it is (l(*sirable In^fore commencing the filtration to remove as 
much solid maU^rial from the juice as possible by filtering through cloth. 
pa|MT and sand. As soon as enough juice has l)een filtered the cott4m 
phiK dosing the lM)ttoin of the main tul)e is removed; one of the steril- 
ized test-tubes is h<'l(l in imv hand, the plug n>moved and discarded, the 
tiilx* thoroughly flaineil s<*v(*ral inches do^Ti from the top and then panst^l 
up int4> the lowrr end of the ap]mratas ]N*h>w the outlet tube. With the 
other hand the stoiw'ock is tum(*<l and some of the liquid run intoth«* 
tulM'. Aftrr shutting off the cork, another tulH» is taken from the ))ask«-t 
with that hand, whilt* the tulx* just RIUhI is withdrawn and its open enil 
hiM in the f1:iine. Th<' ])luK of no. 2 is now transferre<l to no. 1. Nith 
tiilMS ronstaiitly flaiiieii. no. 1 is laid aside and no. 2 filled, continuing 
th»* pn»e«->s with as ipimy tnU-s as «lesired. 

Tht apparatus fiKtirtMl is 14 inches long over all« and holds 200 rr. «if 
li«|iii«l. DitTiTi-nt <izis may of r«iiirse Im» n»ade and it is ver>' pn»l»al»l«' 
th.it •^nim «.f thu'H«' inten-Med in the matter may \h* able to suggt*st im- 
pri*vi lilt iii^ ii)M»n tlie apjiaratii^i. A eontimious glass tulM> n^Khl U> 
n- 'i iM'twirn thr riM-rvoir and filter eandle, thus eliminating tme juint. 
l»iif It hii" In I II thuiiirht that the inerea*<eil liability of breakngi* n^uulti 
m«>ri- than ntT<*et any disulvanta^ce. It n*ight also Im* {MMsible to rnnent 



FACTORS AFFECTING THE PARASITISM OF USTILAGO ZHB 

F.J. PlEMBIBEL 

Because certain facts seemed to indicate a different life hitttorv fmm 
that usually credited to Ustilago Zea (Beckm.) linger., on corn, field inocula- 
tion eicperiments were carried on during the summers of 1913 and 1914. 
The results of the experiments were such as to make a more detailed 
investigation of the spores and sporidia highly desiraUe. 

The works of Von Waldcheim (10), Brefeld (2, 3), Hitchcock and 
Norton (6), and Clinton (4) have given us the salient poinis in the life 
hudory of this parasite, and numerous other investigators have niaile 
additional contributions from time to time, showing that the control 
of the fungus is a difficult problem. The spores of the smut are wi<lely 
distributed by the wind and are produced in large numbers throughout 
the growing season. They are capable of germinating immediately and, 
in a suitable medium, they produce immense numbers of sporidia which 
may bud in a yeast-like manner and produce a host of others. The pro- 
duction of the sporidia in largd numbers in the field is possible in such 
places as manure or compost heaps. 

Brefeld (2) ccmductini a few expc^riments from which he concludctl that 
s|K)ridia arc short livo<l, d\ing in five weeks when dry. The sporidia 
thenifore have l)cen chanicterizeil as Innng *Wiort lived" and ver>' little 
is really known concerning the factors affecting their vitality. Nor do 
wo know the fate of spon's on the com used for ensilage. The prrarnt 
inv(^igation was made in an effort to secure more definite information 
on thes4* jMiiiits. 

INOri'LATIO.V EXPERIMENTS 

Methods 

Pun- (*ultun:9< of tho fuiif^us wort* ohtuimMl by the poured plate method, 
u.*(u:illy on Ix'^Twort aK:ir. Tho c<)loni«'$i wen* later tranjiferrod to agar in 
tulH*^. SiM»ri<iia from pure (Miltun* wrn* then used in the inoculaticin 
ex(NTiiiii*iits. IiiociihitionH wt'n* ni:ui«' either by smearing thi* sporidia 
din-rtly on in tin* plant parts or by |>la('inK th«>m in water and applying 
\\i\> ^u^^M•Il•^if^n of >|H>riiiia by inrans of ji dn>p|H*r or hypodemiic s\Tingiv 
'rh«* hypiMit-niiic >yrin^(' w:i> umsI when it was d4*sin*d to incKruIato the 
vvrv voiinK part> which had not v«*t Ut^n unfolded. 



1917] Piebieisel: Parasitism of Ustilago Zisim 295 

Spores were ako used in inoculating the plants — ^usually they were dusted 
directly into the tops of the plants or mixed with moist soil and then 
applied. In a few cases the spores were applied in suspension in water. 

Factors affecting infection 

During the summers of 1913 and 1914 a total of 2064 plants of Minne- 
sota no. 13 com were inoculated. In all eighty different series of plants 
were used in the tests. The highest percentage of infection in any series 
in the summer of 1913 was 70.8 and in the summer of 1914, 84.2. These 
results were obtained by injecting suspensions of sporidia in water into 
the growing point or as near it as possible. 

Experiments were made to determine the effect of the following factors 
on the success of infection: age of the plants; injury to plants; age of the 
spores and sporidia. Observations were also made on the relation of 
early planting close planting and soil conditions to the amount of smut 
present in tha fields. 

Age of the plants. It was found that successful infection depended very 
largely on the age of the plants or plant parts inoculated. Healthy, 
vigorous plants about 2 to 3 feet high are most susceptible. It was very 
diflBcult to infect very yoimg or very old plants. These results confirm 
those obtained by Brefeld (3) and Hitchcock and Norton (6). 

Injury of the plants. Experiments performed by Chnton (4) showed 
that mutilation of the com plants when about ready to tassel tends to 
increase their susceptibiUty. The experiments of the writer Ukewise 
showed that injury tends to increase the chances for infection. When 
young leaves were injured and then inoculated, the resulting infection 
usually spread from the point of injury as a center. Many of the infected 
leaf areas, however, never developed sufficiently to produce mature spores. 
This was probably due for the most part to the rapid maturing of the leaf 
tissues and the consequent inability of the fimgus to spread through these 
older tissues. Injury is not necessary, however, for successful infection. 

Age of the spores and sporidia. The length of time that the spores can 
withstand unfavorable conditions is important from the standpoint of 
the propagation of any fimgus. Brefeld (2) demonstrated that corn smut 
spores, eight years old, germinated, but he did not attempt to secure 
infection with them. The writer obtained spores, five years old, and made 
field inoculations with them by dusting into the tops of the plants. Six 
per cent of the inoculated plants became smutted near the point of inocula- 
tion. Two per cent of smut also appeared in the check plot but the 
infected areas appeared on various parts of the plants. 

Many fimgi when kept in continuous culture on nutrient media for 



296 Phytopathology [Vol. 7 

some time lone their power to infect. Brefeld (2) found that amut siporidia. 
when kept for a year in continuous culture in liquid media, Iok( their 
viability. The- writer kept the sporidia in continuous culture on lienr- 
wort agar for eight months. The culture tubes containing the sporidia 
were then buried in snow out of doors where they remained for a month. 
Inoculations wore then made in the greenhouse on two com plants. (>no. 
a snuill plant about 2 feet high, became infected in each of the five leaves 
inoculated. The other, about 5 feet high, was inoculated on an ear and 
prcxluced a large smut Imil. Thus it will Ik^ seen that continuous culture 
of the sporidia on a solid nutrient medium for a period of eight month<«, 
followed by freezing for a month, did not destroy their ability to infen. 
Recently, portions of a pure cultiuv, that had Ihwu maintaine<l on l>eer- 
wort agar sinct^ June, 1913, a period of three* and one-half years, were placiNl 
in hanging drops of di.slill(Hi water and also of mo<Iifie<l ( ohn*s s4>lution. 
In th<»se cultures individual sporidia wen* probably no longer present but 
theR* was a miiss of short hyphal thremls, apparently resting segments 
of th<* g<Tin-tulH^s of the sporidia. The ends of thes<* hyphal thn'iMls were 
deiiw»ly pn)t()j)l:ihmic and wlM»n they wen* pUice<l in water, or, l>ett4*r 
still, in a li(]uid nutrient me<liuiii they again pnNiu<*iHl sporidia by budding. 
Tlu^M^ sporidia continucni to bud until the supply of nutrient matf^rial wan 
ex)iaust(Ml when they again sent out long thin g<*rm-tul>es. The writer 
inoculated four plants with some of the pure-i*ultun* material but has not 
as yet succ<h'(Um1 in securing successful inftnrtion. 

Kjftct of varly planting ^ char planting and soil conditions, Arthur and 
Stuart (1) n*iM)rt that early planting, close planting and moist rich M>il 
incn*ji^e the ani(»unt of .snnit. Il^iiny periods were also closely followeil 
by outbn*aks of snuit in the com fields. The following obser\*ations 
niadt* by the writer point to similar condusioiLs. 

The corn us<sl for the inocuLition ex|H*riments was planted at succeMtive 
intervals throughout the s<*ti.son .so as to have at all times an abundance 
of i)lant.s in the sus(*eptiblc stage. The plots wen* carefully examined for 
smut and it was found that a gn^ater amount of smut was present in the 
plots planird carlitT in the M»2ison. The phuits in such fiehls are in tlu* 
ni«»>t .suMTptible condition at a time when the weather Ls still fairly cool 
and iMoiM ami the coiiditinns for infection ver\' favorable. The later 
summer weather 'i> likelv to In* t<M»hot a n<i t<N)drv for successful infection. 
I >:ite Mill in let with its I lion* frequent rains and c<N>ler weather again bring!« 
on a fre.sh <iut)>reak of smut, the parts most aflf(*ct«sl lN*ing themdinientar>' 
ears, siiin* tin? n*st «»f the plant is aln*aily t-o<» matun*. 

W htii rtirii i> L!ri»\\ii in (*ln.s('ly plantiMi n»ws for gH*en fodder or silagp 
purpo-i-. till- >inut i> aUu nmn* pn*valent. probably l>eeause the Mini in 
such tirlils n'Miaiii** Mirruli'ut fur a longer iteritNi of time. In one such 



1917] Piemeisel: Parasitism of Ustilago Zea 297 

field which had been continuously cropped to com a number of years, 
there was 25 per cent of smut as compared with 7 per cent in neighboring 
fields where the com was 3 to 4 feet distant in the rows and on which 
rotation had been practiced. Com on poorly drained soils or on those 
which are too dry has less smut than that on a rich, moist soil. The 
former types of soils produce weak plants that mature rather rapidly, 
while a moist, rich soil produces a very vigorous succulent plant which 
apparently is also more susceptible to smut. These observations further 
confirm the conclusions of other writers. 

Character of infection 

Smut boils are often so generally distributed on a plant as to lead one 
to suppose that the infection may have occurred on yoimg plants and that 
the fungus then spread throughout the growing tissues. It is not im- 
common to find a single plant on which the tassel, leaves and the primary 
and rudimentary ears are smutted while adjacent plants are entirely 
free of smut. It is therefore difficult to explain why the successive 
infections should all have occurred on one plant. If the smut were sys- 
temic such a phenomenon would be easily explained. Brefeld (3), how- 
ever, concluded from his inoculations that the infection is local. 

Field observations. In order to obtain more* complete information on 
this point, the writer made careful observations on plants artificially 
inoculated in the field. The results showed that, when successful, signs 
of infection always appear in from ten to fourteen days after inoculation 
and that the fimgus spreads but Uttle in the tissues. On several plants 
where the inoculum trickled down the sides of the culm, smut boils were 
produced at a number of points along the line, involving the leaves, the 
primary ears and rudimentary ears. In nature, similar conditions might 
easily arise when a spore falls into the water contained in the funnel formed 
by the unfolding leaves and produces sporidia. The sporidia could then 
be easily washed out to the various parts of the plant by rain. This is 
especially probable since the spores of the smut can germinate as soon as 
matiu-e and parts beneath the point of primary infection are particularly 
Uable to attack. 

Brefeld (3) and Kiihn (7) both obtained successful infection on a few 
seedling plants but in all cases such plants were destroyed by the smut. 
In order to further ascertain the results of early infection, ten very young 
smutted plants in a fodder-corn field were selected and marked. All of 
the plants were about a foot high and showed varying degrees of infection. 
Of the ten plants under observation eight were killed by the smut in less 
than a month and the other two were greatly stunted. These two plants. 



298 Phytopathology (Vol, 7 

however, produced healthy ears. Furthennore, many plants that were 
found smutted when quite youn^ matured healthy ears. 

Greenhouse inoculations. It han abeady been stated that in the field 
the infection of verj' young com plants was ver>' difficult. Further inocula- 
tions were made in the greenhouse upon germinating seeds. Forty-three 
seiMllings were dipped into a water suspension of sporidia and then planted 
in pots. None of the plants developed smut although they were allowed 
to gnjw for one and one-half months. These result* indicate strongly that 
infect i(m is purely local and not systemic. 

THK VITALITY OF SPOKKS A.ND SI'(»mi)IA 

It is a well-known fact that corn smut spon»s retain their viability for a 
numlMT of y(*ars, U^ing ext namely resistant to unfavorable conditions. 
V<»ry little, how(»ver, is known con<*(»nung the vitality of the sfMiridia and 
their resi.^'tance to unfavorable con<litions has hitherto Ihhmi supi>oM'<l to 
Yh" very slight. Th(i writ(T al.**o investigated the vitality of the siKin-s and 
sporidia. The cfTcets of the* following factors on the vitality of >|H»n'^ 
wen' considertMl: (1) the silo, (2) t<»mix*ratun», (3) carlnm dioxiilr. 
(4) acids, and (5) s4'asonal factors. Tlu' influence of the following fa<'- 
tors on th<' vitality <»f sporidia w:is rcmsideriMl: (1) tem|MTatun*. \'2* 
desicration, {'^) arids. 

V italHij of spares 

Since a considerable amount of corn .^mut must 1h» carritMJ over into 
silos with the corn in the pnK*ess of .silo filling, it is imiMirtant to know the 
fat" of such spon^s. T<J d(»t ermine this, si>on's wenM*olUM't<»<l inc|uantity 
and phu'ed in several .silos for various h^igths of time. A brief sununar>* 
of the n»sults is given Im»Iow. 

Sufuplrs I. TIh^si' siK)n»s, which had just mature<i, wen* iHilhvt***! 
S<^pt4'm)HT 11. HM4. eiu'los<Hl in a che<*s(M*loth bag and phuM^I al»out on«^ 
third of the way down in a wtMHien silo. A sample of th" .Nune lot w:lh kept 
a> a rheek in the lalM)nitory at nM)iii t«»m|H»nitun*. Tin* sj)ore> utTi' 
n^eovered from the .^^ilo on NovemlxT 2, 1914, after having Iki'Ii th«-r^» 
alM»ut s« ven we<*ks. T\\r .^pon's w<in» fn)W»n and wen», then'fon». thawt^i 
out gradually in the laboratory. 

Satnph- II. TIm^' s|H)n*s w«»n' ('olUvtiMl and phu'e*! in a brit*k >d«» 
S'pleiiilHT 2. 11M4. The s|M»n's wen* eiielosiMl in a bag and plaeeil alN»ut 
l."» ii^i'.i I'rtim the lM»ttom of th<* >\\o and aUmt 2 fe«*t fn»in th«' M«le. Thfv 
\\rr«- reioveHMJ M:ireli 4, nu.*>, aft«T having lKM»n in the mIo for tivor 
t^ii'iilN-'ix wei»k.«». The s|H)n»s when nM'ovenMJ wen* frt>z<'n and then^fon* 
the s:iiiipie wa> dividt^d into thret* {Mirtions :i> follows: (1) A |M»niou 



1917] 



Pibmeisel: Parasitism op Ustilago Zkm 



299 



was kept frozen; (2) a portion was kept moist at laboratory temperature; 
(3) a portion was air dried and kept at laboratory temperature. The 
object was to eliminate, if possible, the method of handling the spores 
as a factor which might influence their germination. 

Samples III and IV, The spores were collected, placed in bags and 
buried in a silo October 6, 1915. Sample IV was placed about 2 feet 
from the side and about 8 feet i^m the bottom of the silo. It was re- 
covered January 20, 1916, and was kept frozen until February 8, 1916, 
and then kept dry at room temperature. Sample III, which had been 
placed in the center of the silo, about two-thirds of the way up, was re- 
covered January 15, 1916. It was also kept frozen until February 8, 
1916, when the spores were gradually thawed out and then tested for 
germination. 

TABLE 1 
Results of germination tests of spores kept in silo 



NUMBER 
or TRIALS 



SPORE LOT 
TESTED 



MEDIUM IN WHICH TESTS WERE MADS 



PERCENTAQB Or 
OEHMINATION 



Sample I 



11 


Silo 


Distilled water 





10 


Check 


Distilled water 


25 


5 


Silo 


Modified Cohn's solution 





5 


Check 


Modified Cohn's solution 


90 


6 


Silo 


Tap water 





5 


Check 


Tap water 


12.5 



Sample II 



42 


Silo 


Modified Cohn's solution 





14 


Check 


Modified Cohn's solution 


90 to 100 


10 


Silo 


Distilled water 





8 


Check 


Distilled water 


5 to 15 


5 


Silo 


Tap water 





5 


Check 


Tap water 


15 



Samples III and IV 



18 


Silo 


Modified Cohn's solution 







Check 


Modified Cohn's solution 


95 to 100 


10 


Silo 


Sterilized distilled water 





5 


Check ' 


Sterilized distilled water 


75 to 95 


7 


Silo 


Tap water 





3 


. Check 


Tap water 


50 to 75 



Sample V 



50 
16 



Silo 
Check 



Modified Cohn's solution 
Modified Cohn's solution 



0* 
75 to 95 



• One spore germinated. 



300 Phytopatholoot IVol. 7 

Sample V. This sample was collected and buried in a silo about 12 
feet from the top and 2 feet in from the side on October 4,1915. It was 
recovered March 16, 1916, thawed out in the laboratory and germination 
tests were made immediately. The results of the germination tests are 
summarized in table 1. 

The table shows that with but one exception the smut spores did not 
germinate after having been in the site. Samples I and II were both 
tested at the time they were collected, when 68 per cent and 28 per cent, 
respectively, germinated in water. The single spore whidi germinated 
shows a spore may occasionally retain its viability after ha\ing been in 
silage. 

The death of the spores may be attributed to a number of possible 
causes — (1) unfavorable temperatures, (2) gases produced during the 
changes in the silo, (3) the acids and other chemical substances produce<l 
by fennentation, (4) pressure. The effect of each of these factoni except 
the last was tried. 

The effect of iemiyerature. The exact changes which accompany the 
fonnatioii of silage from green com arc but imperfectly known. Esten 
and MjL»<on (5), however, have shown that silage fennents best l)etwp«en 
75°F. and 80°?., and that the temperature never rises alx>ve 86®F. in 
profMTly prtjpanxl silage, except in the topmost layers where destructive 
fennentation occurs. Noidig (8) n*|K)rts a nuiximum temperature of 91'F. 
Such toiniKTatures are not in thi»nist»lves sufficient to kill com smut spores, 
since Stt»wart (1>) foiuid that a teinp(»rature of 52*'(\, for fifteen minutes 
was n(*cessar>' to kill tho siK)rt\s when immonHHl in water. He also found 
that expo.Hure to dr>' hoat In't w(»i»n lOo.SX'. an<l 1()G°(\, for fifteen minut4«« 
kille<l th<5 spores. 

In a few tests ina<l(* by the writer some spon* withstood a dry heat of 
103 (\ for fiv(» niinut(*s, hut tus a rule a temiwratuns of lOO^'C. for five 
niinutcs is .Kuflici<*nt to <U^troy the gcnninating powers of the sfxires. 

Fn't^zing tcnijM'nitun's do not w<*in to injure the s|M>rps as they Hur\'ive 
our .sovurest wintrrs. Si>on*s, ston^l in a sImhI when* they were nien*Iy 
shclttToii from t^now and rain but were exposeti to all the rigors of wint4T. 
girnniiiatrd wrll in >pring. S|H)res that were frozen for short periotLn i»f 
tinif and tlicii lasted for germination ap|)eanHl to have l)een Ktimulat4*d 
by \\\v viM. Thr fxtremcs in t(Mn|)eratun^ which the spores cncount4»r 
in tlir >iln, thrn:fnn% can have no intiuenr^' on their vitality. 

Th» tjhtt nj tjnsrs. Littfc IS known of the gases produced in silage 
formaiinii altlmuKh it i> not pmbablo that they would take an active part 
in tli<* ilr.otnK'tinii of the >mut >|)ort*.*<. ('arlM»n dioxide is probably pn>- 
<lii<'«-ii ill ^n*:iif>t ({uaiiiit y a.-* a re>ult of the fermentative action. A single 
exiM-nm«'iit ux'^ made to <iet<*rmiiu! the eiTi*i>ts of the gas on tlie sponrs*. 
I)r\' ^|M>res wen* pla('«'d in a bottlu and carlnm dioxide was passed in. The 



1917] PiEBfEisEL: Pabasitism of Ustilaqo Zrs 301 

spores were thus exposed to the gas for ten days, when germination tests 
were made. The spores were not only imharmed but germinated much 
more quickly than those of the same lot which were used as checks. At 
the end of two days no difference was apparent in the germination of the 
two lots of spores. 

The effects of acids. It seems probable that the loss of viability of spores 
may be due to the chemical substances produced in silage. Considerable 
quantities of acids are produced rapidly , the maximum amount of each 
usually being produced within two weeks after the silo is filled. The total 
acidity of silage, according to Esten and Mason (5), is about 1.0 per cent 
to 1.5 per cent, the principal acids in order of their importance being lactiCi 
acetic and propionic. In experiments to ascertain the effect of certain 
of these acids on the germination of smut spores it was found that a con- 
centration of 1 per cent of either acetic or lactic acids or a combination 
of the two was sufficient to inhibit smut spore germination. However, 
spores germinated in a diluted sample of normal silage juice. 

The above results are significant in that they indicate to some extent 
what happens to the spores in the silo. The optimum for the germination 
of spores is reached at some point in the rise of temperature which accom- 
panies the formation of sUage. The germination of the spores is, however, 
inhibited by the presence of the acids. Acetic acid penetrates rapidly 
and kills plant tissues. Hence, it is not unlikely that the spores, which 
are exposed to its action for a long time, are killed by it. 

Seasonal factors. Fresh spores were collected from time to time and 
observations made on their germination. The first tests were made in 
the summer of 1913 and fresh spores germinated very readily in water at 
room temperatiu^. The tests made in the smnmer of 1914 were more 
complete, begmning with the very first smut spores produced in the field. 
The first germination test of fresh smut spores was made Jime 24, the 
last test on October 10. Fifteen distinct tests were made, the results 
showing conclusively that fresh spores germinate readily in water. In 
fact, fresh spores germinated much better than did spores from the same 
lot kept imtil winter. The average percentage of germination for the 
entire series was 42.8, the percentages in different hanging drops varying 
from to 85, a result often obtained when water is used as the medium 
for germination. This shows that spore germination in water is some- 
what capricious, thus probably explaining the conflicting r^ults obtained 
by various investigators. The germination in sugar solutions and liquid 
nutrient media, especially modified Cohn's solution is more uniform, 100 
per cent of the spores almost always germinating. No difference could 
be foimd in the germination in sterilized distilled water, distilled water, 
tap water or rain water. Incubating the cells at 24^C. to 38"C. did not 
seem to influence the rate or amount of germination of the smut spores. 



302 Phytopathology [Vou 7 

Vitality of sparidia 

Methods. In the studies of sporidia, pure cultures of the smut were 
used throughout. Spores were sown in poured plates of beenn'ort nfcmr. 
In about two days the .spores germinated and the position of the colonies 
was niarke<l. At the end of four or five days when the colonies were 
about the size of a pinhead, they were transferred to beerwort agar slanU. 
A nunil)er of other nutrient media were also tried, \iz.: carrot agar, 
nitn)gen free agar, beef agar, oat agar and a synthetic agar. Of these, 
beerwort agar was foimd to l>o the Ix^, although a good growth was also 
obtaino<l on carrot agar. 

Cultural characters and morphology. When the colonies first appear 
th(»y are round, raistMj, convex, opaque, slightly shiny to dull, light ctvam 
in color. -\s the colonies grow older, the e<lge Injcomes somewhat IoIknI 
and irregular, and the surface l)ecomes convoluUnl, ridge<l, or sharply 
papillaU*. TIm* color (i«^p(»ns with age, lKH*oming light lavender in uU\ 
cultures. The consi.st<»ncy is first soft and n)py, then Ixvomes mucibigin- 
ous or rublxTv; or. when k<»pt inoi.Kt, but\ToiLs. 

TIh» colonics consist of sjKiritiia whi<'h are abjointed fnim the si<les and 
(K*casionally from the end of the promyc<»liuin. These s|>oridia are of 
the same iiatun^ iis those produ(*cd l)eneath the surface in liquid nie<tia. 
The sporidia pro<iu<*cMl in the air from a liquid culturo are small, sharply 
fusoid and fairly thick wuIUmI. Th<\v are pnnluced in long cliains. Thosie 
produceii within the li(iiiid or on solid nutrient mo<lia are larger tlian the 
air cronidia, not as thick walU^l luid aro somewhat roumled at the endf. 
They are pluin|KT, <*ontaiii mon' oil globuk*s and are not priNluceil in 
such long cliains. The walls an^ a[>pan'ntly somewhat nmcilaginoua. 
In continuous cultiux) the s|K>ridia pnKiuce hmg gorm-tubcs, the emb of 
which an^ dens4»ly i>rotophismic and which, therefore, can become nvttng 
si'gnicnts |H)ssessing all the pn)|K'rties of sporidia. The gemi-tulNy Imv 
come much cntangl(*d and give the cultun^ its rublM*r>' consistency, wink* 
the disintegration of the empty portions of the hyphae give it its muci- 
laginous chara(*ter. \ smear from such a culturo dries almost instantly 
and b<*<>onu^ brittle. While s|>oridia pro<luccil in culture may not In* 
exju'tly like thos4* pnMiu(*ed in nature, still they must Iw ver>' similar to 
thos4* which we iniiigine an* phnIucihI in such great abundance in manure. 

Thrrmal rtlatitmfi. A cf)mi)lete understanding of the tliemial relatione 
of com sinut >|M»ridi:i would not only \n* of value in throwing additional 
light upon the phenomena (»f inf(*<'tion, but it would also show more clearly 
the nptitiiiun conditions for the profmgation of the fungus. An attt^mpt 
wa-* thenfon* in.ide to as<*ert.ain the minimum, maximum and optimum 
t4-niiMr:itun*>. Both tlried and actively vegt;t4iting s|)oridia were tested. 

At tem|N*ratun*s nmging from 2i) C (o 2rr(\ the aniall sporidia bud 



1917] 



Piemeisel: Parasitism of Ustilago Z^jr 



303 



profusely in' nutrient solutions. As the temperature is increased to above 
26®C. the sporidia show a greater tendency to produce long, slender germ- 
tubes. At 35°C. growth is somewhat inhibited and the cells begin to 
show an increase in the number of vacuoles. Increasing vacuolation 
continues with a rise in temperature to 40°C. where growth practically 
ceases, while at 46*^0. the cells are no longer alive. 

Attempts to determine the lowest temperature which the sporidia in 
liquids or on solid nutrient media can endure gave negative results be- 
cause they withstood the severest cold of the winter (about — 28®C.). 
Alternate freezing and thawing, however, kills moist sporidia. Desic- 
cated sporidia, on the other hand, were not only able to withstand severe 
freezing but in some cases were not severely injured by alternate freezing 
and thawing. 

When exposed to alternate freezing and thawing, however, there seems 
to be some injury, as no subsequent growth occurred in two out of three 
tests. Smears direct from pure cultures were not killed by drying for 
one day at 21°C. or for fourteen days at a temperature of from 7® to 9°C. 

TABLE 2 

The effect of .temperature on desiccated sporidia of Ustilago Zece, AU sporidia 

dried at tl^'C. 



TBBT 

Km- 

BBB 


KUM- 

BBBOF 
TBIALB 


NUBf- 
BBBOF 

DATB 
DBIBD 


TBMPBBATUBX TO 
WHICH BXPOSED 


TIMB 
BXP08BD 


MEDITJM FOB OEBMXMATION 


BULTB* 


1 


1 


1 


-IC^C. to -7** 


14 days 


Sterilized distilled water 


+ 


2 


1 


5 


43** 


15 min. 


Sterilized distilled water 


+ 


. 3 


1 


6 


Alternate freez- 
ing and thaw- 


31 days 


2 per cent sugar solution 


^— 


4 


1 


7 


ing 
-2*»C. to 3** 


12hr8. 


Sterilized distilled water 


+ 


5 


1 


12 


45'* 


15 min. 


Sterilized distilled water 


+ 


6 


1 


16 


28.6^0. to 3r 


24hr8. 


Sterilized distilled water 


+ 


7 


2 


16 


-7 


12hrs. 


Sterilized distilled water 


+ 


8 


1 


18 


54^C. to 55^ 


15 min. 


Sterilized distilled water 


— 


9 


1 


19 


40^C. to 50« 


16 hrs. 


Sterilized distilled water 


^ 


10 


1 


20 


-5^C. to r al- 
ternate freez- 
ing and thaw- 


12 da3rs 


Sterilized distilled water 


+ 


11 


1 


20 


ing 
-5C^. to 1* al- 
ternate freez- 
ing and thaw- 


12da3rs 


Sterilized distilled water 


— 


12 


1 


20 


ing 
28. 5*^0. toSr 


24 hrs. 


Sterilized distilled water 


- 



• No growth — ; grew weakly ^ ; grew -f. 



304 



Phttopatholoot 



[Vol. 7 



But Bporidia dried six days and then exposed to alternate freering and 
thawing for thirty-one days were killed. 

Sporidial ameara direct on glaas ooverndipe from the pure culture were 
unaffected by drying for sixteen days at 21"^. and then at 28 JS"" to Sl'X:. 
for one day. Sporidia first placed in water, then dried for twenty dajrs, 
also withstood the same temperature. Sporidia in smean were not killed 
by exposure to frotn 40^ to 50^C. for sixteen hours, after drsring for nine^ 
teen days, but appeared to be killed at 54^ to 55^^ for fifteen minutes, 

TABLE I 
The effect of denceatxon on the tntality of eporidia of Uetilago Zem. AU te*U for ger» 

mination made al il*C. 



• 

a 


i 






1 


p 


2 


MKTBOD or FBBrAKATlOir 


KUMBBa or DATS DBIBD 


MBDtm vmM9 worn , f 


I' 






I 


i 


1 


Grown in cells in HtO 


3 


Sterilised distilled 1 






2 days. Slip dried 




water 


2 


3 


Spores germinating in 
H,0 in cell. Slip 
dried 


3 


Sterilised distilled ^ 
water 


3 


5 


In 11,0 in cells. Slip 


1 


Sterilised distilled ! + 






dried 




water 




4 


1 


Smears made on slips 


12 


2 per cent sugar tolu* 
tion 


+ 


4 


1 


Smears made on slips 


50 


Modified Cohn's so- ^ 
lution 1 


4 


1 


Smears made on slips 


G at 21*C. 31 at al- 
ternate f reeling 
and thawing 


2 per cent sugar so- - — 
lution 

i 


5 


1 


In watvr on slips 


12 


2 per cent sugar so- -r 
lution 


5 


2 


In water on slips 


48 


Modified Cohn*8 so- - 
lution 


5 


I 


In water on slips 


20 at 21 T. 

24 hrs. at 2H 5*-3rC. 


Sterilised distilled 1 * 
water 


() 


1 


»Snenrs on slips 


•* 


2 per cent sugar so* + 
lution 


A 


1 


SiiirnrH <in slips 


iA 


Modified Cohn's so- -^^ 
lution 


1 


1 


Siiifiirs on slipH 


1 ir, lit 2r(\ 


Sterilised distilled -^^ 




1 


'2\ hrs. at 2S 5* 31*(\ 


water j 


' , 1 


1 

Siiictrs (»n Hlipf« 


' 1 liny lit 2l*('. 


Sterilised distilled ^ 






11 diiys at 15»-2()t:. 


water j 


s :» 


In W!it4'r on nlipn 


124 


Mo<iifird CofiD's so- ' - 










lution \ 



ilmiiicH vrry :tl>iin(iant grrniination; + abundant; ^ sparse: — no gsniii< 



nation. 



1917] 



Piemeisel: Parasitism of Ustilago Zea 



305 



TABLE 4 



Viability of sporidia of Ustilago ZecB when smeared on a cover slip and desiccated 
in light and darkness. All germination tests made in sterilized distilled water at 
a temperature of Hl^C, 



» 
NVMBKB or TRIAlJB 


• 

• CONDinOK XTNDSB 
WHICH DBISD 


DATS DRTSD 


BBtnXAS 


2 


Tiight 


1 


+ 


2 


Dark 


1 


+ 




light 


u 


+ 




Dark 


IJ 


+ 




Light 


6 


+ 




Dark 


6 


+ 




light 


8 


+ 




Dark 


8 


+ 




light 


11 


+ 




Dark 


86 


+ 




Light 


87 


+ 




Dark 


149 


+ 



after drying for eighteen days. The thermal death point of dried sporidia 
is, therefore, probably about 54® or 55°C. 

Moisture relaiions. In most cases the sporidia were taken directly 
from the pure cultures on beerwort agar and smeared on sterilized cover- 
slips. The sUps were then placed in steriUzed petri dishes and were 
allowed to dry at room temperature for various lengths of time. In 
other cases a water suspension was first made of the sporidia and drops of 
this were then transferred to the slips and allowed to dry as above. When 
the germination test was made a drop of the desired medium was added 
and the slips were then moimted on Ward or Van Tieghem cells. 

From the results shown in tables 3 and 4 it is apparent that sporidia 
can withstand long periods of drying without serious injury. Sporidia 
when taken directly from pure cultures withstood drying for 149 days at 
room temperatiu^. Not all of these sporidia, however, remained viable. 
Sporidia first placed in water and then dried seemed to be less resistant to 
desiccation. Sporidia thus treated grew after drying for twenty days, 
but not when dried for forty-eight days. The latter result may be some- 
what misleading as the number of sporidia in a water drop is much smaller 
than the number in a smear from pure culture. 

There was no noticeable difference between sporidial smears dried in the 
dark and in the light. Light, therefore, ib probably not very injurious to 
sporidia. 

The above results are not in accord with those of Brefeld (3) who found 
that sporidia were killed when dried five weeks. Nor are they in accord 
with the statements of Arthur and Stuart (1) who characterize the sporidia 



306 Phytopathology [Vol. 7 

88 ''short lived" and further add, "These are borne through the air m*hich 
must be rather moist or the aporidia will be killed by drying/' 

Chemical reUUions. Sporidia were placed in various solutions of arettc 
and lactic acid, in com silage juice, and in a mixture of various acids in 
such proportion as to approximate the composition of silage juice. If com 
smut spores germinate when placed in a silo, it was thought that by mean^ 
of tests with various acids commonly produced in silage the fate of the 
sporidia might be determined. The sporidia in each case were obtained 
directly from pure cultures on beerwort agar and were transferred to the 
solution from which hanging drops were then made. 

Sporidia apparently c^n grow in 1 per cent acetic or lactic acid solutions 
or in a mixture of the two. In the lactic acid the sporidia tend to pri>- 
duce a greater numl>er of gcrm-tulxw which probably indicates that the 
medium is slightly unfavonible for gn»i'th. The sporidia also grow mrll 
in expn*sKO(l silage juice. It seems probable, therefore, that if spore?! do 
gonninate in the silo, the sporidia may continue to live in the silo for some 
time. \Vhothc»r long oxposiutj to the action of the acids would ln» detri- 
mental or not was not detenninoil. 

A more concentrated mixture of acids such as was u.^e<l in the silaite 
acid U^t proYtnl to l>e deleterioiw to the growth of the sporidia. The 
sporidia appeariMl starve<l and l)ecame greatly vacuolate^!, a comlition 
which probably pnMMHJes their death. The results here obtaineii are 
not in a<'cor<l with those obtained when silage juices itholf m'as usetl, 
possibly owing to the lack of sugars or other nutrients in the silage acid 
mixtun). The efTect of the traces of but>Tic ami propionic acids alone 
upon the .sporidia hjus not yet Ikh^u determined. 

SUMMARY 

1. Th<» inf<*ctinn of com by ('stilago Zecr (Beckm.) Unger is purely 
IcM'al; no cvidontM; of sv.^teinic info<*tion was obtained. 

2. Whrn very young plants Ikn'oiuo inftK^twl they are often killed. 

'^. Injury to x\\i* host plant. clos4» planting, ver>' early or ver>' late 
planting, and gn»wtli on rich soil ixxv con<iucive to heavy smut attacks. 

•I. ViKonnisly gn)wing plants, Uitwwn two and three feet high, ar^* 
moM .»<n.MTptil)U' tc» .smut attack. 

/). TImj >j>nn'> of !'. Znr can <*au.si» infe<*tion either when young or ohi. 
SiH»n*.s ^t-nniiKitf' readily a.s simhi :ls matun^ and n*tain their viability fur 
!*cvrr;il y«':ir>: infiMiion wa.s o)»taincd by inoculating com plants with 
sjHin"* fivf v<*;ir> old. 

«i. riif rorn->!nur fuiigiL> d<M»s not los4' its vinilcncv quickly mhen 
grown Oh aii.iticial ni(»li:i. 

7. Thi' .'-pon*'* of r. Znr. alnntst without exception, lost their viabiUty 
after having In^i-n kopt in a silo f<ir a few weeks. 



1917] Piemeisel: Parasitism of Ustilago Ziue 307 

8. The factors causing spores to lose their viability in the silo have 
not been determined definitely; it seems probable that the silage acids, 
especially acetic, may be the destructive agents. 

9. Sporidia were kept in pure culture continuously for three and a half 
years, at the end of which they remained viable. Inoculation experiments 
with the same material gave inconclusive results. 

10. Sporidia were desiccated for about five months without seriously 
impairing their vitality. 

11. Freezing injures sporidia but little; alternate freezing and thawing, 
however, is injurious to moist sporidia, less so to desiccated sporidia. 

12. The optimum temperature for the budding of sporidia is between 
20° and 26°C., the maximum at about 40°C. and the thermal death point 
near 46°C. 

13. Sporidia can germinate and bud in silage juice, but are injured in a 
solution containing acids in the proportionate concentration in which 
they occur in silage. 

14. The ability of sporidia, as well as spores, to withstand unfavorable 
conditions is very significant in explaining some of the facts in the parasit- 
ism of U. Zece, 

Agricultural Experiment Station 
University of Minnesota 

literature cited 

(1) Arthur, J. C. and Stuart, Wm. Corn smut. Ind. Agr. Exp. Sta. Kept. 

12: 84-135. 1900. 

(2) Brefeld, Oscar. Hotanische Untersuchungen tiber Hefenpilze. Die Brand- 

pilze I, Heft. 6: 67-75. 1883. 

(3) Brefeld, Oscar. Untersuchungen aus dem Gesammtgebietc der Mykologie. 

Die Brandpilze II. Heft XI: 52-92. 1895. 

(4) Clinton, G. P. Smut of Indian corn and teosinte. Illinois Agr. Exp. Sta. 

Bui. 57. 1900. 

(5) EsTEN, W. M. AND Mason, Christie, J. Silage fermentation. Conn. (Storrs) 

Agr. Exp. Sta. Bui. 70. 1912. 

(6) Hitchcock, A. S. and Norton, J. B. S. Corn smut. Kans. Agr. Exp. Sta. Bui. 

62. 189G. 

(7) KtjHN, J. Uebcr die Entwickelungsformen des Getreidebrandes und die Art 

des Eindringens der Keimfaden in die Nahrpflanze. Bot. Zeit. 32: 121-124. 
1874. 

(8) Neidig, Ray E. Chemical changes during silage germentation. Iowa Agr. 

Exp. Sta. Research Bui. 16. 1914. 

(9) Stewart, F. C. Effects of heat upon the germination of corn and smut. Proc. 

Iowa Acad. Sci. 6: 2: 174-178. 1895. 
(10) Waldheim, Fischer von. Ustilaginea. Jahrb. Wiss. Bot. 7, pt.1-2. 1869. 



SCLEROTIUM BATATICOLA 
The Cause of a Fruit-Rot or Peppers 

William H. Martin 

During the pasKt few years the writer's attention has been called a number 
of times to a rot of ])epper8. Specimens were sent in from various sections 
of New Jersey witli iniiuiries as to the nature of the trouble. Except for 
a drying and shrivelling of the epidermis in the more advanced stages^, there 
was little extenial evidence of the presence of the disease. (>n breaking 
the fruit o|x>n, however, the interior was found to contain numen>u8, 
snudl, l)lack sdcTotia which were also present on the seeil. Isolations 
were made, and in all cases pure cultures of an organism resembling 
Sclerotium Ixitaticola Taub. w:u* securt^I. The marked similaritv of the 
two organisms hsl to exiKTiments to establisli their pathogenicity as m*ell 
as to determine if the>' wen* identical. 

The fungus was isolaltnl by :iseptically breaking the diseasetl fruit; biin 
of tissue were i\un\ pi<*k<»d out with a steriliztnl nee<ile and transfernsl to 
a pounnl plate of nutrii^nt agar. In most cas<»s pure cultures wen* mIk 
taiiied at tlie first planting. Inoculations were nuule as follows: Healthy 
p<*p{MT fruits were inimerscHl for ten minut(*s in a 1 to 1000 s<»lution <if 
mercuric* chl(»rid, w:i>hed in sterilized, distilkni water and place<l in a st<*r- 
ilized moist rhamlKT. .\ttempts to pnxluce the disease by placing bits 
of the rultun* iiiodia together with sderotia <m the unbn>ken surface 
failed. Whitr tufts of mycelium were fornuHi but the fungus Mvmed 
unabh* to |M'nrtrat(* the ei)idermis. However, inoculations on a cut >ur- 
faci- iii:id(* with a fiaiiuMl sralfN^ were uniformly successful. A larg<* num- 
Ut of iikoculatioiiv were nuule in this manner and 100 p(*r cent inftN-tiim 
rr^ultrd. liifrrtioii was rvideiit in fmm four to si»ven days. Tho rpi- 
d«Tini> at thr point of inflection Urame blackemni and the n>t >pn*aii 
throimhoiit the intiTinr. AftiT thr fungus I NH*ame established, its pnign-sv 
wa> rat I If T r:ij>id; in twn \V!t'k> the t»ntire interior of the fruits wen* in- 
vailnl ah<l nunirnniN Mlrn»tia d«'velo|H»4l in the tissue and on tin* m^**!. 
K\rr]»T lot :i M:irkt*ning of tin* I'pidiTmis there wen* no external signs to 
in<li«-:itt' iltf |>ir^iii(-«> of thr di><'a>r. Inoculations wen* also nuuk* <in 
Iniii -nil aTt:ii h««i tn thr pliint and in evrr>* c:iS4» the n*sultii were |Mte^itive. 

.\ • iiip:> ut-rr ni.'nir t<> innnilatr thr roots ant I stems of growing plant>. 
The Mill \\:i> rari'fullv rrni<iv<>tl from around the roots and an incbtion was 



1917] 



Martin: Fruit-Rot op Peppers 



309 



made with a sterilize^ scalpel and sclerotia from young cnlturee were in- 
serted. The soil was then replaced. Roots similarly treated, but not 
inoculated, were used as checks. Stems were likewise inoculated and the 
cut surfaces were wrapped with cotton. On the stems and roots the inocu- 
lations were not as successful as on the fruits. Where infection did occur 
the fimgus was found just beneath the epidermis or in the pith. Death 
of the plant or plant part resulted before the mycelium had advanced far 
from the point of inoculation. 

Reisolations were made from both the fruit and stem and the fimgus 
was again grown in pure culture. Inoculations with these reisolated cul- 
tures were, in every case, successful. 

During the process of the above inoculations, similar inoculations were 
made on peppers with cultures of S. bataticola Taub. isolated from the 
sweet potato. In every instance they were successful. Not only was 
this true but the characteristics and growth of the organism were, in all 
respects, like the pepper Sclerotium. 

In order to more fully prove the identity of these two pathogenes, the 
following comparisons were made: (1) Growth on culture media, (2) cross- 
inoculations on sweet potato and pepper as well as other hosts, (3) develop- 
ment, measurements and the external and internal appearance of scleS^rotia. 

Growth comparisons were made on com meal agar, potato agar, bean 
plugs and nutrient agar. Abimdant growth was made and no differences 
were observed. 

For the cross-inoculations three strains of the organism were used. 
One was isolated from the sweet potato, another, secured from Dr. J. J. 
Taubenhaus, was likewise isolated from the sweet potato. The third was 
isolated from peppers. These cultures may be designated 1, 2, 3, respec- 
tively. The methods employed in the inoculations were the same as have 
been previously described. The following inoculations were made: 

TABLE 1 
ReaiUts of inoculations on varioita hosts with three strains of Sclerotium haiaticola 



HOST 



Sweet potato (Ipomoea batatas) 

Pepper (Capsicum annuum) 

Tomato (Lycopersicum esculentum) 

Cucumber (Cucumis sativus) 

Apple (Pyrus malus) 

Eggplant (Solanum melongena) 

Turnip (Brassica campestris) 

Red beet (Beta vulgaris) 

Parsnip (Pastinaca sativa) 

Carrot (Daucus carota) 



NUMBBB 






INOCULATBD 


NUMBBB or 


PXB CBNT 


WITH BACH 


CHECKS 


INTBCTION 


CULTUBB 






25 


10 


100 


25 


10 


100 


3 


2 


100 


3 


2 


100 


3 


2 


100 


1 


1 


100 


3 


2 


100 


3 


2 





3 


2 





3 


2 






310 Phytopathology (Vol. 7 

In those cases where the inoculations were successful, no differennv in 
gro^^iih of the organism were evident. The time before infection is e\-i- 
dent, varies, however, with different host plants. On pepper, cucuiuImt 
and tomato from four to seven da>'v is required, while on sweet potato, 
apple, turnip and eggplant, from three to seven weeks elapses. 

The development of sclerotia was followed in Van Tieghem cells. Tlie 
method employed wa^ to pour enough of a melt<ed nutrient medium on a 
cover glass to form a thin film. Aft-or this had cooled, it was inoculateil 
and inverted over the glass ring. If care is taken in this procedure no 
contamination results. By this method it is easily poflsible to trace the 
development of a single sclerotium under high magnification of the 
microscope. 

Some cases were not^nl where sclerotia appeared to have developer! from 
a single mycelial strand; in the majority of cases observe*!, however, sev- 
eral or a numlHT of strands were involved. Sclerotial development is 
pre(»ed(Ml by the formation of many s<*pta. Short mycelial tulies are 
formed which ('onniM't the strands. These in turn become ver>* much 
septate, as do the radial hyphae which are forme<l laUT (fig. 1). As tlie 
wlerotiuin enlarges the central cells IxH'ome ccmtorted and fonn a ctMn- 
pact' mass, due p(Thaps to the pn^ssitfe or resistan<*e of the out4*r cells 
(figs. 2, 3, 4). The mature sclerotia are coal-black in color and in nuirt 
cji.**<»s are fnM» fn)m any surface irregularities (fig. 5). No differences wrre 
olx^Tved in the formation or color of s(*lerotia of the different strains. 

In tlM» progress of X\u*si* studies numerous instancies were oIw^tvih! wIhtp 
my<*elial branches united: this took place U'twevn bmnchert of a single 
strand tis well as lM*twcM»n two s<*parate strands (fifp*. G, 7, 8). In stmie few 
ca.*4<»s, this was the first i4ep in sclerotial development, but usually tlie 
mycelium U'comrs M'ptate and irregular. 

Sections of the srlcrotia of the different strains showed them to U^aUke 
with H'gard to tlirir internal struct unr (figs. 9 and 10). In this conntv- 
tioii s4HMis wen* S4H'iione<l to determine if the mycelium pi*iu*trat4\i the 
m^mI inat, liut in nonr of the viim^ exjimine<l was this ol»siTve<i to U» tru«'. 
The apiM'aranre of x-lerotia on the s4»<mI did not ap|)ear to afT«H't germina- 
tion. Ilralthy plants wi»n» grown from disc»;iscHi setnl. Measurement.-* tif 
xUr M-lt-nitia gave nvMihs identical with thos4» of Taubenliaus.' 

Atti'iiipt> to produti* a jHTfecl .»<tage faile<l. In ever>' case, on the ger- 
mination i»f tin* x-lrrotia ih'W sclrrotia wen» formed. 

* J J T:tiiNnh:iUh The Murk rntH iif th«* ffWiH't potato. PbytopAth. S: iy> \%\ 



19171 



Martin: Fbutt-Rot of Psppers 




SCLEROTIAL DeVBLOPUENT 



FiOB. 1, 2, 3, 4 and 5. Stages in Brterotial development. 

Figs. 6, 7 and 8. Anastoroising of hyphae. 

Fig. 9. SectioDS through mature sclerotia. 

Fig. 10. Section of Bclcrotium on epidermis of pepper fruit. 



312 Phytopatholoot [Vol. 7 

conclusions 

The pathogenicity of Sderotium sp. causing a rot of peppers {Capsicum 
annum L.) has been established. 

The following facts warrant the conclusion that the sderotiuni occurring 
on peppers is identical with Sderotium baiaticola Taub. 

a. CroHg-inoculations on sweet potato and pepper as well as other horts 
gave positive results. 

6. With both strains the growth was identical both in culture and on the 
host. 

c. Measurements of the sclerotia are identical. 

d. Sclerotial development, color and structure is the same with liotb 
strains. 

It appcjirs fn)m these studies that the charcoal rot of sweet p«»tat4i«'!* 
(Jinmiaa batata) is common and widely distributed throughout «H'tion«i of 
New Jers<»y, that S. Imtaiicola Taub. can probably |x»rj*L»<t on several nthor 
hosts and that it is the (*ause of a di^e:u<e of minor importance of p<*p|M*i>. 
Laboh.\T()KY ok Plant Patiioi/kjy • 
New Jkicsky AGKurLTiRAL Expeiument Station- 
New PurxswicK, New Jerskv 



A NECTRIA PARASITIC ON NORWAY MAPLE 

Mel. T. Cook 

During the suimner of 1913 the writer's attention was called to an in- 
teresting disease on a group of Noirway maples growing on the private 
grounds of one of the residents of Princeton, N. J. The first symptoms 
of the disease were the wilting of the leaves and dying of branches very 
similar to the well known symptoms of the chestnut bark blight disease, 
caused by Endothia parasitica. In fact, it was the very striking resem- 
blance to the chestnut blight that attracted the attention of the superin- 
tendent of the grounds and led to the writer's being called to make an 
examination. A further examination of the dead branches showed a still 
more marked resemblance to the chestnut bark bUght; the dead branches 
had been completely girdled by a canker which showed a blackening and 
slight sinking of the diseased bark. The older cankers were covered with 
the orange-colored pustules of the Tubercularia stage of a Nectria and 
there was abimdant evidence that this organism was the cause of the 
trouble. 

' The superintendent had been watching the disease for some time and 
had removed many dead branches and cankers. Fresh woimds were very 
quickly attacked by the fungus, which made its first growth in the oozing 
sap, but the careful treatment of these wounds with antiseptics, followed 
by an application of paint, greatly reduced the number of infections. 
The breaking of the small lateral twigs from the trunk and larger branches 
was the most common source of natural infections and most of the cankers 
had started from woimds of this kind. 

An inspection of the trees on the estate and in the immediate vicinity 
showed two others badly affected. These were destroyed, but the clump 
previously referred to was left standing for observation and study. Dur- 
ing the remainder of 1913 the infected parts were removed as soon as de- 
tected and the wounds treated. In the fall of 1913 and the spring of 
1914 heavy appUcations of fertilizers were apphed to all the trees and ob- 
servations continued during the smnmer of 1914. The disease reappeared 
and the fungus was always presentr on the cankers, but was much less 
severe than in 1913. The fimgus was frequently found in the dead bark 
around old wounds, but in many cases did not appear to be parasitic. 
About one-third of the trees in this clump showed the fungus in 1914. 
Another clump of trees on the opposite side of the driveway showed but 



314 Phytopathology (Vol. 7 

vcr>' little of the funf^us. The clump of trees has l)een kept under <»lKM»r- 
vation (hiring 1015 and 1916, and the disease, although present L*« much 
less severe than in 1913. Wounds are frequently infected but the in- 
creased vigor of the trees, and the careful removal of diseased hranche?* 
as soon as detected, has apparently resulted in a great re<iuction (if th«' 
disease. 

Since 1913 the writer has frequently found the fungus on Norway mnpl<^ 
and also on the muUxTry, working saprophj-tically and also appariMitly 
as a weak parasite. 

The idea that Xectria Is parasitic is not new in either Kumpe or America. 
Weluner* reports having found it on the healthy stumi)s of a cut -over thi(*ket 
of tnH»s and shruh.*^, esiKiciiilly on Cnrpinus sp. He also found a I>ipl«Mh:i 
and a TulMTcularia on th<» young twigs of walnut* som«»times associ:it«Hl 
an<l sonu»tinies the Tul>ercularia growing alone. He states that the twig> 
wen^ winter-kill(Mi, and that the fungus gained access to the host thn>ugh 
the dca<l parts from which it worke<l its way into the living tbisues. Tho 
injunnl twigs w(T(» d(»foliat<»d and the tnn* lK)re vcr>' little fniit. 

It was al.*«o reported !)y Hehrcn.s- as attacking Abies iHilsamnt, llie 
terminal buds wcn» fr(^<|uently swollen. This wjis due to thr fomiati<»n 
of a laver of <*ork lH'tw(»en th(» healthv and necnitic tissues. Tlir >\iell- 
ings of the ])r(^vioiis year wen* mo.»<tly dead. Some of the gn^Mi twig> diii 
not develop their l>ii<ls and .•<ome died later. Th<' myct*lium hilN'rnat4*<i 
in the dead wood and |)<Mietrat<'d the living wcmhI the following .*«4*:lm)ii. 

Thr mo>t important .Vmerican rejxirt is "by Polh»ck' who found Xtctna 
CiKcinm (Pers.) Fr. causing cankers on yellow birch. Thes<» cank<T> fre- 
(jucntly ginllc the infected parts. In cas<» <>f inftvUMi twigs hy|M*rtn>phics 
w<'n* frMiueiitly fornuid. Sevctral Am<Tican students have rf*|>ort4Hl >tmi- 
lar observations to the author. 

Atiitn ri/n KVL Kxpkuimknt Station 
Nhw HHrN>wirK. Nkw Jkii.skv 

» Wf-hintr. (' Zuni PrirrfitiMiiniH v<i!i Nrrtriii rinnjilmrinn Fr. Z«*it. Pflniitrnkr. 
4:71 s| 1V»I 

' |i<l»r«'n- J. Kill iH-iiHTki'iiKWiTtrH Vorkniiinicti von "NiTtria ritiiiabannA" 
iiritl till' \•Tl»^l'ltllIlK^•M^lHl• ilif*it'M Pil/c}«. Zt'it. PtlHiizriikr. 6: 1*.K{ \\Ps. Ivj.'i 

■riiliiMk. J. IV A <-:ttiktr (III vi'llow hirrh ami :i NciMriii aumM-inlod with it 
I{«-|)t Mull. Ar.'ui Srifiiif 7: 1*.K).V 



PHYTOPATHOLOGICAL NOTES 

Notes on Razoumofskya campylopoda. Berries of the false mistletoe, 
Razoumofskya campylopoda (Engelm.) Piper, growing on Pinus sabinianaf 
were collected by Dr. E. P. Meinecke in the San Rafael Mountains, Santa 
Barbara County, California (Forest Pathology No. 17026), November 12, 
1914, and sent to the writers. Seeds from these berries were used No- 
vember 19, 1914, for inoculating yoimg pine trees in pots as follows: 
one Pinus hanksiana Lamb., one P. bungeana L., four P. caribaea 
Morelet, four P. contorta Loud., two P. couUeri Lamb., one P. densiflora 
Lieb. & Zucc, two P. halapensis Mill., six P. mayriana Sudw., two P. 
monophylla Torr. & Frem., one P. nigra Arnold, two P. parvifiora Lieb. & 
Zucc, six P. pinaster Ait., one P. pinea L., one P. resinosa Ait., two P. 
rigida Mill., four P. sabiniana Dougl., one P. strobu^ L., and two P. 
virginiana Mill. Two trees of Larix ocddentalis Nutt. and two of Pseu- 
dotsitga taxifolia (Lam.) Britton were also inoculated. The trees used 
were from three to six years old. The seeds, enclosed in pxilp, were placed 
chiefly in the axils of the leaves on the younger portions of the shoots, 
adhering firmly as soon as the, pulp dried. Many germinated, but the 
radicles of only a few succeeded in penetrating the bark of the trees on 
which they were borne. In six months plants became established on the 
following species of trees: one Pinus banksiana, one P. bungeana, one 
P. caribaea, one P. pinea, two P. sabiniana, and two P. virginiana. On 
Pinus bungeana and P. virginiana, dense witches-brooms formed around 
the mistletoe infested region. On the other species spindle-shaped 
swellings without witches-brooms were usually produced at the point of 
attack. All these trees except Pinus sabiniana are new hosts for this 
species of mistletoe in this country. 

All the trees inoculated successfully produced clusters of mistletoe 
plants in 1916, none of which produced mature fruits, apparently owing to 
lack of fertilization. In 1917 mistletoe plants are again developing on all 
trees except those with dense witches-brooms. 

The effect of the mistletoe is to stunt appreciably the growth of all the 
trees inoculated, as compared to other similar trees of the same species 
not inoculated. Only one of the trees successfully inoculated has died 
from this effect after two years' growth, one of Pinus virginiana with a 
witches-broom. In case of trees of the same species inoculated imder 
similar conditions with Peridermium cerebrum Peck, and P. harknessii 



316 Phytopathology (Vol. 7 

Mooro, nearly 50 per cent of the infected tnH»s diinl inside of two yrars, 
indicating that the stem rusts are much more clestructive t4> young pim* 
than the falw* mistletoi»8. 

Th(» mistletoe is a western species which grows \igorousIy on ea»*t«m 
spiK'ies of pines. Since the infect e<l areas on young pines may not !>*• 
conspicinais during the first w^ason's growth and l)ecause of the fact that 
the aerial parts of the mistletm* ])lants are annual, and an; not usually 
observed on donnant trees, insjM»cti(m of nurser>' st^ick is nt)t sufficient to 
insure its freedom fr(»m this harmful parasite. Shipments fn»m the 
Roeky M<»untain and Pacific regions to thos<' farther east should hi* fli-*- 
couraged* as they are likely to carr>' the mistletoe, even though they may 
ap])ear clejin. (hir east<*rn pines are at j)res<*nt fn»e from mistlet<N\i. and 
should remain so. 

(Iko. (i. IlKIMit'CMK AND N. HkX HiXT 

Tht prtufuctinn itf spons by AUiTfiaria Sobini in purr culiurr, Thi?* 
fimgus has Immii the sul»JM*t of s])e<-ial stu<iy l»y thf auth(»r at th«' I'ni- 
versity of Wisc<»nsin during the i)ast three yrars. The seiireity of ••pun* 
pnxhiction in jHin* rultures, which has \HH*n not**^! l»y pn-vitnis work#r«. 
was at th«* nutst't a hindnnu'e to iuo<'ulation experiiiM-nts. TriaN with 
twrnty difTrrt'iit kiii<ls of iiuMlia including some tr>ts <in thi* fffti't nf 
variation «»f :u'i<lity :iud tt'inpfrature wen* iiiadi-, hut thr n*Milt w.i«* 
always tin* samr, frw Np<.n's luing pmduefd. In Ffl»niar>'. llU.'i. ••\- 
pt-rinirnts wt-rr Ingun in whi<"h the moistun* enntmt of thi* mrtlium anil 
th<- huiridity «»f thi' :ur al»«>Vf 1h<- rujture wrre varit-d. Thi** lik«-\%i'^- 
was without ri>ult> rxrrpt whui tin- eulttin* was shrt'ddrd antl thr iii> rt- 
hum srvmly woiunltd. Tinlrr >urh tn*atmi*nt ennrmi»us *i|Minilatioii 
w:i«» alway> mtup d ifig. I. liK A f«'W hjMjrrs wtTi* foriiird whm th»- 
invrt'liiini aloiu- \va> eut. Thr iiio>t sur<'i'ssful lUfthod eonsi>ts in gn»w- 
iiig tJif Alti-rnaria m pttri dish eultun*, on liard ix»tat«» agar, for ti n t«» 
t^\» Ivi I lav-, till II, lir^t, »»hn'dding thi- ag.ar to liits (fig. 1, ^4 » and >tirnne 
ti» -I parati- aii«i i v«nly diMrihutf tin- pitrrs; s<*<'ond. contniHini: f«'r 
t\v«nt\-fnur 1m fnrtv-iiuht honrs tlnnaftrr thi* mojMurr nlation ^. that 
jiarti.il ilr>inu out i< itY«rt«'«i without :dli»wing tht* more exposed -urfai • -* 
Tc Im ( i.rcr i:(*-i(iatt «i and hai»l. 'V\m- lattrr ol»ji-<*t is acrompli*ih(*«l imi-t 
n a«:i!\ l\ r« ri.iviiii: t l:i lid and i \|M'-iiii; thi- di<h t4» sunlight in a >tinliz« d 
riji !-• < 1. .1/1.1 r I'T 1h]1 i:ir. It » vapi»rati«»n i- to«i rapiil. on-a'^ioiud :it<- 
II i/mi: ui»!: -ttiili/ii! \\:ttir i- n« ci «»-ary. Spon-s W(*re «il'taintil \*y thi* 
J- • t : I d III t.»:tl iliiikii' -- in »!n iriiul'atur at *J»i ( '. hut tIomt att«iitii*n 
\\ : r« 'iijii' ■!. 

*'*.-!?:• . uT jii.l t \]i' -I •! -nrf:ii t - ni thi :iuar thi ndivrlop- fn»m th« "-id 
ri.'''!iir' t ii'U\..ik « t" rl..-i|v -t ptati-. t l-.iik-wallrd hyphar. from whii'h 



1917] Phytopatholoqical Notes 319 

Phytaphthora infestans, causing damping-off of tomatoes. Phytophthora 
infestans has been recorded as occurring on tomatoes by both American 
and European pathologists. So far as literature on the subject is avail- 
able to the writer, no one appears to have noted this organism as causing 
damping-off of yoxmg tomato plants. The following brief accoimt of a 
severe outbreak of damping-off of tomatoes caused by Phytophthora 
infestans may be of interest therefore to pathologists. 

In June, 1916, a number of young diseased tomato plants were received 
by the Ontario Agricultural College from J. W. Noble, Essex, Ontario. 
In the letter accompanying the plants Mr. Noble stated that thousands 
of late tomato plants in that district had been destroyed. The affected 
plants were first observed shortly after the tomatoes were set in the field. 

A glance at the plants revealed brown lesions and constrictions on the 
stems near the surface of the groxmd. Many of the plants showing these 
symptoms had fallen over, due to the collapse of the stems at this point. 
On examining the stems with a hand lens a white fimgous growth was 
clearly seen on the lesions. This when examined \mder the microscope 
proved to be the conidiophores and conidia of Phytophthora infestans 
(Mont.) deBary. After this all the plants were examined very carefully, 
and on some of them the same fimgus was found, apparently causing a 
blighting of the leaves; but the chief damage done jbo all of them was by 
the destruction of the stem near the surface of the ground. The falling 
over of the plants by hundreds in the field was what first brought the 
disease to the attention of the growers. 

Some idea of the severity of this outbreak of damping-off of tomato 
plants may be had by considering the fact that out of 288,175 tomato 
plants supplied by the Heinz Pickle Company, Leamington, Ontario , 
to Pelee Island growers, only 45,000 reached maturity. At least 50 per 
cent of the plants that did not survive succumbed to damping-off due to 
Phytophthora infestans. 

It is interesting to note that weather conditions during June were 
exceptionaUy favorable to the spread and development of Phytophthora 
infestans, the rainfall being much above the average for June, and the 
temperature relatively low. 

J. E. HowiTT 

State and National quarantines against the white pine blister rust. The 
following table shows the State and National quarantine action taken to 
date against the white pine blister rust. The action is so varied in char- 
acter that it seems necessary to present it in this form. Similar action 
is under consideration in a number of other states. 



320 



Ph ytopatholoo y 



(Vol. 7 







arses. 






UTAT* 


WaiTB riMBS 


OSOMrLAS- 
lA 


DATS 


QCASAMTIXBD ABBA 


CJanadfi 


All 


None 


November 14, 


All foreign countries 


^^^^••••M^4M ••••■•••• 






1914 


United States.. 


P. strohus, 


None 


September 16, 


Great Britain. France, 




monti- 




1912 


Helipum. Holland. 




cola, 






Denmark, Norway. 




laml>er- 






Sweden. Kuasia. i^wrr* 




tiana, 






many, Austria, Italy. 




cembra 






Switserland 




All 


None 


May 21. 1913 


Kurope and Asia 




All 


All 


March 10, 1916 


Canada and Newfound- 
land 




All 


All 


June 1. 1917 


All points east of. and 
including the states of 
Minnesota. Iowa. 
Missouri. Arkansas. 
I^uisiana 




AH 


U. ni- 
fcruni 


June 1, 1917 


States of New Kngland 
and New York 




None 


All 


Juno 1. 1917 


Kurope and Asia 


(California 


All 


All 


February, 1917 


F^ist of Mississippi Ki%'er 


Delawan* 


All 


All 


March 2. 1917 


All |K)ints outside state 


Idaho 


AIL 


All 


March 1, 1916 


New IIam|Nihire, Ver- 
mont, Massachusetts, 


• 








Connecticut, New 
York. Pennsylvania 


Indiana 


All 


All 


March 13. 1917 


All |M>ints outside state 


KanHaa 


All 


All 


March 10. 1917 


All |Miints outside state 


MaMuichuBctta . 


All 


None 


June 1. 1912 


Kun)|ie 


MicluKAn 


All 


All 


March 19. 1917 


All |M>ints outside state 


Minnesota 


All 


None 


Apnl 30, 1917 


Maine. New Hampshire. 
Vermont. Maasarhu- 
si*tts. RhrMie Island. 
Cofinertimt. Nrw 
N ork. N«'W JvTm \ . 

Pennsylvania, uhi<i. 
Wisconsin 


Montana 


All 


All 


July 17, 1916 


New llampshirr. Vrr- 
mont. Massachusetts. 
(Connecticut, New 
York. Pennsylvania 


Nrvftd.n 


All pines 

1 

1 


All 

1 


March 10, 1917 


Fast of Mississippi 
Kiver and Minnesota: 
all foreign countries 


Nr*» Jrrwy 


All 

1 

1 


1 NolM' 


April 16. 1917 


Maine. New llamfishire. 
Vermont. Massachu- 
setts, Rhode Island. 
Connect tcut. IVnnsyl- 
vania. New York. 
Minnesota. Wisconiun 



1917] 



Phytopathological Notes 



321 



BTATB 



New York. 



Ohio. 



WHITE PINES 



All 



RIBE8, 

OROSSniiAR- 

lA 



None 



DATE 



March 24, 1917 



Oregon. 



Pennsylvania. . . 
South Dakota^... 
West Virginia... 
Wisconsin...' 



P. strobus, 


None 


monti- 




cola,lam- 




bertiana, 




cembra, 




excelsa, 




flexilis 




All 


All 


All 


None 


All 


All 


All 


All 


P. strobus, 


None 


monti- 




cola, 1am- 




bertiana, 




cembra. 




excelsa 





February 21, 1917 



QUARANTINED AREA 



July 24, 1916 



March 12, 1917 
April 3, 1917 
April 18, 1917 
June 1, 1916 



Ohio, Indiana, Min- 
nesota, Wisconsin, 
Maine, New Hamp- 
shire, Vermont, Mas- 
sachusetts, Rhode Is- 
land, Connecticut, 
Pennsylvania, Illi- 
nois, New Jersey 

All points outside state 



East of Mississippi 
River; all foreign 
countries 
All points outside state 
All points outside state 
All points outside state 
All points outside state 



Perley Spaulding and Roy G. Pierce 

Personals, Arthur S. Rhodes, assistant in forest botany at the New 
York State College of Forestry, Syracuse, New York, has been appointed 
assistant in the Office of Forest Pathology, Bureau of Plant Industry. 

Miss Ruby J. Tiller, scientific assistant in the Office of Forest Pathology, 
Bureau of Plant Industry, has resigned her position to become the wife 
of Prof. S. F. Acree of the University of Wisconsin. 

Prof. L. H. Pennington of the New York State College of Forestry, 
Syracuse, New York, has accepted a temporary position as expert with the 
Office of Forest Pathology, Bureau of Plant Industry. Doctor Penning- 
ton will have charge of the season's work on white pine blister rust eradi- 
cation in the state of Michigan. 

Mr. G. H. Godfrey, of Iowa State College, was appointed scientific 
assistant in Cotton, Truck and Forage Crop Disease Investigations, 
Bureau of Plant Industry, effective June 8. Mr. Godfrey was formerly 
scientific assistant in Cereal Disease Investigations, but during the past 
year was granted leave of absence to engage in post-graduate study. 



LITERATURE ON PLANT DISEASES 

Compiled bt Eunice R. Oberlt, Librarian, Bureau or Pu^nt Induhtrt. akd 

Florence P. Smith, Absihtant 

April to May, 1917 

American Phytoptthological Society. Report of the eighth annual meeting. Phyto- 

patholojo' 7: 14,>-149. Ap. 1917. 
Pacific Division. Report of meeting .... Phytopathology 7: l.SO- 

151. Ap. 1917. 
Held at UnivcrHity of California. Rerkelcy, D. 2K and 29. 19!r>. 
Anderson, Jacob Peter. Plant diiieases. Alnnka .\gr. Kxpt. Sta. Rpt. 191i: .19 41 

1910. 
Ashby, S. F. Report on l<*af R|>ot8 of okra and tomato. Jour. Jamaica .\gr Soc. 

21: 13. Ja. 1917. 
(Vrrospora on okra; Cladonporium fulrum (m tomato. 
Australia. Minister of Lands. I)i8ea«efi in plane trees. .Aust. Internat. NurM-rv- 

munl6. no. 2: 15. F. 1917. 

Ur|M)rt of c'onferenrr relative to arrioufi fungoid diiieaee. which has recently 

Imth attacking plane tn*cH. 
Avema Sacca, Rosarto. MolcHtiiis cryptogamiriifl do caf6eiro. IM. Agr. i.Sln 

Piiulo): 17: S7S 922. ilhw. N. 1910. 
MoIcHti:!.** (Typtoganiirafl da canna do aMUcar. R<>1. Agr. (Siko Paulo) 17: 

IW-lKiS. illiw. I). 1910. 
Bancroft, C. Keith. Tht* Iraf ditvenfip of ruhlMT. CNinditionn in Surinam. Jour. 

]\i\. Agr. Hrit. (luiana 10: 93 1(». Ja. 1917. 
Beattle, Rollo Kent. TUv intriMlurtion of fon*ign plant diM*a»eii. (.\lwtrairt 

Sriinn- n. H. 46: 139. .My. 1. 1917. 
Bethel, Ellsworth. Pun-inia Hultnitrnn and ittt iu>fial hunts. I'hytopatholog> 7: 

H2 'M. Ap. 1917. 
Bols, D^slri. Snnt'>t«' dr |iatltologir v^grtalr. Stance du 2 mars 1917. \U-\- 

Unrt 89: "JIM .Mr. 10. 1917. 
Brown, Harry Bates. I.ifr Iti^tnry and poisonfiUH pro|»orti«*s of (Mavicciw panpali 

Jniir \4!r Ki ..«:irrli 7: 40l t<N>. 2 «« . pi .TJ. N. 27. 1916. 
Brunner, Stephen C. Jd'pnrt uf a irip to Pinar did Rio.| .Xgricultun* jCulia' 1: 

■JJ J**. I 1917. 
Burkholder, Walter H. 'Mh- ]HrfiTt htap* of (ilceoHlNiriuni vi>ni*tiun. Phylopa- 

thnlnirx 7: <» *i|. 3fik[. .\p. 1917 

/*.'»|-.'m»/- ■" f I'/'l \ I 1.1 til II Mp, 

Butler, Edm'ln John. 'Ihi- dir-fiiiiiKitinii i»f p:ir:ii«itir fungi and international Irgis- 
l.»ti..!i Mini Dfpt. Visr. India Hnt. St. 9. no. I, 73 p. F. 1917. 

Chtlds, Leruy. < il>«i-r\ :itifi>.>* <iii tin- r«-l:iti«>n of thr hi'iglit of fruit to apple scab 
iiif>.*ii>ii ()ri-k:<>it Awr. Kxpt St:i Hnl 111:1 17. fig 1917. 
Ki-piirt 4i( thi- lltMMl Kivi-r )ir:iiii-h rxpi-niin lit ittatioh for 1916. 



19171 Literature on Plant Diseases 323 

Cook, Melyille Thurston. Report of the department of plant pathology. New 
Jersey Agr. Expt. Sta. 36th Ann. Rpt. [1914]/16: 365-374. 1916. 
Most common diseases of the year, p. 367-374. 
Darnell-Smith, G. P. ''Brown spot" of Emperor mandarins. Elxperiments in 
its control. Agr. Gas. N. S. Wales 28: 190-196. Mr. 1917. 

The prevention of bunt. Experiments with various fungicides. Agr. 

Gas. N. S. Wales 28: 185-189. Mr. 1917. 
Doidge, Ethel M. A bacterial spot of citrus. Ann. Appl. Biol. 8: 53-81, pi. 3-13. 
Ja. 1917. 
Literature cited, p. 80. 
Bacillus citrimaculans n. sp. 
Elliott, John Asbury. The sweet potato "soil rot'' or "pox/' a slime mold disease. 
Delaware Agr. Expt. Sta. Bui. 114, 25 p., illus., 5 pi. 1916. 
Cystospora batata gen. nov., sp. nov. 
Fawcett, Howard S. A bark disease of avocado trees. Ann. Rpt. California Avo- 
cado Assoc. 1916:152-154. 1917. 
Pythiacystis citrophthora. 
Freiberg, Geoige W. Studies in the mosaic diseases of plants. Ann. Missouri 
Bot. Gard. 4: 175-232, pi. 14-17. Ap. 1917. 
BiWiography, p. 223-225. 
Galloway, Beverly Thomas. Newton B. Pierce. Phytopathology 7: 143-144. Ap. 
1917. 
Died O. 13, 1916 at the age of 60 years. 
Carman, Harrison. A new sweetcorn disease in Kentucky. Kentucky Agr. Expt. 
Sta. Circ. 13, 4 p., illus. 1917? 

Destructive bacterial disease undoubtedly the same as that described in 1897 
by F. C. Stewart. 
Oermano de Souza, Raul. Tylenchus acuto-caudatus nos cafezaes de Indaiatuba. 

Bol. Agr. [Sao Paulo] 17: 873-878, illus. N. 1916. 
Giissow, Hans Theodor. Report of the division of botany. Canada Expt. Farms 
Rpts. [19141/16: 951-965, pi. 63-66. 1916. 

1. Administration of the destructive insect and pestact. 2. Plant pathology. 

Harris, James Arthur. The application of correlation formulae to the problem of 

varietal differences in disease resistance data from the Vermont experiments 

with potatoes. Amer. Nat. 61: 238-244. Ap. 1917. 

Heald, Frederick De Forest. Potato diseases. Washington Agr. Expt. Sta. Pop. 

Bui. 106: 17-94, fig. 1-26. 1917. 
Higgins, Bascombe Britt. Notes on some disease of collards. Georgia Agr. Expt. 
Sta. 29th Ann. Rpt. 1916: 21-17, 5 fig. 1917. 
Black mold, Altemaria hrasstcce; sclerotinose, Sclerotinia libertiana. 
Humphrey, Clarence John. Timber storage conditions in the eastern and southern 
states with reference to decay problems. U. S. Dept. Agr. Bui. 510, 42 p., 41 
fig., 10 pi. 1917. 

Decay in timber is almost exclusively due to the action of fungi, the greater 
part of the destruction being referable to one of the higher groups of these 
organisms, namely, the Hymenomycetes. 
Humphrey, Harry Baker. Puccinia glumarum. Phytopathology 7: 142-143. Ap. 
1917. 
Occurrence in United States. 



324 Phytopathology [Vol. 7 

Jensen, Charles A. CompoHition of citrus leaves at various stagi's of ntfittlioK. 
Jour. Agr. lieseurrh 9: 157-166. My. 7, 1917. 
Litrruture cited, p. 166. 
Jones, Lewis Ralph. Lif(htninK injury to kale. PhytopatholofO' 7: 140- 14 J. 1 fit 

Ap. 1917. 
Kezer, Alvin, and Ssckett, Walter G. B(*ans in Colorado and their difloanon. < *<•!•»- 

nido Agr. fbcpt. Sta. Hul. 226. 31 p.. illuH. 1917. 
Lewis, Arthur Carr, and McLendon, C. A. Cotton variety tests for lN>n-wc«>vtl ami 
wilt ronditionH in ( Georgia. Georgia State B<i. Knt. liul. 46. 36 p.. illiui. Ja. VM7 
Link, George Konrad Karl. PhyHiological ntudy of two strains of Kusariuni in ihnr 
caumil relation to tu)x>r rot and wilt of ]>otato. Nebraska .\gr. Flxpt. Sta. 
liem^arrh Hul. 9, 45 p.. illus. 1916. 
Reprinted from Hot. Oaz. Noted in previous list. 
Lint, H. Clay. Report of potato neah ex|)eriinents. 1915. New JerM*y Agr Mxpt. 

Sta. 36th Ann. Rpt. [1914] 16: 375-3K1. 1916. 
Lipman, Charles B. More "mottle-leaf" discussion. Science n. s. iS: 3l)v:{4ip. 

Mr. 3(). 1017. 
McAlplne, Daniel. Hitter pit. itH cauM* and control; ex|)erinients in pruning, mnnur- 

ing, irrigation, cool ntoring. Fruit World Aust. 18: 92-lHi. illiui. .\p. 1917 
McClintock, James A. Sclerotinia blight, a serioiu* dirM^am* of nnap lN*anji rauM-d 
by Sclerotinia lilM»rtiana Kckl. Virginia Truck Kxpt. Sta. Hul. 2<>: 419 4>. 
iliuH. 1916. 

Sweet-potato dis4'as4'H. Virginia Truck Fjcpt. Sta. Hul. 22: 455 4>«*i. iWnn. 

1917. 
Literature, p. 4S5. 
McCubbin, W. A. Contributions to our knowledge of the white pine blinti-r runt 
rhytop:ithol<igy 7: 95 KM). 1 fig. Ap. 1917. 

Report from the field laboratciry at St. Catharines. (*ana<la Flxpt h.-ftrnui 

RptH. (19141 16: IHWV 9s9. 2 fig., pi. 6()-73. 1916. 
IniiNirtHiit diiM'aM<>Hduring the year 1914. 
Bflalns, E. B. The relation of .xome runtH to the phyMology of their hiMitii .\niff r 
Jour. Iii»t. 4: 17«» 22f). pi. 4 5. Ap. 1917. 
Lite nit lire ritetl. p. 21«V 220. 
— . .. S|N'cieH of Nh'l:ini|tMora occurring uptm Kuphorbia in North .Vnierira. 
Phytop.itliology 7: 101-105. Ap. 1917. 
Literature cited, p. 105. 
.1/. tnntitirnhi II. .H|». 
Matz, J. A RhiKoi tniiia of the fig. I'hytopatliohiKy 7: 110-llH. 3 tig., pi. 2 Ap 
11U7. 

HibliMKraphif*al fontnoteH. 
H. mnrttf^rlrrntm ii. Hp. 

Melnecke, Emil Pepe Michael. H:h>ir problems in foreM pathology. Juur. l-nrrn- 

try 15: Jl.VJ.'l I". 1'.»17. 
Melsnder, Aiel Leonard, and Heald, Frederick De Forest. 11h* control of fr*itt 

lie**!- and dlh«>a.<M-*< \\ :L>*blli|Etiin .\Kr. Kxpt . Sta. l*op. Hul. ItMt. (il p. Y . l*.M** 
1 iiiik'oii** aiHJ Mtlii-r «h-i:ixi- nf tree antl KUiall fruit!*, p. .'MMil. 
Melhus, IrTing E., and Durrell, L. W. The burlN'rry biif<h and black utmi ni^t uf 

-rii ill k'r.iin-. fiiwa \i:r l.xpt Sta. C'irr. .'i.'i. t p . iIIuh. .\p. 1*.»17. 
Murphy, Paul A. Ilic iiii'**.ih lii-ia"!* nf |Hitat«H*f». .Xier. (iai. Canada 4: ^i45 .%!*•. 

jll'j- M\ l'»17 



1917] Literature on Plant Diseases 326 

Nowell, William. The fungi of internal boll disease. West Indian Bui. 16: 152-159, 
illus. 1917. 
References, p. 159. 
Fetch, Thomas. Black rot disease of tea. Trop. Agr. 48: 15G-158, illus. Mr. 
1917. 
Dept. of agriculture, Ceylon — Leaflet no. 2. 
Hypochnus sp. 
Povah, Alfred H. W. A critical study of certain species of Mucor. Bui. Torrey 

Bot. Club 44: 241-259. My. 1917. 
Reddick, Donald. Serious diseases of the season. Proc. West. New York Hort. 
Soc. 62: 59-65. 1917. 

and Toan, Lewis A. Control of leaf -curl disease of peaches. Proc. West. 

New York Hort. Soc. 62: 28-32. 1917. 
Rosenbaum, Joseph. Studies of the genus Phytophthora. Proc. Nat. Acad. Sci. 

8: 159-163. Mr. 1917. 
Salmon, Ernest Stanley. On the resistance to fungicides shown by the hop-mildew 
(Sphserotheca humuli (D. C.) Burr.) in different stages of development. Ann. 
Appl. Biol. 8: 93-96, pi. 15. Ja. 1917. 
Scott, Charles A. A practical method of preventing the damping off of coniferous 

seedlings. Jour. Forestry, 15: 192-196, pi. 1-2. F. 1917. 
Shaw, Jacob Kingsley. The varietal relations of crown gall. Science n. s. 46: 

461-462. My. 11, 1917. 
Sherbakoff, Constantin Demetry. Buckeye rot of tomato fruit. Phytopathology 
7: 119-129, 5 fig. Ap. 1917. 
Phytophthora lerrestria n. sp. 
Shive, John Wesley, and BAartin, William H. The effect of surface films of Bordeaux 
mixture on the foliar transpiring power in tomato plants. Plant World 20: 
76-86, tab. Mr. 1917. 
References in footnotes. 
Smith, Erwin Frink. Chemically induced crowngalls. Proc. Nat. Acad. Sci. 8: 

312-314. Ap. 1917. 
Stevens, Ftank Lincoln. Noteworthy Porto Rican plant diseases. Phytopathology- 

7: 130-134. Ap. 1917. 
Stevens, Neil Everett, and Wilcox, R. B. Rhizopus rot of strawberries in transit. 
U. S. Dept. Agr. Bui. 531, 22 p. 1917. 
Literature cited, p. 21-22. 
Stewart, Fred Carlton. Apple diseases in relation to the apple grading law. Proc. 

West. New York Hort. Soc. 62: 18-22. 1917. 
Stewart, Vem Bonham. Dusting experiments in the nursery for the control of leaf 

diseases. Proc. West. New York Hort. Soc. 62: 40-44. 1917. 
Taboureau, L. Sur le traitement du mildiou. Prog. Agr. et Vit. 67: 255-258. Mr. 

18, 1917. 
Taylor, A. M. Black currant eelworm. Jour. Agr. Sci. 8: 24^-275, illus., pi. 3. 

Mr. 1917. 
Thaxter, Roland. New Laboulbeniales, chiefly diptcrophilous American species. 

Proc. Amer. Acad. Arts and Sci. 62: 647-721. My. 1917. 
Turconl, Bftalusio. Una nuova malattia del cacao (Theobroma cacao L.) Atti R. 
Accad. Lincei Rend. CI. Sci. Fis., Mat. e Nat. ser. V 26, sem. 1 : 75-78. Ja. 1917. 
Physalospora theohrom<B n. sp. 
Stachylidium theohromcB n. sp. 
Helminthosporium theobromae n. sp. 



326 Phytopathology (Vol. 7 

U. S. Department of Agriculture. Federml Horticultural Botrd. Service and rrcii- 
latorv annoiincenicntH. Kcbruarv: 7-14, Mr. 26; March: 1.V35. M%-. 5. r.*17 
Waters, R. DyinR of younK fruit-trees. Sour-nap ami its associated fungi. Jour 

Aur. New Zeal. 14: 190-196. Mr. 1917. 
Weimer, J. L. The orifdn and development of the galls produced by two rr*\%T 
ruRt fungi. Amer. Jour. Rot. 4: 241-251, pi. 12-16. Ap. 1917. 

Gymnosjtorangium juni j)cri-virginiiitnrt O. glohonum on Juniperum nrgtnft'ii 
Weir, James Robert. New hoatH for Rafoumofskya americana and R. Occident :tli» 
abietina. Phytopathology 7: 140. .Ap. 1917. 

and Hubert, Ernest E. Pycnial stagi*s of important forest tree rtui«. 

PhytopathoIog>' 7: Kio i;n). 2 fig. Ap. 1917. 
Bibliographical footnotes. 

Recent cultures of f<ire8t tree rUHts. Phytopathology 7: 106 IW 

Ap. 1917. 
West, F. L., and Edlefsen, N. E. The freezing of fruit buds. Utah .\gr. I-Ixi t. 
Stn. Hul. ir»l. 24 p.. illuH. K. 1917. 
Hil>liography. p. 22-24. 
Wolf, Frederick Adolf, and Cromwell, Richard O. Xylaria rootn>t of apple. Jour. 

Agr. Research 9: 2tH> 276, 3 fig., pi. 3. My. 21. 1917. 
Wormald, H. The relery-rot bacillus. Jour. Agr. Sci. 8: 216 24:>, pi. 1 2 Mr 
1917. 

Bibliography, p. 243 245. 
.\bri<lgiiient of a thesis, Mr. 1916 Univ. I<ond. 
Zeller, Sanford M. Stu<lies in the physiology of the fungi. III. Physical pri»p- 
erties of winmI in relation to decay induced by licniitim sippiaria Fries. .\nn. 
Missouri Bot. (;ard. 4: 93 164. pi. 9-13, 11 charts (partly fold.). Ap. 1917. 
Bibliography, p. 154-155. 
Running title: Durability of yellow pine. 



iPiiYioi'Mii(»LcHiY, for Juiu\ I1M7 '7: \'ut'2'Mi wan iiwued June 2. 1917 , 



PHYTOPATHOLOGY 

VOLUME VII NUMBER 5 

OCTOBER, 1917 

ALTERNARIA ON DATURA AND POTATO 

R. D. Rands 
With Four Figures in the Text 

During the progress of studies on the early blight of potato caused by 
AUernaria solani (E. & M.) J. & G., an investigation has been made of the 
various host relations attributed to this fungus. Throughout the litera- 
ture the early blight organism is claimed to be the cause of the leaf-spot 
of Jimson weed {Datura ^ various species). One author (Chester, 1892) 
goes so far as to state that this was probably the original host, the fungus 
going from it to the potato and tomato. The object of this paper is to 
present some comparative studies of early blight and the Datura leaf-spot 
in order to clear the apparent misunderstanding of the relationship be- 
tween these two diseases. 

The Datura leaf-spot has been under the observation of the author in 
the University Pharmaceutical Garden, Madison, Wisconsin, during the 
summers of 1915 and 1916. The spots show a zonation similar to that 
of early blight but they are straw colored rather than deeply stained 
(fig. 1). They first appear on the lower more shaded leaves. Under 
favorable conditions the disease spreads gradually upwards when finally, 
in late autumn, the seed pods often develop dark sunken lesions (fig. 2). 
When a leaf becomes weakened by a number of enlarged spots it is usu- 
ally shed from the plant. 

The disease was noted on the following species and varieties growing in 
the Pharmaceutical Garden September 15, 1915:^ 

Datura tatula Linn., D. tatula inermis, D. stramonium Linn., D. stramon- 
ium inermiSj D. stramonium gigardeum, D, inermis Jacq., D, fastuosa Linn., 
D. ferox Linn., D. laeviSj D. querdfolia H. B. K., D. leichardtii F. Muell., 
D. metel Linn.(?). 

* The species and varieties are listed in the form in which they were found on the 
garden labels. Since the seed was originally of German origin the names are pre- 
sumably those in common usage in the foreign seed trade. 



328 Phytopathology (Vol. 7 

The pod blight was especially conspicuous on D. tatula inermin. ftra- 
manium inermis and fastuosa^ while the leaf-spot occurred on all to a 
greater or less extent. Datura stramonium giganleum showed grpater 
resistance than the others. 

ECONOMIC IMPORTANCE OF THE DISEASE 

As is well known, the Datune furnish one of the sources of the drug 
atropin or daturin which is obtaineil from the leaves. The leaves are 
picked in late Septcmlx»r sufficiently early to avoid frost. It is evident 
that anything which tends, particularly in the latter part of the 9ew^m. 
to reduce the leaf an*a st»riouslv interferes with its economic use. Ki^tiniatrs 
made in SeptemlHT 11)15, placnnl the average for all varieties at M) to'iO 
per cent of the total leaf surface destroyed. The dr>' season of llUli pn^ 
ventetl much apiK»araiice of the disease* prior to the rains of SeptenilnT. 
But even after that, favorable weather continuing, a loss of 10 to 15 |mt 
ct»nt in leaf area occurn'd. 

1I18T(»IIY OF TIIK DISEASK AM) ITS CD.NFl'SIOX WITH EARLY HLKiHT 

The first refenMic(» inferring that a n^lationship exists l>etwe«»n this* 
disease* and early blight is that by (\K)ke ( lS8.*i). He d<»scril)es. as though 
they wen* i<ieiitiral. the fungus fn)iii Datura and that fn)m the tomato .v 
Macrof<f)ifrium solani (*<M>ke. Me was apimn'iitly unaware that tlu* same 
binomial had Im^mi applied by KUis an<l Martin to a simikir fungus ontlie 
I)otato the yi'ar U'fon'. Sareanlo (ISStij lists Cooke's fungus as .Wnrri*- 
^fHtnutn nn»hi Saec. I>iit4T Kllis (s<»<» .Iom*s ISIW) affirms that this is the 
saiiM* fungus whieh he and Martin deseriU'd. Thiw the confu.iion wnmu^ 
to have originated. It is shown by the follr»wing n'fen»nces which an* a|»- 
pan-ntly ronrerned with this Datura leaf-s|K)t. Kellemian (ISHo) fn»!n 
Manhattan. Kan>as. Halsted i IS*KV) from New Jer>*ey, Briosi and C'avara 
<lV»2i and Terrari** ' P.M^V) fn>m Italv. St4»vens ilSlMi) fnnnOhio. I'mltT- 
\mhh\ iin«l liailr lV.»7i and Atkinson ilS*»7) fn>m .\lal)ama, Jon^^ an^i 
<Irniit |s*»7i :nnl Orton isiHji funi V«Tniont. So far as the hteraiure 
n'\i:il> thr ab«»vr determinations were bas4'd entin*ly on liiorphol«»|cir:d 
evitli-rni and on tin- Niinilarity of the <lis4'ast» to early blight of pi»tat«» 
an<l iiMt nil iii<>iiil:itinn work with the causal organism. 

In onl« r to ilrtiTniinr wliether the leaf->|><tt as found at Madinm i*^ 
iIh- ^aiiif a* that r('|Nirt4'd i-UrwIuTe. ex>i«*eat:M' lalti'lkHl .W#ifriv/h»»-;:*Fn 
.^"'' i . (V M. on Datura. Were e\annnt>d and eoni|KinMl with typir:tl 
in;it«i.:il lol'ii . i«i| JM-rr. Tlif ni.irroMopie apfN-araiiee of the S|X>ts of tlif» 
<\ .'.i^ii- ni Si\nHi;ir ami I-irlr No. lilo, and other eollection?» fn»m 



1917] Rands: Alternaria on Datura and Potato 331 

atomized with a spore suspension in water and for forty-eight hours kept 
moist by a fine spray from a nozzle. In most eases reisolations made 
from the infected plants were successful. 

On September 4, 1916, further inoculations with spores of AUernaria 
solani were made on mature potato and Datura plants growing in the 
field. Several leaves were atomized with a heavy spore suspension, while 
with others spores were introduced into pimctures. Successful reisola- 
tions of the fungus was secured from both atomized and needle punctured 
leaves on the potato. In one instance tissue plantings from the browned 
needle punctures on Datura stramonium five weeks after inoculation gave 
the fungus. The results corroborate the green house tests and show that, 
in no case, was A. solani able to form spots on even the old and weakened 
leaves of Jimson weed. However in toto fixations showed that penetration 
and incipient infection occurred in many .cases. But the fungus seemed 
unable to establish itself and bring about enlargement of the spot. 

inoculations with the fungus from datura 

The Madison culture of the parasite from Datura stramonium was tested 
comparatively first in the greenhouse, and later in the field on Jimson 
weed, potato, tomato, and on Solanum nigrum, the common black night-, 
shade. Several methods of inoculation in which myceUum or spores wei'e 
placed in needle pricks and the spores atomized upon the surface were 
used. Most of the tests were carried out at the same time and under the 
same conditions as those already reported with Alternaria solani from 
potato. These experiments may be briefly summarized as follows: On 
the Jimson weeds including Datura stramonium, D. inermis, and D. tatula, 
typical spots 3 to 10 mm. in diameter invariably resulted after two weeks. 
On potato, tomato and Solanum nigrum, incipient infections in the form 
of tiny brown specks often occurred. They were less abundant on the 
nightshade and vigorous leaves of tomato. These spots in no case en- 
larged, even after the leaves were yellowing and dying. The fungus was 
reisolated readily from the Datura leaves but only in a few cases could it 
be obtained from the incipient spots on the other plants. The needle 
punctures on the latter were in most cases entirely healed after eight days. 
Therefore, it appears that we have here an Alternaria which, though bear- 
ing much superficial resemblance to AUernaria solani, is nevertheless dis- 
tinct in its host relationship. In no instance has there been observed any 
crossing over to the potato or other hosts of A, solani tested, and also no 
crossing of the potato fungus to Jimson weed. The above conclusion is 
further confirmed by a comparison of the two fungi in other particulars. 



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334 Phytopathology (Vol. 7 

comparison of the fl^gus from datura with alternaria 80l.\m 

On hard potato agar the colony of Altcrnaria from Datura is at first 
of a light olivacious color with faint pinkish margins; later the entire 
growth becomes a grayish white while from the lower surface often blackish 
mycelium can be seen through the agar. With A. 9olani the grayi^h or 
brownish colony produces a deep pinkish to yellowit*h pigmentation of the 
agar which often extends in advance of the mycelium (fig. 3). This fur- 
nishes at once a distinct physiological ba.^is for the differentiation of the 
two fungi. Morphologically they are similar in many respects. <>ne 
of the most prominent characters which distinguishes the Datura f unguis 
from A, i<olani is found in the terminal prolongation or beak of the spore. 
In the former the beak is coarser, more elongated, rarely has any pro- 
nounced tapering to the tip, and is never forked or divided (fig. 4). ( >ften 
a.** high as 75 per cent of the spores of -4. solmii l)oth from cultures and 
from s|)ots, have l)eeii ol)ser\'ed to possess forked or variously di\'i*kHl 
l)eaks, the sulnlivisions ta|Kring more or less to the tip. One hundred 
HIK)res from typical early blight s|X)ts from potato gave a range in Mie erf 
12() to 2<U) by 12 to 20 /i and an average of 2(K) by 17 fi. With the Datura 
fungus the range in size was 128 to 448 by It) to 40 m with an average of 
2t)l by 23 /i- 'i'he latter it is sc*<*n has spores considerably larger in both 
dimensions than -4. W/iri/. However, the difference is not such as to 
make sjwre measureineiits n»liable when not supplemented by the oth«*r 
distinguishing characters mentione<l. 

IDENTITY OK THE DATURA PARASITE 

The fungus has U»imi refern»<l to as an Altemaria. This was. howeviT. 
inen*ly on account of its great similarity to Aliernaria nolani. As in the 
(*as4' of the latter, cultun^s. on oatnieal agar oi*casionally develop f(port> in 
catcnulute pairs (fig. 4). Acconling to the pn^sent delimitations of ttie 
g(*n<Ta Alt4*nmria and Macros|)oriuni this catenulation of spores make:« the 
fungus an Alt4*rnaria. However, it is n^aliauMl that the conditioa< under 
wlkirh s])on' i>airs are fonned an* |M>ssibly abnonnal and it is doubtful 
if the fungus U'liavf^s similarly under natural (conditions on its hoe»t. At 
any rate the exanii tuition of many sfxits has faile<l to reveal it. Tints 
tlie taxononiir iN)siti(»n of the fungus is problematical. Until these two 
fzi'iM-ni are more <'learly <ietined it will U* calletl provisionally an Altemana. 

To what >|MTies the fungus should U» refiTred was a matter ef doubt for 
>oini- time. A rareful M'areh of the literatun* failtnl to reveal a <lesrnf>- 
lion of a s|M'rirH of Altemaria on Patura. One Macmsporium. M. #ij- 
tunt Taut. ■ I^iinUtttr and Fautrey 1 8*. M >, is d(B<TtlM»d as occurring tm 



1917] Randb: Altehnakia on Datdba. and Potato 335 

Datura stramonium on the sterile spots of an undetermined gpeciee of 
Sphaeropsidales 

The Bpore measurements (150 to 190 by 18 to 20 >i) fall within those 
given in this paper and the loi^ slender " pedicel" (referring to the termi- 
nal beak) also is characteristic of the fmiguB under consideration. While 
it is probable that the two may be identical the description is entirely too 
brief for one to be certain. The question was referred to Dr. J. J. Davis. 
After looking over the various fungi described for Datura, he expressed 
the belief that this Altemaria (or Macrosporium) , in an immature condi- 
tion, was probably the same which Saccardo (1877 b) describes under 



Fia. 3. Sevsn-Dats-Old Coltdreb of Alternaria Solani (left) and Alterkaria. 

CRASBA (rIOHT) 

The colony in the former ie light brownish and produces a pinkish diacoloratioit 
of the Agar (bard potato) often extending in advance of the mycelium; the colony- 
of the. latter is grayish white and there is no discoloration of the medium. 

the name Cercospora crassa Ss.cc. sp. n. He also found that later Peck 
(1882) describes under the name Cercospora dalurw n. sp. from New York 
State what seems to be the same. The fungus corresponds with Peck's 
description in all essentials except that the spore measurements (50 to 
75 by 12 n) fall considerably short. The type specimens collected by Peck 
have been examined and the appearance of the spot leaves little doubt 
of their identity with the Madison material. From Saccardo's original 
illustration (1877 a) and the description in Michelia where the spore meas- 
urements are given as 100 to 150 by 15 to 18 **, there is every evidence 
that he was dealing with immature material of this same fungus. In 



336 



Phytopathology 



[Vol. 7 



order to relieve all doubt, however, a type specimen distributed in Myro- 
theca Italica No. 090 Padova. August 1901 was examined.' 

This well-preserved specunen of a spotted leaf of Datura atramontum 
collected by Saccardo was s milar in almost every respect to specimens 
from Madison and from various other parts of this countr>'. Though 
the spots are small, their characteristic appearance leaves no doubt of the 
identity of the two diseases. Furthermore, some spores were obtaincHl 
from the spec*imen and they add still further confirmation. As the pn*9^ 





Via. 4. CoMPAHisoN OK Spork C*ii.\ka(^kkh or Altkknaria tka-sha and Alti nWKl * 

HOLANI 

In thr KctMip tif A. rniHAii (to tho U*ft : the firnt two arc typical uporrs from lf*.if- 
H|M)t oil Datura Htraiiiniiiuin; tlu> third rcprcmMits .i rnAc of rAtcnuIntion on a<-i«l'i- 
iHtnl (MitHto iifiiiT. To the right, typical HporcH of A. iiolaiii Hhowing van.itinn in 
niic Hiiii ffinii: tht'M* an* uiiifonnly Htnnllcr thnn A. craiwa and fn*qiic*ntly bav«* thr 
iM'nkit )>rnnrhrti. >: 3N). 

vurv of l<)ii)i[itii(linal S4'pta in Ioiik fKuntiMl single sfMrn^s of Alternana or 
Marn»|N>riuin is the imfK)rtunt cluinicter which M*parat4*s them fn»in 
('<Tro<«|H>r:i. it may In* n*mlily iindcrst<N)d how immatun* s|Min*s of thr 
furincr inii^ht In* mistaken for the latt4'r. .\nd Saccanio olis<'r\'(*<i a longi- 
tudinal si'ptuiii. as is shown bv his illustration, but he calls it a fal^* oih*. 
**H-ptulo ^purio." Sint-e it is true that the lonKitutiiiuil |mrtitioii> m 
.'Mtcmaria an' p*iHTally abs4*nt until the sfMm's attain full siie, it Mvnis prt*l*- 
ablr, a> Dr. Pavis sufj^i^t'sts. that Saecardo's c*onreption was obtamini 
from iiiiinaturr material. 



* I III- unt«r i<4 iiitlrtitfd \n |)r A. H. Stout of thr N«*w York Itotanical tiardm 

fur .i^-*l*>t ilii 1 III tti;tktllie thl*» ('\:illliliatli>ll. 



1917] Rands: Alternaria on Datura and Potato 337 

Cercospora crassa is listed by Tassi (1906) at the University of Senna, 
, Italy, and also by Ferraris (1910 who gives as its distribution northern 
Italy, Switzerland, and Germany. The latter describes in addition the 
following which he considers forms of Cercospora crassa: (1) lunarice, on 
Lunaria biennis; (2) ihiridiSj on 76ms umbeUata; (3) solani-^igri, on So- 
lanum nigrum. 

These are recorded* from Italy alone. The inoculations already de- 
scribed show that Solanum nigrum cannot act as a host for this fungus, 
thus throwing some doubt on the vaUdity of the form reported for this 
plant. No tests were made on the other plants. 

In order to avoid future confusion the probable synonomy of the fun- 
gus and a description of the new combination are here given: 

Alternaria crassa (Sacc.) n. comb.' 

Cercospora crassa Ssicc. Michelia 1 : 88. 1877. 

Cercospora daturcs Peck. Rept. New York State Museum 35: 140. 1882. 
Macrosporium solani Cooke (in part). Grevillea 12: 32. 1883. 
Macrosporium datura Fautrey. Rev. Myc. 16: 7B. 1894. 

Alternaria solani (E. & M.) Jones & Grout (in part). Bui. Torr. Bot. Club, 
24:257. 1897. 

Conidiophores I'ght brown, erect or ascending, somewhat irregular, 
septate, generally 2 to 3 cespitose, 70 to 90 by 9 to 10 /i; conidia light 
brown, obclavate, with very long, septate, filiform, terminal beak, gener- 
ally much exceeding in length the body of the spore, total dimensions 
128 to 448 by 16 to 40 m, average 261 by 23 /i; body of spore 56 to 140 m 
in length, 7 to 9 transverse septa, 1 to 3 longitudinal septa in mature 
spores (sometimes absent); colony, in potato agar culture, Ught grayish, 
cottony, no pigmentation of the medium. 

Destructive, causing a leaf-spot and pod bUght of Jimson weed {Datura^ 
various species). 

University of Wisconsin 
Madison, Wisconsin 

* Inasmuch as the fundus in nature produces spores singly, and catenulate spores 
have been observed only in culture, some authors may prefer the combination Af oc- 
rosporium crassa. ' 



338 Phytopathology [Vol. 7 

LITERATURE CITED 

Atkinson, G. F. Some fungi from Alabama. Cornell Univ. Bui. 3: 40. 1997. 
Briosi, G. and Cavara, F. Funghi parassiti; fasc. VII, VIII. Pavia, 1992. liiC 

Jahresh. 90: 176. 1892.) 
Chester, F. D. A leaf bliRht of the potato, Macrosporium aolani K. A M. IVLi- 

ware Agr. Exp. Sta. Rcpt. 4 (1891): 5H-60. 1892. 
Cooke, M. C. New Ajiicrican fungi. Grevillea 12: 32. 1883. 
Ferraris, T. Flora Italica cryptogama pars 1:441. 1910. 

I parassiti vegetali dclle piantc coltivate od utili. pp. 892-893. 1913. 

Halrted, H. D. Weeds and their most common fungi. New Jersey Agr. Kxp Stt 

Kept. IS [18921:348.. 1893. 
Jones, L. H. The new potato disease or early blight. Vermont Agr. Kxp. Sta 

Kept. 6 11892]: G6. 1K93. 
Jones, L. H.. andCtKocr, \. J. Nutcs on two species of .\lternaria. Hul. Torr. B«it. 

Club 24: 257. 1S<«. 
Kkllerman, W. a. a partial list of the Kansas parasitic fungi, together with thrir 

host plants. Kansas Acad. Sci. Trans. 9: H3. Aliui Wash. I^b. Hul. 1 : 7S. 

1H8.5. 
L.\mhotte. K., and Favtrey, F. Ksp<Ves nouvellesde la (Yue d'Or. Rev Myc. 

16: 70. 1S94. 
Orton, W. .\. .\ second partial liHt of the parasitic fungi of Vermont. Vermont 

Agr. Kxp. Sta. Kept. 12: 179. 1H<K». Also Contr. liot. Vermont 7: 179. 

ISIK). 

Vkck, (\ U. He|H)rt of the liotanist. New York State .Museum Kept. 31: 140. 

1SS2. 
SAct'ARDo, P. .\. (a) Fungi rtalici aut4igraphice delineati. No. 09. 1877. 

(b^ (Vrcoi!p*)ni crassa Sacc. .Michelia 1: HS. 1877. 

Sa(X'ari>o, 1*. \. Macros|M>riuiii cookei Sacc. Sylloge fungorum 4: 530. IHM). 

Stkvenh, F. L. Ohio parasitic fungi. Ohio State Acad. Sci. Kept. 4: 23. 1K9C. 

Tas.hi, Flaminio. Klcnco generale dei funghi della provincia Senese rinvenuti 
fino a tutto Tanno IWh. l^ib. Ort. Bot. Siena Bui. 8: 226 1906. 

I'nderwood, L. .M., and Karlk, F. S. A preliminary list of .Vlabama fungi. .Ala- 
bama Agr. Kxp. Sta. Bui. KO: 155. 1H97. 



SUSCEPTIBILITY OF NON-CITRUS PLANTS TO BACTERIUM 

CITRI 

R. A. J E H L E 

With Three Figures in the Text 

Various non-citrus plants have been inoculated with pure tested cul- 
tures of Bacterium Citri Hasse in order to determine their susceptibility 
to the citrus canker disease. Special attention has been given to related 
species belonging to the Rue family (Rutaceae). The plants are growing 
directly in the soil in a securely screened inclosure. No results have been 
obtained from any of these experiments excepting in the case of Murraya 
exotica (Orange Jessamine) and Zanthoxylum fagara (L.) Sarg. (Wild-lime). 

In the case of Murraya exotica a few watery swellings developed around 
some of the needle-prick inoculations in the leaves and the canker organ- 
ism was recovered from the interior of one of the swellings a few weeks 
later. Inoculations were also made by spraying the twigs and leaves 
with a suspension of canker bacteria, but the results of these latter tests 
were negative. 

Many inoculations were made on the twigs of all sizes and on the leaves 
of Zanthoxylum fagara. On the leaves watery swellings sometimes sur- 
roimded by a yellow halo developed around most of the needle-pricks into 
which canker bacteria were introduced (fig. 2, A). These swellings never 
burst open, but Bacterium Citri was recovered from the interior three 
months after inoculation. On the twigs a total of about one hundred 
needle-prick inoculations were made. In every case watery swellings 
developed in about ten days. These swellings on the twigs continued to 
increase in size and finally longitudinal splitting of the bark took place 
exposing a mass of corky cells much resembling canker infections on the 
twigs of Citrus trifoliata (figs. 1 and 3). Bacterium Citri was repeatedly 
recovered from these swellings, which produced typical canker on grape- 
fruit seedlings (fig. 3, D and E), On Zanthoxylum fagara twigs the same 
organisms produced infections identical with those from which they were 
isolated. Check inoculations were made by pricking the tissues with a 
sterilized needle, but the wounds soon healed over (fig. 1, C). 

Twigs of Zanthoxylum fagara were inoculated by spraying a suspension 
of B, Citri in distilled water on the uninjured surface with an atomizer. 
These twigs were covered for several days with a lamp-chimney plugged 



340 



Phytopatiioumiy 



[Vol. 7 




I !■. 1 i:f-»ii"i \i I HI I -l*iiii k I\iM I i.Mi 'N- wi III HuTKitn w C'lTiii IN T»i«i' 

<i| / \\ I liiiX^ I 1 M I \i. M(\ 



1 I -.4 II iiifn •:••[ >• ••Ti ;i \i. :!ii: t \\ i^; Ml' /•I'l'^.nj 7/iitM Nji/iiru |iriNliii-i'«l liy iittriMiiir- 
.T.fcj /•'. • .'.' ;ti' .1'' t i-xiio \\ I' fi .1 >!i-rili/i-il iii'i-illi*. • !{. 'I'hi* Inn t-r li-«i'in 

;i i: ■ -• • :.■ .T .1 > ri- • ;l' I ii-'i 'sla'i ■! \ii\ finlM-r Jl». l'.tl*» l*liii1iiKr!i|ih Ili3<i« }»'- 

I ~ 

• • ■ _ . I'll 

/." I ■ '■ •:•"• ■■■.• ■.!! ■ •■•ji: t.f /,'t} 'i.'-i (l-tm /iii/iir*! iiriiiliiri-il l»y intr<N|>ii :ri( 

/ ' .!■■•■.• ..-A I'll I -fi nii/«il iiniilf ■ :t IimruLiivd Niiit ini^r 

)'■ ■■■■■J' ■!.■ '. -i. .liii;.iT\ J7 l'«I7 

' '•■ ■ : ' . - :i. .!.'. ^ ■./■»•'••■■..' 4". ■"■:!/.;? fi ml <i wliifh li<i iir|C:iiii«{ii« »• rr 

:••..: !'■ - I., ill \..'.. r-i'-i • .■*». I'»lii IMii>li«k;r.ip)ii-«l J.iii . .-\ .T. 



1917] Jehle: Citrus Canker 343 

with cotton at the ends. Other twigs were treated in exactly the same 
manner excepting that sterilized water containing no B. Citri was Used 
in the atomizer. No swellings developed on the twigs sprayed only with 
sterilized water but five cankers developed on the twigs sprayed with 
B. Citri. The five cankers which developed as a result of the atomizer 
inoculations were almost identical in appearance. They very much 
resembled young citrus canker infections on the twigs of Citrus trifoliata, 
but differed from the latter in having a distinct transverse split across the 
center. In one instance the development of one of these cankers was ob- 
served for several months. When the infection was found it was a small 
dark green watery swelling with a small transverse split in the bark across 
the center. The swelling continued to increase in size, and the transverse 
split in the bark became more conspicuous. When the canker had reached 
about three millimeters in diameter, longitudinal splits began to appear 
in the bark at the outer ends of the transverse split. The cracks exposed a 
corky mass of cankerous tissue similar to that on other hosts. The largest 
canker reached a diameter of five millimeters seven months after inocu- 
lation. It was surrounded by an oily zone, indicating that the bacteria 
were still alive and active in the interior. One of the smallest cankers 
was removed from the tree (fig. 3, C) and isolations were made from the 
interior. The bacteria recovered from this canker did not differ from 
other strains of Bacterium Citri, They produced typical citrus canker 
on grapefruit seedlings and infections on Zanthoxylum fagara identical 
with infections produced by other cultures of Bacterium Citri- 

A grapefruit seedling badly infected with citrus canker was set so that 
its branches interlocked with those of Zanthoxylum fagara. Infections 
identical with those resulting from inoculations with B, Citri have de- 
veloped on iminoculated twigs and leaves of tanthoxylum fagara near to 
the infections on the grapefruit seedling. These infections imdoubtedly 
resulted from B, Citri washed by rains from the infected grapefruit tree 
to the twigs and leaves of Zanthoxylum fagara. 

Fig. 3. Result of Inoculations with Bacterium Citri on Three Different 

Hosts 

A. Result of an atomizer inoculation with Bacterium Citri on a twig and thorn of 
Citrus trifoliata, X 3. 

B and C. Result of atomizer inoculations on twigs of Zanthoxylum fagara. X 3. 
Both twigs inoculated November 17, 1916. 

Bf photographed July 18, 1917; C, photographed February 14, 1917. Isolations 
were made from C on February 15, 1917 and pure cultures of Bacterium Citri were 
recovered. 

D and E. Result of needle-prick inoculations on twigs of grapefruit with organ- 
isms recovered from interior of canker on a twig of Zanthoxylum fagara, X 3. 



344 Phytopathology [Vol 7 

Although lesions have been occasionally noted on the twig}> of Zan- 
thoxylum fagara in Dade County hammocks, they have been I'arefully 
examined and no evidence has been secured indicating an abundance t»f 
natural infestations of this plant with the bacteria of citrus canker. 

Florida State I\.ant Board 
Hedland Tropical Laboratory 



SOME DISEASES OF ECONOMIC PLANTS IN PORTO RICQ 

L. E. Miles 
With Three Figures in the Text 

ISARIOPSIS ON THE BEAN 

The Isariopsis leaf -spot of the cultivated bean is a disease which occurs 
on both the foliage and pods of the bean plant, often resulting in consid- 
erable damage to the crop, due to the lessening of the active leaf surface 
or sometimes to the partial or complete premature defoliation. The dis- 
ease has not been considered of any great significance commercially, but 
according to Halstead^ it is much more common in the United States than 
is usually supposed, and to it should probably be ascribed much of the 
trouble formerly attributed to other fungi. It is easily confoimded with 
the leai-blotch of the bean (Cercospora). The chief points of difference 
between these two diseases will be considered later in this paper. 

The fungus causing the disease, Isariopsis griseola, was first described 
by Saccardo in 1877, as occurring in northern Italy and southern Austria. 
Briosi and Cavara also report it as occurring in Italy, and it is represented 
in their exsiccati by a specimen collected near Pavia in 1888. In the ex- 
siccati of Rabenhorst, Winter and Pazschke a specimen is found collected 
near Zurich in Helvetia. Rabenhorst reports the disease as occurring 
also in Belgium, Poland and Argentina. It is represented in the collec- 
tion of North American Fungi of Ellis and Everhart by a specimen col- 
lected by J. B. Ellis at Newfield, New Jersey in 1889. In the Fungi 
Columbiani of Ellis and Everhart, as continued by E. Bartholomew, a 
specimen is found collected by C. L. Shear at Takoma Park, Maryland, in 
1906. Halstead of New Jersey in 1901 reported it as occurring in that 
state. F. L. Stevens of the University of Illinois found it in abundance on 
beans in the garden of the Experiment Station of Porto Rico in 1912 and 
1913. It is also represented in the collection of J. A. Stevenson by a 
specimen collected at Rio Piedras, Porto Rico, in 1916. The writer has 
examined specimens collected by J. L. Sheldon at the following places in 
West Virginia: Morgantown, 1904; Martinsbiu-g, 1905; Sink's Grove and 
Bull Run in 1906. The Plant Disease Survey of the United States De- 
partment of Agriculture reports it as having been noted in Monroe and 

> Halstead. B. D. New Jersey Agr. Exp. Sta. Bui. 151. 1901. 



346 Phytopathology (Vol. 7 

Jackson counties of the same state in 1906. Specimens on pods were also 
collected in Preston Country, Connecticut in this same year by (1. P. 
Clinton. In 1908 it was reported as having caused considerable damaice 
to pole beans and some injury to bush Ix^ans at Central Village and Vohin- 
town, Connecticut. In this case the pole beans were killed half way up 
the poles. The writer has also examined specimens collected by (i. P. 
Clinton at Westville, Connecticut in the years 1902 and 1905. During 
the summer of 1916 M. F. Barrus found it occurring on beans in the mar- 
ket at Washington, D. (\, and the writer has looked over some material 
which he collected that same year at Chevy Cha.se, Mar>'land. Recently 
also the writer examined some material collected near Managua. Nica- 
ragua, in Central Ain(»rica, by Mrs. (i. V. Ix)ng« who, not IxMUg ac(iuainte<i 
with the (Iis(*as4\ gathered spotted leaves of the lx»an at random. Since 
all the leavers gathered showed this dis(»as<>, it is prolmble that it occun* in 
that locality in considcTahle abundance. 

In spite of this general world distribution, the literature cono^ming the 
fungus is meagre. With the exception of Ilalsteacrs pri»viou.sly men- 
tioned note of its oeeurn^nee and a similar one by Clinton- all of the pul>- 
lishe<i referencH's to it are brief <lescriptions of the s|>ecimens in exsieeati 
with the date and i)lae<» of eoll(»otion. Furthermon» the tigun*s and dc*- 
seriptions an» not in aeeord. Saecardo^ si)eaks of the hypluie which con- 
titut4' the con»miuin on which the sfWH^s are Inmie as liaving reflexwl 
tii)s and his figure* repres<»nts this character as Inking ver>' pronouncetl. 
Hriosi and Cavara^ have the only other figure that the writer haslieen 
able to find with the <»xception of a copy of Saccardo's in Comes' text- 
b<K)k. This figun» <io<»s not n»pn*s4»nt the tijw jis l>eing at all retiexwl an<i 
examination of the s|M»cimen of Hriosi and Cavara .shows agreement with 
their figun* in this resfx^ct. In all the material that the writer lias exam- 
ined including the gn»ater part of that mentioned pn»viously in this paf^er 
no n»flc»x(»<l hyphae have lH*en found. 

The Isariopsis leaf-s|K)t is different from the other diseases of the U»an 
in that it is confined more exclusively to the foliage, though in one or two 
instances it has U'en n»iH)rted its occurring on the po<is also. On the 
under side of the leaf an* pnxluced numenms small angular s|)ots without 
a colore<l l)order of any sort (fig. 1 ). It is this angularity of the spots an«i 
abs<»nc<» of a colonel lH)rder that diffen»ntiat<^ it so readilv fn>m the leaf- 
blotch of the lM»an caus4*d by ('crcnHporn cruenta. In this latter dist»ase. 

' Clinton. (; IV. ConniMtiriit Ajfr Kxp. Sta. Iti'pt. 190S: 30H. 
» .<.i«i ;inlo. P A S>IIoK«- Kiinic'»nini 4: tytt). 1H7S. 

* StuvAniiK V \ FiinKi Italiri. rr; s:r. |S7S 

* lini»?»i .trhi (*:iv:ir:i. FiiriKhi IVirii.Hsiti »l«»llt» IN.'tntr (^uItiv.Hto e<l t'lili. F 
N»). 17. IVivi.i. ISSH. 



1917) 



Miles: Diseases of Pohto Rican Plants 



347 



the spots are less angular and are surrounded by a pronounced red-brown 
border. The middle portions of the spots are also likely to fall out in the 
older specimens, producing a shot^hole effect. The angularity of the 
Issriopsis spots is due to the fact that they are bounded and limited by 
the small veinlets of the leaf. In youth these spots are covered by a gray, 
moldy coating due to the laige number of spores produced but as the spot 
ages it becomes a pronounced light brown. On close observation it will 
be seen to be studded with small dots, the coremia, on which the spores 
are borne in large numbers. 




Fio. 2. IsARioPsis Gribeola 
A, mycelium; B, germinating eporea; C, Coremia 

The coremia are columnar and are formed of rather dark brownish 
hyphae closely aggregated, though seemingly not at all united with each 
other (fig. 2, C). The members of the fruiting column tend to separate, 
especially with age, thus indicating that the structure should perhaps not 
be regarded as a typical coremium at all. The number of hyphae in a 
column varies considerably. In some as few as eight hyphae were ob- 
served while in others the number often reached thirty or forty. The 
hyphae are continuous, brownish, becoming paler toward the tip and av- 
erage about 200 ji in length. The average thickness of the coremium is 
from 20 to 40 li. 



348 Phytopatholooy [Vol. 7 

The conidia are borne on the smooth tipe of the hyphae which consti- 
tute the coremium (fig. 2, C). These tips commonly spread at the top, 
especially in the older specimens, giving a capitate appearance to the 
spore cluster. The writer was unable, however, to observe the reflcxrd 
tips as described and pictured by Saccardo. The conidia are light gray 
in color, cylindrical to spindleform, slightly curved, and scarcely, if at all, 
constricted. They measure 50 to 60 m in length by 7 to 8 m in thicknens, 
and are 1- to 3-septate. In a few cases they become 4-septate. The 
mycelium, though composed of crooked and branching cells, is of prac- 
tically uniform diameter throughout (fig. 2, A). It lives in the leaf tis- 
sues and forms darkstromata in the cavities beneath the stomata and from 
these the coremia arise. 

On germination the end cells only, of the 3- or 4-septate spores, send 
forth mycelial hyphae. These young hyphae are non-septate in the 
earlier stages and in a short time begin to branch as shown in figure 2. H, 

No experimental work has yet been done with reference to treatment 
of the diseases prol)abIy Ix^cause it has not been considered of sufficient 
economic importance. However, HaLstead suggests that, owing to the 
superficial character of the fungus, the same treatment ordinarily ap- 
plied to the leaf-blotch or the rust of the l)ean would probably be effective. 

Specimens examined: Kal>enhor8t, Fungi Kur. 3998; Kunic, Fungi 
8el. 595; Kriosi and Cavara, Funghi Parassiti, No. 17; Saccardo, P. A.. 
Fungi Ital., Fig. 8iJ7; Thimion, Herb. Myc. Sec. G54; Ellis and Everhart, 
Fungi Columbiani, 24IM; Ellis and Everhart, North American Fungi, 
2487. 

Other specimens collected by: Sheldon, J. F., Morgantown, W. Va.. 
1186; Martin.sburg. W. Va., 1989; Bull. Run, W. Va., 2696; Sink's (irtivo. 
W. Va., 2719; Barms, M. F., Cluvy Chase, Md., 9057; Clinton. C. P.. 
Westville, Conn., two packets; liong, Mrs. O. V., Managua, Nicaragua; 
Stevenson, J. A., Kio Piedras, Porto Rico. 6198; Stevens, F. L., Por*o 
Rican Fungi, Jayuya, 7108; Managuez, 5989; Dos Bocas, 7382; 7952. 

CERCOBPORA .VICOTIAXAE E. A E. ON TOBACCO 

Tolmcco is thini in rank among the exports of Porto Hico, though only 
a small iwirtion of the area of the island is devotinl to its culture. The 
CVrc<»siN)ni (ii.seaM' may n^ult in great damage to the standing tobacco. 
and in »<oiiie instance;* xhv crop may In> practically ruine<l. It is mniit 
abundant on the lower leave.*<. ap|H'aring as brown, circular spot*, from 
the si»» of a pin-head to a cf»ntimeter or more in diameter, thickly scat- 
tenti oviT the entin* leaf surface. The older spots are bordered by a 
dark. rais4><i line, and xhv vvuXoth dr\' up and liecome white, often falling 



1917] Miles: Diseases of Porto Rican Plants 349 

away and leaving irregular holes. The leaf does not decay as a result of 
the spotting, but turns yellow from the tip downward and ripens 
prematurely. 

Dos Bocas, 7980; Ste. Ana. 7612; Quebradillos, 7270; Caguas, 469; 
Cailes, 23. 

CERCOSPORA HENNINGSII ALESCH. ON CASSAVA 

Cassava, Manihot lUillismaj is cultivated for its thick, fleshy root- 
stocks, which are densely stored with starch. Although it is not used in 
Porto Rico nearly as much as it is in some other tropical countries, it is 
cultivated by the natives to some extent for use as bread and for the starch 
which it contains. Cercospora henningsii causes a small dried-out spot on 
the leaves, but it is of but little importance, as it probably injures the 
host but little. 

Hormigueso, 233; Santurce, 254. 

CERCOSPORA HIBISCI TRACY A EARLE, ON OKRA 

Okra is cultivated for its large fruit capsules which are used for food. 
Cercospora hibisd occurs on the lower side of the leaves, not in spots, but 
as an almost continuous coating. It causes the leaves to turn yellow and 
fall, weakens the plant and reduces the quantity of pods. 

Quebradillas, 5030; Aguadilla, 5229; Cario Raja, 6465. 

CERCOSPORA CANESCENS ELL. & MART. ON THE BEAN 

Cercospora canescens does some damage to the bean crop, due to small 
spots on the upper leaf surface, but, as a rule, it does not prove serious. 
Guayanilla, 5872. 

CERCOSPORA COFFEE ZIBCM. ON COFFEE 

Coffee is by far the most important product of Porto Rico. Cercospora 
CoffeoB causes the appearatice on the leaf of spots and the leaves fall, thus 
reducing the vitality of the plant and preventing the proper maturing of 
the berries. These spots, as a rule, are round or oval in form, clear brown 
on the lower side of the leaf, dark brown on the upper side. By uniting, 
they frequently cause large blotches which dry out and become gray in 
color at the center. Badly infected leaves appear more or less brown. 

Afiasco, 3211; Maricao, 4827. 

PUCCINIOPSIS CARICiE EARLE, ON THE PAPAW 

The tropical papaw [Carica papaya) is attacked by a leaf-spot fungus, 
Puccinopsis CariccB, which occurs as small, erumpent, black masses on 
the under side of the leaf, and causes more or less yellowing of the surround- 



350 



Phytopathology 



(Vol. 7 



ing tissue. The attacke<l leaves die and fall prematurely. The diM*a.*«r i« 
not destructive, but is sometimes reported to be severe on young neetlUng!*. 
Associated with the causal fungus in all specimens examined by the au- 
thor was found a ver>' p(»culiar fungus, Zygosporium oftchiouUn Mont., 
which is represented in figure 3. It occurs as a saproph>'te on the Puc- 
ciniopsis spots, and is mentioned here only on account of its ver>- inten*?*!- 
ing peculiaritii^ which are shown in the figure. 
(Uianica, .348; Vega Baja, 1913; Mona Island, 0,334; 6432. 






PHYLLA<'H<)IC\ (JR.\TIS8IMA RKI1M. OX THE AV(H'ADO 

This fungus raus4»s jel-hlack, erumfXMit pustules to appear on the up- 
|XT side of the leavi^sof the iwavixiXoiPersva americana Mill.). The?*|M»t!* 
an* from one to two inilliineters in diameter, but by coalescing they may 
Imh'ouu* considerably larger. The injury to the plant is pn>bably not 
ver\' gn»at. 

Javuva, 5974 ; t*)()72. 



.MYCOSni.KllKLLA PKKSE.E MU-KS (iN KD.) OS THE AVOCADO 



This fungus cause's very large. irn»gular spots on the leavi»j* of thr .iv*v- 
rn< lo. ( >n tin* up|MT sidr of the leaf the siK)ts an* coven»<l by a cint-n^iiu-. 
pa|NTy tnen))>nine. and an* without a limiting Ixmier. On the Iowit <»idt* 
thfv an* brown, with a narrow I Harder darker brown in color. A ^insli' 
s|x>t may i»ftrn covrr S4'veral s<|uan' ct»ntimeters of tlieleaf surfac*e. Thr 
diM-an* is not of any gn'at imfMirtance, though it may les^^en the vitality 
of th<> ho^t S4>inr\vhat. The drscription of the fungus may 1m> found m thr 
PriH-4'rdiiiu> nf tlir Illinois Academy of Scienn' for 1917. 

.Man. ao. 1X\\ |H0«»; 44Sli ity|M»: Hio Picnlras. 217ti; 2501 : San Otennan. 
5797; l)os Hora>. Im'Iow rtuad(», titM)l. 



1917] Miles: Diseases of Porto Rican Plants 351 

cercospora carbonacea miles (in ed.) on the yam 

This fungus causes very conspicuous, black spots, burned or charred in 
appearance, on the upper side of the leaves. The spots are usually angular 
in form, limited by the veins or veinlets, and are from one to one and one- 
half centimeters in diameter. From the number of collections made in 
Porto Rico, it would appear to be common there, and it cannot be other 
than injurious to the plant, since it renders so much of the leaf surface 
inactive. The description of the fungus may be found in the Proceedings 
of the Illinois Academy of Science for 1917. 

Vega Alta, 4178 (type); Cabo Rajo, 6469; Vega Baja, 4234; Anasco, 
3563; St. Ana, 6687. 

HELMINTHOSPORIUM MAYAGUEZENSE MILES (iN ED.) ON PASPALUM r 

Paspalum conjugatum Bregius, a forage grass of some commercial im- 
portance in Porto Rico, is attacked by a leaf-spot fungus, Helminthospor- 
ium mayaguezense. The spots occur both on the blades and culms and 
are quite conspicuous. They are of uniform light yellow color, surrounded 
by a narrow, dark brown border, regular in outline, oval, and vary from 
small to a centimeter in length, being usually about one-half as wide as 
long. In the somewhat paler centers of the spots the unusually large 
conidiophores of the causal fungus are plainly evident to the unaided eye 
as small, dark, hair-Uke bodies. The spots may be so numerous as to 
practically cover the leaf and must of necessity be of material injury to 
the general vigor of the host. The description of the fungus may be 
found in the Proceedings of the Illinois Academy of Science for 1917. 

Mayaguez, 970; 1066; 7142 (type); 8232; 8279; 8941; Dos Bocas, 1093; 
San German, 5803; Anasco, 4904; Maricao, 8776. 

University of Illinois 
Urbana, Illinois 



TWO NEW FOREST TREE RUSTS FROM THE NORTHWEST 

H. 8. Jackson 

CHRYSOirrXA 

A large collection of ruais made by Dr. J. R. Weir in variouB sections of 
the Northwest, was, through the kindness of Dr. J. C. Arthur, to whom the 
material was sent in the fall of 1915, referred to the writer for stutly. 
Among the material were specimens of a curious rust occurring on the 
leaves of Picea Engelmanii collected in Idaho. Carefully made sec- 
tions of this form showed that the rust belonged to the genus (*hr>*i^o- 
myxa. I'^amination of undetennined material on the same host in the 
Arthur herbarium at the Purdue Experiment Station led to the discovery 
of another 8|)ecimen of the same rust collected in 1911 in British ( olumbia 
by Prof. E. W. D. Hoi way. Recently Dr. Weir has sent to the writer a 
third collection made in Oregon in 191G. Since no similar rust has appar- 
ently l)een n*corded for America the results of the study of these speci- 
mens are considered worthy of record. 

The genus Chrysomyxii was established by Unger* in 1840 with i\ 
Abietis (Wallr.) l*ng. as the tyfx' species. This is an autoecious lepto- 
fonn as shown by Him'ss,- telia only, unaccompanied by pycnia being known 
in the life cycle. This genus has g(*nerally l)een interpreted as including 
l)oth short and long cycle fonns. The Sydows* describe sixteen specie:*. 
Fourttvn of tlM*s4» an* long cycle fonns all of which are known to lie. or an» 
assumed to Ik» lu»tcrcx»cious and o<'<'ur on various members of the P\Tolarwp. 
Kricacvie or Va(*ciiiia<*c(p with pycnia and aecia so far as determine<l on 
PiccMi. Two short cvcled fonns C. Ahieiin and C. Picea BarcL are in- 
clu<led. The fonner o<'('urs on the leaves of various specic« of Picea 
throughout continental KurofN*; the latter is known only from India on 
P, Mnrnula and is n»ferrt»d doubtfully to this genus. 

.Arthur^ ni^tricted the genus Chrysomyxa to include only the short 
cycle aut<MM*ious forms and establishe<l MelampsoropsLs (8chn)t) for thow 
sfnTies having all sjKm* forms. He has recogniaed* eight specie« of tlie 

' Ik'itraico iiir VrrKi<'i('hrii4l<*ii I*athf)loKir, p. '24. IH40. 

' liot Z4it. 23::iHS 1S»m; Ahh. Nntiirf. (H'Aolliirh. Hiillcll:32. 1969. 

* M..ri«.K \ Tvii. 3: :»<L» :..ti. i*.»i:>. 

* KiMult. Sn. CoiiKr. Hot. Viiiim- .TiS. IWW. 

* N. Am. Flora 7: lis IJl. Vmy;. 



1917] Jackson: Two New Forest Tree Rusts 363 

latter genus in America, four of which have been definitely connected 
through cultures by European or American investigators with their aecial 
stages. No American representative of the genus Chrysom3rxa has been 
previously recognized. 

A careful study of the collections on Picea Engelmanii^ referred to in 
the introductory paragraph has led to the conclusion that they represent 
an undescribed species, a diagnosis of which follows: 

Chrysomyxa Weirii sp. nov. 

O. Pycnia imknown, probably not formed. 

III. Telia foliicolous on yellowish spots, prominent, waxy in consist- 
ency, elongate-elliptical, 0.5 to 1.5 nmi. long, occasionally confluent, dull 
orange to orange-brown, ruptured epidermis conspicuous; teUospores caten- 
ulate soon separating, oblong or fusiform, 5 to 7 by 16 to 28 M; truncate or 
attentuate at either end, abutted or overlapping, sometimes only sUghtly 
so at one side; wall colorless, thin 1 /« or less, smooth. 

OnPinaceje: 

Picea Engelmanii Parry. Gold River British Columbia, June 10, 1911, 
E. W. D. Holway; Priest River, Idaho, May 1915, J. R. Weir 68; Whit- 
man National Forest, Oregon, July 17, 1913. J. R. Weir 27 Ij type. 

This species differs from C. Abietis in the narrower, somewhat smaller 
spores which do not long remain in chains but soon break apart. No evi- 
dence of germination* has been seen in any of the collections. The writer 
takes pleasure in dedicating the species to Dr. Weir who collected the 
type specimen and whose work has contributed much to a better under- 
standing of Northwestern Uredinese. 

MELAMPSORA 

Two species of Melampsora on Populus have been recorded from the 
Northwest. One of these M. albertensis Arth. is apparently confined to 
P. tremuloides. The other, known on various species of Populus, has gen- 
erally been referred to M. Medusce Thiim. While working over a large 
collection of rusts from the herbarium of the Montana Agricultural Col- 
lege in the fall of 1915 certain collections were found which did not agree 
with any species described. A careful study of all the Northwestern and 
Pacific coast collections has led to the conclusion that all of the material 
examined on P. acuminata, P. angustifoliay P. balsamifera and P. tricho- 
car-pa from that region is identical and shows certain distinct morpho- 
logical characters which enables it to be easily separated from M, MeduscB 
and M. albertensis. A diagnosis follows together with a list of the collec- 
tions in the Arthur herbarium and those from Oregon in the herbarium 
of the writer. 



354 Phytopathology {Vol. 7 

Melampsora occidentalis sp. nov. 

O & I. Pycnia and aecia uncertain, probably on Larix. 

II. I'redinia chiefly hypophyllous, scattennl, roundish, rather larRf*. 0.5 
to 1.5 nun. across, early naked, somewhat pulverulent, orange-yellow, fail- 
ing to pale yellow, ruptured epidermis conspicuous; ure<iiniospon*s oblong, 
ellipsoid or pyriform, 16 to 29 by 32 to 48 m, slightly flattened laterally; 
wall colorless or slightly tinted with brown, 2 to 3 m thick or up to 7 ^ 
on the flattened sides; mo<lenitely and prominently verrucone-echinulate. 
without smooth spots, pores obscure; paraphyses numerous, intermixed 
with the spores, capitate or davate, 16 to 24 by 42 to 77 m, wall colorle^, 
2.5 to 3 M thick, uniform, or thickened to 6 m at apex. 

III. Telia chiefly hyfwphyllous, scattereil or more commonly crowdetl 
and sometimes confluent in gnmps surrounding the unnlinia, im*gularly 
rounded, small, 0.2 to 0.5 nun. jutoss, slightly elevatetl at maturity. suIh 
epidennal, waxy, at first light cirmamon-brown Ixvoming blacki.^h bn>wn; 
teliospon^s |)risniatic, 10 to 20 by 40 to M /i, wall cinnamon-bmwn. smooth. 
1 to 2 M thick, darker and thicker at a|M»x, 3 to 5 m; apical pore evident. 

On Salic.mk.*:: 

Popiiliis acuminata Hydb., II, Stevensville, Montana. Sept. 10. IIHW*. 
D. B. Swingle (fJJ: II, lil, Libby, Montana. Oct. 15, 1911. J. H. Weir Jiff. 

Populua amjuMifoUa Jas., II, Livingston, Montana, Sept. 1. 1913, E. 
T. k Vs. Hartholom(»w (Harth. Fungi Colomb. ^SS2, X. A. TrtHl. 7,^/.*. ai» 
A/. Mvdum- Thinn.); II, III, Libby, Montana. Oct.«l5. 1911. J. R. Weir; 
II, Big Horn Mts. Wyoming. Aug! 1S98, Williams & (Iriffit lis (('.riff. We^t. 
Am. Fungi .:^//y lis M. impuUna I^»v.); II, III. Willis, Montana, Oi't. 1SS8. 
J. W. .Vnderson; II, S4»attle (?) Washington, IIKK), Ik>nser tS: II, Yowm- 
ite Valley, ('alifornia, HK)9. P. II. Rolfs. 

Pnpulus baUamifcra L., Ill, Sour Dough Canon near Boz4*man, Montana. 
Apr. 1, 1914, H. M. Jenni.s<m SS; II, S<»pt. 4. 1913. K. Bartholomew ( liiirth. 
Fungi Colomb. ^J^«*? as M. aHHrUnaiH) \ Bn^merton, Washington. St»pt. X^, 
1912. K. Bartholomew (Barth. Fungi ( ollomb. II, 44^4, HI. ^^-^.i. Barth. 
N. A. Tred. StMl us M. Mrtiusa): II, III. Mc( arthy Mts.. m»ar Willrt.s 
Montana. Oct. 1SS8. F. W. .Vnderson *iS3: II, III. IxK)nia, Montana. St-pt. 
14, 1<HH), J. W. Blanken.'^hip o^7cJ, O2o4: II. III. KalisfM^l. Montana, July 
21. HMM). ,L W. Blankenship 0J5r,: II. Caldwell. Idaho. S4»pt. 2S. 1912. 
K. B:irtho|(»mrw (Barth. Fungi (*olomb. 4f^^4 ^^ -V. Mtdu^r); II A III. 
Madi*»oii, WiMoiisin, 0<-t. 14, 1910, K. T. Bartholomew (I^irth. Fungi 
(\>lomb. .>7^/.i :l** M MtflufniK 

Pitpiilu.'^ cantliratiS Ait. II. III. Mi.^*«oula. Montana, Oct. 10. l81Wi, Wil- 
liams iV ( iritfith>. 



1917] Jackson: Two New Forest Tree Rusts 355 

Populus trichocarpa Nutt., II, Corvallis, Benton Co., Oregon, Sept. 
1909, H. S. Jackson 1069; II, III, Oct. 15, 1912, H. S. Jackson 10^^ type; 
III, March 12, 1916 G. B. Posey; II, III, Trail to Sulphur Springs, Ben- 
ton County, Oregon, Nov. 2, 1914, H. S. Jackson 3369; II, Scott's North 
of Fort Klamath, Klamath Co., Oregon, Sept. 20, 1913, E. P. Meinecke 
CrD2; II, Clatskanie, Columbia Co., Oregon, Oct. 6, 1914, F. D. Bailey 
3358; Oct. 29, 1914, F. D. Bailey 3306; II, III, Sumpter, Baker Co., 
Oregon; Aug. 21, 1915, J. R. Weir 265; II, Medical Springs, Oregon; Aug. 

1913, II, III, J. R. Weir 117; II, Spokane Washington, July 1915, J. R. 
Weir 4^; II, III, Cour d'Alene, Idaho, Sept. 1915, J. R. Weir 72; 11; Libby, 
Montana, Oct. 15, 1915, J. R. Weir 40; 11, Pasadena, California, Dec. 29, 
1895, A. J. McClatchie; III, Foothills, near Stanford University, Santa 
Clara, California, April 1, 1902, C. F. Baker 435; III, Seattle, Washington, 
Oct. 8, 1892, A. M. Parker HI; Grizzly Trail, Beaver Valley, British 
Columbia, July, 1907, E. W. D. Holway; Puyallup, Washington, Aug. 23, 
1909, E. Bartholomew (Barth. Fungi Columb. 4143 as M, Medusce); Ver- 
non, British Columbia, 1916, W. H. Brittain; Dillon, Montana, Aug. 3, 

1914, J. R. Weir 37; II, III, Leclede, Idaho, Sept. 1913, J. R. Weir 20. 
This species differs from all other species of Melampsora on Populus in 

the large size of the urediniospores which are only slightly flattened and 
are evenly verrucose-echinulate. The teliospores are much longer than 
those of M, Medusce and are thickened at the apex. The character of the 
telial eori suggests that this species may be closely allied to M. albertensis. 
The sori are much larger as are also both uredinio- and teliospores. 

This species may be the same as that recently cultured by Weir & 
Hubert^ who used telial material from P. trichocarpa referred to M. Medrp- 
8(B and obtained successful infection on Larix europea and L. occiderUalis. 
The actual material used for infection and the aecia resulting have not 
been seen by the writer but telial material sent by Dr. Weir from Montana 
agrees with the form described above. Aecia from the same locality on 
L. ocdidentalis agree in general with aecia of Melampsora Medusce and Af . 
Bigehwii, The walls of the aeciospores are, however, somewhat thinner, 
1 to 2 M, and considerably thickened on opposite sides to 3 to 5 m- They 
measure 17 to 19 by 19 to 26 m- Additional culture work, and a careful 
comparison of the resulting aecia with those of M. Medusce would be de- 
sirable. In any case, the morphological characters of the uredinial and 
telial stages are considered sufficient to warrant separation. 

Purdue University Experiment Station 
Lafayette, Indiana 

• Phytopath. 7: 108. 1917. 



RELATION OF TEMPERATURE TO THE GROWTH AND 
INFECTING POWER OF FU8ARIUM LINI 

W. H. T I 8 D A L K 

With Plate XI and One Figure in the Text 

Studies on the nature and inheritance of resistance in flax to the wilt di«- 
ease^ caused by Fusarium Lini Bolley, were begun with the departments 
of plant pathology and experimental breeding of the University of Wiscon- 
sin in the winter of 1914-15. While growing plants in the greenhouse for 
these breeding experiments in the winter of 1915-16 the writer noted that 
marked diflferences existed in the rate of wilting of susceptible flax plants 
which were growing at different distances from the heating system. The!«e 
ol)servations, combined with temperature records, suggested the possi- 
bility that soil temperature might be one of the chief factors influencing 
the rate of infection of these plants. In order to determine this point 
experiments were arranged so that lK)th the relation of temperature to the 
growth of the fungus in pure culture, and the relation of soil temperature 
to the infection of susceptible flax plants might be studied.* 

RELATION OF TEMPEKATrRK TO THE (JKOWTH OF THE FUNGUS IN CULTrilE 

After ascertaining l)y careful measunnnent that actual correlation ex- 
istiHl l)etwcvn soil tem|x^ratures and the rate of wilting of the flax plants, 
a study was undertaken of the n^lation of the fungus to various teni|iera- 
tures while gn)wing in pun* culture on artificial media. An investigation 
of this kind was considennl of fundamental im|)ortance in order to work 
out and und(*rstan<l thoroughly the relation of soil temperature to infec- 
tion. By using an incomplete series of temfx'ratures ranging from to 
37^(\ it wju* found that the organi.Hm failed to grow l)elow lO^C*. and at or 
al)ovt' 'MH\ This pn'liminar>' exix»riinent showe<l approximately the 
tcm|NTatun* limits of the fungus and gave some indications as to what 
teni|¥Tatun»s witc lM»st suitinl for its growth. Another experiment was 
arniii^tMl. u>ing a mon* complete scTies of temperatures, in which plates 

^'Vhv uritrr uinhrH to rxprrw hin h(>:trt y appn>rintif)ii to Profrmor H. L. lUJlry 
fif th<' Nnrth Dakota AKnriiltural Kx|MTiiiu'nt Station for BupplyinK flax trrtl And 
tl:t\ Mrk Mill ftir thi* ufirk. Hi* if* uIho iiidcht^'tl to Profi^iwor L. K. Jonet cif thr I'di- 
\f r«ity of WiTiiiiMiti for invaliialilr nuggrMtiunn .'intl kindly criticismi of thr vork m 
It proKrcfiftrti. 



1917] 



Tisdale: Temperature Relation 



357 



poured with a 1.8 per cent potato agar and inoculated in the center with 

bits of mycelium were incubated in duplicates at different temperatures 

for six days. After incubation the colony diameters were measured 

(table 1) and the plates arranged in a temperature series and photographed 

(plate XI). The plate numbers in table 1 correspond to the numbers in 

the photograph. 

table I 

The effect of temperature on the growth of Fusarium Lint. Cultures six days old 



PLATE NO. 


TEMPERATURE 


DIAMETER OF COLONY 






•c. 


tntit. 




1 


8.5-10 







2 


11 


7 




3 


12-13 


20 




4 


14 


215 




5 


15 


29 




6 


16 


34 




7 


17 


38 




8 


19 


43 




9 


22 


68 




10 


24r-25 


70 




11 


25-26 


72 




12 


26-28 


78 




13 


29-30 


75 




14 


34 


17 




15 


37 






It appears from table 1 that the minimum temperature for growth of 
the fungus Ues between 10** and ll^C, the optimum at about 26® to 28°C., 
and the maximum between 34° and 37°C. Another set of experiments 
showed that the fungus is able to grow slightly at a temperature ranging 
from 35° to 36°C. Judging from the vigor of the fungus at the various 
temperatures, it would be expected that flax plants would wilt more 
readily with soil temperatures between 20° and 30°C. This was actually 
found to be the case with susceptible plants growing in the greenhouse. 



relation of soil temperature to infection^ 

While growing flax plants in the greenhouse for breeding experiments in 
the winter of 1915-16, as previously stated, a series of flats was placed 
near a system of heating pipes, while others were placed at a greater dis- 
tance from the pipes where the temperature was lower. A more rapid 

* Tisdale, W. H. Relation of soil temperature to the infection of flax "by Fusarium 
Lini Boll. (Abst.) Phytopath 6: 412. 1916. 



358 Phytopathology (Vol. 7 

wilting of susceptible plants was noticeci in flats near the heating 8>'ytem. 
Soil temperatures were taken and it was found that the temperature in 
flat« near the heating pipes ran at 18"^ to 20^C.» while the temperature in 
flats farther from these pipes, where there was much less infection, ran 
at 14° to 17°(\ This seemed to indicate that the critical temperature for 
the infection of flax by Fusarium Lint is somewhat below 17**C., which 
was of the more interest, in view of the fact that Gilman found that the 
lowest temperature for the infection of cabbage by Fusarium cangluiinann 
Wr. is a>)out 17**(\ 

Following thes<» observations an attempt was ma<le by controlling the 
soil temix»rature to determine more accurately the lowest temperature for 
infection of flax by Fusarium Lini. The first attempt was made by pUc- 
ing pots of infected soil containing germinating flax seeds in the cold- 
storage cellar near a small window where they could get lifi^t. Other 
pots plante<i at the same time were kept in the greenhouse as controb. 
The tempcTatun* in th«» cellar often ran Inflow 1()°C. during the nighU. 
This temix»nitun» was too low for the plants to remain- in a \'igorou8 con- 
dition. The plants in the control |x)ts Ix^gan wilting in ten da>'8 and 
ninet<*cii of the twenty-two plants were wilted at the end of twenty-two 
days, wheieiis none of th(» plants at the lower temp(*rature in the cellar 
had wi!t<Ml. The cxixTiment nas then terminated by a sudden drop in 
temjKTatun* which froze the plants in the cellar. 

A second attempt was ma<l(» at controlling the soil temperature by ar- 
ranging a c(K)l. circulating water jacket (fig. 1). A six-inch earthenn'are 
jar was filled al>out thn'<'-fourths full of infecte<l soil and susceptible 
flax siHMis planted. This jar was then support<Hl in a larger jar, throuKb 
whi<*h cold water rtowe<l continuously, as .shown in the figure. Seeds were 
plant<Hl in a similar jar and pla(*e<l nearby at gnn^nhouse temperature as 
a control. At the tinu* th(».*«» expcTiments were l)egim the temperature of 
the water wit*« aUnit 0°('. Hy careful regulation of the flow by meaiL** of 
th(» faucet valve* it was |)ossibU» to hold a fairly constant temperature lie- 
tw<H'n this |)oint and the gnH»nhou.s<» temiM»nitun». A temperature rang- 
ing lM*tw(H>n 12 and \i}^i\ was maintaimnl for eight days and the plants 
n'maine<l fnM» from infection. The temfXTatun* was then raised to U\' to 
17°( '. for two days and lowen»<l again to 12*^ to 15**(\ Four of the twenty- 
thn»<» plants in th<' jar show(»<l signs of the wilt within two days even at 
the.*^' low t«»m|M»ratun*s. Infection evi<lently (XTurred during the brief 
|)eri<Ml at the higher temixTatun*. The snmll earthenware jar was found 
to In* unsati.^actorv <iue to the fact that the material allowed t<x> much 
con<len.^tion or S4H»pag<» which kept the m\\ almost saturatixl. The ex- 
IMTiment W2i> then re)M»ateii with a ghiss battery jar sul)stituted for the 
earthenware jar. The gla»<s jar provtnl mon* satisfactory. In the second 



360 Phytopathology (1917 

peraturc at which the parasite will grow, especially since the host plant 
thrives well at the lower temperatures. In this case it seems clear that 
the host plant which is susceptible at the higher temperatures is able to 
resist or overcome whatever weak attempts at invasion the fungus can 
make at the lower teinpcratur&s. 

The evidence here presented supplementing that secured by Gilman' 
should at least warrant further careful attention to the relation of tem- 
peratures to infection with the soil parasites, and especially the species 
of Fusarium. 

CONCLUSIONS 

1. Fusariuffi Lini grows on culture media at temperatures between 10^ 
and 37**(\, with its optimum temperature at 26"* to 28**r. 

2. Flax thrives well with soil temperatures as low as 13^. 

3. The critical temi)erature for the infection of flax by Fusarium Lini 
is about 15®(\ ,' 

4. Then* is a close corn*lation between the temperatures at which Fum^ 
rium Lini gn)ws U'st in pure culture and those at which flax wilt is OKWl 
destructive. 

University ok Wisconsin 
Madison, Wisconsin 

' (lilnian, J. C\ The rrliitinn of trmporaturo to the infection of cabbage by 
Kuiiarium conglutinnnH Wollonw. Phytopath. 4: 404. 1914. 

(*nM»u|co vol low 8 aiitl th«* ri'lation of tcm|)oraturp to its orcurrenre. Ana. 

MiMouri liot. (;urd. 3: 25 H4. 1010. 



Pi.^n: XI. Ukl.\tion or TKMPKH\TrHR to thk Growth op FrHARirM Lini 

ThcHi* ciilturr pl.it4*H > l.S |N*r rrnt {Mitato aKiir) witp inorulatrci with much care 
M t«i iiiiifoniiitv Hiui ih«'n iiiruliatcd fur nix (iavH at «lifTprent t^mpcratur^a, as f«»l* 

irm^ 1 k:, io\ J ir, 3i ij i.r. ^\^ ir, .5. i.r. *«• ir>-, 17. i7'. 'S) 19'. (9 ir 

•10 J I 20'. 11 Ja Jil' . IJ 3i J-S". 13 i".* »)•. '14 :i4'. JlSi 37*. 



A SIMPLE AND EFFECTIVE METHOD OF PROTECTING 
CITRUS FRUITS AGAINST STEM-END ROT 

John M. Rogers and F. S. Earle 

During the summer and fall of 1914, while studying the various rot 
organisms of citrus fruits at San Pedro, Isle of Pines, some very interest- 
ing facts were noted. 

The percentage of rot in transit during the previous year was abnor- 
mally high and in the year of 1914 studies were made of the various con- 
ditions and organisms to ascertain the causes. It was decided at first 
that improper handling of the fruit had had much to do with the high 
percentage of decay during the season of 1913. In 1914, however, the 
fruit was handled in the most careful manner, having been picked under 
direct supervision of competent foremen, by laborers wearing cotton gloves. 
The fruit was placed in standard field crates and hauled to the packing 
house on wagons with bolster springs. The fruit was graded by expert 
graders and everj^ doubtful fruit was culled out. Despite this careful 
handling a large amount of decay occurred in transit, but the rot was con- 
fined almost entirely to the variety of grapefruit known on the Isle of 
Pines as the Pinero or Native, a variety very similar to the Florida 
Triumph. 

Counts were made of the rotten fruit from the culls and it was found 
that over eighty-three per cent of the rot was caused by a species of Di- 
plodia. In many cases the organism had gained entrance through some 
injury, but in the majority of the fruit the rot started from the stem end 
with no apparent injury. 

Inoculation experiments were made with the spores and hyphae of the 
Diplodia and it was found that perfectly sound fruit in all conditions of 
maturity could be rotted down through the stem end if moisture conditions 
were favorable. In this connection it wa« noted that the fruit that had 
been chpped showed more rot in the inoculation experiments than did 
the fruit that had been pulled, thereby removing the calyx. This was 
accoimted for by the fact that the small cavities beneath the calyx under 
humid conditions, do not dry out quickly and make an excellent infec- 
tion court. The small portion of stem left when the fruit was clipped, 
frequently became infected and through this source the infection entered 
the fruit. When the fruit was pulled the stem cavity had an opportunity 



362 



Phytopathology 



[Vol. 7 



to dry quickly and there was less chance of spores lodging and germinat- 
ing than where the calyx had not been removed. 

With these facts in mind some method was sought of sealing the stem 
ends to prevent the entrance of the organism. ParaflSn was first tried. 

Fruit was gathered from trees in poor condition and showing some 

TABLE 1 
Showing numbers of fruits rotted on various dates in each of the loU 



BBOIKNINQ •BPTBMBBm 10 


LOT 1 


LOT 2 


LOTS 


lot4 


LOTS 


vat% 


tori 


Lorl 


September 27 


1 
3 

7 
2 
1 

2 
1 






2 
4 



2 





2 

5 


1 

3 
4 

1 


1 

1 



1 
2 
1 




2 

1 

2 


1 

2 




1 

1 


1 










2 






October 4 





October 10 





Octol)cr 14 

October 16 




1 


Octolwr 20 

Noveinl)er 1 



1 


Novenil>cr 10 





November 10 









Total 


17 


4 


20 


6 


8 


3 


2 


2 



DipUnlia die-hack. Eight lots were maile of twenty fruit each and treated 
in the following manner : 

Lot 1. Fniit clipped and rind paraffined. 

Ix)t 2. Fruit pulled and rind paraffined. 

I»t 3. Fruit rlipp<»d. (Check.) 

lA>i 4. Fniit pulled. (Check.) 

Ix>t 5. Fniit clipp<Ml, rind and stem en<l paraffimnl. 

I»t (). Fruit pulled, rind and Ktem end paraffininl. 

Ia}\ 7. Fruit clipiMMi, stem end paraffined and rind not paraffimMl. 

I^>t H. Fniit pulled, stem end paraffine<i and rind not paraffine«i. 

Thr numlHT of rottinl fniits was recorded and is shown in table 1 
Many decaycHl fruits uppcMircHl in the lots that were clipfMHl anti the 
results (tahle 1) suhstantiatcMl previous knowle<lge of the fact that the 
clip|MMl fruit did not hold up as well as pulle<l fruit. The chfferencv U^ 
twe^'u the* pulled and the (*lipiMHl lots is so great that it seems as though 
sonir otlMT fH<*tor must have Ihmmi partially res|Kmsihle for the verj* high 
p<»r vm\ <»f dr<*ay. 

The treitment of the stem ends gave very pnnnising results ami the 
piTcentage of n»t in the treattnl lots was greatly nnlu^^ed. The iitaraffining 
of the rind gave no |>artirular protection against nit. but this treatnietit 
did bring to light another fMiint of much intert^t and e(*ononiic value. 



1917] 



Rogers and Earle: Protecting Citrus Fruits 



363 



The fruit in the lots that had the rind paraffined did not shrivel and the 
rind did not dry out as did the other lots not so treated. 

There have been two serious troubles in connection with the production 
of lemons on the Isle of Pines. These have been Diplodia stem-end rot, 
and the quick shriveling and drying of the fruits. The lemons are so 
thin-skinned that the rind dries out and becomes hard in a short period 
of time. By giving the fruits a good coating of paraffin it has been pos- 
sible to keep them in excellent condition for from two to three months 
with practically no shriveling. 

On October 17, 1915, lemon fruits were pulled and were divided into 
two lots of fifty fruits each. The stem ends of one lot were paraffined, the 
others were not. On January 24, 1916, there were a total of nine rotted 

TABLE 2 
Showing number of rotten fruit on various dales in each of the lots 



BEOINNINQ NOVEMBER 19 



December 10 
December 30 
January 26 

Total 



LOT 1 


LOT 2 


LOT 3 


LOT 4 


LOT 5 





4 


20 


16 


8 





8 


8 


6 


6 


1 


3 


18 


4 


4 


1 


15 


46 


26 


18 



lotO 

18 

8 

10 

36 



fruits in the paraffined lot and twenty-one in the untreated lot. These 
data and those in table 1 show clearly that the treatment of the stem ends 
is beneficial in the prevention of rot. Paraffin gave very promising results, 
but was not altogether satisfactory because it did not stick well and it 
was therefore difficult to seal the stem ends perfectly. 

The next material to be tried was shellac. It was diluted to a thin con- 
sistency with alcohol. This material gave such satisfactory results that 
it was not necessary to seek further. It is easily and quickly applied, 
sticks well and seals the stem cavity perfectly. 

The first experiment to be made with the shellac treatment consisted 
of six lots of fifty-six fruits each. The lots were treated as follows: 

Lot 1. Fruit pulled and stem end shellacked. 
Lot 2. Fruit clipped and stem end shellacked. 
Lot 3. Fruit clipped and a cut made in the rind with a knife. 
I^t 4. Fruit clipped, rind cut with a knife and shellacked. Stem end 
shellacked. 

Lot 5. Fruit pulled. (Check.) 
Lot 6. Fruit clipped. (Check.) 

The number of rotted fruits was recorded on various dates and is 
shown in table 2. 



364 Phytopathology |Vou 7 

The results shown in table 2 are ven- striking, particularly liotwwn 
lots 1 and 2, and 5 and 6. The results of lots 3 and 4 show that fn^ 
injuries to the skin of the fruit can 1x5 protected to some <l<»isree by «^»v- 
ering the injur>' with a thin coating of shellac, letter results would have 

TABI.K 3 
Showing numlter of rotten fruit on varlomt flntn* in t'nrh i»/ thr lot' 



Bi:(iIMIIX<: Iil<-IMBKH 12 t.oT I ' U*^ 2 ' liiT3 M>T 4 l«»r S li>T 4 



Jniiii.'iry ]'} 
F<'l»ru:irv 1. 



Total 



Total 



pi-ci-riilu'r J I 
J:i unary \'t 
Krliruary I 

Total 



n 


I 


1 


*f 


I 


» 





1 


:{ 


m 

.1 


1 


I 


1 


-> 


1 





li 


i 



II «r''« r's tjrn /hJi 'i, t 



DrrrinlNT Jt) M n J 1 u n 

January 4.". o J 1 '2 I 

FrKrnarv I 1 J 1 * J n 1 



I f.'/« /If I* i.nifiift M 



Jai!ii:tr\ |.'» nil) 

Ii-)>r>.ti\ \ u n 1 

1..?..! n 1 J 

I»t .. It. I . > Jl 

J • ri-i II \ ].'i 

I I If M <r '. I 

I'" '. 1 N L» S 



II 


t; 


n 


o 


n 


n 


n 


) 


t; 


.1 


1 


1 


n 


•1 


n 











n 


1 


II 


1 i 


n 




1 


•» 


■1 


II 


1 1 


t) 




1 


I 


a 


II 


1 


n 




■» 

« - 


:t 


i; 


t) 


I 


I .'/<! Fnihi It t* n, 


nil 













1 


(1 


!• 


I 


(1 


II 


•1 


If 


i 


1 


II 


• 
1 



,1 



m 

1917] KOGERS AND EaRLEI PROTECTING CiTRUS FrUTTS 366 

undoubtedly been secured in these lots had the fruit been pulled instead 
of being clipped. 

The next experiment was made in order to determine the eflfectiveness 
of the treatment on the various kinds of citrus fruits. Twenty fruit 
were used in each lot and the lots treated as follows: 

Lot 1. Fruit pulled, stem ends shellacked, dipped in a suspension of 
spores of Diplodia. 

Lot 2. Fruit clipped, stem ends shellacked, dipped in a suspension of 
spores of Diplodia. 

Lot 3. Fruit pulled and dipped in suspension of Diplodia spores. 

Lot 4. Fruit clipped and dipped in suspension of Diplodia spores. 

Lot 5. Fruit pulled. (Check.) 

Lot 6. Fruit cHpped. (Check.) 

The results of the experiment are shown in table 3. 

The results of the experiment show that the fruits of some varieties 
and species of Citrus are more subject to the Diplodia rot than others, but 
that the treatment is just as effective in all cases. The Native grapefruit 
and the Persian lime showed the highest percentage of rot m this experi- 
ment, but the lemon has been found to be very subject to the Diplodia 
rot, particularly diu-ing the curing process. 

The fruit when dipped in an aqueous suspension of Diplodia spores 
showed more rot than the check lot. The shellac gave protection even 
when the fruit was dipped in the spore suspension. 

In the next experiment two boxes of Native grapefruit were sent to Dr. 
C. L. Shear, Washington, D. C. The fruit was packed and in transit fully 
two weeks before being opened. It was fully ripe when picked, in fact, 
some of it was nearly ready to drop from the tree and the trees were in 
more or less weakened condition from Diplodia die-back disease. This 
was the most severe test that the shellacking treatment could be subjected 
to, as the fruit was too ripe to warrant shipping. 

One box of fruits was washed by the overhead sprinkler and revolving 
brush system, with clean rimning water, no soaking tank being used. 
Half of the fruit in this box was shellacked and the other half was not. 
The second box, after being rim through the sizers and polishers, was 
packed dry. Half of the fruit in this box was shellacked and half was 
not. The fruit in all four lots was pulled. The results, as tabulated by 
Doctor Shear, appear in table 4. 

The results shown in this table were most satisfactory from several 
standpoints. The shellacking treatment reduced the amount of rot over 
25 per cent in both the dry and the washed lots. Washing fruit, even 
with clear running water, greatly increases the amount of rot from the 
stem-end organism on many kinds of citrus fruits. 



366 



PHrrOPATHOLOOY 



(Vol. 



TABLE 4 
Report on f/rapefruU received from Mr. Roger$, February 7, t$l7 



DATE 



February 9, 1917. < 



Febniarv 19, 1917 



March 1, 1917... 



March 10, 1917. . . 



Total .. 



DMT 



Stem •nd 
•h«lUK!ked (48) 



1 rotten. 
Started in 
wound 



End not 
ftbelUeked (48) 



1 rotten. 
Wholly rot- 
ten covered 
with Peni- 
cillium* 







1 rotten 



2 rotten 



4 rotten. 3 
apparently 
started 
from stem 
end. 1 from 
wound; all 
show IVni- 
cillium 

3 rotten 



rotten. 5 
typical Di- 
phniia rf>t 



15 



Htmmmtd 
•MhdMd (M) 



1 rotten. 
Wholly rot- 
ten. Seems 
to have 
started 
from wound 






3 rotten. 2 
rotten, l>e- 
gan at stem 
end. 1 lie- 
gan at Imt- 
tom end 



4 rotten 



17 rotten. 

10 all rotten. 
Penieillium 
present ; 7 
partly rot- 
ten. Deeav 

m 

apparently 
at stem end 

7 rotten. 5 in- 
volve stem 
end; 2 en- 
tirely rotten 
show IVni- 
cillium 



3 rotten 



11 



13 rotten. 6 
all rotten: S 
stc*m-en«l- 
rot; 2 doubt- 
ful 

2 rotten 



* The presence of th<* Penieillium mentioned does not necessarily indicate that 
this was the primary cause* of rot. It probably followed and obaeured the Diplodia. 

HVMMARY 

C'itni.** fniitH Hubjert to Htoni-<»n«l n)t may \to protected to a Rrrat cWw 
gnM» by shHlnrking the stem end. 

If the sbrlbirkiiiK trnitiiiont is t<( U* iii(»st ofTortivc, it in iiccf*i«ar>' that 
tbr fruit \h* pulbMJ iind n<»t rlipixMi. In thin mnncH'tion it should )io Ktat^nl 
tluit the pulling of gni|H'fniit without toaririK n portion of the rind i?» a 
difiicult unt)(Ttakin»c. thouKli it ran 1h> ar(*oniplisho<l. Orangtv. If*nuin.« 
an<l Ihiii**< may Ik* piilitMl more easily than rlip|)ed and with no injury* to 
th«* rind. 



1917] Rogers and Earle: Protecting Citrus Fruits 367 

Washing the fruit increases the amount of decay to a very great extent. 
The use of a soaking tank, where the stem-end rot organism is present, 
is the greatest possible folly. 

A stemless lemon, having been pulled and shellacked, will hold up as 
long as a lemon with the stem intact. 

Fruit may be practically guaranteed against rot if given this treatment 
and handled properly. 

Avocados, watermelons and other fruits could possibly be protected 
against stem-end rot if given this treatment. 

Some citrus fruits are more subject to the attacks of Diplodia rot than 
others. In this locality the Pinero or Native grapefruit, the Persian lime 
and the Villa Franca lemon suffer most from this rot. 

A thin coat of paraffin prevents shriveling and dr3ring, and keeps the 
fruit in a marketable condition ^rom a month to six weeks longer than 
iruit not so treated. 

San Pedro, Citrus Pathological Laboratory 



ARTHROPODS AND (lASTEROPODS AS CARRIKRS OF 
CROXARTIUM RIBICX)LA IN (;REENH0USF25 

G. Flippo (iravatt and Kr8H P. Marhuall 

Tho litcnituro on dissemination of fungi in general hy insects has lioon 
recently siinitn!irize<l by Studhaltcr and Ruggles.* Nunieroiis writon* 
have railed attention to insects as possible carriers of rust spores, or have 
shown that rust spores actual ly were so carrie<i. WolP notes that vast nuni- 
Ihts of uredini()siK)res of the morning glory rust, Pucdnia cassif}es U. & ( \. 
were pres<»nt in th(» fecal deposits of a katydid. So far as can lie doter- 
m'ne(l no previous infonnation has lMH>n noted on the dissemination of 
rust fungi by (lasteropods. 

Studies with insects, sow bugs, and snails allowed to UhhI on variou-* 
species of tlie genus Ril)es grown for inoculatiitn ex|M»rimeiits %vith Cn^ 
nariium rihicohi Fi'-ch. in the pathological gre(»nhoases at \V:kshingt«>n. 
D. (\ during the past winter, have shown that these animals have a lio* 
eided i)n»ftTence for the infected leaves. Obs(»rvation indicate4i that th#» 
greater part of the fecnling was done by a gre<*nhouse weevil, but on leavoj* 
growing close to th<* ground, snails, slugs, an<l sow bugs were |x^rhaps more 
active. A small slug wjus ob.served eating the telial colunms of Cromir* 
tium ribicnUi from the under si<le of a black currant. Apparently, the 
unnlinial pu^^tules and the leaf ti.ssue were untouched. Judging by the 
thorough manner in which the telial columns hail Ihmmi eaten off the leav«^ 
of this bush, tlx' slug had be<>n at work for some days. In the gnM*nhoa*<4^ 
on a whitt» pine {Pinus stntbuJi), infected by (yonartium rihicoln, a miw 
l)Ug has been observtMl eating out pycnial pustules and the surrounding 
tissue of tin* blister-rust swellings. 

SPOIIKS O.V TIIK HOniKS OF A\IM.\LS 

.\nts. weevils, and one slug were collect e<l <lirectly from infect<»<l plant.<>^ 
in the urc«»nhoU''(». In most cases, however, the suspects were eonfintNl cm 
RiIm'< bu'-hr> undtT bi»ll glasses or in dishes with infectf^l leaves. Marh 
individual w:i^ rcnif>ved from the leaves with fiameii twtvzers to a stuall 

>r 'iiih liN r K A . .iml HuKKlfH. A i\ hiM*<*t!< :ih r:irrirri« of th(* chmtDiit l«ti|t^( 
fiiiiKi'* I'* iih«\l\:iiii:i Dipt liin-Htrv liiil 18: .'U. \ fd VM't. 

' Wolf. I \ I iirtlMT ftlijflicH (III |N>:iiiut l«*:if!<i>iit . JiMir. \^ HmrmiTh §: Wt- 
\nt: l'i|ii 



1917] Gravatt AND Marshall -.Carriers OF Cronartium RiBicoLA 369 

TABLE 1 
Examination for spores of Cronartium ribicola on the bodies of animals 











es 1 2 fls 

IS 2*" H 
B «• •< 


§88-5 


DATE 1917 


ANIMAL* 


PLACB COLLECTED OB 
CONTINBD 


TOTAL NU 
U BED 
SPORl 
WA0BW 




January 


11 


1 weevil. Panlmno- 
rus fuUeri 


On infected Ribes 
plant under bell 

• 


21 


2 


January 


11 


1 weljvil, Pantomo- 
rus fulleri 


jar 
On infected Ribes 
plant under bell 

• 


85 


10 


January 


24 


1 weevil, Paniomn- 
rus fulleri 


jar 
Confined in dish 
with infected 
leaves 


425 





January 


31 


1 slug, Agriolimax 
agrestis 


Confined in dish 
with infected 
leaves 








January 


27 


1 slug, Agriolimax 
agrestis 


On infected plant 
in greenhouse 


10 


110 


January 


10 


5 red ants, Pheidole 


On infected plant 


25 









anastassii 


in greenhouse 




• 


January 


17 


12 red ants, Pheid- 


On infected plant 


200 





« 




ole anastassii 


in greenhouse 






January 


25 


1 red ant, Pheidole 
anastassii 


Confined in dish 
with infected 
leaves 





8 


January 


25 


1 red ant, Pheidole 
anastassii 


As above 


5 


135 


January 


25 


1 red ant, Pheidole 
anastassii 


As above 





220 


January 


25 


1 red ant, Pheidole 
anastassii 


As above 








January 


25 


1 red ant, Pheidole 
anastassii 


As above 





20 


January 


25 


1 sow bug, Armadil- 
lidium vulgar e 


As above 


3 


85 


January 


25 


1 sow bug, Armadil- 
lidium vulgare 


As above 





450 


I'^obruary 


2 


1 sow bug, Armadil- 
lidium vulgare 


As above 


27 





February 25 


1 small spider 


As above 





30 



* Identifications through the kindness of Paul Bartsch, W. Dwight Pierce and J. 
R. Horton. 



370 



Phytopathology 



(Vol. 7 



TABLE 3 
Tests of adherence of spores to bodies of animals 



AlffUIAL 


TBBATIIBIfT APTBB BBINO 
OIPPBO 


f»3 


• 

H 

m 

o 
•b 

• > 

11 

is 

b 


8 

m 


A 

a 

s 


pabMTTBUA OB 
TBUAI. 


Sow hug, Armadilli' 


In petri dish on filter pa- 


1 


2 


35 


4 promyre- 


dium rulgare 


per 








lia, 1 te- 
lial col- 
umn 


Sow bug, Armadilli' 


In petri diah on filter pa- 


7 





13* 




dium rulgare 


per 
Transferred to clean quar- 
ters on second day 










Sow hug, Armadilli- 


In heaker with soil l>ot- 


2 


5 


17 




dium rulgare 


tom 










Sow hug. Armadilli- 


In )>eaker with soil )>ot- 


7 





2* 




dium rulgare 


toni 
Transferred to clean soil 
on second day 










Cockroach, Blatta or- 


In petri dish with filter 


1 


4 


20 




ienialis 


paper 










Cockroach, Jilatta or- 


In petri dish with filter 


2 










ientalis 


pa|>er 
Transferred to clean quar- 
ters on second day 










Cockroach. Blatta or^ 


Transfern>d to clean quar- 


4 










ientalis 


ters on M*cond day 










Rod ant . Pheidole an- 


On soil 


1 


4 


!()• 




astassii 












Red ant. Pheidole an- 


On soil 










as toss ii 




2 





6 





* Heveral sporidia in those* counts were partially germinated. A number of the 
sp«iridia were in this condition when insects were treated. 

viul rontHining a mouHuriMl (piuntity of (iiHtillcHi water and thoroughly 
wiu<hfMi to frcH» tiny a<iheriiiK sp<>ro8. 

At \oiist one-tenth of the water serure<i fnmx the first waahing wan cx- 
aniineti un<ier the microHeope, and the Kporen eounted. Tlitn result was 
eonip:ire<| with the examination of the wanh water as a whole. In a few 
ea><>> ininlifirations were made of the ^e^<ults ohtaintMl by eouDting onc^ 
tenth of the total amount. The figure.*! given in the tahlt^H are only ap- 
proxiniat<'Iy ai-rurate. due t<» the methcHi of counting and the fact that 
ail of x\ir H}M»rcs wfTe not removed from the InMlieH by the first washing. 



1917) Gravatt AND Marshall: Carriers OF CronartiumRibicola 371 



TABLE 3 
Examinations for spores of Cronartium ribicola in excreta 



DATE 1917 


ANIMAL 


LOCATION OP ANIMAL 
BBPORE EXAMINATION 


UREDINO- 
SPORE8 


•< 

A 

at 

s 


PARTS OP 
TBLIAL 
COLUMNS 


January 11 


Weevil, Pantomorus 
fulleri 


On Ribes bush un- 
der bell jar 


120 







January 11 


Weevil, Pantomorus 
fulleri 


On Ribes bush un- 
der bell jar 


10 







January 12 


Weevil, Pantomorus 
fulleri 


On Ribes bush un- 
der bell jar 


1,870 


210 




January 12 


Weevil, Pantomorus 
fulleri 


On Ribes bush un- 
der bell jar 


780 







January 12 


Weevil, Pantomorus 
fulleri 


On Ribes bush un- 
der bell jar 


400 


60 




January 12 


Weevil, Pantomorus 
fulleri 


On Ribes bush un- 
der bell jar 


210 







January 27 


Slug, Agriolimaz 
agrestis 


On Ribes bush in 
greenhouse 


7 


17 


16 


January 27 


Slug, Agriolimaz 


On Ribes bush in 


7 


28 


28 


• 

• 


agrestis 


greenhouse 








January 27 


Slug, Agriolimaz 
agrestis 


On Ribes bush in 
greenhouse 


20 


180 


128 

> 


January 27 


Slug, Agriolimaz 
agrestis 


On Ribes bush in 
greenhouse 


8 


65 


96 


February 15 


Slug, Agriolimaz 
agrestis 


Confined on infect- 
ed leaves 


1,050 







February 15 


Slug, Agriolimaz 
agrestis 


Confined on infect- 
ed leaves 


960 


a 




February 15 


Slug, Agriolimaz 
agrestis 


Confined on infect- 
ed leaves 


120 







February 3 


Snail, Subulina oc- 
tona 


Confined on infect- 
ed leaves 


2 







February 3 


Snail, Subulina oc- 
tona 


Confined on infect- 
ed leaves 


9 







February 3 


Snail, Subulina oc- 
tona 


Confined on infect- 
ed leaves 


50 







February 3 


Snail, Subulina oc- 
tona 


Confined on infect- 
ed leaves 










February 3 


Snail, Subulina oc- 


Confined on infect- 


60 







• 


tona 


ed leaves 








February 3 


Snail, Subulina oc- 
tona 


Confined on infect- 
ed leaves 


30 







February 2 


Sow bug, Armadil- 
lidium vulgare 


Confined on infect- 
ed leaves 


750 







February 2 


Sow bug, Armadil- 
lidium vulgare 


Confined on infect- 
ed leaves 


300 








372 • Phytopathology (Vol. 7 

Several ant^, sow bugs, and eookroaches were thoroughly shaken in a 
water suspension of urediniospores and sporidia and after l)eing drietl 
were confined in various dishes to determine how long, un<ler eertain con- 
ditions, the spores would remain on their Indies. The methods use<i in 
making exammation for siK)res were the same as those previously given. 

SPORES IN EXCRETA 

In determining if the entire spores pass through the alimentar>' tract, 
the animals tested were either taken while feeding on diseased plants in 
the gnnmhouse, or were confined with fungus-l)earing material. Aftor 
Ix'ing thoroughly washed in several changes of distilled water to n^move 
any adhering spores, they were confined in petri dishes with blotting |>aprr 
in the bottom to collect excreta. Deposits were removed singly and each 
macerated in a small quantity, usually ten drops, of distilleil water. At 
least one-t(»nth of this was carefully examined under the microscope for 
spores. When the count was not high the entire quantity was examintMl. 
rather tlian a part. Due to the difficulty in counting, and the fact that 
in manv c:ises onlv a portion of the material was used, coimts were onlv 
approximately ac'curate. 

VIABILITY OF KXCRKTKD SPORKS 

(lemiination t<»sts wen* made of the urt»diniosix>n*s n^covt^nnl fnimeacb 
excn»tal dcjHjsit. using distilletl water at al)Out 13®(\ in watch glass's or 
hanging-<lrop (>ells. Of the un»diniosiK)n»s, only thos<» piLS*^Mi by the slug 
in the first and m'coiuI fx^llets of Febniar>' 5, 1917 gave genninat ion.^. 
The H'sults showed less than one jxt cent gennination. which is consider- 
ably lowcT than the* average* germination sc»cun»d with sfxin's of th<* same 
age when taken directly fniiu infected leaves. .Vltemarfa s|k)ivs which 
pasM>d thnnigh the >ow bug on February 3, 1917 showed abundant gi^mii- 
nation. huN'ulations made from the first and s<*c(md pellets of the wivvil. 
collei-ti'tl January 12. 1917 gave |)osiiive n»sults when ino<*ulated on one 
unidentified western s|)iM*ies of Riinn, .Vnother w(»st€»m s|H»cies anti two 
plaiit> of Httns UuHiMium, togctluT with th«» check, remaininl healthy. 

The four excretal <ie|K>sits obtaintMl on .)anuar>' 27, 1917 fnmi the sIuk 
were ('oin|M»«>4'd by volume. n's|M»etively, of 25, WW, an<l 9'> |x*r c<'nt of \vm\ 
of teli:il ('oluinn>. (leriniiiation tesl> of thes4' |>ortions of telial column 
gavf an avt-raire KiTinination of only a little over thn»<» jkt ct»nt. cimsider- 
iiiK the triTHiniation of trlio>|N)n*s of a column :u< the unit. Nearly all t»f 
thi-M- <n|imiiiH |ia«l Ihh'ii rut into S4*veral pieces by the slug. Ti»sts ma<l<* 
with fri'^h. wlinlf. t«'lial rohnnii^ and with fn^sh, broken, columns «*how 
Hilly -Imiit ijifri'iriiri'*. in the jM'rrentaise"* obtaintMl. .\s the average ger- 



< 
4 



1917] Gravatt AND Marshall: Carriers OF Cronartium RiBicoLA 373 

mination of telial columns tested a week after they were removed from 
the leaf is above 50 per cent, it may be concluded that alimentation greatly 
lessens the viability of the teliospores. 

DISCUSSION 

Cronartium ribicola produces abimdant urediniospores and teliospores un- 
der greenhouse conditions but spreads ver>' slightly during the winter, 
the new infections being confined to infected plants having leaves within 
an inch or less of the ground, where moisture remains on leaves for some 
time after watering. The importance of Arthropods and Gasteropods in 
causing new infections of the fungus in the greenhouse is probably very 
slight. 

In the field, wind must play the major part in the dissemination of 
Cronartium ribicola, as various tests in and around a diseased Ribes plant- 
ing show that urediniospores are in the air in decreasing frequency up to 
fifty feet from the nearest bush and, of course, are carried by strong winds 
for indefinite distances. However, it seems fairly certain from these re- 
sults obtained with C. ribicola^ and those of other investigators of insects 
and birds with various fungi, that animals are important agents in the 
dissemination and spread of this fungus. 

SUMMARY 

1. The small animals tested were bearers of numerous urediniospores 
and sporidia of Cronartium ribicola. 

2. Urediniospores and sporidia will adhere to bodies of the animals 
under certain conditions for at least a week. 

3. Small animals feed on the different spore-stages of the blister-rust 
fungus. Their excreta contain abundant urediniospores and in some cases 
sporidia and pieces of teUal columns. 

4. Alimentation lessens the viability of both the uredinio- and telio- 
spores. 

Office of Investigations in Forest Pathology 
Bureau of Plant Industry 
Washingon, D. C. 



PRELIMINARY REPORT ON THE VERTICAL DISTRIBITIOX 

OF FUSARIUM IN SOIL* 

Minnie W. Taylor 

For the past throe years considerable difficulty has been experienced 
with the dam ping-off of seedHngs of Pinuji resinosa Ait. and P. ponderoMa 
Dougl. in the seed-))eds of the pine tree nursery at the Metcalf Botanical 
Ganien of Brown University, Providence, Rhode Island. 

The Botanical (iarden was originally farm land. It has been unculti- 
vated for some time although the hay is cut each year. The top soil is 
moderately light colored, sandy loam alx)ut 14 inches deep. Below this 
there is a IkhI of light yellow, coarse sand from 4 to 10 feet deep under- 
laid by hanl pan. The land in the vicinity of the see<l-bed« slopei^ very 
gently to the northeiu^t. 

So far as the writer can leani Fximrium has never lx»en definitdy 
reporte<l much mon» than 7 inches lielow the surface of the ground. 
The lowest (h>pth at which Jcns4»n' collected .»*oil samples appears to have 
been 8 inches, but thc»re is no sixM'ific mention at what depths the vari- 
ous fungi ocTurretl. Waksman' in s|M»aking of the deptlis at which 
fungi, including Fni<arium, wert> found states tliat *'most of the other or- 
ganisms wen» isolate<l from thc» upper 8 inches of soil," but as he does 
not say just what th(»S4» wen\ it is iin|)Ossible to tell whether Fwtanum was 
in this gnmp. Beckwith^ coll(M*ted all of liLs samples of soil 2 inches 
bc*low the surfaces Manns* mentions exfx^riments with "sick soil" in the 
greenhous(% but dtx^s not stat<' that tlu* soil was taken at any iwrticular 
depth. He In^Hcvcs that the rate of iN'iietnition of Fuiiarium thn>ugh the 
soil de|M*iids u|)<>n the sixties of FuHarium, that of potato blight Ixnng 

1 Till* invoHtiKHtion whh condiirtiMl iiithr Inhonttory of thi* liotanical Drpartint'ni 
fif hrown I'liiviTHity. <liirinfc th«' your 1915 WW. :ih h partial fulfillment for thr cir* 
%rvv of MjtHtor of ArtH. T\w writer wiHlirn t«» rxprrMH Imt apprrciation to Dr. Har- 
lan II. Vnrk fi»r liiH kind din*rtion and aHKiHtanr«* during thr proKfeas of the work 

' JchM-n. (*. N. KungfMiM Hf»r:i of the Hoil. (*firnrll \gr. Kxp. Hta. But. 315 
Vj\2. 

* \\:ik»«tii:in. S'Iiiki A. I)(»ftinfci livi* and prodiirrmyri'liuni in thr soil? Scirncr. 
n H 44: :{J(> :\S2. P.Mti 

* h«Tkuith. T. I). Hoot iind nilni infect i(»n of wheat liy noil funip in North 
Dakota. Phytopath 1: \m 17«V l«ill. 

^ \f:tiiii.>i. '1' r. l-'uM:iriiini liliKht and dry-rot f»f the |M)tato. Ohio .\Kr. £sp. 
Sta Hill .'.-♦. I'Ml 



i 



1917] Taylor: Vertical Distribution of Fusarium 375 

slower than that of flax wilt or cabbage wilt. Werkenthin* took samples 
from 1 to 7 inches below the surface and says that "in deeper regions 
below 4 inches, no viable fungous spores seem to be present." He 
adds that *'of special interest in the study of soil fungi is the fact that • 
the virgin soil contained fungi which are known to be parasitic to culti- 
vated plants, e.g., Fusarium Solani (Mart.) Sacc, F, oxysporum Schlecht. 
and F. radidcola WoUenweber." In summarizing he says that "patho- 
genic fungi, especially species of Fusarium^ Uve in the soil as saprophytes 
throughout the winter." 

In a large number of cultures, on nutrient agar, which have been made 
from pine seedlings that had damped off, Fusarium sp.' was the only fungus 
found that is known to cause damping-off. Moreover, it was observed 
that in the seed-beds made from sand taken 18 to 24 inches below the 
surface of the ground, damping-off occurred just as abundantly apparently 
as in the beds made from surface soil. 

The beds in all instances were made in the usual way. Because of this 
fact, the present problem was suggested, namely to determine to what 
depth Fusarium occurs in the soil of the nursery and also whether it is 
present at different places in the grassland surrounding the nursery. The 
following is merely a preliminary report, the first to be made on the results 
of a series of investigations. 

METHODS 

Six lots of soil Aj B, C, Dy E and F, were collected. The first three lots 
were taken in November and the fourth in December, 1915, the fifth in 
January and the sixth in March, 1916. 

Trenches were dug varying from 12 to 34 inches in depth, one trench 
for each lot. Soil samples were collected from the upper side of undercuts 
in the sides of the trenches at intervals of about 2 inches, from the sur- 
face of the ground down to the bottom of the trench. Lot A was taken 
from the grassland about 10 feet north of the northwest comer of the 
nursery. Lot B also came from the grassland 100 feet north of the north- 
west comer of the nursery. Lot C was taken from a seed-bed of Pinus 
resinosay planted in 1914 in which all the seedUngs had "damped off." 
It was neither planted nor cultivated in 1915 and contained no green 
plants. Lot D consisted of samples taken no deeper than 12 inches from 
a white pine grove several miles from the garden. E was collected in a 

• Werkenthin, Frederick C. Fungous flora of Texas soils. Phytopath. 6: 241- 
253. 1916. 

' In the preliminary experiments no attempt was made to determine the species 
of Fusarium. Consequently the term Fusarium as used in this paper is to be taken 
in the collective generic sense. 



376 



Phytopathology 



[Vol. 7 



portion of a transplant bed which was made in 1914 and in which the 
treeH had died from drought. This plot although cultivated in the ffn^Mm 
of 1915 contained no seed plants of any sort. I^t F was taken alxnjt 4 
feet from E in the same sort of soil. 

In the digging of the various trenches no precautions were taken againM 
contamination from the air with the exception that the collectionj* were 
made as soon as jwssible after the earth was exposed so that the sterilized 
boxes in which the soil was placed were not open to the air any longer 
than was abs<)lut<*lv n<'n»ssarv. 

TABLK I 

Shoii'ttiij til ffihs II* iihi'rh stimplrs wtTv voUevted ami in which Fiinarium *H'rHrr«ti 



D 



E 



»' r, F 

ovl^ 1-^ I. . I lovi^ /l 1 . I »TVi'. L .1 I I *I^** WhiU-riri#' 24Jal« Tran*- ISMrl« Trat- 

Orovo |:lant neti |»lAAt lW«t 



■ I 



Surfarc 

1 


Sill 


f;irr 


Siirfarr* 


1 
'2 incfirs' 


:\i 


licfir?** 


1 iiicfi* 


;} 


.'i 




2 iiichcH 


.'» 


() 




:r 


s 


s 




4 


10 

1 


10 


1 


ti 


I- 


11 




s 


11 


i:{ 




ur 


u\ 


n 




12 


I'lr 


n; 




It 


Jl 


IS 




u\ ! 




M 




IS 


* 


•>•» 




JO 




•Ji 




■»•) 


'■ 


2t\ 




2\ 
Jti 

2S 



Siirfan* 

•Jinrlu-j* j 

4 

i) 

10 ; 

12 



Surface 



I 

*< i 

10 

12' 

II 

JO 
J I 

! 



Siirfar** 

4' 

H* 
10* 
12* 

!»•»• 
IS- 

JO* 
■»■»• 

21* 

25* 



• c 



S.-impIr-* in wliirli h'u-m . •mt 0('riirri-«l. 

Twci kinds (»f rultun' media were UM*d. oatmeal agar and soil agar, the 
foriiHT nil th«' wliolr up|M'aring t<» give the ln'tter n*sults. The S4>il agar 
wa^ niatie art'ording to the s4»eon«l formula <lewrilKxl by Jensi^n. Al- 
tlKMjjjIi tlii?< medium was very satisfactory thire wiu* ap|iart*ntly too little 
ditTeren(*e in the reartioii of the fungi toward it to pay for the additKinal 
tin If HI pre| firing it. IVaetieally tin* only advantage w:is tliat a more 
ro*»y rujor \va^ pn>dure«l by the Fusarmm <»n the soil agar than on tlie 
o:itiii(:tl a^.'ir. 

riir rultiiri-*- wen* made in the following mann«'r: aUmt 1 gram c>f Miil 
fmni raeli siiiiplc ua^ ^li:'ken up witii 1(N) vr. of di>tilled water in a }Kt4*nl- 



1917] Taylor: Vertical Distribution of Fubarium 377 

ized bottle. With a sterilized pipette 1 cc. of the solution was taken from 
each bottle, added to 10 cc. of melted agar and plated. Two plates were 
usually made from each bottle. The samples of lots E and F were placed 
in sterilized glass jars and thoroughly shaken to mix the soil well before 
making the solutions. At first the solutions were allowed to settle five 
minutes before pipetting ofif, but in E and F the 1 cc. was taken immedi- 
ately after the solution had been well shaken. There was practically no 
diiference in the number of colonies produced by the two methods. When 
fungous colonies appeared in the plates isolations were made in the usual 
manner for obtaining pure cultures. 

RESULTS 

As was to be expected a great variety of fungi developed in culture. 
Fusarium was found in the cultures from the soU taken both from the 
nursery and the grassland; in the nursery Fusarium occurred practically 
at all depths examined, not in all lots, from the surface to a depth of 24 
inches, while in the grassland it was found at only three depths, 2, 3 and 
20 inches. The finding of Fusarium in the cultures made from the soil 
of lot A taken at 20 inches from the grassland may have been the result 
of contamination although every precaution was taken to prevent it. 

In lot A Fusarium was found at 2 and 20 inches below the surface; in 
B at 3 inches below; lot C, at the surface, 1, 3, and 10 inches. Micro- 
and macrospores were found in lots A, B and C. No fungi which are 
known to cause "damping-off^' were found in lot D. In Ej Fusarium oc- 
curred at 2, 12 and 16 inches and in these cultures many chlamydospores 
were observed as well as micro- and macrospores. Fusarium was found 
in lot F at every depth examined from 2 inches down to 24 inches, micro- 
and macrospores being most abundant, and chlamydospores fewer than 
in the cultures from lot E. 

A possible explanation for the occurrence of Fusarium at the lower 
depths is that it may follow down Uving roots of such plants as clover 
and grasses as a parasite or the dead roots as a saprophyte. Sackett* 
beUeves that the character of the soil influences the depths at which bac- 
teria occur; possibly the same is true of fungi. In arable soil Sackett 
finds that bacteria occur most abundantly in the first 7 or 8 inches, while 
in soil whose texture is loose and open they are found at lower depths. 
In irrigated soil he states that bacteria are carried down to a depth of 
8 to 10 feet by irrigation water and alfalfa roots, and that in compact soil 
the lower limit is much nearer the surface. 

■ Sackett, W. G. Some soil changes produced by microorganisms. Colorado 
Agr. Exp. Sta. Bui. 196. 1914. 



378 Phytopathology [Vol. 7 

Moreover, it is probable that other agencies such as spiders, earthworms 
and larvae of May-lx^tles and other insects play a considerable part in 
the distribution of fungi in the soil, since spores may be carried down on 
their Ixxiies or may be washed down through their tunnels from al)ove. 
Earthwonns and larvae of insects were found at the lowest depths at 
which soil was taken and cultun*s made from the contents of the ali- 
mentary canals of two earthworms revealed the presence of Fu^ariutn. 

BoUey* l)elieve8 that a certain amount of moisture is necessary for a 
large development of cc^rtain fungi in the soil and mentions drainage 
water as a means of distrilmtion. 

Various investigators consider climate an important factor in conne**- 
tion with soil fungi. 

Heckwith thinks it is |X)ssible that climatic conditions may intlui*nre 
**the myrological flora>i lM)th siiprophytic and parasitic/* 

Conn^" finds more l)act(»ria present in frozen soil than in unfrozi'U S4»il 
and points out th<' nivd of investigation along the line of seasonal varia- 
tion auHing soil bacteria. 

The rrsults obtained by the writer also se(»m to indi(*ate a jxis^ibh' -M-a- 
sonal variation of fungi since Fusarium (K'curred at so many nion» depili?* 
in March tlian during the previous winter mctnths. It is also evident 
that what i> true for bacteria may not necessarily U» true for fungi a.* 
mon» Fu.'^nnnw wa> found in unfroz(»n than in frozen soil. The (|ue>ti«>n 
of seasonal variation of soil fungi is reci'iving further inve.*^tigation which 
is to Ik' reiM)rte(l lat4'r. 

SIMMAIIV 

1. Preliminary investigations to determine the <lepth to which Funtiriurn 
is pn*sent in soil in<licate that Fusttrium <H'curnMl to a <h*pth of 24 inch**" m 
thi' iiurMTV soil. 

'2. Fu.snrium occurred in mon» .»<ampl<»s of soil from the nurs^Ty than 
from the grassland. 

.'{. Fu>ariufn ap|M'ared in culture from mon» siunples in March tlum in 
the previous winter months indicating a |)ossible s(*a.s4mal variation. 

' liollcy, 11. I.. Flnx wilt and flax nick Hoil. North Dukotn .Xgr. Kxp St.i HiI 
" ( oi.ii. H. JiH'l. Hartrria in fn>Xi*n *»il. Now York '(loneva .\ur. Kxp St i 



BRIEFER ARTICLES 

NOTES ON WOOD-DESTROYING FUNGI WHICH GROW ON BOTH CONIF- 
EROUS AND DECIDUOUS TREES. II. 

James R. Weir 

Since the appearance of number I of this series,^ additional collections 
of fungi growing on the wood of both coniferous and deciduous trees 
have been made. Correspondents have also contributed several inter- 
esting specimens with notes on host, range, and general habits of growth. 

The mere Usting of unreported hosts for saprophytic wood-destroying 
fimgi which may occur on any woody substratiun in the absence of the 
typical or common host is in most cases of mycological interest only, 
provided the species are correctly interpreted and a nomenclature of 
recognized standing employed. The preparation of such Usts possibly 
serves a useful purpose, if much material is handled, in that it brings the 
collector to the realization that a new species does not lurk in every 
unusual form encoimtered. A thorough imderstanding, on the other 
hand, of the host relations of wound parasites is of great economic im- 
portance, for on this may be based plans for the proper silvicultural man- 
agement of mixed forests. It is also of interest to note the occurrence on 
coniferous wood of fungi commonly found on the wood of dicotyledoneous 
trees which, although of no practical importance so far as wound parasites 
are concerned, may be so considered with respect to the destruction of 
fallen timber. It is to be noticed that a greater niunber of fungi commonly 
associated with the wood of deciduous trees is found on coniferous wood 
than is the reverse. This is particularly true in Western United States 
where great bodies of pure coniferous forests exist. 

Dcedalea confragosa (Bolt.) Fr. on branches of Abies grandiSy Belling- 
ham, Washington. Owing to the fact that the fungus is so closely asso- 
ciated with deciduous trees, especially willows and birches, its discovery 
on coniferous wood is surprising. The fungus was abimdant on its 
usual hosts at BelUngham. The specimen collected is of the form known 
as Trametes rubescens (A. & S.). 

Dcedalea unicolor (Bull.) Fr. on fallen branches of Abies lasiocarpa, 
Priest River, Idaho. Semi-stipitate form but otherwise typical. 

Irpex lacieus Fr. on Betula occidentalis, Priest River, Idaho. Speci- 

* Weir, James R. Notes on wood -destroying fungi which grow on both coniferous 
and deciduous trees. I. Phytopath. 4:271-276. 1914. 



380 Phytopathology [Vol. 7 

men collected and contributed by J. Huot. Fungus usually occun* in 
this region on Tsuga, Abies, and Picea. 

Polyporxis albellus Peck, a common birch wood fungus in the North- 
west, has l)een collected once at Laclede, Idaho, on dead branche?* of 
Abies grandis, 

Polyporus elegans (Bull.) Fr., usually on soft wood of deciduous trees*, 
collected on branches of Tsuga heierophylla, Priest River, Idaho. 

Polystidus abietimis (Dick.) Fr., snudl s|K*cimens on Populus trtcho- 
carpo. Typical. 

Schizophyllum commune Fr. on Tsuga heterophylla^ Seattle, Washington. 
Sj)ecimen contributed by Dr. J. W. Hotson. 

Trametes cornea (Ne<»s) ('cK)ke, on fallen trunk of Arbutus menztesit. 
Grants Piiss, Oregon. One small sporophort*. Species is usually zonate. 
Collection luis no surface* markings but otherwise* typical. 

Trametes heteromorpha (Fr.) (Lemites heieromorpha Fr.) iDtnialra 
heteromorpha Fr.) This plant usually grows on conifiTous wood but is 
found occji>ion:illy on Alnus. Lloyd* recently descrilH»<l a new s|M*rir* 
(Trametes lacerata) colhTted on Alnus which probably Ix^longs liere. The 
port*s of Trametes hetrromorpha are ver>' variable. It is V(»r>' seldom a 
true I>»nzites and i> a In^tter Trametes. 

Trametes hispida Hagl. on I'sntdotsuga tajifolia. (\>ntribute<l l»y Dr. 
J. W. Hotson, Seattle, Washington. Very unusual host. In Ain«*ncm, 
practically c<mfined to Populus and Salix. CollecttMl by the writ«T in 
Eurojx* (Bavaria) <m Fnixinus. Other collections by the writer in 
Bavaria and Serbia are cIomt to the Am<»rican plant known as TrnmtUM 
peckii Kalch. tlum any Kuro|H*an material so far examincMl. In view of 
the fiu*t that tlie Kuroi)ean plant has usually smaller pores, is thinner. 
• and of a distinctive* brown color, it nmy cause* less confusion if tin* two 
fonns arc* held distinct. Anwrican pliuits in the writer's herl»ariuni rt*- 
ferred by Peck to Trametes tragi i Berk, more nearly r<»pr<»sent the Kun>peaii 
plant in this country-. 

Tramdes scrialis Fr. is usually foimd on conifenMts woexi. Speciinrns in 
the* write*r's herbarium jire lalK*le*d **(\)lle*cte»d on Populus trtmuUndes, 
(iila National Fon*st, Ne*w Mexico.** The mune of the e'oIU*ctor i.* not 
given. The sjXTimens luive smaller |X)n*s than is u.*<ually the case. 

Tramdes variiformis I\*ck, on lietula iKcidentalis^ Bellinghani, Wa?»h- 
ingtoii. This si)e»ries may U* consi<len»<l a rare fungus e\*en on conifirous 
wesKl. 

OKFK K OF LWKSTKiATloN IN FoRKST PATHe)UKfY 

BiHKAr OK Plant Indistky 
Miss4»i LA, Montana 

MJoyd, (*. (;. MyrttloKirnI SnU-B. .\o. 43. p. (MM. 1916. 



THE SPRAY METHOD OF APPLYING CONCENTRATED FORMALDEHYDE 
• SOLUTION IN THE CONTROL OF OAT SMUT 

R. J. Haskell 

The treatment of oat seed for the control of the smut diseases, caused by 
Ustilago avenae and U, kevis was placed on a commercial basis at least in 
North America when BoUey^ announced the effectiveness of dilute for- 
maldehyde solution. The sprinkling method as perfected by him and 
his contemporaries was adopted generally by American plant pathologists 
and is, at the present time, the common method of oat seed disinfection. 
In spite of the fact that it is one of the easiest, cheapest, and most efficient 
methods of plant disease control, it is not as widely employed as it should 
be, even with the great amount of publicity that has been given it. The 
wetting of the seed is objectionable to many. 

Bolley* recognizes that a dry formaldehyde treatment would prove 
more popular with farmers and made some tests with this idea in mind. 
He obtained very encouraging results but has not yet proposed a method 
that can be put into practice on a large scale. Clinton' performed an ex- 
periment in the laboratory which indicated strongly that formaldehyde 
can be employed as a vapor in disinfecting oats to prevent smut, but noth- 
ing further seems to have been done by him looking to the elimination of 
the great volume of water called for in the original formula. Wheeler's 
work* with the influence of formaldehyde vapor on wheat seed and stinking 
smut also indicates the possibiUties of this substanceas a smut preventive. 
Arthur's* rapid method of spraying falling grain in elevators with a 25 
per cent formaldehyde solution is in reality a wet process rather than a 
dry one. 

In view of the desirabiUty of a dry treatment the writer has conducted 

^ Bolley, H. L. New studies upon the smuts of wheat, oats and barley. North 
Dakota Agr. Exp. Sta. Bui. 27: 109-162. 1897. 

* Bolley, H. L. The prevention of smuts of cereal grains and prevention of po- 
tato scab. North Dakota Agr. Exp. Sta. Bui. 37: 363-379. 1899. 

' Clinton, G. P. The smuts of Illinois agricultural plants. Illinois Agr. Exp. 
Sta. Bui. 57: 289-350. 1900. 

* Wheeler, W. A. Preliminary experiments with vapor treatments for the preven- 
tion of the stinking smut of wheat. South Dakota Agr. Exp. Sta. Bui. 89: 1-19. 
1904. 

* Arthur, J. C. Rapid method of removing smut from seed oats. Indiana Agr. 
Exp. Sta. Bui. 103: 257-264. 1905. 



382 Phytopathouhjy * [V«>l. 7 

laboraton' aiul field experiments covering a period of four yeaiv, with the 
upe of concentrated solutions of formaldehyde. 

As a result of the investigation it has been found when one pint of un- 
diluted 40 per cent formaldehyde solution Ls well distributed through 
fifty bushels of viable oats seed, which are then covered for five hours, 
that the germination of the oats is not impaired and the smut* dbtea.^ b« 
controlled. 

The amount of formaldehyde gas given off in evaporation is gn^at 
enough to penetrate through the pile and to destroy all smut spon*?*. 
(>n th<» other hand, the small amount of concentrated solution applied a.« 
a spray is insufficient in quantity to wet the seed to such an extent as to 
pennit any absori)tion and cons<Hjuent injur>'. In fact it often happea-* 
that s(M'd thus treated genninate cjuicker and more vigorously than tho^e 
remaining untreated. This may indicate that the formaldehyde vapor 
has a stimulating influence on germination comparable to that resulting 
from etherization, or there is a |>ossibility that the phenomenon may in* 
explained by th<» fact tiiat the treatment fret*s the sc»<mI from (vrtain s^Mni* 
parasitic and injurious organisms that may Ih» associated with it. 

When this method wits first put into practice it was found that one 
pint of fonnal(lehy<le solution was hardly sufficient to satisfactorily cover 
fifty bushels of oats. Subs(H|U(»nt tests brought out the fact that the com- 
mercial 40 per cent solution could Ik* dilute<l with water to one-half stn^ngth 
and then applied at the rate of one quart to fifty bushels of mhhI with 
U'tter results. 

The metluwl as n»vi.sed and as at present n*commende<l may In* briefly 
outline<l i\s follows: As the s^hmI is l>eing shovelcMl fnmi one piletoan<ithi-r 
each shovelful is spray<»d with a sohition consisting of one part of 40 per 
cent licjuor of fonnuldehyde and one part of water. This solution is u««»«l 
at tlu» rate of one (piart to fifty bushels of see<l. A small quart spniyer i* 
a <*onvrnicnt one to u.^» for the puri>ost». After the oats are all tn*at4^i m 
this way they an* piled in a heap and covennl with blankets, canvsis. t>r 
sarks to <-onfine the vai)or. .\t the end of five hours the seeil may !»«• 
uncovered and planted. As fonnaldehyde va|)or acts as an irritant %•* 
the mucous membrane of the eyes, nose, and throat, the sprayer >hould 
be held down close to the pile and a circulation of air should be pruvidt*d. 

T\\r conclusions stat^^l alM)ve :ls to the effect ivem^ss of this met hoil an* 
ba.M'<l on thn^* iK'rsonally conduct^^l field exp(*riments in two difTen^nt 
M'a.M»ijs. and ninet(*en c(M>|H'rative exiKTiments. all of which were acc«>in- 
pani<<l l>y gennination tests for schmI viabiUty. In addition to thi*. to 
in>un' that \\\vyv imi'cI Ik» no* hesitation whatever in reconunending the 
tnatiiM'iit to fanners, it should Im' stated that numennis favorable ti*^ti- 
in«»iiial> liavr ln'«*n rrfrived from thoM* who have trii»<l th«» method. 



1917] Haskell: Control op Oat Smut 383 

• 

The field experiments were carefully checked, there being in one case a 
control for every two trial plots. All precautions were taken to avoid 
recontamination of the seed after treatment. These precautions in- 
cluded the use of clean containers, disinfection of the drill, and a considera- 
tion of the order of planting the different lots of grain. In all germination 
tests from one to two hundred seeds were used, and in recording the per- 
centage of smut two or three thousand panicles were coimted in different 
parts of each plot. The amount of smut in some of the checks ran as high 
as 25 per cent while that in the plots of treated seed was negligible. 

In the cooperative experiments the amounts of treated seed varied from 
two to thirty bushels. In these cases the treatment was supervised or 
made by farm bureau agents or other competent persons. Treated and 
untreated seed were in all cases sent to the writer and tested by him for 
germination in the laboratory. Suitable checks were left in all cooper- 
ative fields and the percentage of smut in them detennined in most in- 
stances by the cooperators themselves. Some of them reported qs high 
as 25 per cent smutted heads with practical freedom from smut in treated 
plots. 

The chief advantage of the dry method over that in which the 40 per 
cent solution of formaldehyde is sprinkled at the rate of one pint to forty 
gallons of water Ues in the fact that the seed is not wet. This makes it 
possible to drill immediately after the disinfection is completed, a very 
important item when weather conditions are considered. The oats do 
not swell nor do they cause trouble by sticking in the drill. The opera- 
tion is simpler than that of sprinkling, and the treatment is effective and 
non-injurious to the seed. Furthermore seed disinfected in this way can 
be kept several weeks after treatment without danger of deterioration. 
The method has met with favor in practically all cases where it has been 
tried. 

Cornell University 
Ithaca, New York 



REVIEWS 

Inlaxicating Bread, N. A. Naumov. P'iany Khlieb (Intoxicating Bread). 
Trudy Biuro po Mik. i Fitopat. No. 12, pp. 1-216, pis. I-YIII, 
Petrograd, 1916. 

A. Pomafwki. Ob Izmienen. Khim. Sostava Kzhi pod Vliian. Zhixn. 
Niekot. Form Fusarium (C^hemical Changes in Rye Due to the Ac- 
tivities of Certain Forms of Fusarium). Soobshch. Biuro po Chastn. 
Rasten. No. 1 (1916), pp. 1-32, Petrograd, 1916. 
Considerable attention has been given in reeent years by the Ruivian 
pathologists to an epiphytotie of eereals, known locally as drunk brea^l or 
intoxicating brt»a<l, ascrilx»d to certain species of Fusarium. It afFects 
rye, wheat, barley and oats, the maximum infection olwer\''ed being 88 
per cent on barley in 1912. The general appearance of the affcK*ted ceremb 
in the field is practically identical in all varieties, a pale gri»en color when 
young, smaller straw and heads, pink to red and orange-red sponxlochiA, 
and, in isolated cases, perithecia at the bases of the stems or in tlie nodes 
and on the sheaths. The affected grain acquires toxic qualities which are 
subsequently communicatee! to the flour and the breml. When thojie 
latter are used by men and animals typical symptoms of poisoning n*»tult» 
i.e., headache, gc»neral weakness, and fn^juently nausea and vomiting. 

The dis<»ase is known Iwth in Kuropean and Asiatic Russia, but with 
res|MH*t to its refx^atedness, vigor, and proportions the Primorski region 
of Piistem Silx*ria appt'ars to Ik? classical.* It was recognized there 
long ago by the Chin(»s<» farmers by the surface film on the affected grainn, 
callfMi mi-chun. Russian colonization of this region Ix'gan in 1862. an<l 
first m<*ntion of the disease* by a scientist was made by Palche\^ki in 
1HS2. Since then a numlxT of pe^rsons, including mycologists, path<4o- 
gists, and physicians have lxH*n working on this phenomenon, f*. rattrufm 
almost invariably (x*cumMl in cultun^s made from the diseaMnl (^ereab, 
and (). K. Ctabrilovitch in 1906 demonstrated the toxicity of this funinia. 
HyfMMlrnnic inje<*tions have l)een made into frogs with the extract fffHn 
purr rultun^ of the Fusarium with the n»sult that the latter died within 
thn-i* to f(»ur hours after in(K*ulation. The toxin was suppcxted to lie a 
nitn»griH>us gluro(^id<*. 

S'vrral y<'ars ago the Bureau of Mycolog\' and Phytopathology of Pr- 

•Ofthf <ithrr rotintrirH it ban In^rn n»|)<>rt4Mj in SwtnJi»n and Francr 'Prtltirus 
and Di'larruix, .MalHdi(*ii dm plantt'H). 



1917] Reviews 385 

trograd determined to make a thorough investigation of this trouble and 
formulated two distinct problems: (1) my co-pathological, isolation and 
exhaustive study of the causal organism with possible reference to the 
control measures, and (2) biochemical, a study of the chemical changes 
which take place in the affected grains and the isolation of the active 
toxin. 

The first problem was taken by N. A. Naumov, who just recently pub- 
lished a very interesting report on his work. He submits evidence that 
the phenomenon "drunk bread" may be caused by either of two species 
of Fusarium, namely, F. roseum Link, (also its ascus stage Gibberella savbi- 
netti Sacc.) and F. svbidatum App. & Woll. The chief distinctive feature 
of the disease outside of chemical and physiological pecuUarities, accord- 
ing to the author, is the presence of the mycelium inside of the grain tissues, 
which can be proven either microscopically or by means of -germinating 
the seed. Red or pink color of the grain and presence of sporodochia or 
perithecia cannot serve as leading characters, as they sometimes may be 
absent even when the grain is plainly affected. In the stems grown from 
the diseased seed the myceUimi has been found nesting in the tissues and 
penetrating the cells and intercellular spaces, but it is absent in the vascu- 
lar bimdles as well as in the primary meristem. No anatomical changes 
were observed in the infested stems, but the seeds suffer severely, as starch 
is dissolved and frequently the embryo is miunmified. The disease is 
communicated to the new crops through infected seed or infected soil, or 
from an adjoining infested field. The germination of ascospores and 
conidia takes place in neutral^ slightly acid or slightly alkaline media, a 
sUght alkalinity being tolerated better than the corresponding acidity. 
An excess of moisture in cultures favors the growth of mycelium but is 
imfavorable for the production of conidia. The best media were found 
to be rye in grains, heads of wheat, heads of rye, and milk. The minimum 
temperature for germination of conidia is 4°C., optimum 28^0., and maxi- 
mum 32®C.; for ascospores, 8**C., 30*^C., and 32®C. respectively. Opti- 
mum growth of mycelium occurs at 30^C. ; there is no growth below 3°C. 
or above 33°t). The best formation of the conidia and perithecia is at 
20**C. Change in temperature is more beneficial for fruiting than injuri- 
ous. Heating of ascospores for twenty-four hours at 65°C. destrojrs their 
ability to germinate. The mycelium completely loses its vitaUty in 
grains if the latter are stored under ordinary conditions for a period of 
three years. Heating rye for twenty-four hours (and up to three days) 
at 66°C. and wheat, oats and barley at 60°C. does not affect the vitality 
of the seed, but kills the infesting mycelium. This may prove to be the 
chief method of treatment. Other control measures suggested are, (1) 
selection of healthy seed, (2) two to four years crop rotation with root 



386 PinTOPATHOLOGY (VOL. 7 

crops and legumes as intermediate crops, (3) threshing at oum* aftor har- 
vesting and iH)ssibly treatment of the portion intended for seed with 0.5 
to 1 per cent copper sulfate to prevent spread of the disease in storafce 
(in this ca.se the s^^ed should be drietl Ix^fore putting in granaricj*), and 
(4) general sanitation and disinfection of sacks and implements. Positive 
results were obtained in artificial inoculations when soil, shoots, and 
heads were infected with the conidia and the ascospores and when soil 
and shoots were infected with the mycelium. Considerable attention is 
given by the author also to the taxonomic side of the problem. 

The bi(H*lu*mi(*ul |)art of the problem lias iKH'n studied by A. Toniawki, 
and a preliininur>' \m\yL*T dealing with this work has l)een aln*ady publi>hed. 
In it the author shows the chemical changes which take place in r>*e as 
the result of the activities of F, rosrum and F. subulatuffi. He fincb ttiat 
thes<» activiti(»s lead to a mark<Ml loss of dry substanc<*s, which decn*as«» to 
GT.Ii |HT cent in ton days and to 25.1 {mt cent in two niontlis. Tlus \tt»A 
takiv place <'hi(»fly at the exiH»nse of starch and proteins. IX»cn»aM» of 
starch in one month of decomiM)sition n^aches from t)l toSOfiercent and 
in two months from 80.5 to 89.5 jxt cent of the original <|uantity. De- 
crease of the general amount of nitrogen in two-month'scultun*s equals 12 
to Hi JKT cent. Both forms of Fusarium affect r>e in more or les» the 
same way. Other changes as well as the products of deconifMisition are 
to a certain extent determined. A detaile<l stuily of thc»se products and^ 
particularly, isolation and .*<tudy of the toxic substaniT of ''drunk bread" 
will constitute a subject for the further studi(»s of the author. 

Ml( ll.VfX SHAP<»VAUJV 

Maunal of FruU D^sm^a*. By Ix»x K. Hesler and Herl)ert Hice Whetsel. 
XX -f 4<)2 pp., 12ti illustrations. I^ibli.stuHl by the Macmillan (\impany. 
New York. 1917. 

Tlu' UN)k is one of the publisher's si*ries of Rural Manuals and has U*en 
written with the definite aim of giving the fruit grower a working knowl- 
edge of fruit (li.M'2L<M»s. The treatment of the .Mibject is fmni ttie field 
rather than from the lalH>nitory stand|K)int. 

The arrang(*iiient is alphaU*tical by rro|>s, the dis(*ascs under each crup 
lieing approximately in the ord<*r of their eeonomic importance. Tlie 
fruit «ri»ps include<l an» applt\ aprieot. blaekU»rr>', cherr>', cranberr>\ 
currant, giMix-lM-rry, grajx*, |)(*a4'h, |H»ar, plum, (|uinc(*, rasplierr\' and 
^trawlNTry. There i> a ('onris4* ehapt4T on the pre|>aration and applica- 
tion of fungi(*ide>. Disea^^s eonuiion to more than one host are discusscHl 
fully under the moM imjMjrtunt one and listed under others with such 
h|N'ei:il eomment a** may l»e warranted. 



1917] Reviews 387 

The discussion of each disease of major importance includes its general 
history, geographical range with special reference to regional occurrence 
in the United States, the nature and extent of losses caused, general effects 
on the host and diagnostic symptoms, relative susceptibilities of host 
varieties, the cause of the disease with discussion of contributory factors, 
the life histories of parasites with particiilar reference to seasonal develop- 
ment and conditions influencing outbreaks, control measures with em- 
phasis on the rational basis for such measures as well as on the practical 
details of their application. Well selected illustrations give typical gross 
features of the diseases. Minor diseases are accorded unusually f\ill dis- 
cussion. Reference lists imder each disease direct the reader to the more 
important readily available pubUcations, mainly American. 

Out of consideration for the grower technical details of taxonomy, mor- 
phology and histology have been omitted; and the use of technical terms, 
while not by any means avoided, has been reduced to the bare require- 
ments of concise statement. A glossary gives brief definitions of many 
of these terms. 

The style is not the unfortunate kind that sometimes characterizes the 
popular treatment of a technical subject. It has the directness, clearness, 
exactness and suitableness expected from scientists who are also teachers. 
The book can be read by either layman or specialist without mental fatigue. 

Any student of plant pathology will find the book helpful for reference. 
With the usual laboratory work to supply a proper morphological and 
histological framework, the only important limitation to its usefulness as a 
textbook in general plant pathology courses is the restriction of its scope 
to a particular group of diseases. 

A few defects will be apparent to the critical grower or pathologist. 
These cannot be pointed out in detail in this review; they would require 
in the main but sUght revision for remedying — a shifting of emphasis 
here and there, a fuller explanation and illustration of certain technicali- 
ties, the correction of occasional lapses from the usual excellence of treat- 
ment, the addition at times of another desirable reference, the inclusion 
as synonyms of imperfect stage names of fungi that have been known com- 
monly by such names, the amplification or modification of details in cer- 
tain control procedures, the giving with greater reserve of recommenda- 
tions for control by dusting with sulphur, a broadening geographically 
of the intimate statements about orchard conditions Attention may be 
called to dijBferences in the usage of common names from the provisional 
list prepared by the conmiittee of the American Phytopathological Society. 
For apple, apricot and blackberry, thirty of the diseases listed by the 
committee are treated in the Manual; twelve of these are under preferred 
conmion names different from the committee's recommendations; and in 



1917] Phytopathological Notes 389 

Methods for the differentiation of pathogenic fungi in the tissvss of the 
host. In the investigation of problems in plant pathology it is frequently 
desirable to be able to locate and trace the mycelium of a pathogenic fun- 
gus in sections of the tissues of the host plant. To this end recourse is 
usually had to some method of staining by which the hyphae may be differ- 
entiated from the cells of the host. For this purpose several special 
stains and methods have been devised, notable among which are Durand^s^ 
and "Pianeze III b," as described by Vaughn.* It is said that these 
stains, while producing excellent differential effects with some material, 
can not always be depended upon to define sharply all mycelium regardless 
of species and fungus and host. 

The writer has been fortunate in the application of two methods which, 
so far as he is able to determine, have not been described heretofore in 
this connection.^ These methods are stated here in the hope that they 
may be effective when others fail to give the desired results. 

The first method consists of a methylene blue-clove oil-eosin combina- 
tion* applied to paraffin or free-hand sections as follows: 

Having dehydrated the sections in absolute alcohol, stain 3 to 30 min- 
utes, or longer, in a filtered, saturated solution of methylene blue in abso- 
lute alcohol; rinse off excess of stain in water; dehydrate rapidly by flooding 
inclined sUde with a few drops of absolute alcohol; drain immediately and 
flood sections with a few drops of a filtered saturated solution of eosin or 
erythrosin in clove oil; watch extraction of methylene blue and taking of 
counterstain with microscope until desired effect is produced (which 
should be in from 1 to 10 minutes) ; flood inclined slide with a mixture of 
equal parts of absolute alcohol and xylol to remove excess of clove oil 
stain and prevent formation of an objectionable red precipitate, and place 
in xylol to clear. 

This method, judiciously followed, produces a deep blue stain in the 
protoplasm of the fungus and a lighter blue in the protoplasm of the host 
cells, while the cellulose cell walls of the host take a deep pink or red, 
as well as the walls of the hyphae. Hence, if a piece of mycelium traverses 
or lies in a cellulose host cell wall, its course is shown by the blue stain 

* Durand, E. J. The diflferential staining of intercellular mycelium. Phytopath. 
1: 129-130. 1911. 

* Vaughn, R. E. A method for the differential staining of fungous and host cells. 
Ann. Missouri Bot. Gard. 1: 241-242. 1914. 

* Dr. Neil E. Stevens and Dr. Lon A. Hawkins have been kind enough to men- 
tion the first of these methods in the Jour, of Agr. Research 6: 362, and 635 (foot- 
note), 1916, respectively. 

* Zimmerman, A. Botanical Microtechnique (Translated by Humphrey, 1893). 
On p. 185 the use of eosin in clove oil as a counter stain in Gram's gentian violet 
method is mentioned. 



390 Phytopathology (Vol. 7 

of its protoplasmic contents, while if it passes through protoplasm of the 
host, its path Ls marked by the pink-stained walls of the hypha and it« 
frequently more dense protoplasm. The presence of fungi in liicnified 
elements of the host is shown by the pink hyphal walls afcainst the blue 
background of the lignified walls. 

It has lH?en found that the methylene blue sometimes washes out too 
easily from the protoplasm of the fungus. Mordanting the s<»ctions in an 
aqueous solution of tannic acid (al)Out 10 per cent) for half an hour, 
washing in water, and dehydrating to al>solute alcohol lx*fon» applying 
the methylene l>lu(» l«u< provinl to l)e of considerable advantage in hohl- 
ing the >tain in the protoplasm of the fungus. 

The s<»cond method, anilin water, safranin an<l clove oil — lichtgnuiMnay 
Ik? des(TilK»d as follows: Stain s4»ctions 1 to 12 hours in anilin water safra- 
nin;'' rins«» in wat<T: d<*hydrate by giving .slide a (juick dip into ea<'h of 
70 |KT cent, [)!\ jht cent an<l absolute alcohol; flood s<H'tions imnieiliau*ly 
with a few drops of a filtcn»d, saturate<l solution of lichtgriin in dovt* oil 
(twice notified); prorcrd as for first method. 

The dilTen*nliatioii of th(» fungus in thisca.s4» deiM»nds ufxm the de<»p m\ 
stain of its protoplasmic <'oiit4*nts against :• light griH'n in the crllul<»4' ivU 
walls of the hoM or the light gnM»n hyphal walls against the pink or nni 
protoplasm or lignified cell walls <if the host. 

The S4'cn»t of success with thcM* .stains si^ems to lir in retaining as much 
as |K>ssible ot" thr first stain in the protoplasm of the fungus U^fon* the 
application of tlu* clovr oil stain. This latter extracts the first >tain in m 
difTen*ntial mannn* an<l at the .saiiH* time has a coimter-staining rfTit-t. 
hei)cr thr iiccrssity of can»fully watching the fir.»*t few slitles of a st'rit-H 
from a lot of mat«Tial in order to detennine the time n^quin^d f<ir i*aib 
oiMTation. While >lidi»s stain^nl l»y tlu»s<» metho<ls have U»en pn»panil 
for ovrr a yrar and still show gcKxl difTcreiitiation, the stains will doubt- 
less fa<l(» in time an<l th(»refon* may not Im» desirable when* it is plannt^l 
to |)res«rv<* xhr pn*parations indefinitely. The advantage's of the ni«*tlMMl« 
lie in tli(» facts that, in <<'rtain cas4»s at least, they pro<luc<» excellent diffrr- 
entiation, that thry an» ca.sy to apply, and that they art» n^atively sunph* 
and inrx|M'nMVt' in <'omiH>sition. 

Moth of thi'H' mt'thoils havi* Ut^n found efTrctive in wmnection niih 



1917] Phytopathological Notes 391 

Botrytis (cinereat) and Rhizopus {nigricans?) in strawberry fruits,^ Pythium 
debaryanum in Irish potato tubers,* Fusarium sp. in tobacco stems, the 
aecial stage of crown rust of oats in leaves of Rhamnus calharticaj and 
several unidentified organisms in the roots of various plants. 

Charles S. Ridgway 

Development of blister rust aecia on white pirhes after they had been cut 
down, A small plantation of badly diseased pines set out for seven years 
at Cookstown, Ontario, was cut down between November 9 and 15, 
1916. The trees, many of which were two to three inches in diameter 
were left lying on the ground or more or less loosely piled until the spring 
of 1917. On May 10, 1917, the field man assigned to this district re- 
ported that fresh aecia were appearing around the old blister areas in these 
pines, which had not meanwhile been distiu-bed. A visit was at once 
made, which confirmed his observations. Where the trunks still retained 
some moisture new aecia were pushing out around the old bUster areas. 
They were apparently as numerous as usual, though rather smaller than 
normal in size. In the drier stems, aecial development had occurred 

• under the bark, where spores were being produced in immense numbers in 
irregular masses, forming an almost complete layer for 6 inches or more 
beneath the bark. This layer-like mass of spores extended under the 
old infections as well as beneath the bark of adjacent tissue, which had 
up to this time borne no blisters. Since about 25 per cent of the stem 
cankers were thus producing their usual crop of blister spores in this case, 
the menace that may arise from pines not completely destroyed, is clearly 
apparent. 

During the course of field observations upon an area of diseased pines 
at Kittery Point, Maine, trees eight to thirty-five years old with basal 
diameters 2 to 8 inches were cut down in November and December, 1916. 
Many cankers were collected for exhibition material and the remaining 
slash left on the ground over winter. On May 2, 1917, maturS blisters 
were found on stems and branches of various sizes which were cut Novem- 
ber 18. Subsequent observations showed that aeciospores were produced 
on approximately 60 per cent of the infected stems and branches Normal 
blisters were formed in many instances, and in several cases where the cut 
ends of stems were placed in running water spore production continued 
until June 18. On infected stems 3 to 8 inches in diameter which 
began to dry out before blisters showed through the bark, spores were 

• produced in irregular masses under the hardened bark. Some of these 

^ Stevens, Neil E. loc. cit. 
• Hawkins, Lon A. loc. cit. 



392 Phytopathology |Vol. 7 

spore masses retained normal color until June 25, after which the oraniKe 
color was lost and the spores appeared in light gra>nsh masses when the 
bark covering was removed. On June 3, 1917, a sporulating canker on a 
limb 2 inches in diameter which had remained on the ground since Novem- 
ber was sent to Washington. Germination tests made of the spores^ at 
Washington, June 6, gave positive results. Spores from this canker were 
used for inoculating a plant of Kibes nigrum under greenhouse conditions 
on June 8, and normal uredinia were 8ul)sequently produced. On March 
20, 1917, frt^shly cut infected branchcH and one section of a stem 4.5 
inches in dianioter wore n»ceived at Washington. The Iwanches m*ere 
set in watiT and blisters apiK*are<l in a f(»w days. The stem se<'ti<m was 
about thnr f(H»t long. All side* branch(»s w(»re closely trinuned off and 
it was s<»t on top a cast* near tlu* ceiling of the lalK)rat<)ry. Alx)ut May 
1 blisters were pushing throiigh the bark in spite of the dr>'ing eflfert of 
the lu^at. 

TlM*se findings show that whenever diseased pinc^ an» n»move<l the 
brush an<l afTeeted i)arts of the trunks must \h* eart^fully colU»ct«I ami 
bunied in order to inak(» the work efTcrtive. 

W. A. McCriuuN .\nd (5. (S. IN^hky 

(\)utrnl of Uitucr rot. A .^^oft rot of lettuce of the tyjx* ch^crilNMi by Mb** 
Brown^ and aserilHul to HdcUnum viruiiUvidum, has Imvu sivn in many 
fields in Michigan doing (*norinous damage to the crop. What ap|M'ar> to 
1k» the same dis4»iis<' has In^en found in the market at (*hicago in lettuce 
from New York as well jis from other stati»s. Carload after carload <»( 
lettuce arrives in the great markets almost a total loss. Fifty |w»r cvnX 
loss is not uncommon in the field, and this, couplcMi with the Iohs whirh 
occurs in transit, mak(»s the gn)wing of hea<l lettuce in some seasons ver>* 
precarious. 

The di.»*4»a.»H» starts first at the ti|)s of the l(»aves, prolmbly in tht* (h^aii 
an»its which come at the edgc»s of the oldiT leaves. TIm^si' aresis shrivrl 
an<l curl and are marked ofT frf>m the healthy tissue by a definite lint*. 
With the inner leaves the rot progress<»s ver>' deep into the head. tuminK 
their tendtT leaves into a gluey slime. The diM»p involvement of the m- 
n(T leaves and the c(»mparatively small sunount of n>t of the outer leavt*^ 
is (•harart4Tisie of the viixfy stage's of this trouble. Kventually the whole 
head n»t>. 

'I'he puriM>s4' (»f this note is to rail attenti(m to the n*markable control irf 
the diH*a.H4* obtained by spraying di.s(*as4Hl plants with fomialdehyde. 1 

» Hrouit Nrlln- A. A h:trt«'rial «li««r:i*«- nf K'llurr. J«iur. \%T. H«*«€arrh 4: 47^ 

4:v P»I.V 



1917] Literature on Plant Diseases 393 

pint to 30 gallons of water. In tests in 1916, at Bay Port, Michigan, the 
disease was checked by this treatment in fields which were about to be 
given up as a total loss. The weather had, however, become very cool, 
hence the relation of the formaldehyde spray was not definitely proved. 

The present season the rot began to be serious during an extremely wet 
and cold period in July. Spraying with formaldehyde has completely 
checked the trouble. In an adjoining field, the owner, seeing the success of 
the formaldehyde treatment, sprayed a portion of his field. In the sprayed 
portion the disease is checked while the unsprayed field shows a high 
percentage of rotting. A third field in the neighborhood, unsprayed, is 
almost a total loss. 

Attention is called to this control measure because the results of the 
trials during two seasons warrant extensive tests of treatment. It may 
be pointed out that we have here a method which differs from the ordi- 
nary protective spray, in that it seems actually to check disease already in 
progress. It is believed that this treatment will be found to have a wide 
range of adaptability in the treatment of diseases of this type. 

Ezra Levin 

LITERATURE ON PLANT DISEASES 

Compiled by Eunice R. Oberly, Librarian, Bureau of Plant Industry, and 

Florence P. Smith, Assistant 

June to July, 1917 

Arthur, Joseph Charles. Orange rusts of Rubus. Bot. Gas. $3: 501-515, map. Je. 
1917. 

For the short cycle form makes the new genus Kunkelia, comprising Coeoma 
iJBcidium) nitens of Schweinitz, and C. RoscB-gymnacarpag of Dietel. Con- 
firms Kunkel in ascribing long cycle form to Gymnoconia inter stiiialU. 

Avema Sacca, Rosario. Molestias cryptogamicas de laranjeira e do limoeiro, Hetero- 
sphaeria? sp. Bol. Agr. [Sao Paulo] 18: 49-86, illus. Ja. 1917. 

Molestias da laranjeira. Bol. Agr. [Sao Paulo] 18: 334-346, illus. Ap. 

1917. 

Sobre una nova forma de fructificao encontrada nos estromas do Mirangium 
[sic] citri P. Henn. (i.e. forma espermogonifera), p. 342-346. 

Bancroft, C. Keith. Report on the working of the botanic gardens, Georgetown, 
for the period April 1 to December 31, 1915. Scientific investigations. Rpt. 
Dept. Sci. and Agr. Brit. Guiana 1916, App. 2: 7-12. 1916. 
Summary of plant diseases of the colony, p. 9-10. 

Barthe, A. £. La cafia de azucar cultivo tecnico-moderno, con datos sobre la indus- 
tria azucarera en la rcpublica. III. Patologia de la cafia de azucar. (B) En- 
fermedades criptogamicas. (1) La podredumbre de la raiz. Rev. Agr. [Santo 
Domingo] 13: 71-74: Je. 30, 1917. 

Bessey, Ernst Atheam. Report of the botanist. Michigan Agr. Expt. Sta. 29th 
Ann. Rpt. 1916/16: 262-277. 1916. 



394 Phytopathology [Vol. 7 

Notes on Michigan plant diseases for 1915, p. 271-274. 

Includes reports of G. H. Coons, research assistant in plant patholoio'. R- P* 

Hibbard, research assistant in plant physiology, and J. H. Mtincie, aMistant in 

plant pathology. 
Blake, Maurice A., and Connors, C. H. Peach yellows and little peach at Vi net and. 

New Jersey Agr. Kxpt. 8ta. 36th Ann. Rpt. [1914] /15: 51-53, illus. 1916. 
Chllds, Leroy. New facts regarding the period of ascospore discharge of the Applt 

scab fungus. Oregon Agr. Expt. 8ta. Bui. 143, 11 p., 2 fig. 1917. 
Chupp, Charles. Studies on clubroot of cruciferous plants. New York (Cornell > .\gr. 

Kxpt. Sta. Bui. 387: 417-452, illus. Mr. 1917. 
Bibliography, p. 451-452. 
Flasnuxiiophora branRxctK. 
Coleman, Leslie C. Spike discaAc jf 82indal. Mysore Dept. Agr. Mycol. Ser. Bui. 3, 

52 p., front., 18 pi. 1917. 
Collins, Jam«8 Franklin. On using an ether freezing microtome in wanu and damp 

weather. Phytopathology 7: 222-223. Je. 1917. 
Cook, Melville Thurston, und Martin, William H. Disc^ases of tomatoes. New Jer- 
sey Agr. Kxpt. Sta. Circ. 71: 1 S, illuH. .\p. 1917. 
— and Schwarze, C. A. .Vpplc scab on the twigs. Phytopatholog>* 7: 221 TTl 

Jc. 1917. 
Cooper, J. Ralph. Spraying experim<'ntH in Nobraiika. .\ebrai«ka Agr. Kxpt Sta. 

Research Bui. 10. 97 p., 2 fig. 1917. 
Copeland, Edwin Bingham. Dihc^mo}} and i>o8t8 of HUgar cane in the Philipfnrirs 

Philippine Agr. and Forest. 6: :M3 340. F. 1917. 
Cunningham, Gilbert Cameron. Rc|M>rt from the field laboratory of plant path(»lo|Q-. 

Frodericton, N. B. ( :inacla Kxpt. Farms Rpts. (1916) 16: 1147 114*). 1917. 
Dash, J. Sydney. Invi'Htigtition of a nrw diHcase of augtir cane in Barbadcis. R|»i 

Dept. Agr. BarbiubM 1916 16: ;iH 40. 1917. 
CcphtdoHjttirium np. Not of a virulent nature. 
Davis, W. H. The aerial Htago ofaUike clover rust. (.Xlwtract. i S(*ience n. » 6ft: 

48. Jy. 13. 1917. 
Douglass, C. W. H. "Witches broom" on Japamve cherries. .Vnier. Forest S: 

340 :m. illus. Je. 1917. 
Floyd, Bajard Franklin. Some eaat^M of injury to eitriia trees apimrently induerd \*\ 

ground limesttme. Florida .\gr. Kxpt. Sta. Bui. 137: 101-179, illus. Je 1917 
Fromme, Fred Denton, and Thomas, H. E. Black r(M)trot of the apple. Jour Agr 

Ri^fM-.'ireh 10: ir>:M7l. l fig., pi. 15 17. Jy. -23. 1917. 
I.iter.'iture rited. p. 172 173. 
\*/litrm hijintjifioH prob:ibly the chief eaUM* of black rootnK of the applr m 

Virginia. 
Gladwin, F. E. \Vint«T injury of graiM^n. New York State .Vgr. Kxpt. Sta. Btil 4.S3 

107-i:{*». s pi. iy|7. 
Great Britain. Board of Agriculture, .\nnual re|Hirt of the hfirticulturr branch f.»r 

th.- y.ir VMt\. Jour. M. Wr. ib»n.l.»n| 24: 142 \:>S. My. 1917. 

DtM'rt^ert nf plants, p. 14'» l.'iJ. 

Giissow, Hans Theodor. Thi* pathogenic aotii»n of Rhiioctonia on iMitato Iti} t«»* 

patholM^y 7: 2<»'» 213, I Tik Jf VM7. 
-— Keport of divi.NiMii of iMit.itty < *:tnaila Kxpt. Farms Rpts. jltii] 16* v 

J 10.»7 ll.',(). pi «il «»;{ P.H7. 

I 1 )c'*trii< ti\ (' iii>e' t aiiij |M'-t :i<t :i4liiiini*>t ration IMant diiiraM' stH'iitin 



I 



1917] Literature on Plant Diseases 395 

II. Plant pathology. III. Economic botany, by John Adams. IV. Report 

from the field laboratory of St. Catharines, Ont., by W. A. McCubbin, V. 

Report from the field laboratory of plant pathology, Charlottetown, P. E. I., by 

Paul A. Murphy. VI. Report from the field laboratory of plant pathology, 

Fredericton, N. B., by G. C. Cunningham. VI. General. 
Gttnderson, A. J., and Brock, W. S. Field experiments in spraying apple orchards 

in 1916. Illinois Agr. Expt. Sta. Circ. 194, 14 p. 1917. 
Hall, C. J. J. van. Ziekten en plagen der cultuurgewassen in Nederlandsch-Indie 

in 1916. Meded. Lab. Plantemsiek. [Batavia], 29, 37 p. 1917. 
Hawkins, Lon Adrian, and Stevens, Neil Everett. Endothia pigments. I. Amer. 

Jour. Bot. 4: 336-353. Je. 1917. 
Bibliographical footnotes. 
Hedgcock, George Grant, and Hunt, N. Rez. New species of Peridermium. Mycolo- 

gia 9: 239-242. Jy. 1917. 

Peridermium ipomoece sp. no v., P. terebinthinacecB sp. nov., P. helianthi sp. 

nov., P. fragile sp. nov., P. minutum sp. nov. 
Higgins, Bascombe Britt. A CoUetotricHum leafspot of turnips. Jour. Agr. Re- 
search 10: 167-162, pi. 13-14. Jy. 23, 1917. 
The fungus causing the disease is tentatively referred to Colleiotrichum brtiS' 

sicce Schulz. and Sacc. 
Hiley, W. E. Chrysomyxa abietis. Quart. Jour. Forest. 11: 191-192. Jy. 1917. 
Hodgson, Robert W. Citrus blast — a new bacterial disease. Mo. Bui. State Com. 

Hort. [California] 6: 229-233, illus. Je. 1917. 
Hoerner, G. R. Raspberry diseases in Minnesota. Minn. Hort. 46: 236-243, illus. 

Je. 1917. 
[Howitt, J. Eaton]. Botany. 42d Ann. Rpt. Ontario Agr. Coll. and Expt. Farm 

1916: 15-18. 1917. 
Fungous diseases. 
Jones, Dan H. Tomato blight. 11th Ann. Rpt. Ontario Veg. Grow. Assoc. 1915: 

60-67, illus. 1916. 
Not of a parasitic nature, neither insect, fungous or bacterial. 
Kauffman, Calvin Henry. Tennessee and Kentucky fungi. Mycologia 9: 159-166. 

My. 1917. 

RusaiUa ochroleucoides sp. nov. ; Stropharia ccesiospora sp. nov. 
Kern, Frank Dunn. North American species of Puccinia on Carex. Mycologia 9: 

205-238. Jy. 1917. 
Keuchenius, P. £. Ziekten en plagen van de klapperkultuur in Nedcrlands Indifi 

en hun bestrijding. Teysmannia 27: 579-642, pi. 1-7 (on 4). 1917. 
Lit^ratum-, p. 633-635.. 
Hoof dstuk II : Plantaardige ziekten, p. 624-628. Pesiallozzia [sic] pcdmarum; 

Pythium palmivorum; Bacillus coli; Tielaviopsis ethaceticus; Diplodia wortelrot, 
Kibbe, Alice L. Chytridium alarium on Alaria distulosa. Puget Sound Mar. Sta. 

Pub. 1: 221-226, pi. 39-40. D. 1916. 
Citationa, p. 224. 
Lek, H. H. A. Over het voorkomen van ''biologische of physiologische rassen" 

bij plant^nparasieten ende oeconomische beteekenis daarvan. Tijdschr. Plan- 

tenz. 23:85-98. 1917. 
Lem^e, £. Les ennemis des plantes: phan^rogames parasites. Jour. Soc. Nat. 

Hort. France IV, 18: 33-36, 48-50. F.-Mr. 1917. 



396 Phytopatholoot (Vol. 7 

McCabbin, W. A. Report from the field laboratory of plant pathotogr, Ht. Catha- 

rines, Ont. Canada Expt. Farma Rpta. 1916: llM-1144. 1917. 
Martin, WUliam H. Common dtaeaaea of cucumbera and melona. New Jersey Agr. 

Expt. 8ta. Circ. 66: 1-11, illua. Ap. 1917. 
Matz, Juliua. Report of the iairaratory aaaistant in plant patholocr. Florida 

Agr. Expt. Sta. Rpt. (1916)/16: 99R-112R, fig. 17-22. 1917. 
Pecan dielmck, leaf blight of the fig. 
Malchara, Leo Edward. Puccinia triticina Erikaa. Leaf-mat of winter whcet 

causea damage in Kanaaa. Phytopathology 7: 224. Je. 1917. 
M«ncle» J. H. A girdling of l)ean atema rauaed by Baet. phaaeoli. Seienee n. e. 

46:88-89. Jy. 27, 1917. 
Murphy, Paul A. Report from the field laboratory of plant pathotofy, Charlotte- 

town, P. E. I. Canada Expt. Farma Rpta. [19161/16: 1144-1147. 1917. 
Murrill, William Alphonao. (.\garicale8.) .\garicaceip (para), Agarices (para). North 

Amer. nora 10, pt. 3: 145-226. Je. 25, 1917. 
()thi*r parts of North Amer. Flora of mycological intereat are ▼. 3, pt. 1. 1910: 

V. 7, pt. 1-3, 1906-1912; v. 9, 1907-1916; v. 10, pt. 1-2, 1914-1917. 
Newman, L. E. The blister rust of white pine*. Uiltmorean 4: 1-9, illui. Mr. 1917. 
An American bibliography of OonarfiMfii ribic^la and Ftrid^rmivm »Slro^'. 

p. 7-9. 
O'Gani, Patrick Joaeph. Notes on the distribntion of the bacterial diacMe oC wwt* 

ern wheat-grass. Phytopathology' 7: 225-226. Je. 1917. 

The occurrence of Colletotrichimi aolanicolum O^Gara on eggplaal. Pbyto* 

pathology 7: 226 227. 1 fig. Je. 1917. 

PiBtch, Thomaa. Black rot disease of tea. Dept. Agr. Ceylon Leaflet 2, 8 p., illua. 

F. 1917. 
Jiy/MKhnus sp. 
Pleper, Ernest J., Acree, S. P., and Humphrey, Clarence John. On the tonrtty tea 

wood-deetm^-ing fungus of maplewood ereoaote and of aome of ite eoMtilvettti 

and derivAtivf*M, together with a comparison with lieechwood creMote. lour. 

Indus, and Engin. Cliem. 9: 566-569. iltus. Je. 1917. 

Humphrey, Clarence John, and Acree, S. P. Hynthetic culture iBcdin Hft 

wiKMi-destroying fungi. Phytopathology 7: 214-220. Je. 1917. 

Pierce, Roy Giffbrd. Early discovery of white pine blister rust in the Uaited States. 

Wiytopathology 7: 224-225. Je. 1917. 
Povah, Alfred H. W. \ critical study of certain species of Mueor. Bui. Torrey 
Bot. Hub. 44: 287-317. pi. 17-20. Je 1917. 
IJtrrature cited, p. 311-312. 
Pratt, H. C. Prt'vcntivc measures against black thread (Phytophtliorm fabrn . 

Agr. Kul. Fed. Malay States 6: Ift>-1K2. F. Mr. 1917. 
Bamsbottora, J. K. I^ecture on Narcissus diseaae. Oard. Chron. III. ft: 307, My. 
19: 2I7-2IR. .My. 2tl, 1917. 
S«*c also I'tlitorial r.otc. p. 2(M. 
TylrnrhuM tinaMntrii. 
Ramsey, Glen B. A ff»rm of potato disease produced by Rhiaoetonia. Jcmmt. A|r. 

Kiwarch 9: 421 42f'». pi. 27 30 J** l«. 1917. 
Raat, Roy E. Cotton viiri«'ti(*H in (Georgia. Variation of the oil content of cotton «erd 
;infi rcKi^tnnrc to dii«r»i«' (if^vrgia State (^oll. Agr. Bill. 6, no. 12, 2S p.. ill«a. 
Ap 1'.»I7. 
Ti-st of v.'iriotif(«if»r n'HiHt:iiiro to :iiithr:irno"*i»or ImiII rot, p. 27^30. 



1917] Literature on Plant Diseases 397 

Ritzema Bos, Jan. Het stengelaaltje (Tylenchus dovastatrix) en de tegenwoordig 
in de bloemboUenstreek heerschende aaljesziekte der narcissen. I. Tijdschr. 
Plantenziekten SS: 9(m35. 1917. 
Roberts, John William. Apple blotch and its control. U. S. Dept. Agr. Bui. 534 
11 p., 3 fig., 2 pi. 1917. 
Literature cited, p. 11. 
Phyllosticta solitaria. 
Bose, Dean H. Blister spot of apples and its relation to a disease of apple bark. 
Phytopathology 7: 198-208, 3 fig. Je. 1917. 
Paeudomoruu jxxpulana n. sp. 
Rosenbanm, Joseph, and Shapovalov, Michael. A new strain of Rhizoctonia Solani 

in the potato. Jour. Agr. Research 9: 413-420, 3 fig., pi. 25-26. Je. 18, 1917. 
Rnddph, Bert A. A new leaf-spot disease of cherries. Phytopathology 7: 188-197, 
3 fig. Je. 1917. 
Altemaria Citri Pierce var. Cerannov. var. 
Saccardo, Pier Andrea. Pugillo du funghi della Val d'Aosta. Nuova Gior. Bot. 

Ital. M: 31-43. Mr. 1917. 
Sharpies, A. A die-back disease on Hibiscus. Agr. Bui. Fed. Malay States 4: 
217-218. Ap. 1916. 
Fuaarium sp. 
Sherbakoif, Constantine Demetry. Report of the associate plant pathologist. Flo- 
rida Agr. Expt. Sta. Rpt. [1916]/16: 80R-98R, fig. 12-16. 1917. 
Diseases of vegetables. 
Smith, Brwin Frink. A new disease of wheat. Jour. Agr. Research 10: 51-54, pi. 
4r«. Jy. 2, 1917. 
Probably of bacterial origin. 
Soxmner, Paul. Manual of plant diseases. Translated by Frances Dorrance. 1, 

pt. 6. [1917?J 
Spcvlding, Parley. Needle rust on Pinus resinosa. Ph3rtopathology 7: 225. Je. 
1917. 

Coleoaporium aolidaginiSf C. delicattdum. 
Standtejr, Paul Carpenter. Fungi of New Mexico. Mycologia 8: 1^^177. My. 1916. 
Stanford, £. B., and Wolf, Frederick Adolf. Studies on Bacterium solanacearum. 
Phytopathology 7: 155-165, 1 fig. Je. 1917. 
Literature cited, p. 165. 
Stevens, Frank Lincoln. Bacteriology in plant pathology. Trans. Amer. Micros. 
Soc. a6: 5r-12, fold. tab. Ja. 1917. 

Table showing progress in knowledge concerning American plant diseases of 
economic import. 
Stevens, H. £. Report of the plant pathologist. Florida Agr. Expt. Sta. [1915]/16: 
66R-79R, fig. 10-11. 1917. 

Gummosis, melanose, citrus canker, li^tning injury, lemon brown rot fun- 
gus, citrus diseases, pecan diseases. 
Stevens, Neil Everett. Some factors influencing the prevalence of Endothia gyrosa. 
Bui. Torrey Bot. Club 44: 127-144, 5 fig. Mr. 1917. 
Literature cited, p. 143-144. 

and Hawkins; ton Adrian. Some changes produced in strawberry fruits by 

Rhisopus nigricans. Phytopathology 7: 178-184. Je.'1917. 
Literature cited, p. 184. 



398 Phytopathology [Vol, 7 

Stewart, Fred Carlton. Witchos-broomt on hickory trees. Phytopathology 7: 185- 

187, 1 fig. Jc. 1917. 
Swinfle, Deane Bret, and Morria, H. E. Arsenical injur>' through the bark of fruit 

trees. Jour. Art. Research 8: 283-318, pi. 70-Sl. F. 19, 1917. 
Literature cited, p. 317-318. 
Tanaka, Tydzabiiro. New Japanese funfp. Notes and translations. Mycologia t: 

167-172, My. '249-253. Jy. 1917. 
Taubenhaus, Jacob Joseph. The culture and diseases of the sweet pea .... 

XX p.. 21, 232 p. incl. front., illus., pi. New York, 1917. 
Trotter, Alessandro. Tna intcrcssantc controversia intorno a presunti danneggia- 

nionti di viti od alt re piante |)or anidrido Holfonisa. Hiv. Patol. Veg. II. f: 

1-24. .Mr. 1917. 
U. S. Department of Agriculture. Federal Horticultural Board. Service and regula- 
tory unnfuinccinonts. April: 37 -47. Jv. 1; May. 49-56, Jy. 7. 1917. 
Waters, R. (;ravy-<»y(*. orinattrry-eyr. in |)c>tat(M*H. liacterial outbreak in Pukrkohr 

diHtrict. Jour. Ap-. New Zeal. 14: liol -363. My. 1917. 
Watson, J. R. Control of root -knot by calcium cyanamide. Florida Agr. Kxpi. 

Sta. Bui. 1»5: 147-160. 1917. 
Weir, James Robert. Montana forest tree fungi. I. Mycologia 9: 129^-137, pi. 6. 

.My. 1917. 

Bibliographical foot notes. 
I. Polyptiracea*. 
A ne«'<He Might of Douglan fir. Jour. Agr. H(*searrh 10: 99-l(M. 3 fig , pi. 

12. Jy. 9, 1917. 
The funguH iH vigorously paranitie and ih apparently c<»nfined to the Douglas 

fir. 

Note on .\ylaria polymorpha and X. digit ata. IMiyto|Mtholog>' 7: '. 



•224. Je. 1917. 

SimraAsiM radicata. an und<*tferil>ed fungus on the rcKits of conifem. Ph>to» 

patho|og>- 7: m\ 177. 5 fig. Je. 1917. 
Bibliographical f (Hit notes. 

and Hubert, Ernest E. OlisiTvations on forc^st tree rusts. .\mer. Jour. Hot. 

4: 327 liXi, illus. Je. 1917. 
Bibliographiral ftHit notes. 
Wester, Peter Johnson. Notes on the ritrus ranker. Philippine .Vgr. Rev. t: 15i>- 

i:»7. 1916. 
Woolman, H. If. The prewntion of \%heat sniut. IVoc. .\nn. Conv. Washington 

Stat«- (;rain (Jrow. .\ssoe. 10: 47 19. 1916. 
Wormald. H. .\ bbmsom wilt and canker i>f apple trees. .Vnn. .\ppl. Biol. 8: IS& 
jrn. pi. -22 24. Ap. 1917. 
Bibliography, p. 2ltt 'JfM. 
M nut I ill Hp. probably M . ciurrra. 



lPini..p\rn.»MMiv. for .VugiM. 1917 i7: 235-;r2(). Pis. III-X\ 

i.**^!!*"*! S ptfinlKT 7. 1917.) 



PHYTOPATHOLOGY 

VOLUME VII NUMBER 6 

DECEMBER 1917 

A TWIG AND LEAF DISEASE OF KERRIA JAPONICA 

V. B. Stewart 
With Seven Figures in the Text 

A fungous disease caused by a species of Cylindrosporium is commonly 
found on Kerriajaponica DC. The disease not only results in premature 
defoliation but it also affects the shoots, often injuring the bushes to such 
an extent that they die during the winter. In one ornamental nursery 
observed by the writer the growing of Kerria japonica stock has been dis- 
continued on account of this malady. 

SYMPTOMS 

The first sign of the disease on the leaves are small discolored areas 
which soon become reddish brown in color. These areas' are irregular in 
outline and vary from one to four millimeters in diameter (fig. ly A), 
Often several lesions become confluent, involving a considerable portion 
of the leaf. The center of the lesion is slightly raised and may appear as 
a white velvety pustule. Severely affected leaves turn yellow, shrivel 
and fall prematurely. There is no shot-hole effect produced on the 
leaves as in case of certain Cylindrosporium diseases of other plants. 

The lesions on the shoots are circular, reddish brown to black in color 
and vary from one to several millimeters in diameter (fig. 1, B). Usually 
the lesion is slightly sunken with the central area somewhat raised and 
covered with a white mass of conidia. In old lesions portions of the corti- 
cal tissue may fall out leaving the woody tissue exposed. Often times 
the diseased areas are so abundant as to completely girdle the shoot, this 
being especially true in case of small plants in the nursery. 

THE FUNGUS IN THE TWIGS 

The disease was first observed on K. japonica twigs in November after 
the bushes were de^oliated.^ No spores were apparent in the lesions when 

* The affected twigs were examined by Prof. F. C. Stewart of the Geneva Agri- 
cultural Experiment Station, who stated that the cause of the disease was a species 
of Cylindrosporium. Professor Stewart also informed the writer that on several 
different occasions he had received specimens of the disease. 



400 Phytopathology [Vol. 7 

exainiiH'cl l)ut after placin)^ twi^ in a moist rhamlx*r for threo days tlifn* 
was siirh an abundant production of spores that the masses <if them Wi-re 
apparent to the unaided eye (fiK. 2). 

( Voss-seet ions of the affeeted area on a slicxit show a stromatie lavrr of 
myeelimn which extends throuf^h the cortical tissue to tlie wood. Tlif 
stroma mav Im» several hundre<l microns in thickness. The cortical tbv'iie 
is thsorKanized but appan*ntly there is practically no breakin|( <lomi of the 
individual cells, isolated host cells often \muf^ enclosed in the Htrcwna. 
From the upjMT surface of the stromatie layer short coniiiiophon*> ari- 
develo)KMi which |)nNluee mass<>s of conidia. With the accumulatifin of 
the conidia the ei)id(*rmis is broken and the spores are ex|)os4Nl on the 
surface of the twi);. The fruiting body is a typical acervuius and the 
s|>ores are characteristic of the j;<'nus ( Vlindrosporium. 

(*<niidial product i(»n on the twi^s ceases in the autunm and the funfcus 
remaiii> dormant until tli<> following >prinK at which tiuu* it aicain lH*conit*9 
active. 

On April S. P.H«». tji-^eased twi^s which had been exiM»se«l to the weatlit*r 
throuf^hout the wiiittT. >liowed in the renter of the le>i(»h^ a detiiut*'. 
slight ly rai>ed. rirrul:ir areM which was somewhat darker in color and *»harply 
outlined. ( 'ross-sert ions of the h'sions showed tlu* d(*velopmi'h! of ip-u 
hvphal threadsand. with the «MMMirn*nce of warm, rainv weather, rnnidii*- 
phore> were jiroduced from the outer surface of the stroma, ('oriidi:! :tp- 
p4>ared about the time the new foliage developed on th«' bu<«he**. AKiiii- 
dant >pore produrtion was obs(*rved also in old lesion-^ on livinu A*'- -i 
jiipntnra bu^he*. wliirh had been affected the previtMi*> >eason. 

Thf >JM ire-bear in ir hvphal threads in the stroma ""tain mon- mt*-!:"* *. 
and have the appearanre of asco^eiious hvphae but in all of tin* iiriT> ri i! 
examined there ha^^ been no deve|o))m(>nt of a H'xual fruit itiK ImnIv on *>.• 

INK H \«;l S IN IHK !.K\K 

Tlif i;ro\\th of thi' fun^u** in the leaf i^ lik«' that of oth«*r sintji-^ nf 
t '\ Iimlro'^pnrium. The »»troma lir>t c<Mi'*i-'ts of a layer <if i>ne or lw«i «-rlU 
and m«ri*a''e'» in !hij'knt"*> a** thi* aeervulu> urows older. The coniiii.t. 
which ar«' borne on •*liort roiiidiophore> bn^ak the epidermis ami acriiiiiu- 
l.iti- a- a wliiti- ma— in thr c*rntfr «»f th*- |f«.ion ffiir. 2'. SjMire pnM|ut-Ti**7i 
ef»niin;n- ihrf»in:li«iut tin- -^ummiT. A«'ervuli may ap|M*ar i'ither «»n Th«- 
uppt r "I l»>u«r *idi- «>!' tin- Ifaf. Thi- mye«'lium is intervellular an«l den\«'* 
If'* imiir i-liMniit b\ iipan^ of liau^turia uliith piMielrate th«' \\i^\ «•?■![• 
Ap)».ii«-iiH\ rlii- i|i^(»ruani/a(ion of thf ti>*>ue i** mo^tly mechanical. *>iie •- 
iln-n- I* n«» «\ i«l«-f!«'- that th«' funiru* priMliin-H an en/yme which bri'ak* 

d"\s n Un- r«ll \\:ilN. 



404 



PHYT(IPATHOLO(iy 



(Vol. ; 



as«>si»or«'H arc cjcctcil with foriM' from the nsri (fif[, (>, ,4). \o jKirt- hv 
been observct] in the tip of the iiscus. 

The (levelnpinent of the aseoenrpis siiniliir to that of Coreomyee* hiemaU* 
deferilH'd hy Ili(ixiii^* who diseitsHes in detail (he presenee of hyphal miU 
and t richoK>-ne-lik<' iMxiies. In case of C. hicmaliH the end of each hyphal 
eoil extends ulmve the snrfuee of the stroma and terminates in a swollen 
trielio(!_vne-likc structure. The writer ha.^ made diligent search for the 
trielioK_vm'-likc structures in the fiiUKiiM on Krrria }n}>oitira. Hyphal 
coils have been traced |i> t)ic surface iif the stroma, but no swollen stnic- 
tnres have liccii seen which arc comparable to the trichiiKj-nc^ of T. hirmo- 




V / 



:.2.-.;/(.R.-r 



n.-..rili.- 






K'llt <>r:i ( 



fM. Nuincrnu, hyphal ihreads with swollen tii». liav.- Inen c>I»^t%-.-<I bill 

it hif not I II [Kissible to di-tcrminc- whether thcM' were irichiqo'no or 

enLirited ci>niilio|iliorcs. The oricanisins arc similar in the faet that the 
imxlnrliiin r>f filiform, curved, eoniilia (macnx-onidiui on the foliaiti- 
cciws in late .summer and in the .-iame acervnii minnte niicnK'uniihn 
(s|ieniiatiai ili'vel<i|i instead. The micrm-onidia or sjNTmatia of the fiin- 
EiiH on Kerriii tncaMin- alHinl 2 by I)..'* ^ )H-in|i sHjchtly smaller tlrnn \\v*m- 
off. I,;m„h^, nrea^ionally the sfMrmalia an- cnclos4-d in definite pyc- 
nidia-hk>- .-|M'rmaK<tnia which are alMiul 441^ in diameter. The ttpt'niinfcoiiLt 



1917] Stewart: A Disease op Kerria Japonica 405 

with spermatia have been observed on leaves of Kerria japonica exposed 
throughout the winter and even when the ascocarps are mature in the 
spring. 

systematic position 

The'ascocarp of the fungus herein discussed is similar to the forms in- 
cluded in the genus Coceomyces of the Phaeidiales, but so far as. the writer 
is aware no fungus of this genus has been described as affecting Kerria 
japonica. The name Coceomyces Kerrice^ is therefore proposed for the 
species and the following characterization given: 

Coceomyces Kerrise n. sp. 

Ascogenous stage. Ascocarps embedded in tissue, usually on under 
side of leaf, scattered or somewhat aggregate, ovate, dark brown to black, 
100 to 220 fi in diameter, at first closed but opening at maturity in a stel- 
late manner; hymenium grayish; asci clavate, slightly papillate at apex, 
55 to 74 by 11 to 13 /x; paraphyses simple or branched, septate, slightly 
swollen at tip; ascospores 8, hyalin, slender, slightly curved, continuous 
or once-septate, 33 to 48 by 2.8 to 4 fx. 

'Conidial stage. Spots numerous, reddish brown, 1 to 5 millimeters in 
diameter, often confluent; mycelium intercellular with haustoria which 
penetrate the host cells; acervuli scattered, amphigenous, subepidermal, 
finally breaking through and exposing the spores; conidia filiform, curved, 
hyalin, 1- to 2-scptate, 40 to 76 by 3.2 to 4.8 /x. Spermatia very minute, 
hyalin, non-septate, 2 by 0.5 m in old acervuli, occasionally in small 
pycnidia-like spermagonia. 

Coceomyces Kerrise n. sp. 

Ascomatibus hypophyllis vel amphigenis, spar sis aui suhaggregatis, puncti- 
fomvibuSy ovatiSj negris, 100-220 /x lot., primum clausisy deinde in lacinias 
plures aciUas dehiscentibus; disco griseo; ascis clavatis, apice leviter papil- 
latOf 55-74 X 11-13 /x; paraphysibtis filiformibus, simplicibus aut ramosiSy 
septatiSy apice tumido; sporidiis 8y linearibuSy leviter curvisy hyaliniSyS^im- 
plicibus aut 1-septatiSy 33-48 x 2.8-4 M- 

Hab. In dejectis foliis Kerrice japonicce. 

Status conidicus: maculis numerosis, minxitiSy rubrofuscisy 1-5 mm. lai.y 
soepe confluentibus; acervulis solitariisy amphigeniSy svbepiderviiciSy disci- 
formibus; conidiis JUiformibuSy flexuosisy hyalinisy 1-2 septatis, 40-76 x 
3.2-4-8 fi; sporulis viinoribus auctumno hyalinis, continuiSy minutissimisy 2 
X 0.5 /x. 

• Type material is deposited in the herbarium of the Department of Plant Pathol- 
ogy, Cornell University and in the herbarium of the New York Botanical Gardens. 



406 Phytopatholo(jy (Vou 7 

cultural 8tudie8 

The fungus is readily cultured on ordinary media such as potato agar, 
sterilized bean pods, or sterilized twif^s of Kerria japanica. On June 2. 
1917, an abundance of ascospores was obtained by inverting petri dishes 
containing a thin layer of agar over ascocarps which had been moistened. 
The ascospores were ejected with force and lodged on the agar a half centi- 
meter or more alx)ve the ascocarps. Individual ascospores were trans- 
ferred from the petri dishes to tubes of potato agar where the ascosporcB 
germinated (fig. 0, B) after twenty-four hours and developed cultures* of 
the fungus. 

The growth at first was slow and consisted of a thin grayish stroma of 
mycelium. On June 22 the stroma was al)Out 4 or 5 millimeters in diam- 
eter, slightly raised and darker in the center. From the central area of the 
stroma conidia were produced similar to those found in lesions on the host 
plant. Portions of the mycelium were transferred on June 22 to te«t- 
tubes containing Ix^an pods and twigs of Kerria japanica and a copious 
mycelial growth was obtained on both media. When the cultures were 
examined July 2 the older mycelium wns turning black and pinkish gray 
masses of conidia were apparent. Only a small proportion of the conidia 
germinated when placed in water. However, five to ten per cent of the 
conidia showed germ-tulws after twenty-four hours (fig. 7) and the per- 
centage of gennination was slightly increased after forty-eight hours. As 
is characteristic of certain other species of Cylindrosporium. the conidia 
ap|x?ar to lose their vitality very rapidly, in all the test^ made of conidia 
from different .sources only a small percentage of germination being 
obtained. 

INOCULATION RXPKRIMKNTS 

On May 28, 1917, ascospores wliich had lx*en ejected to plates of agar, 
wen* placed on leaves of two healthy bushes of Kerria japanica which 
were growing in the greenhouse. The plants were then moved out-of- 
dcK)rs when» they were exi)osed to a rainfall that lasted for sixty bouri. 
ThnH* other plants which were not inoculated were also placed otitnide 
and S4>r\'ed as checks. When examined June 12 several of the inoculated 
leav<»s showed infection. Five days later conidia of C'ylindrosporium 
wen* ap|)arent in the lc»sions. The check plants remained healthy. 

On .May 2^), 1917. isolated ascocarps of the fungus were crushed in 
water and the s\isf)ension of ascospores sprayed on the leaves of two bushes 
of Ktrnn jnpimiai outside the gre<*nhou.si». Hainy weather prevailed for 
twenty-four hours after the inoculations were made. On June 12 numer- 
ous le.'^ions of the (Ii.^'as4* were apparent on the inoculat€*d leaves and an 



1917] Stewart: A Disease of Kerria Japonica 407 

occasional lesion was noticed also on the twigs. Two check plants which 
were not inoculated remained healthy. 

On July 2, W17, conidia which had developed in a culture from a single 
ascospore, were used for inoculating one bush of Kerria japonica growing 
in the greenhouse. A suspension of the spores in water was sprayed onto 
the leaves by means of an atomizer. Another plant was sprayed with 
water for a check. Both plants were placed in a moist chamber for 
thirty-six hours. On July 13 the characteristic lesions of the disease 
were apparent on the inoculated leaves and on July 18 conidia of the fun- 
gus were being produced. The check plant remained healthy. 

The above experiment was repeated on July 10 and on July 21 conidia 
were observed in the lesions which developed in the inoculated leaves. It 
is to be noted, however, that only a relatively small number of lesions 
appeared on any of the inoculated plants where conidia were used. In 
spite of the fact that an abundance of conidia was sprayed onto the plants 
only a small proportion of them germinated and produced infection. In 
most cases there was an average of only one or two lesions on each leaf. 
Of plants inoculated with ascospores many of the leaves showed numer- 
ous infections. These results are in accord with the germination tests 
previously discussed. 

Secondary infection occurred throughout the summer on the inocu- 
lated plants and in the autumn many of the shoots were severely affected 
and the plants were completely defoliated. 

CONTROL 

No carefully conducted experiments have been performed for the con- 
trol of this disease, but preliminary tests made in 1916 indicate that a sul- 
fur fimgicide will prove effective in checking the malady. Bushes of 
Kerria japonica were growing in a nursery and severe infection had oc- 
curred before they were treated in 1916. However, four treatments dur- 
ing the summer greatly reduced the amount of infection and premature 
defoliation as compared to untreated bushes. One plat was treated with 
a dust mixture of ninety parts finely ground sulfur and ten parts powdered 
arsenate of lead. Another plat was sprayed with lime-sulfur solution 1 
to 50 and the third plat was left untreated for check. 

The production of conidia in the old lesions on the shoots early in the 
spring along with the liberation of the ascospores from the old leaves 
makes it exceedingly diflScult to prevent the primary infections. This is 
especially true when weather conditions are favorable for the fungus. 

Cornell University 
Ithaca, New York 



THE C^ROWN CANKER DISEASE OF ROSE 

L. M. M A 8 8 E Y 

With Three Figures in the Text 

On Sfptc!iil)er 9, 1916, while visiting rose houses in the vicinity of 
Philadelphia the attention of the i^riter was ealled to a numlier of Ameri- 
can Heauty plants affected with a hitherto unrejwrted disi^ase. to which 
Xhv name crown canker has lHH»n given. Tlie gn)wer states! tiiat he liad 
hml the disea*^» under ()l)ser\'ation durinf^ the past four or five years, a few 
plants lH»inK aflfected each year and the disease* Ix^iuf^ confineil to a sinitle 
housi'. 

Subsequently plants aflfected with the crown cank(»r dise^ase have U«en 
H'ceived from eijjht Kn)wers, the states of Missouri, Pennsylvania. Indiana, 
Michiji^an, Massachusetts, and New York Ixmuj^ n»pn's<'nted. A Missouri 
>j:n)wer ol)s<*r\Td the di.s'ase* in 191() on the varieti«»s I{(M)sirr Ik*auty and 
()[)helia gniwin^r on their own nnits. A Massitchusetts j^niwer was of the 
opinion in 19n> that his entin* stock of ()(),(NK) or mon> plants was afTectoii. 
and it is the ofunion (»f the writer, after having examiiUMi his plants, that 
at h'ast a very largr ptTrrntagi* of them wen* dis^'ascnl. During the fcnir 
years jirior to 19ir> iiicrra>iiigly p(M»r results werr ol>taine<l by this gn»wvr 
who when intcrvicwtMl in NovcmU'r 1910 was planning to destn»y iiii»!»l 
of his plants. st4'rilize housc^s and soil, and U*gin anew with healthy plant.*i. 

HoM* plants of the varieties Hoosier Heauty, Ophelia, Hadley, Ruh?^*ll. 
Sunhurst. American Heauty. and many se<»dlings have UM»n ol)s<'rvi*4l af- 
frctrd with the dis<'as(\ Hoth grafti^l plants :uhI thos<* gn>wing on tln-ir 
own HMits an* afTtM'tiMl. It is (iU(*stional>le wlu'ther or not anv variriv is 
immune. Indications are that this may prove to Ih' the most im|M>rtant 
diH»as4' of n>s<»s grown under ghiss. To date no n»cord of the disi*aM* on 
i»ut-4>f-doors plants has Ikm'Ii made. 

SYMPTOMS 

DiseiLM'd filants are aflftMte<l at the crown, usually just at tlie >urf:irr 
of the S4»il. the lesion in advaru^fMl ras<'S fn*<|uently exten<ling several inch*** 
:il>ove the soil. The writer has not <leteniiin(Ml to what extent the nmt 
M-t«-mv ;in* commonly aflr<M'te<l. However, lesions liave Urn oli«*rvwl 

• 

iirar till' tips of nM»ts of four-yea rs-4»ld plants, and of several plants rxarii- 
ined unr|ueHtionaMy the eiitin* nM>t system of each plant was affecttHl. 



1917] Massey: A Disease of Rose 409 

The union of the scion and stock, and the area immediately above, is 
the most common point of attack. 

The first indication of the disease is a slight discoloration of the bark. 
As the disease advances the color rapidly deepens to black and the tissue 
appears waternsoaked (fig. 1, A, C), At first tne lesions are irregular in 
outhne with a somewhat sharply defined margin. Later as the affected 
area increases in size the blackened color of the diseased area is blended 
more with the healthy tissue. The lesions frequently encircle the stem. 
Soon cracks appear in the bark extending in to the wood (fig. 1, i5). Later 
a swelling of the stem as from girdling occurs at and above the affected 
area, the cracks becoming deeper and more evident. In old lesions the 
black, water-soaked appearance is lost. Sometimes the stem is encircled 
by a shrunken area which contrasts sharply with the swollen area immedi- 
ately above. 

One very noticeable characteristic of this disease is the punky consist- 
ency of the diseased tissue, especially that affected under ground. When 
scraped, the bark, sapwood and frequently the roots appear punky and 
lifeless, not uncommonly in areas where no definite lesion is evident. 

Suckers developing from the roots of diseased plants are usually spind- 
ling and yellow. They are commonly affected at the point of attachment 
to the main stem, the tissue being blackened and of a punky texture. 

Affected plants do not die quickly but linger on and yield increasingly 
poor and few blossoms. It is practically impossible to force such plants 
to increased activity by the heavy application of fertilizers. The foliage 
of plants affected with this disease is frequently of a lighter green color 
than that of healthy plants. Probably the number of plants actually 
killed within the duration of time they are usually kept by growers is very 
small, but the normal activities of the plant are so materially interfered 
with that diseased plants can be grown only at a financial loss. 

ETIOLOGY 

The crown canker disease of rose is caused by the fungus Cylindrocladium 
scoparium Morgan. This organism has been hitherto described only as a 
saprophyte and, so far as the writer is aware, never reported on the rose. 

In 1892 Morgan^ reported on a fungus collected in Ohio growing on an 
old pod of Gleditschia triacanthos L. The fungus belonged to the group 
DidymosporsB in Saccardo's^ system (and to the group Mucedinaceae- 

* Morgan, A. P. Two new genera of hyphomycctes. Bot. Gaz. 17: 190-192, figs. 
2. 1892. 

« Saccardo, P. A. Didymospora*. In Sylloge fungoriim 4: 176-187. 1886. 



410 Phytopathology [Vol. 7 

Hyalodidyime in LindauV s^'stcin subsequently published), but dif- 
fon'd from other meinl)ers of the group in the possesnon of cylindric ^pom. 
(V)nse<|uently Morgan erected the genus Cylindrodadium^ on the* liatdii of 
the oyHndric character of the spores and used the specific nanie M»panum 
for the single representative of the genus, probably liecause of the brmim- 
like natun* of the fruit ing-lxnlies. 

In July 1899, L. W. Nuttall sent specimens of a fungus on deail leavm 
of Asimina triloba fmm Xuttallburg, West Virginia to Kllis who in 191M>' 
nununi it IHplocladium cylimirosporum K. & K. The specific name iiswl 
would indicate that Kllis was impn'ss<Nl by the fonn of the sporetf. How- 
ever, the fungus was pla(*(Hl in the g(*iuis Diplocladiuni in spite of the 
fact that the other memU^rs of this group have oval to ol>long sporm. 
No n»fen»nre wjls mjwh* to Morgan's ( ylindn>cl2ulium. 

An examination made by the writer of tyjN^ material of Cylituirocladium 
scnimrium and of DipUycladium cylindnM/Mtrum shows thc^se two forms to \v 
id(*ntiral. The <lesenpti(»ns of the two forms var>' but slightly in detaiis 
and eompanitiv(> studies show sufficient variations to include all difren>niii*tK. 

The genus Diplocladiuni was establish<Ml by Bonorden^ in 1851 whik' 
the gemis (\vliii<lr<M'lu<limn was not (^stablishcMl by Morgan until 1H92. 
The s|M»<*ies of Diplocladiuni descriU»d prior to 1892* fXKss<»ss more €>r li*?** 
ovul to oblong s|)orrs. Then* may )m' some question as to whethcT <ir not 
Morgan w:is justified in (v*<tablishing a new genus on the liasis of si»* and 
sha|M' of s|M)n»s. Tin* moqihologiral diffen»rices in tlu^se grou|)s an' not 
v«»ry gn»at and the classifiratioii at |)n's<'nt is ver>' artificial at liest. At 
least a dcfiniti' morphological basis for s4'paration was utiliziMl so that tlx' 
writer ff*4*ls that Morgan was justifie<l in i^stablishing the giMius Cyhfuirth' 
vUidtum on the Iwisis of the singlf> siM*cies scofmrium. 

As stattMJ by Morgan tln» sfsm's of i^ylindrtKlndium Mcufparium an» 44) 
to .'lO n long and ta|M»r from 4 ti in diameter at the a|)c*x to .i m at the liast*. 
Kllis and KvtThart state the measun'ments of the spores of IHjAtKUtdtum 
rylindrosfHtnim as Inking M) to 'A) n long by 4 to 5 ^ in diameter, but tiM-n- 
tioii no ta|NTing. An examination of tyfM* material of thesi* two foniu^ 
••hfiws tlir s|H)rrs to Im» fn»m 'M to .V) m by W.W to 4.51 ^ in <liiimet«T, tin- 
average In'ing alM>ut 4H.:{ by 4.13 n. 'Y\\v\ ap|M*ar to tafXT slightly but 

' LiiHlaii. <•■ Miirf«iiii:irf:i*-lly:iI(Mli<|yiti:iv /n Dir tinttirlirh«*ii I^Hatiif nfanii- 
liin I l.iiKirr :iml Prniitlll: 1** \\\ t«7 P.O) 

* l.llirt, .f \\. iiihI Kvrrhart. It M Nfw K|M>rit'H of fiinin frntii ynrioim liN-alittt** 
with rioti-H oh HfiiiH* piiMi!«lii-«l H|MTif!» Hul T(»rr lint. (*liil». 87: -!*> fA l!4in 

hijAtH-ltititum t tilintir*n^lt*>rum \\ .'iImI K , p. .V* 

* HiiiKirtini. II. F. Il»ii<llitirli iIit :illK«>iiifiiirti iiivki»l«igi(*, p (lh. iSTil 

* Ir ,fTt,j,iJium Aiin:il M>i-(it 1: 1J7. lUL't ucin i|«*KrriUM| liy liniinilola in l*«K3 
II* )i.i\ lliK «*pnrf)« IIH':i.**uririK 1(> '17 \ .'{ '» t n. 



4i2 I'llYTOl'ATHOLWiV (VoL. 7 

it is difficult to <ift<'ct a mcHMiir»l>k' <lifft'n'nce betwroii the iliaiiH-trr 
of thp apex oiiil of the Imiw nf the f pores. Sixtres pnM)uc»t Ity ttK-fiinfciis 
ciiusinK tlip pn>wii laiikor disciuic of rose »n- identical in all mtiMH-tt' with 
those of tyjie iimtorial of ('yUnitrnrUidium Kvojiariiim and I)i}>li>rlnilnim 
cylin<iros}>i}rinn. 

TIh^ fertile hy|)liac an stat<><l hy Mon^aii for Culiiulroclailiuni Kcii/iarinm 
iitc-iisim- 12*1 l(J I')0 hy .') t(. 7 ii at thi- l>!isc. while th(»sc- of Ihiilirliulmm 



m 






./^. 



uml {rrlili- hyplin ujtli iKiolK'ii tip; H, cnnitli.iph'Tr inurh (nlnrp-d ■ho-inR n»niw-r 
iif 1>rani-liinit; ''. Icrniinal lirnnchp* iit roniiliii|>hi)riv A, hahit Hkrlrh. X J33 H 
nml C. ruiiiiTa lufiiU riMwinpi, X 700. 

rt/liinlriixiHiruiii an iiiea.'<uni) Iiy Kllis and Kverhart are .50 to III) by .*» 
to () II. The writer in exiitnininfc ty|)f niatcriat of (he nuppoMtlly t«tt 
difTenril forins found exceptions to lM>lh nicasun-menls. the nuiRe Im-uiic 
fmni '*) to Hi5 hy '> to 7 p. Fertile hyphne developed on diac&se^i niN- 
plants placed in u nioiat chamber and others produced in culture had «a 



1917] Masset: A Disease of Kobe 413 

even greater range in length and diameter, so that it is probable that 
conditions of temperature and moiature under which they develop mate- 
rially influence their size. 

Fruiting bodies of the fungus frequently develop in from two to five 
days on diseased roae plants when kept in a moist chamber. They are 
usually borne in fascicles, those observed containing some twelve or more 
components. The fertile hyphae areerect, hyaline, septate and di- or tri- 
chotomously branched {fig. 2). The terminal branches exist in pairs or 
threes and are arranged in a level-topped cyme of branches. The spores 
are cut off from their conidiophores by constriction. They are held to- 
gether by a sticky substance, forming a more or less cylindrical head, but ' 



FiQ. 3. Mycelium and Hporem of Cvlinddocladiuu Scoparium 
Some of the aporcB have Kcrminated. Camera lurida drawings. X 700 

separate quickly when placed in water (fig. 2,^). Neither Morgan nor 
Ellis and Everhart mention this point, but an examination of type mate- 
rial shows this character to be present. 

Ellis and Everhart' note that "with the fertile hyphae are a few much 
larger simple straight ones swollen at the tip." This character can also 
be foimd in type material of Cylindrocladt'um scoparium and the fungus 
developing in culture from tissue plantings and on diseased rose plants 
kept in a moist chamber. These sterile hj'phac (fig. 2, .4) may nrise 
from any part of the fertile hyphae but usually exist as the terminal part 

' Bui. Torr. Bot. Club 77: 49-64. 1900. 



414 Phytopathology [Vol. 7 

of a main hypha from which the fertile hyphae arise as lateral branchm. 
When the fungus is subjected to extremely moist conditions the sm-ollen 
tips may resume growth by sending out slender hyphae. 

The spores (fig. 3) of Cylifidrocladium scoparium are solitary, c>'lindrir, 
1 -septate/ hyaline, obtuse at each end and appear to taper slightly from 
the apex to the base. They are 36 to 55 m in length by 3.3 to 4.51 §i in 
diameter, the average being 48.3 by 4.13 m* Those produced in culture 
have al>out the same range. Spores from culture when placed in water 
on slides germinate after three to twelve hours, (lerm tubes may develop 
from one or both cells (fig. 3). 

PATHOGENICITY 

On July 21, 1917, twenty-four rose plants, variety Ophelia, growing in 
the greenhouse were inoculated with vnlUirt'S of ('ylindrocladium ncopanum 
growing on |K)tato agar. The fungus had l^een previously isolatcnl fn>m a 
<lLs(»a.Hed American Beauty plant. The plants inoculates! were alx>ut s^ix 
months old having l>cen grafted in January' on Manetti root stocks. A 
bit of medium in which the fungus was growing was smeare<l ovc*r th«* 
stem of the plants at the graft union, twelve of the plants l)eing previously 
injured by cutting with a sharp scalpi»l while care was exercise<l in hand- 
ling the remaining twelve to s<»e that they wen* uninjured. Six plants were 
similarly treated, except that the medium .smeannl over the plant c'tm- 
taine<l none of the fungus, three of thesi* plants l)eing injurcnl and thn*«* 
lK*ing uninjured. In some cases moi.st cotton was then wrappeil aUnit 
tli(* inoculated areas while of other plants the infection courts wen* !<ur- 
rounded with moi.st soil. The phmts were kept moist for the following 
four clays to prevent the inocula from drying. 

When examined on July 25 all of the incK*ulated plants showed typical 
Mark. irn*gular. water-soaked an>2is at the |X)int of inoculation. Tht* 
cheek i)lants remaineci healthv. Ten davs later there were cracks in thf 
lesions on the inoculated plants which extended in to the wood. Plants 
in which the infected areas were kept moist with wet cotton showwl mon* 
pronounrtnl cracking of the bark than thos<' kept moist with soil. In somr 
ea.**es the bark was badly rotted and sloughed away. To date (XovemU'r 
10) the plants have .shown no g(>neral effect of the disease* as com|HinNl 
with li<>althy plants as eheck. Tissue plantings witc made from five «»f 
the inoculated plants and the .Hitme fungus obtained in cultun*. 

<>n August 10. 11M7. t<>n Manetti plants such as an* usc*<l for stork f«>r 
irrriff'* were ino<*ulated with cultures of ('ytintintrlafimm scoparium. Th«' 
pi int^ were obtained from Holland during the autunm of 1916 and wen* 
Krouin^ in the ^nMiihcMise in six inch |K)ts. .\ bit of nuMlium containing 



1917] Massey: A Disease of Rose 415 

the fungus was smeared over the uninjured surfaces of these plants at the 
surface of the soil and the inoculated areas were then surrounded with 
moist cotton. Four plants were similarly treated with the exception 
that they were not inoculated with the fungus. The cotton on the plants 
was kept moist for five days to prevent the inocula from drying. 

When the plants were examined on August 25 the outer bark had cracked 
and the tissue about the moculated areas was somewhat brown and punky 
in texture. No definite lesions were evident. Cylindroctadium scoparium 
was obtained in culture by means of tissue plantings from inoculated 
areas. Judging from results of these inoculations it would seem that the 
Manetti plants were more resistant to the attacks of the fungus than 
OpheUa plants. 

Infection of stems of eight-months-old Ophelia plants was readily ob- 
tained at distances of several feet above the soil. A bit of medium con- 
taining mycelium of Cylindrocladium scoparium was smeared over the 
surface of the stems, the inoculum being kept from drying by means of 
moist cotton wrapped about it. Black, irregular water-soaked lesions 
on the plants were evident after three to eight days. After the removal of 
the moist cotton the lesions slowly increased in size. No general effect 
such as wilting or yellowing of parts above the infected areas were evi- 
dent on September 18 from inoculations made on August 27, although 
some of the lesions had completely encircled the stem and were an inch 
or more in width. 

Viable spores when sprayed upon plants under favorable conditions also 
produce infection, as is shown by the following experiment. On August 
27, 1917, the stems of six eight-months-old Ophelia plants were sprayed 
both at the surface of, and eighteen inches above, the soil with water 
containing in suspension, viable spores from a culture of the f imgus. Three 
plants for a check were similarly sprayed with water containing no spores. 
The plants were then placed in a large, moist propagating chamber for 
ninety-six hours. An examination of these plants eight days later showed 
infection to have resulted. Numerous small, brown areas surrounded by 
a narrow zone of black water-soaked tissue were apparent on all plants 
inoculated. The lesions measured from two to six millimeters in diameter. 
Fourteen days later the lesions had increased very little in size. The fun- 
gus was again obtained in culture from plantings from diseased tissue. 
The check plants remained healthy. 

CULTURAL CHARACTERS OF THE FUNGUS 

Pure cultures of Cylindrocladium scoparium are obtained readily from 
tissue plantings and from spore dilutions by ordinary methods. Good 



416 Phytopathology (Vol. 7 

veRotativo jq^wth and an abundance of spores are produced by the fun- 
l^is when growing on nutrient agar and agars containing decoctions of 
rose, prunes, beans, oats and potatoes. The mycelium (fig. 3) is at finrt 
white and mostly aerial. After from three to five dajrs it changes to a 
brownish color, l)ecomes comparatively more resupinate and the medium 
is changed to a darker color. Medium to which no acid is added is changed 
to a brown color more quickly than an acid medium.' The color imparted 
to the medium quickly deepens to a reddish brown in from seven to ten 
days, the ultimate color produce<l lK»ing a mahogany-red. The mycelium 
changes to a brown color more slowly than the surrounding medium, the 
aerial mycelium fr(»quently remaining white for months. Usually the 
mj'celium is l(H)se and somewhat tufted. Colonies in p(»tri dishc^s on an 
acid' agar containing a decoction of potatoes mejL*<ured four to five cen- 
timeters in diameter after five days, and six to eight millimeters after 
ten days. 

Thr(»e-week.s-f)ld cultures of Cylindrocladium scoparium in petri dishes 
frequently dev(»lop a darker-colored ring consisting of heavy-walled hy- 
phae. Other cultures develop these darker areas more or less irregularly 
over the entire an^a of growth after two to three weeks. The cells of 
thes<» hyphae thick(»n. assuming a glol)osi» form (fig. 3). Well-defined 
globular iMxIies which apiKMir to Ih» oil drops soon app<»ar within the cells. 

Spores in culture are usually formed abundantly in from seven to four- 
teen days, their presence often giving the culture a white, granular ap- 
fx'aranc(». They are formed more ({uickly and abundantly when the fun- 
gus Ls growing on an acid medium.' Like thos<» pro<luced on diseaseti 
plants subjected to moist condititms, the spores in culture are held to- 
gether by a sticky substance which is quickly di.Hsolved in water. The 
sjK)re-m:i.s.ses produce<l in cultun* have more irregular outlines than thotM* 
pHMluced on the host where the tendency is for tlM»m to 1m» gn)U|>e<l mto 
a cvlindrical head. 

Fertile hyphae develojHMl in cultun' are variable in size, measuring friHii 
KM) to 4(M) /i high by 4 to 9.2 n in dianiet<T at the bas<», the average Iw^ng 
about 2(K) by <)..'> /i. The sterile swollen ti|>s are ver>' abundant in cultun*. 

MOISTIRE KELATIO.N 

Moisture apjiarently plays an im|M)rtant r6le in the s«» verity of this 
disi'jise. Lesions on steins well alK)ve the surface of the soil resulting 
from artificial inoculations app(*ar to <lry and make no further pn^cn-jv 
unless kept moist by Inking surroundi'd with wet cotton or some such *iul>- 

• ThriT tIrupM of fifty imt rcfit Inrtir arid wore n<l<l<'<l to each fifteen ciilur rriitt- 
rnctiTH (»f inrditirn. the tlffcref* <if nridit v not iH'inK ti«*trmunr<i. 



1917] Massey: A Disease op* Rose , 417 

stance. Inoculations made at a point several inches above the soil fre- 
quently result as above. One grower who has had considerable experi- 
ence with crown canker is of the opinion that the disease is lessened by 
placing plants with the graft union above the soil, thereby preventing 
infection at this point. The same grower stated that the seriousness of 
the disease is reduced by pulling the soil away from the crown of the plant, 
thus cFCftting: a more* dry eaaditioa at tlua point* Tkeae are uadafiiBable 
methods, for grafted plants usually develop roots at the graft union when 
planted sufficiently deep. It. is the opinion of the writer that Cylindro- 
cladium scoparium is a fungus low in parasitism and that conditions of 
moisture are important factors in its development. 

CONTROL*^ 

Ahhoup^ experiments are imder way in tbe* hope of dievelopHig some 
method of controUing tW crown canker of rose narestdte- ar% yet at hand. 
From the narture of the fundus it would seem that control will pesohreiteetf 
into some nethod of soil ta^atment. The fungus* gpcyvro well on botk aeid 
and alkalin media so that the possibilities of contr^ by d^BTel^^nng an 
acid or alkalin condition of the soil do not appear to be ppomning. Soil 
sterilisation, and the exercise of care in using only healtiisr 8<»ok and'sokms 
for grafting^ may be the only feasiUe method* of oontPoHiAg t^i^disooBO^ 

CORNBLL UkIVBRSITY 

Ithaca, Nhw York 

' Investigations of control measures are being conducted in cooperation with 
the American Rose Society and with Professors A. V. Osmun and P. J. Anderson of 
the Massachusetts Agricultural Experiment Station. 



AN EPIPHYTOTIC OF CANE DISEASE IN PORTO RICO 

John A. Stevexron 

With Two FiorKRH ix the Text 

During the pixsi two seasons a most alanning epiph^iotic of cane hsM 
appeared in I'orto J{ico, and is still spn'a<ling at a rapid nite. ThU 
trouble first ap|M»anMl in the western end of the Islan<i, in the nidon U*- 
twc^en ArtH'ibo and Aguadilla, and in the summer of 1910 wa^praetirally 
confined to that area. Sinci^ that time not only have its ravaices roiitinutii 
in the original territory, hut its lM)undaries Iiave Ix^^n cxtende<l (>» as to 
indude an an^a exten<ling fnmi near I)ayain6n to Aftasco, or apf>n)xiiiiatv!y 
a quarter of the Islaiui. 

It ha^ not Inh'U (M)ssible as yet to ascertain how long the disi*:iMi* ha«i 
lx*€»n pres4»nt lM»fon» tin* first n»|H)rt wjis nreiviMl but certainly a year, i**i 
that as near as is now known it has In^c^u aetive alnnit thret* years. 

The tnMible is as yet eonfined to the up|H»r reaches of the river valleys, 
to small enrlos^^l inland valleys, and partirularly to fieldsamong thefiMit- 
hills. The broad stn?tch«»s of the eoiu^tal plain, but little alM)Ve si-a l«»vrl. 
an* still fnH* of <iis<»as4', although they an* plant<'<i to the sus4*(*ptilil«* 
varieti(*s of carK*. and fonii gn*at rontiiuious an'iis. The gn*atf*st darnaiE** 
has (MTurnnl in the nilling stn^tch of <*ountr>' U'twc^^n .\nM*ilMi and Akii:i- 
dilla. a region which suffers much fn»m dn»uth. Cane cultun* ha*« Ufri 
abandtmcd on hundriMls of acn*s. 

All obnTVations show an appan^nt tendency of the dis4*as4* to (N*rur in 
upland fields. In its ca.*^tward progn'ss it has appan*ntly juiuimmI fnitii 
Valley to valley, M»m(* distance Uuck from the (N*eaii. or ha^ ap|M*art^| 
s|N iradirally rather than working along through the continu«>u*» ci»hh|:iI 
fiehN. 

I.ns>K> I\ri iiliKI» 

Tlif ili-e.'tH* :ip|M*:ir>* to fulluw a n'Kul;tr eour>e. a given field ^howine tin* 
fir**t yeai a v.'iryiiic iiuiiiImt of iiiferteil ^tiMiU. often oidy a ft*w. M-atii-n-d 
irn-Kulafly. Then* i** no :ipparent lo^s m tin** eri»p. The siM-ond >i-ar 
'tir^t rntiMin* tlit* greater portion of the field i** afTeeted and there may U* 
a jd-.^ iif from ten to fifty per cent in yield. 'i*he thinl y4*ar the gmwtli at 



1917] Stevenson: A Cane Disease 419 

the cane is so poor, and such stalks as are produced are so small, and pithy, 
that the crop is a total loss. 

The loss occasioned is very difficult to estimate since the many fields 
will show a variation of from one to a hundred per cent of infection and 
each infected stool, depending upon its age gives a greater or less amount 
of merchantable cane. 

In addition to the decreased yields, there is the loss of all cane which 
shows evidences of disease, even though it contains a considerable amount 
of sugar, since the Centrals all refuse to receive cane of this nature, for 
reasons to be explained later. The figures for 1917 are not yet at hand 
for comparison, so that it is impossible to give a statement of the monetary 
loss, but that it already runs into the hundreds of thousands of dollars is 
agreed. As a single instance, one Central, in spite of three thousand addi- 
tional acres planted over last year, and the purchase of some thousands of 
tons of cane from outside districts, dropped behind their previous yearns 
production over half a million pounds of sugar. A considerable number 
of small planters have been completely forced out of cane growing in two 
years' time. 

NAME OF THE DISEASE 

Various names have been used for this disease. It is universally known 
among the planters as La Enfermedadj the disease, and the writer has 
called it at various times the new disease, the mottling disease, and cane- 
canker, and at the present moment at least, prefers the use of cane-mot- 
tling or the mottling disease. Chlorosis is already in use for a very dis- 
tinct non-parasitic disease occurring to a limited extent on the south coast 
of the Island, and hence cannot be used, as has been suggested for this 
other quite distinct malady. 

SYMPTOMS 

The one marked and constant symptom of this disease, and the one by 
which it is easily recognized by any one who has occasion to visit diseased 
fields, is the peculiar mottling of the leaves. In contrast to the uniform 
yellowing or whitening of the leaves characteristic of chlorosis, there oc- 
cur innumerable white or at times yellowish spots and stripes with irregu- 
lar, indefinite margins (fig. 1). In mild cases the background may be 
practically normal green, but more often and especially after the first 
year the leaves are yellow-green to yellow interspersed with the white 
markings. It is not apparent that mottled leaves die any sooner or are 
more subject to parasitic leaf fungi than normal leaves. 

For some time there are no further symptoms than the mottling, it 
being impossible to distinguish, except for this one point, diseased from 



idbMM 



420 Phttopathologt [Vol. 7 

normal st<x)ls. Mottled leaves do not die and fall any sooner than normal 
ones nor do they cling ahnomially to the stalk. The stalks are not stunted 
or visibly change<l internally. It Ls quite possible to find stalks which 
show from one or two to ten or twelve lower leaves appan^ntly nonnal. 
with all those alx)ve mottled. The mottling Ls apjiarent as soon as the 
h»av(»s unfold. Th(» rc^versc^ condition of normal leaves above, has not 
Ikm'U (»l)served. It is not certain vet whether a leaf which unfolds nor- 
nuilly may lH»(*ome mottled later. A varying numlxT of stalks in a Ht<¥>l 
may show mottling, often oidy one, more often thrive or four out of a 
dozen. 

The statements in the previous paragraph n»pn\s(»nt conditions the finit 
year of infection. The nitoon sh(M»ts from all infected stools and from a 
var>'ing proportion of thos(» that wen» ap|)an»ntly normal, show mottling 
from the instant the new shoots arc o})s<'rvabl('. This crop ran*ly reac'hes 
normal conditions of height and stand, more often only thirty to fifty j^t 
cf»nt. At this stage, in addition to \\w mottling, another marker I chanu*- 
teristic a|)|M^'lrs a cankering of the stalks. Thes<» lesions ap[M>ar first, 
jis far as oliMTvations show, U'fore the leaf sheaths fall, but after they liave 
lK»comesom<'what loos4'ne(i. At first they are linear spots, somewlmt sunken, 
and bn)wn in eol(»r. They soon Iweome ashen or «lull gray, juul f»ft«»n 
coalesce to form eontinuoiis patches practically covering the intemodi*^ 
(fig. 2). They never, however, pitss from one intenuKle to another. 
They an* su|K»rfi<ial only, never |H'net rating for mon* than 1 to 2 nun.. 
exct»i)t along such eraeks as occur. liven here the n»<ldening that is fiMind 
is seldom mon* than that usuallv found in such locations in nonnal cane. 

The cracking or splitting is not considennl a symptom, U»ing merely a 
rc».sult of the drying of the cane. Splitting normally occurs in many 
varieties, although of cours<» it is mon' marked with this disease*. Then* 
is n(» internal hmI i*ot or other form of n)t accompanying tlu» cankers, but 
then* is a shrinking of the internod(*s and a general condition of pithint*ss 
and lack of juice. All canken*d canes show mottling of the k•av«^s. but 
the revers<» is nc»t true. 

It UKiy U' note<l at this |M)int that not only is then* a la<'k of juice in 
cankennl canes but what d<M»s occur is of an objectionable natun*. .\ 
ver>' high glucose* ratio is n»|>ort<M| (non-<T>'stallizing sugars) and tin* 
juice lM*haves badly during clarification and other process's to which it 
is subjected. \ compn'hi»nsive s<»ri(*s of chemical tests is altout to U» 
made at this Station, to Ih» n»|M)rte<l u|K)n later. 



Stevenson: A Cane Disease 



Continurd pfforf-s have he<>n mode to ascertain the cause of the mottling 
disease but it stiil i-eniains obseure. During the first year, as will be noted 
in the fii-st report on the disease,' the opinion was held that the condition 
was merely the result of too extensive planting, without seed selection 
or proper cultivation practices acting in combination with very unfavor- 
able weather conditions — ^a rirouth followed by an excessive wet period, 
resulting in what is commonly referred to in the literature of cane dis- 
eases as an epiphytotic of root disease. It has become only too apparent, 
however, since then that thore is more involved than merely a situation 
arising from bad weather and bad agriculture. 



Fic. 1. Healthy and Mottled Cane Leaves 

The usual course of procedure to find a parasitic cause has been fol- 
lowed; various fungi have been investigated, cultured, and used for in- 
oculation; and all without result. The juice of mottled stalks has not 
proved infectious. However, it has been found that "seed pieces" taken 
from stalks showing mottling, invariably produce mottled shoots no mat- 
ter how carefully they may have been disinfected. The "seed pieces" 
used appeared to be normal both externally and internally. The leaves 

'Stevenson, John A. Cane dtgenBe. Rept. Board of Comm. of Agr. Porlo 



432 Phytopatboloot IVol. 7 

were romovod to make sure and in some oases the pieres wen' pUnlod in 
sterilized -soil. Such further t^'st.s us have iK-en made with soil of di-t-aiv*] 
fifIdH and .so forth, have l)eon ineonchisive. 

The broad (jueslion of (iegenerat ion of varieties romes up at thi*" point, 
and i.t coiiwidered the eatise hy many. If the white eane only were in- 
volved, a t>-r»*' whieh ha.'* Iieen p-own here for many yearn, it niifchi Ik- an 



i-iiMV way (iiil of a very ilitlinill !>il nation to ],-ty the entire hlanii- oti thi- 
K<'n<Titl term Inil oiIiit, and Mune nf tlieni Minijianitivfly new varit-lH*^ 
an- attarki-d a.- well, Hiiwivir, it is not ini|Kis.til>h- that defcenemtion i- 
involved to M»w extent. 

VAIlli:ilK> AKKHlTKII 

Miiyl of thr ram- of ihe affrited diftrirt ha.s Ix-t-n of two varietiiit: tlif 
NtrijNil or nii/iiihi and the white ih/ntton or Otahritr. probnhly ihefAiiK- ait 
the old BoiirlHtn enne. The white enne was fir>t nfTeetod luid in at pmt*^t 



1917] Stevenson: A Cane Disease 423 

most subject to the disease, the cankers being especially characteristic of 
this variety. Its elimination, as has already occurred in other parts of 
the Island, seems certain. In many places the rayada, during the present 
year, has been as badly affected as the white, although there is still the 
possibility that strains from outside districts may remain immune. 

Other varieties grown on a smaller scale and brought in for trial have 
been imiformly affected, bamboOy penang, 8-3412 j 3-208, yellow Caledonia^ 
Cavengerie and others. A dark red variety, locally known as sarangola 
has been fairly resistant but unfortunately is not a good milling cane, nor 
is it probable that it would have any great degree of resistance if planted 
on a large scale. New seedling varieties are to be tried as rapidly and 
extensively as possible. 

COMPARISON WITH OTHER CANE DISEASES 

In order to distinguish the mottling disease from the other common and 
at times serious cane diseases which might be confused with it, or which 
are to some extent connected with it, some account of these will not be 
out of place here. 

The more the disease is studied the more it appears to resemble the 
mysterious sereh of Java. It is unlikely that it is that exact disease, but 
it is not improbable that it is of the same general nature, produced by the 
same or similar environmental factors. Many of the symptoms are the 
same, although none, it must be admitted, are those that are considered 
essential. Some of the important points of similarity are: the course of 
the disease over three years, the stunting of stools and shortening of inter- 
nodes (in advanced cases), the fact that the disease is carried over from old 
plants to new ones by cuttings, and a poor development of the root sys- 
tem. On the other hand, this new disease in addition to the leaf mottling 
and stalk cankers not ascribed to sereh, does not show gumming, internal 
red lines, more disease at the base of the stalk, or the abnormal stooling 
giving the grassy appearance from which the sereh takes its name. 

Rind disease caused by Melancotiium Sacchari Mass. as a factor was 
quickly eliminated, no more of this fungus being present, than can be found 
in normal cane. In the very heart of the affected territory a large field 
of rdyada cane was found which had been allowed to become over-mature 
and was rapidly going to pieces under this fungus, but there was abso- 
lutely not a sign of mottling. 

Other stalk diseases were as easily removed from consideration by the 
absence of their respective symptoms or the fruiting bodies of the causa- 
tive fungi. There was little, if any, internal red rot {CoUetotrichum falca- 
turn), brown rot {Diplodia cacaoicola), dry rot, {Nectria sp. and other 



424 Phytopathology [Vol. 7 

forms) or of Cytoapara Saccharic serious at times as a cause of disoai«e. 
These as well as other fun^, {Trichoderma lignarum^ Fu^arium sp., Valjta 
sp., Leptaaphaeria Sacchariy and others) were common at times, but only 
as saprophytes as was demonstrated by inoculation tests. 

It is not so easy to ascertain the relation of what is commonly known 
as root disease, and certain phases of the problem are yet unsoIve<l. It L« 
the common assumption of most writers on cane disease that cortain 
fungi, notably Marasmius Saccharic when favored by weather and cultural 
conditions, act parasitically on the roots of the cane, producing stunting 
and final death of the stools. It is, however, not at all clear which of the 
various fungi found in such locations are truly parasitic, if any, and whi<4] 
only saprophytic, and, alK)ve all, whether the weather and cultural c<in« 
ditions alx)ve mentioned are not in reality primar>', making it possible to 
relegate the fungi to a secondary status. 

In the affected territory under consideration, a region habitually subject 
to drouths, and where good agriculture is the exception and not the 
rule, the presence of rcx)t disease, esp<»cially on the long-time ratoons at- 
tempted, iM'comes almost universal, so nmch so that for a long timi* in 
agreement with all agriculturists and others who investigated thesituation* 
the writer considered the trouble root disease. However, more extensive* 
studies have necessitated a decided change of opinion. Fields Imve \n*vn 
seen on land never l)efore in cane, which showed mottling but no root 
disease and on the other hand fields have been encountere<l in the lian 
stages of root disease but without a sign^of mottling. It now appcmrs lie* 
yond any rciisonable doubt that there are two dLseas(*s to l>e considered. 
One a disease characterize*! by a mottling of the leaves and later by a 
cankering of the stalks, and the other the old so-called root disc^ase markfsl 
by n)tten roots iM^nneated by a white mycelium, and by a binding togi*tlu*r 
of the lower leaf sheaths in characteristic fashion. Roth may l)e pn*M*nt 
together with fwirtictilarly disastrous results for the cane, or either may Iw* 
pn*s(*nt alone, with a sinular result hh far i\n the cane is concerned. 

CONTROL 

Practically ev(»r>' conceivable measure* whi(*h has ever lK»en recommended 
for the control of cane disi»a.»*e and esiK»cially those usually given tut ef- 
ficacious for nK>t disea.«*e have In^en tried, and without any other n*s*uh 
than the continued progress of the disease*. Liming, increaseel cultiva- 
tion, treatment with lM)rdeaux niixtun*. s<*ed of established varietie<» 
brought from outsidt* regions, seed of new varieties, and the use* of lanti 
not iM'fore |>lanted to cane, have Imm'H trieel. 

It is app.'irent that v«Ty dnt^^tic meaMires will Im» necessar>' to rh(H*k thf 



1917] Stevenson: A Cane Disease 425 

epiphytotic. The foremost requirement apparently will be the introduc- 
tion of a rotation system, (a heretofore unknown practice in Porto Rican 
cane culture), and one which will include a legume. In the meantime 
continued efforts are being made with new seedling varieties, particularly 
those produced at this Station, and it is hoped that some will ultimately 
be found which, under proper care, will succeed. 

In many instances the growers are turning to other crops or pursuits- 
tobacco, cotton, cattle, and to some extent minor food crops. There is 
no reason why it would not be possible to combine one or more of these 
in a rotation with cane so as to maintain the latter industry. Whatever 
the outcome it will at least result in an absolute revolution in the cane 
agricultiu*e of the Island. 

SUMMARY 

A new and alarming cane disease has appeared in the western end of 
Porto Rico and is spreading rapidly. The loss which varies greatly from 
field to field, being complete in the third year of the disease, has already 
reached a total of hundreds of thousands of dollars. 

The disease is known as the mottling disease of cane. 

It is characterized by a peculiar white mottUng of the leaves and in 
advanced stages by gray cankers of the rind of the stalks and by a shrink- 
ing and drying of the stalks proper. 

The cause is obscure, although possibly due in part to weather condi- 
tions and poor agricultural practices. Of the many fungi found in and 
about cane fields none are considered to have any direct connection. 

All varieties are affected, especially the native white or Otaheite and the 
rayada. 

The mottling disease has some characteristics in common with sereh, 
but there are also many points on which the two diseases differ. Rind 
disease and other diseases of the stalk have no causative connection with 
mottling. Root disease is also distinct, but may occur in connection with 
it. 

No definite control is known. 

Insular Experiment Station 
Department of Agriculture and Labor 
Rio Piedras, Porto Rico 



THK KFFPXT OF ROENTGEN AND TLTRAVIOLtrr RAYS TP^iN 

FUNCI 

H. L. T R U M B r L L AND J. \V. H O T 8 O N 

With Two Ficji-rks in thk Tkxt 

The iniLseuin of the rniversity of Wiishiiiirton, Seattle, which aen'ed 
as u forestry Imildiiif^ (fi^. 1) <iurinK the Alaska- Yukon-Paeifir Kxpositioo 
in 19(K). W2IS huilt of lo^ of f^nH*i\ Douf^las fir {Psnidotnuga taxifolia) and 
Western hemlock {Tsuga hrUmphylla). Five yf»ar« after the building 
was (T(*rteil. it was observed that many of the logs showed sifpi8 of decay 
n^sulting from a serious attack of a wo< m Idlest roying fungiWt Fames pi ni^ 
cola {Ft.) Cke. I^ach siH'eeediiiK year an inen'asing numlxu* of sporo- 
phores ap|K»are<l over the lops varyiiiK from the white rounded Imttons* 
(fig. 2. A) just protruding from th(» hark to well develope<l shelving foniis. 
Where deep) notches w(»re cut into the lops, the characteristic nil rot in 
the heart w(mmI with the broad, white, felted masses of inyeeliuin wn» 
readily <lete<'ted. Occasionally also the s|M)rophon*s of PolyiMruM jtcAim- 
nitzii Fr. (fiK. 2. H) apiM*an»d on these logs, but by far the greater dniimite 
was done by Fimus pinicohi. It was with the latter that the following 
ex|XTiments were made. 

I'lMm recommendation of the forestry <lepartnu*nt, memiswenMleviMHl 
to combat the ravages of these fungi, including the installation of ii hf*at* 
ing syst«*m to facilitate tlu* drying of the timb(*rs and impregnation of the 
wchnI with fungicides, notably copfXT sulfate aiui mereurie ehlorid. Al- 
though the ex|M*rimcnts with copfMT sulfate W(*re the most Hue(*eiwful, the 
impregnation was ol>served to pnM*eed (mly in a hmgitudinal direction 
and for short distances. This was doubtless due to the high water c«»n- 
ti'iit of the cells and to the sixe of the logs which are five to six fe«*t in 
diam«*ter and varying from forty-two to tifty-six feet in length. 

On aeenunt of the fiartial success of the trials with cop|>f*r sulfate fur- 
ther rxiM^rimental work with it was contemplated. It was I he intention 
to a|>ply a considera)>Ie (|uantity f»f a solution of thi*^ coui|MMind to the 
top of i*:ieh of the vertical log colunms and allow it to|)en*olatedownwani. 
In (»rder to do thi^ it wouM have involved raising the r«M>f of the liuilding. 
piifTiim a tii;lit fitting collar aroimd the top of each log and filling thL« 
^(i:ire with the fungicide. Although thi*« was the most pronib^ing niiMie 
of rt>nrr(»llim; the diM*ase. the ro^t of *»urh an i'X|M*rimi*nf pnM*lude«l il . 



428 • Phytopathology [Vol. 7 

It was in the ho|>e that a feasible remedy might be found that the folUnr- 
ing experiments were undertaken. 

From the large mass of data* relative to the action of X-ra^-s on liviii|( 
organisms, it seemed reiusonable to suppose that the spread of the fungus 
might be checked by this agency. From the work of numerous investi- 
gators it has l)een shown that X-rays together with rays from radicMicti%*r 
sources exert a profound influence upon organisms, in some cases, modify- 
ing and, in others, totally inhibiting life processes. Thus, in summariiifif 
the work in this field, Clager' states that Ro<'ntgi»n and radioactive ni>> 
I)roduce similar physiological effects and that s<»nsitiveness to thi»s<' my* 
varies with the si)ecies in the case of plants as well :ts animals. He fur- 
ther states that the sensitiveness varies with age, the older tissm*^ Iteinit 
less sensitive. Hardeen's (»xjM*riments-^ with the ova of toacU and fro^ 
show that exiK)sun* to X-rays results in abnormal it i<'s in the eml>rvf»i. 

It should be stated, however, that there are eas<»s on n»eord* in which 
exfKxsure to X-rays has failed to prcMluee a notieeable efTeet on thr lif«* 
proeesM's of organisms, particularly in the case of baeteria. Weinzirl.* in 
an investigation along this line, found that cultures of liacitlus ntit ami 
of Hnrtllns tuf^erculosis were not affected in any way by exiH>**un's varying 
from five to thirtv minut<'s. The cultures enn)loved bv him wen' oiir 
(lav and thirtv davs old respe<'tiv<'lv. 

' HirhanlH, A. H<M*<'nt rttiidit'H on tin- hiolnf^iral rffiTtw of r;Mlio-;irtivit> Sri- 
vnrv. n. 8. 42: 2X7. 191.*). Tin' rfTortn «»f X-rayn on thi>nt'tioii of rfrt:iin rrii%nir» 
Amor. Jour. Phyflioj. 36: 224. 1914. Kx|H*rini('ntM on X-radiation ai* tht* r^iiw <i| 
pcniioahility rlianKi'8. AnM»r. Jour. PhyMJol. 36: 4(K). IIM.**. Thr cfTiM-i of X-ray* on 
the rntr of cell diviMion in the early cleavage of PlanorliJH. Hii»I. Hull. IT: 67 l*#I4 

Bardeen, C K. Ahnomml development of toa<l c»va fertiliied l»y ffperrtiAioiifti 
exposed to U(»entgen rayn. Jour. Kxp. 7ahA. 4: 1. 1007. Variationfl in niinrrptt- 
bility of aniphihtan ova to the X-rayn at different stages of development. AiiAt 
Record 8: 163. 1909. Further studies on the variation in susceptibility nf amphib- 
ian ova to X-rays at different stages of development. Amer. Jour. Amit. 11: 419 
1911. 

Packard, Charles. The effect of radium radiatidns on the fertiliiation of Nerrts 
Jour. Kxp. Zii6l. 16: 85. 1914. 

* (iager, Charles Stuart. Kffects of the raya of radium on plants. Mrm New 
York Bot. (.arden 4: 1 278. 1906. 

* L. c. 

* Hubs, Viktor K. Kiniges Ul»er den Kinfluss der Hontgenstrahleu aiif Mikr»- 
organismen. Archiv f. Hygiene 66: 341 300. 1906. 

Allen, (^harles W. Radiotherapy and Phototherapy, p. 363. 1901. 

* Weinsirt, John. Private communication to the authore, baaed on unpuMiahed 
data. 



I 



1917] Trumbull and Hotson: Roentgen Rays 429 

experimental 

Samples of the infected wood and of the sporophore of the fungus (Fomes 
pinicola) were collected from a number of logs and subjected to varying 
exposures of X-rays. These samples were kept in sterilized bottles before 
and after exposures. The media used for cultures were potato- and 
prune-agar, using twenty grams of agar to the litre. The latter medium 
proved the more favorable for the growth of the fungus. The samples for 
cultural study were in each case taken as far as possible from the center 
of the specimen, which was removed from the container, cut with a steril- 
ized knife or broken, and a small portion taken from a location that seemed 
least affected by the rays. The mode of recognizing the mycelium of 
Fomes pinicola in culture tubes was more or less imperfect. Known pure 
cultures of the fungus were grown on the same media as those of the experi- 
ments. These were used for comparison as to the gross and microscopic 
appearance of the mycelium. As a species of Penicillium was the only 
other form appearing in these cultures, it did not prove a difficult task to 
distinguish them. Apparently the X-rays had no inhibiting effect on the 
growth of the Penicillium. For comparison three tube cultures were made 
of each sample before exposure and the same number after. The growth 
of the cultures was observed and compared at intervals of four to ten 
days over a period of several months. 

Experiment 1, Four samples of wood from infected logs were exposed 
to the rays from an ordinary Roentgen tube for over an hour at a distance 
of about eight inches from the bulb and directly opposite the anticathode, 
at a potential which was not known accurately, but which corresponded 
to a spark gap of about four to six inches, the humidity of the air being 
high. The cultures from three of the exposed samples showed healthy 
growth at the end of a week and exhibited no exceptional features by 
comparison with the control cultures. The fourth culture as well as one 
of the controls failed to grow. 

It seemed advisable to carry out further experiments so that the samples 
could be subjected to repeated and more intense exposures, such for ex- 
ample, as those furnished by the Coolidge tube. Through the kindness 
of Dr. J. H. Snively of Seattle, the authors were permitted to make uso 
of one of these tubes in performing the experiments which are described in 
the following paragraphs. The exposures were made under conditions 
substantially like those employed so widely at present by practitioners of 
radiotherapy. The main advantage of the Coolidge tube over those of 
the older type for work of this sort is that reproducible conditions can be 
re'alizcd by controlling the voltage and amperage of the thermionic current. 

Experiment 2 (with a Coolidge tube). Two samples of infected w