Plant disease surveys in the Northeastern United States in 1943

Historic, archived document

Do not assume content reflects current
scientific knowledge, policies, or practices.

Issued by

_ THE PLANT DISEASE SURVEY, DIVISION OF MYCOLOGY AND DISEASE SURVEY »
he BUREAU OF PLANT INDUSTRY, SOILS, AND ACRICULTURAL ENGINIERING
AGRICULTURAL RESEARCH ADMINISTRATION
UNITA&D STATES DEPART: ENT OF AGRICULTURE

LIB aye
CURRENT StEiAi REPpARA ee

wee Ep.
q 40% , .
19 544. 2

U.$. DEPARTRERT o

KY wee Eee

eae PLANT DISEASE SURVEYS
> IN THE NORTHEASTSRN UNITED STATES IN 1943

June 1, 1944

be SP as We n- ty, Aer | LO
j

e Plant Disease Reporter is issued as a service to plant pathologists _
roughout the United States. It contains reports, summaries, observations
d comments submitted voluntarily by qualified observers. These report.

=n gre.in the form of suggestions, queries,and opinions,freouently pure
entative, offered for consideration or discussion rather than as mat
of established fact. In accepting and publishing this material the

ision of Mycology and Disease Survey serves merely as an informatior
ring house. I , does not assume responsibility for the subject nat

* » ‘

IN THE NORTHEASTERN UNITED STATES IN 19h3.

Plant Disease Reporter ee
Supplement 147 BLE See Satetes ats. wh, die, dit. June 1; Lb
‘CONTENTS: |

Forevore: 4 i ae ek ee

‘

New England, by Robert C. Cassell

New York, by Leon J.- Tyler ..
Pennsylvania, by Leon J. Tyler .

New Jersey, Delaware, and Maryland,
ir A

Hie. Rie’ Weer arg ak Sieh cca Neve rl
Chie, “by Ms Be Barris 2 yee oes
Indiana, by R. C. teaves eee thers
Pdehios es By We Go Baines aueutiers
Michigan, by M. R. Harris sete ee
Wisconsin, by Edwin E. Honey, and R. E. Vaughan
Minnesota , by Ian W. Tervet asa a a Sais

Towa, by T. W. Bretz

PLANT DISEASE SURVEYS

a -
IN THE NORTHEASTERN UNITED STATES IN 1943 :
FOREWORD | a

The following summaries report the resuit of surveys conducted by
members of the Emergency Plant Disease Prevention Project of the Bureau
of Plant Industry, Soils, and Agricult tural Engineering. Since the in-
clusion of all the summaries in one supplement would result in a volume
too bulky for easy handling, the material has been divided on a roughly
geographical basis, as foilows:

Supplement 147 1h7 -- Neriicastern Ua od States, tee eee area north am
of the Chic and Potomac xXivers, west to Minnesota and Iowa, ae

Supplement 148 -- Southeastern United States, south of the Ohio and Bas:
Potomac, west to Missouri, Ae: and Louisiana. ies

Supplement 119 -- - Western ee ne See oS Great Plains States
we sty ard S

>

| The considerable variation in the conditions under which the surveys

were conducted in the different States has resulted in a corresponding

- variation. in content and form of the summaries, and no attempt has been

made to have them conform to a uniform method of presentation. Some of
them report only data obtained during the surveys; while in others in-

formation from additional sources has been incorporated into a more ccom-
Be oe of disease occurrence in the State during the season. |

BPP a ve ae Uae ED ae pee ee be Cig. Zea Fri aie Sek) WO as POR ERE:
y Dit eee i ee aaa ee ts 7 bts Ney fers et, < ae eA es a ad ee ae
SE te SR BM Aer eal etc aig Pe N EES Se

PLANT DISEASES IN NEW ENGLAND, 1943

Robert C. Cassell

References are made throughout the Mew England report to drought
areas and areas of excessive rainfall. The following table, showing
the monty precipitation and departures from the normal, by peace
will help to explain some of the unusual situations.

Total wont aly Precipitation and Departures from Normal during the
Period April to September, 1943, in the New England States.
(een from U. S. weather Bureau, Boston)

Eee Precipitation (inches) in
Month eee New tHlaine:Massachusetts: Connecticut:khode
ia nee eee _tHampshire: eas Pease es Se
pra : cf : : : ;
Total MeN Raa SER Pe 3.49 > SO mame ie 2S
Dewar ture 2) 42 Geo, et ewes : : Sees
- 3 : ees C505 : O.26 se eae
Nay 5 : : = : :
Total SL eh Sis peer eye erect 5.50 : 551 oo ee Oe
Departures: Fs) 25595 dese. 2 0Ls3" 212) : er ieee
- 2 : : : See ame © Bi
June : : : ; ; Sexeaties
Total Repeater y 6h See Pe Pete) lig: Aca : 3434 S te18
Departures. chee - O.60 © og) ee Os : a
eee : Kae : dbeatleun : OZ rg Bee a:
July : ae : : ee : |
Total money yee 2 Me | ee Se Oe 4.80 ‘ Bele <8 Sep
Deparuures + <: OsOh -: LC. espe eZee = 3
= Gis ; : 5! : Ore Dues Se genes
August 3 San ae : Oe :
Total nee? Oh Se ik: Soule one 2.43 : 1.627 ae
Wepartunecs ay fs 75 4 POG. ts. Maer : : a
are : : : Pg : Zee : . Looe
Sentember™ ; ‘ ; ; : gece
“Tone bk Si cepa ey GG 8 cpa) 1.49 : Lo5oC Sa
Deparbure: i" 2 ; : } | ; : a
oe eee 2 1408 2.20: 25. eee

Total for ——-
2h.65 \s22(27: °° 20013. °. <. fe

period Bs ee ae :
Departure: + 2). dhe. 2 4 eese Sees : :
phi ae gs SS a Gs eee rey oe 16 | ees

* Not final, subject to possible slight correction

Aika
ned

ROME PR Renker ames OREN PRY AOR LY Sri ct Olmste p Lieb au mlemye d
cPealti alt ISI IG ase a NS 4 Vays

127

The actual drought area of New England in 1943 included Connecticut,
“Rhode Island, and southern and eastern Massachusetts, ard extended as
far north as Portland, Maine, constituting a coastal belt line termi-
nating at the north in lower Maine. Yields of all mid=summer and fall
crops were appreciably lowered unless irrigation was employed. Apple
and potato yields were strikingly affected. In Connecticut and Rhode
Island apple yields were reduced probably 25%, principally through re-
duction in size of fruits, and potato yields were lowered 3C to 50%.
In ilassachusetts, even.in the Connecticut Valley and the Ber':shire Hills
to the west, potato yiélds were 10 to 4C% below normal. These lowered

-. potato yields. include reductions due to all contributing factors, among
which aphids, leafhoppers, and flea beetles played no small. part. this

- year. in’ aine, on the other hand, the 71,040,0CO bushel potato crop

was figured at an average yield of 370 bushels per acre, which is con-
oe, . Sadered a very good yield.

‘

‘J

PT Whee aay ee CLS ee

ie ss DISEASES OF VEGETABLE CROPS

K _ALLIUi: CEPa,. ONION

, Colletotrichwa circinans, smudge. A single light case wes found in

: some ‘recently. stored onions in Waltham, iWassachusetts. Danage was

: slight.

ee. Fusarium sp., root rot. From a July observation of 0. C. Boyd and

iG Thomas Soroston, Jr., it is noted that root rot was more prevalent than

usual in. assachusetts, especially in set onions. Where observed, from

5 to 35% of the plants were affected, with premature lodging and death

of tops accompanied by some bulb decay. age to heavy Ones were

expected in storage.

| Peronospora destructor, downy mildew, Was severe in Presque Isle,

‘oa Waine, according to Reiner Bonde.
Phoma terrestris, pink root, was reported once in En
Urocystis cepulae, smut. Early in the season smut was more ae

oo for several years in the Connecticut River Valley of iiassachusetts.

A 30% reduction in yield was found in 1 ae oe seeded white pickle:

- onions.

Ree. STE epee

APIUM GRAVICLENS, CELTRY

Cercospora apii, early blight, was generally prevalent in Connecticut,
Rhode Islenc, and Massachusetts, but damage was apparently less than in
most seasons. Only a few isolated severe casés were noted and these were
due either te at requent OrEey applications or to the use of overhead
irrigation.
esr. OepLoria. anti, late blight, was found in Connecti cat) Rhode Island,
ie Massachusetts, and New Hampshire, but was much less prevalent generally

Be _ than early blight. A few isolated cases of 4 to 6% damage occurred, but
. in en at no appreciable damage was noted where ences protection was
x Black heart ae Two severe cases were noted in Lassachu-

setts; one case was an almost total loss of a 7-acre field. A case of
slight proportions was found in Connecticut.

Ne : Wetae ee eae, eae ae

iz at i

128

pM lane Laem Supe ee es a ces ae ines. ei a al | Died ne ns Ao a
7 33 SS peg ckcaes E Sig he

os a

ASPARAGUS OFFICINELIS, ASPARAGUS

Puccinia asparagi, rust. In spite of the serious Sabeneuk of rust in
Massachusetts in 1942, the disease did not appear this year until Sep-
tember 17, about 2 months late. One severe case was observed on tiary
Washington late in September. Losses were negligible in Massachusetts
in 1943, and no rust was found in the ether New England States.

BETA VULG:RIS, BEET ; Oa ee

Actinomyces scabies, scab. One moderate case was reported in cone
cut.

Cer Cercospora beticola, leaf spot. Light infections were recorded in scat-
tered areas in Corinecticut, Rhode-Island, and Massachusetts.

Phoma betac, root. rot. One light case was reported in Connecticu

BETA VULGARIS var. CICLA, SWISS CHARD
Cercospora beticola, leaf spot. A 100% infection was observed in 1
heme garden in Bristol County, Massachusetts, with moderate damage.

BRASSICA CA: PESTRIS, RUTABAGA

Gercosporel1s albo sacutaae white leaf spot, was generally spread over
one field in Massachusetts. Damage was severe in spotted areas Senne
eive| Gh.

Xanthomonas “campestris, black rot, was ore in one field in Massachu-
setts, “with very slight damage.

aed

BRASSICA OLSR4CEA var. BOTRYTIS, CAULIFLOWER

Alternaria cixcinans (A. brassicae), black leaf spot, was recorded in
Connecticut and lassachusetts, but prevalence was far less than in most
past years. Slight to moderate damage was neganaa ss 3 Massachusetts
PLES.

Plasmodiophora brassicae, club root, was found in 1 field in i.assachusetts
and 1] field in ‘iaine. Except for an occasional severely stunted plant,
loss was slicht. | 3 3

Pseudomonas maculicola, peppery leaf spot. A light localized infec-
tion was observed in 1 field in Massachusetts. The disease was far less
prevalent than usual.

BRASSICA OLERACEA var. BOTRYTIS, BROCCOLI
Alternaria circinans (A. brassicae), black leaf spot, was recorded in
Connecticut, iiassachusetts, and Vermont. It-was usually confined to the
lower leaves and in no case was any appreciable damage involved.
Peronospora parasitica, downy mildew, was recorded once, in liassachu-
setts, with no damage.

BRASSICA OLIR4CEA var. CAPITATA, CABBAGE

Alternaria circinans (A. brassicae), black leaf spot, was récerdecsties
Rhode Island, ‘llassachusetts, and New Hampshire, but never in serious pro-
portions. It was usually confined to the older leaves with practically —
no damage involved. ;

129

Fusarium oxysporum f. conglutinans, yellows, was reported from 3 coun-
ties in Massachusetts and 1 in Connecticut. A 25% loss wes estimated for
one ilassachusetts field, and 20% for another. Growers are rapidly turn
ing to resistant varieties. In Massachusetts, yellows was reported from
Bristol County this year for the first time.

Peronospora perasitica, downy mildew, was rather prevalent on the early
and second-early crops in Massachusetts, but was less prevalent on late
cabbage than usual. Infection was usually confined to the lower leaves
and no severe damage was recorded.

Phoma lingam, black leg, was observed in various places in jiassacnu-
setts. Severity ranged from traces to very light infections. The dis-
ease was less extensive and damaging this year than usual.

Plasmodiophora brassicae, club root, occurred in rather serious pro-
portions in certain areas of Massachusetts and Maine this year. Home
gardens as well as commercial fields were affected. +he most serious
case observed was 25% loss in 1 field in Naine.

Xanthomonas caipestris, black rot, was found in Connecticut, Rhode
Island, and Massachusetts. The disease accounted for a 5 to 10% loss in
1 field in rhode Island and a 90% loss in 1 in Massachusetts. In general

black rot was scarcer in New England this year than in most past seasons.

BRASSICA PEKINENSIS, CHINES® CABBAGE
_ Alternaria circinans (A. eae eee black leaf spot. A single record
was made in lew w Hampshire, of no damage.

CAPSICU!: FRUTSSCENS, PEPPER

Zanthomonas vesicatoria, bacterial spot. A single case of leaf spotting
but no fruit infection was observed in eastern Massachusetts. ansge was
not appreciable. |

Mosaic (virus) was found in Connecticut, Rhode Island, and 2‘essachusetts,
and appeared as the most serious disease of oeppers in New England. lost
fields had from a trace to 10% infection with an occasional field, es-
pecially in Connecticut, showing up to 50 or 60%.

Blossom-end rot (physiogenic) was quite common throughout Connecticut.
The damage ranged from slight to moderate depending upon the location.

Sun scald (non-parasitic) appeared in severe proportions, esvecially in
victory gardens of the New Haven-Hamden area of Connecticut.

CITRULLUS VULGZ2IS, WATE MELON

Colletotrichum lagenarium » anthracnose, was recorded from a single plan-
ting in Xhode Island. ee. some of the fruits were badly merizec, prob-
ably reducing the sale value of a quarter of the crop.

CUCUMIS MELO, CAXTALCUP

Alternaria cucumerina (Macrosporium cucumerinum), leaf blight, occurred
in approximately the same proportions as scab and anthracnose

Cladosporium cucumerinum, scab, occurred as light uk Betieda in several
counties of jassachusetts, without ae losses, decidedly lower
this year than usual. :

Colletotrichum lagenarium, anthracnose. Occurrence was approximatdy

a ee ee ee

the s: same as for scab.

wee - SPs 3 4 yt Vaal ory “es : ~— 1e ;
4 ; . " : ot bevel “ é ¥ as aa 7 as 7» 4
130 Met Da Sterile tbe hos aides
: aE ee oe Ry . rh y Sort ao sasaki 294 a ary a

Erwinia tracheiphila, bacterial wilt,. Light infections were noted ani
“several ii Massachusetts counties. . Losses” were very light.- i

Fusarium sp. and Verticillium oes root rot, wilt, caused heavy ‘Louse
on 2 Jlassachusetts farms. in b both fields most of the plants of all var-
ieties were wilting and dying prematurely. from root dieback and cankers.

Pseudoperonospora cubensis, downy mildew, was found in Connecticut,

.: Rhode Island, and New Hampshire. In Rhode Island it was widespread and
accounted for considerable damage, even to total: loss. It was found in
small amounts in a single field in Connecticut and New Hampshire.

Septoria sp. (probably cucurbitacearum), leaf spot, occurred as local
light infections’ in 2 Massachusetts counties.

Mosaic (virus). One observation, of 50% infection, — was made in Nassa~

chusetts. O |

CUCULIS SATTVUS, CUCUMBER .

Cladosporium cucumerinum, scab, was found in Massachusetts and Haine.

It became widespread and damaging in Massachusetts about August 15. Scab
i ran its usual course in the upper Connecticut R diver Valley but was much
less. severe in the drier sect tions of the southern and eastern parts of
‘ the State. Scab was found in 2 places in Maine, but only around la
, .Grange was the damage severe enough to reduce the market value aporecia-
bly.

Colletotrichua he Selon ha anthracnose, was found in idea eee
and Vermont. About 50% of the fields observed in Massachusetts had fol-
iage infection this year, with actual losses light. Anthracnose caused
some loss in victory gardens in Burlington, Vermont... :

rwinia tracheiphila, bacterial wilt. Boyd and Sproston report that
bacterial: wilt was first observed in Massachusetts June 26; later it
Si, could be found in practically every field and garden 4 wie Losses
ae ranged from about 5% to 50% of the plants, in spite of the fact that the
43 Eee ee was generally less damaging than in most past seasons. .
RG Erysiphe cichoracearum, powdery mildew, was found in one location in
i New Haapshire.- Prevalence was or in hae field, but damage was *
is very slight, if any.
,Pseudomonas lachrymans, angular teaf wee Following bacterial wilt
. and. scab, ancular leaf spot was the next most widely distributed disease
Rey of cucumbers in hiassachusett Prevalence was general but infection was
phate mostly light except under pe es in the éastern part of the State,
Li where the disease was most severe. ae leaf spot was quite general
ae A in the Portland=Scarboro area of Maine and caused some appreciable
Bs -losses in the Portland region.
Hh Pseudoperonospora cubensis, downy Hie =) appeared in Miseachude chee
second week of September and later was found in most sections of the ~
State. Some heavy losses were suffered in the eastern part, especially
in Bristol ang Plymouth counties where there were 2 known cases of 75 to
80% losses. . L. Howard also reports downy mildew in Rhode Island.
Mosaic ae appeared somewhat later than usual this season but spread
rapidly after the delayed start. It was found in Connecticut, Rhode Is-
land, Massachusetts, Vermont, and Maine. Tnere was a probable loss OL
20 to 25% of the Connecticut River pickle crop, with less damage to the.

ee

a ee ee
x. bs

ES Cae eee Oe

ane
ae ;

aa

‘

= els

it:

slicing cucumbers. There was also probably 5 to 10% loss to the cucum-
ber crop in eastern Massachusetts, the Burlington area of Yermont, and
the La Grange area of Maine.

Sun scald (non-parasitic). Early leaves were badly damaged by sun
scald, followed by later recovery of the plants in the eee Connec=
ticut area,

CUCURBITA MAXTMA, SQUASH, and CUCURBITA PEPO var. CONDENSA, SUR SQUASH
Alternaria sp., fruit rot, was found in several locations late in the
season in New Hampshire, and in Burlington, Vermont. Losses were gee

gible, if any, as only immature fruits appeared susceptible.

Alternaria cucumerina (Macrosporium cucumerinum), leaf blight, caused
no damage as it appeared on immature fruits late in the season in east-
central Massachusetts.

Choanephora cucurbitarum, brown rot, blossom blight, was found in Con-
necticut, Rhode Island, Massachusetts, and New Hampshire. It was ver
severe in Rhode Island, where a loss in set of 2/3 of the summer squash
and 1/2 of the winter squash was reported. In Massachusetts losses were
heaviest in the eastern part, where they were recorded as slight to mod-
erate. Moderate losses occurred in the Hamden, Connecticut area, while
in New Hampshire brown rot was well distributed but the loss light

Cladosporium cucumerinum, scab, was observed only in Massachusetts,
where its occurrence on summer squash was much less common than usual.

It appeared to be most orevalent in the western part. On winter squash
in storage scab seemed confined to the seconds or immature sinall squashes.

Colletotrichum lagenarium, anthracnose, was found only in New Hempshire,
but was generally prevalent there in the Litchfield=Pittsfield-Barnstead
area, Damase to the fruit ranged from slight to moderate.

Erwinia. tracheiphila, bacterial wilt, was found in Massachusetts, Rhode
Island, and “aine. It was generally comaon but less extensive and dam-
aging to sumer squash than usual; more damage, although light, was caused
to fall and winter varieties in Massachusetts. Only one case was found
in Maine, at Scarboro, with very slight damage.

Erysiphe cichoracearum, powdery mildew, was found generally prevalent
in Connecticut, Rhode Island, Massachusetts, Vermont, and New Hamoshire.
it was much more severe in southern New England than in the northern
part. In the southern section, greatest damage was caused to foliage
early in the season, while new leaves produced under drought conditions
later were almost free frommildew. Many older leaves of the plants were
killed by the disease, and severe stem infections were common.

Fusarium solani var. cucurbitae, foot rot, was generally distributed in
Connecticut, damage appearing moderate to severe.

Mycosphaerella citrullina, leaf spot, was observed on the aging foliage
of winter squash in east=central Massachusetts late in the season.

Pseudomonas lachrymans, angular leaf spot. A single case with very
light infection was found in Portland, Maine.

_ Pseudoperonospora cubensis, downy mildew, was found on summer and win-
ter squash in Bristol County and on summer squash only in Middlesex and
Plymouth Counties, Massachusetts. Infections were mostly light to mod-
erate but in some fields of summer squash. there were areas of marked de-

132

“Island. ilost severe losses probably occurred in Hampshire and Franklin =

ine

foliation. Boyd reports this to be the first outbreak of downy miidew on —
squash in iiassachusetts since 1932. Downy mildéw was also found in Rhode ~
Island. ee
Rhizopus sp,, black mold rot, was found in 2 fields in southern New ~
Hampshire. Damage was negligible as the rot appeared late in the season
on immature fruits. Rares Notes
Septoria cucurbitacearum, leaf spot, was observed in Franklin, Hamp-
shire, and ifiddlesex Counties, Massachusetts. In Franklin County heavy
foliage spotting caused moderate damage to the crop in 1 field. ‘
Mosaic (virus) was present throughout most of Massachusetts and the ~-
Connecticut River Valley of Connecticut. In Middleton, Connecticut, dam
age was most severe; many fruits were not marketable. Mosaic was less
severe in Messachusetts than in most past seasons. a
Yellows (aster yellows virus). One case was observed in Maine, with
practically no damage. ; ~] . . .
Sun scald (non-parasitic). In the Mansfield, Connecticut area the early ©
leaves were badly damaged by sun scald.

CUCURBITA PEPO, PUMPKIN :
_Erysiphe cichoracearum, powdery mildew. A single case was noted in a

Kingston, Rhode Island, where the disease was general in the field and con- ~

Siderable damage followed severe defoliation. |

_ Pseudoperonospora cubensis, dowmy mildew. A singie case of light to.

moderate infection with no appreciable damage was observed in Bristol .-

County, s.assachusetts.

DAUCUS CARCTA, CARROT es Se
Cercospora carotae (C. apii var. carotae), leaf spot, and/or Alternaria —
carotae (!‘acrosporium carotae),leaf blight, were observed in Connecticut,
Rhode Island, liassachusetts, and Vermont. These 2 leaf diseases appeared
late but became fairly widespread and caused some loss in local areas.
One large field in Southington, Connecticut, suffered a loss of about 1/3
of the totel leaf area. Some noticeable loss occurred in Apponaug, Rhode

Counties, ilassachusetts, where yield reduction amounted to 15 to 20% s.23° ©
mostly from Cercospora. In the Burlington=Essex Junction area of Vermont
losses were light and cafined to victory gardens. ;
Yellows (aster yellows virus) was. observed in all the New Zngiand .-
States. Infection was scattered with no serious losses anywhere. Losses
probably reached 5% in a few fields.
Root branching (non-parasitic). = single case of 100% loss was ob-_
served in a 5-acre field in Southington, Connecticut. Dry weather and a
hard-pan soil appeared to be causing the roots to develop from 2 to 4
branches, | | |

LACTUCA SATIVA, LETTUCE ~ iat the , TS
Septoria lactucae, leaf spot, was found in Massachusetts, Vermont, and
Maine, causing only slight damage. to the leaves in most cases. ioderate
to severe damage was noted in 1 irrigated Massachusetts field. - =
Yellows (aster yellows virus) was the principal disease observed in

° 133

‘August in all sections of Massachusetts. It was most prevalent in the ~
drier eastern counties where infection ranging from 10 to 70% and losses
from a trace to 50% were observed. The disease was also the source of
considerable concern in the Portland-Scarboro area of Maine, where most
growers suffered from'25 to 35% loss.

LYCOPERSICOM ESCULENTU:M, TOMATO

Alternaria solani, early blight, was found generally distributed through-
out ilew England. No appreciable losses were observed in Vermont or
Maine, and only 1 case was found in New Hampshire where defcliation
was severe enough to reduce the yield. A few scattered cases of serious
defoliation were found in Rhode Island, and 1 case in Connecticut where
damage was slight to moderate. In Massachusetts a field of Bonny Best in
Worcester County suffered 25 to 35% defoliation. A planting of the same
variety in Hampden County was reduced 30 to 35%. In1 large field of
trellised Comet in Plymouth County, the disease caused failure of the
first 2 or 3 hands, severe defoliation, and a 25% reduction in yield. Ex-
cept for these cases cited in Massachusetts, early blight was less dam-
aging late in the season than in most former years. |

Cladosporium fulvum, leaf mold, was found in field plantings in Connec-
ticut, Rhode island, Massachusetts, and Maine. In Connecticut damage to
the foliage ranged from slight to moderate in Hamden and New Haven. J.

G. Horsfall reported that leaf mold was the general complaint of victory
gardeners in New Haven. The disease apparently caused no noticeable
losses to ficid tomatoes in Rhode Island, Massachusetts, or Maine, al-
though some losses were known to occur in greenhouses in Rhode Island and
Massachusetts.

Colletotrichum phomoides, anthracnose, was observed in Connecticut,
Rhode Island, and Massachusetts. Most severe infections occurred in
Rhode Island where the disease was recorded in Kingston, Apponaug, and
Newport. In Newport fruit infection prevented harvesting of practically
all of the later fruits. Occurrence was least extensive in Massachusetts.

Corynebacterium michiganense (Phytomonas michiganénsis), bacterial can-
ker, was common in the Waltham section of iiiddlesex County, iiassachusetts.
One grower there lost his entire crop of Victor and up to 70% of other
early=planted varieties.

Fusarium oxysvorum f. lycopersici (F. bulbigenum var. lycopersici), Fu-
Sarium wilt. One case with moderate damage was noted in southern Essex
County, Massachusetts.

Phytophthora infestans, late blight, was observed in Massachusetts,
Vermont, New Hampshire, and Maine. In Scarboro, Maine, it was found
spreading from potatoes to tomatoes on August 22, when infection spots
were evident on the tomato fruits. Subsequently, tomatoes throughout
Maine became infected and considerable loss of fruit resulted. Some fruit
infection was found in southern New Hampshire about the middle of Sep-
tember. Considersble loss of fruit occurred as far north as Burlington,
in Vermont. In liassachusetts a limited amount of fruit loss occurred in
a few scattered areas. |

Septoria lycopersici, leaf spot, was found in Connecticut, Rhode Is-
land, Massachusetts, and Vermont, in widely scattered areas and in vary-
ing amounts. Infection ranged from very light to moderately severe.

hea, wo Oy |. + >
in“ t. Roa ele
aS oe pon + iS
- 7

. ‘ 134 gi Pa ie i ; ; sa a , : Oe i rk es rat aes Ee ae +4, eee “a

Verticilliua sp., verticillium wilt, was observed Ths field in aactes
ern Plymouth County, Massachusetts, where it was causing slight to moder-
ate damage.

enamine rot (physiogenic), accompanied by physiggenic fruit--
cracking and sun scald, accounted for the greatest loss to tomatoes in
: SECS Rhode Island, and eastern Massachusetts, the drought area :
é of New England. In eastern Massachusetts Boyd estimated from 5 to 10%
loss due to blossom-end rot; in Rhode Island Howard estimated 5% loss;
and in Connecticut the loss was at least 5 to 10%.

Mosaic (tobacco mosaic virus) was found in Connecticut, idassachusetts,
and New Hampshire. Occurrence was rather scattered in Connecticut and
Massachusetts, but was always most serious on trellised tomatoes. One
severe infection was found in greenhouse tomatoes in Massachusetts. Only
1 observation was made in New Hampshire. No appreciable losses were re-
corded for mosaic in New England.

Streak (virus). One light case was observed ina Massachusetts green-
house.

Lae hens

-

A) a

Ld be
wl

PASTINACA SATIVA, PARSNIP 3

Cercospora pastinacae (C. apii var. pastinacae), leaf spot, was found
rather rarely in Rhode Island, Massachusetts, and Vermont. Only inl
field in Rhode Island and in 1 in Massachusetts was the foliage infection
recorded as moderately heavy.

Ramularia pastinacae, leaf blight, was recorded in Massachusetts as
less abundant than Cercospora.

De a ee WT Te wa Ar na terse
mal on ~, ar ‘ ' -
i

way cl een

ay

aes eee Pi by he eT
oe erp ase cee

—_— ere
Maas

et

<

PHASEOLUS spop., GARDEN BEANS |

Botrytis cinerea, gray mold rot. Isolated cases were found in Massachu-
setts and Maine, particularly where vine growth was heavy. It caused
very little loss, -if any. ;

Colletotrichum lindemuthianum, anthracnose, was found in Connecticut,
Massachusetts, \ Vermont, New Hampshire, and Maine. In Massachusetts it
was far less prevalent than usual; especially in the drought area of the
eastern part of the State, the only severe case recorded being 1 field
with a 90% loss. No appreciable losses were recorded in Connecticut,
Vermont, New Hampshire, or Maine.

Fusarium solani f. phaseoli (F. martii var. phaseoli), dry root rot,
(Aliso Fusarium spp. and Rhizoctonia spp., root’ pehes 4 o ias Masanchiselttee
according to Boyd and Sproston, most plantings early in the season —
showed above-normal amounts of root rots. A 50% loss in 1 field this
year was the heaviest loss ever recorded from F. solani phaseoli in the
State.

Isariopsis griseola, aneee leaf ae was observed once, as a trace :
in a Massachusetts field. ;

Pseudomonas medicaginis var. phaseolicola, halo blight, was found in |

Massachusetts, Rhode Island, New Hampshire, and Maine. In Massachusetts - q:
the disease occurred in all counties but in much lighter amounts than
usual. In Haine the disease seemed more virulent, the systemic phase . .
being quite pronounced, and it probably caused some reduction in -yield.® 7.

Uromyces phaseoli var. typica (U. appendiculatus), rust, was observed a

reubit

dee

in Massachusetts and Vermont. Two severe cases occurred in iassachusetts;
both on Kentucky Wonder, 50% defoliation being noted in 1 field and 80%
loss in the other. Slight infection was noted on a bush variety. In
Vermont some losses up to 36% were observed.

Xanthomonas phaseoli, common bacterial blight, appeared in Nassachu-
setts later than usual. Only one heavy field infection was found and
that was after harvest. In Rhode Island a single case was noted, with
very slight damage if any.

Mosaic (virus) was found in Connecticut, Rhode Island, Massachusetts,
Vermont, and iiaine, apparently causing less damage this year than in some
other seasons. The heaviest infections observed were only slight and dam-
age was negligible. |

PISUM SATIVUi:, PEA :

Erysiphe polygoni, powdery mildew, occurred extensively with sight to
moderate damage in Aroostook County, Maine.

Fusarium sp., root rot, was common in Connecticut wherever late peas
were planted.

RHEUM RHAPONTICUM, RHUBARB )
Phyllosticta straminella, leaf spot, was found in Connecticut, causing
very slight damage in 2 locations.

SOJA nAX, SOYBEAN. See with forage crop section

SOLANUM MELCNGENA, EGGPLANT

Alternaria solani, leaf spot, was reported by Boyd and Sproston to be
generally »nresent but causing very slight damage in Massachusetts.

Phomopsis vexans, leaf spot, fruit rot, occurred in local outbreaks in
- Connecticut and Rhode Island, causing slight damage as infection was con-
fined mostly to the foliage. Damage this year was less than usual.
_ Verticillium albo-atrum, wilt, was generally distributed in Connecticut,
hhode Island, and Massachusetts. Losses were slight to moderate in Con-
necticut and Rhode Island. Severe infections with losses of 50 to 75%.
were observed in 2 counties in Massachusetts. This disease is considered
the principal limiting factor to successful eggplant culture in Massachu-
setts and southern New England.

Mosaic (virus) was observed to be causing very slight damage in one
Connecticut planting.

SOLANUM TUBSRCSU::, POTATO’ :
Actinomyces scabies, scab, was probably the most common and serious disease
of potatoes in home gardens this year, and in some cases it was also more
damaging than usual to the commercial crop. In many cases potatoes were
grown in new locations this year, both in victory gardens and in fields,
which fact contributed to losses from scab. In New England, scab was ap-
parently of least consequence in Rhode Island. A few severe cases were
found in Connecticut, the most serious one being an estimated 5% loss for
200 acres in East Windsor. In Massachusetts, light to moderate damage
occurred in many fields in the valley area of Hampshire and Franklin Coun-

136

was found in all of the States exeept Connectic., and New Hampshire.

limited survey previous to digging timc, it was found in 4 fields, and

fat. Fa eS Ve ~~ Se ee ie OS SE ba en ee Pek ea es 2 Oe
SE Et RN ee Dt ae hy eee ep: Sete ee
. , "Ss < on ani ene scale

2 wd Ula

eet Pes "
iio “
ange +

*

a

ties where the land in past years had been limed for onion or tobacco
culture. In-a 20-acre lined pasture in Essex County put into potatoes By
this year the tubers were 100% infected, with a 40 to 50% loss in crop i
value. In Vermont, scab seemed to be unusually bad with a higher than
normal crop loss in places, . Some cases of 60 and 90% tuber infection :
of the deep crater type were found, although, in general, commercial loss-
es were not large. scab did not appear to be as important in New Haimp-
shire and Maine as in the other States. It was unusual not te find at
least traces of scab in northeastern lew England, but it is not believed
that the disease will account for any appreciable crop loss there.
Chippewa and “reen Mountain appear tobeihe varieties most susceptible
to deep scab.
Alternaria solani, early blight. xcept for Rhode Island, this disease
occurred throughout New England in more widespread and damaging Dropor—
tions in 194% than in the average year. General, light to moderate at-
tack was the rule in practically all fields with possible yield recuc-
tions up to 5 or 10% in places. ap
(Corticium solani) see Pellicularia filamentosa.
Corynebacterium sepedonit cur, , bacterial ring ros, appeared in hew Sngland
in the most serious propoztioz is ever experienced. Definite occurrence

¢

-

Only one affected field was found in lihode Island, a 10-acre field that
showed about 0.5% rotted tubers at digging time. The owner reported the
seed as certified Green Mountain. The disease wes found in 4 counties in
Massachusetts. One 150-acre planting showed a general but light infection ©
of parts already dug, except one part in which at least 2% of infected
tubers were left inthe field. This fieid was planted with No. 2 seéd
supposedly from a certified crop. In Vermont, EH. L. Bailey reported that
bacterial ring rot was fairly well distributed over the State. During a
iggi
indications were that 2 of the affectcd fields weald contain at least 2
or 3h Totted tubers when dug. iIniaine, the disease was rather ‘generally
distributed throughout potato-zsrowing oa ae andcreated considerable
concern among the growers. Of 44 fields in Aroostook County examined dur- 2
ing digging, 53% contained ring rot. In about haif of the affected fields —
severity ranged from a trace to 1% of rotted tubers. The greatest amount
found in any one field was 10%. | aks
urwinia phytophthora (5. atroseptica), black leg, appeared to be of
little consequence, generally speaking, in southern New England in 1945.
In Vermont, according to Bailey, it was unusually widely distributed.
In central laine Bacon stated that 3 fields of the 35-acre class were
refused certification because of black leg. Yield reductions in this
area ranged from a trace to 12%. In Aroostook County early field in- |
spection indicated that black leg was generally present. Counts ranged
from a trace to 20% infected plants in certain fields. At digging time
rotted tubers ranged from a trace to 0.5 or 1% in an occasional field.
Fusarium solani var. eumartii, wilt, was founca in 2 fields in Massachu- a
setts, one showing 10 to 15% general infection, the other a general bus
light infection.
Pellicularia filamentosa (Corticiun ben avesh saving Seca According ae
to Boyd at and ‘Sproston, ereatest damage from rhizoctonia in Massachusetts

:

137

took place'early in.the season. Injury was evidenced in missing and weak
hills and light tuber sets due to severing of the stolons. As "rhizoc"
was found generally: present in light amounts on the tubers in all liew
imngland States, it is likely that early-season damage also was general.
it was not possible to estinate actual losses, although 5% tuber infec-
tion was cstimated in Rhode Island.

Phytophthora erythroseptica, pink rot. A single case was observed in
Massachusetts in 1944, of a trace of tuber decay, where moderate to se-
vere losses had occurred in recent years.

Phytophthora infestans, late blight, occurred in 1944 only in central
and northern liew England. None was found in.or reported from Connecti-
cut or Khode island, probably because of the general drought conditions
and warm weather in those States.

In liassachusetts, late blight was first found in the Connecticut Val-
ley on July 27, and it was not until September 1 that it was distributed
over the entire State, including the drier regions in the eastern part.
Very little damage was caused to either tops or tubers where vines were
properly sprayed. In general, owing to infrequent and light rains,
tuber decay was negligible except in occasional gardens or low wet fields.

In Vermont, where rain was general throughout the summer, the disease
Was more severe over the whole State than it has been for years. Pre-
harvest samplings indicated that many ficlds would contain from 2 to 4%
of late blight rot at digging time. In 2 or 4 fields particularly se-
vercly attacked, limited samplings indicated 25% of late blight rot by
digging time. Northwestern Vermont (Franklin County) was apparently the
worst affected by late blight of any area in New ingland. A few fields
were not dug because of combined tuber rots (late blight, bacterial ring
rot, black leg), and practically all fields dug were reduced in yield
from 45 to 75% by late blight, with an average reduction of about 50%.

in southern New Hampshire late blight generally caused slight to mod-
erate damage to the foliage, but dry weather in early September checked

its development and no serious losses were anticipated.

in ijaine, the disease appeared late but increased rapidly toward the
end of the season prior to digging. Late.in the season it was more se-
vere in central Maine than usual and moderately severe in Aroostook
County. At digging time a field survey in Aroostook County found 2/3
of the fields to contain blight-affected tubers. liost fields showed from
a trace to 2 or. 3%, and the most noted was 12%. Ina later inspection
late blight rot was noted in 60% of the 45 storage houses inspected in
Aroostook County; of the affected lots 45% had fron a trace to 5% blight
rot, 1 lot was 25% affected, another 60%, and another 95%. One grower

_ estimated 200,000 loss resulting from early digging while the vines were

Still green and freshly infected. A commercial deale in central laine
estimated his probable loss (incluGing certified and table stock Green
Mountain) at 15,000 to 25,000 bushels or 45 to 40% of his total storage.
The loss in this case was from late blight followed by bacterial soft
rot. * 2
Spongospora subterranea, powdery scab, was found in trace amounts at
Presque Isle and Van Buren, Maine. ea
Leafroll (virus) seemed to occur in about normal proportions in New

_ England in 1943. Following are counts made in Massachusetts, laine, and

ee a ee

Rhode Island. In Massachusetts, Cobbler, Sebago, and Green Mountain
showed from 5 to 15%, Chippewa from 10 to 40%, averaging 25%, Katahdin
from a trace to 10%. One grower reported that his Katahdins from No. e2
seed showed from 25 to 60% leaf roll. In Maine, the following counts ©
were made in the most severely affected fields: Ft. Fairfield 30%, Cari-
bou 40%, Amity 54%, Dexter 6% in Green hiountain and 25% in Chippewa. In
Rhode Island, counts of 7 fields in the Tiverton-Little Compton area
showed infection ranging from 20 to 40%. Pert |

Mosaics (virus). Even mild mosaic was so masked in Massachusetts that
it was hard to detect. However, an occasional light infection was recor-
ded. In Maine, the only other New England State where mosaic was found,
3 cases were seen; 2 of mild mosaic with 40% infection in 1 field, and
the othef a light case of rugose mosaic.

Net necrosis (leafroll virus). A single case Was observed at Houlton,
Maine, where a larse fidd of Green Mountain showed 35% infection.

Purple top (aster-yellows virus). Except for an isolated case in New
Hampshire, and several fields of Sebago severely attacked in Rhode Island,
purple top seems to have centered very largely in Massachusetts, where
it was far more prevalent in 194% than in most past seasons. It was most
pronounced in the Connecticut River Valley,but was also present in most
fields visited in other sections aftcr August 1. Plant infections usual-
ly ranged from a tracc to at least 2A%, although one field with nearly

100% was found in Pittsfield. Katahdin generally appeared to be affected

more strikingly than other varicties. Yicld reductions wefe very slight
even in the late varieties.

Spindle tuber (virus) was not noticeable in the growing fields from cer-
tified seed, but was very evident in many fields during harvest. One
typical case was found in Massachusetts, in which the yield from home-
grown seed was 150 bushels per acre less than in an adjoining field
planted with certified seed.

Frost damage. arly in October when the Maine potato growers still
had between 50,000 and 75,000 acres to dig, a heavy freeze injured some
of the potatoes. Ina survey of 20 fields in Aroostook County 90% of :
the fields showed frost damage, ranging in severity from a trace to 4bj,
with an average of about 2 or 3%. )

Growth cracks (physiogenic). . About 40% of the Naine fields showed
from a trace to a slight amount.

Hollow heart (physiogenic). About 35% of the Maine fields produced an
extraordinarily large proportion of big potatoes ("bulls"; one specimen
in Caribou weighed 4 lbs. 9 oz.). Not all large potatoes are hollow,
but so many are that such overgrown potatoes are discarded on size under
suspicion:of being hollow. Bulls were present in many lots from the hill
areas of western Massachusetts, and from Vermont and liew Hampshire. in |
Barnstead, New Hampshire, a 6-acre field of Sequoia produced 99% hollow yy
potatoes, and across the road a 4-acre Katahdin field showed at least 7 O%
hollow heart. . |

Leak (physiogenic). A 5-acre field in Kingston, Rhode Island, showed
about 1% of leaky potatoes at harvest time. (This is "sprain" according :
to Howard).

Stem necrosis (physiogenic) was apparently almost statewide in Connec- 2
ticut, especially where new ground was used.

Ae halal sh eA ARE Nel at a saan

139

Sunturn omeatoseqiols Every field visited in Avoustcok County, Maine,
was affected with sunburn to some extent, sone very slightly .In the stor-
age houses sunburn was presant in 7 3% of the 45 lots inspected, severity
ranging from a trace to 7506 About 50% was observed in most Katahdins
and Sebagos; in other varieties, for the most part, from a trace to 15%.
The loss due to sunburn is almost in proportion to the amount present as
very little is allowed to pass in grading. 1944 is the worst year for
sunburn on record in Aroostook County, owing very largely to the wet sea-
son and to shortage of labor for cultivation resulting in incompletely

_made ridges and exposure of the tubers.

Stem-end browning (cause unknown). In Aroostook County, Maine, 50%
of the fields were affected, usually only in trace amounts, but 1 field
of Katahdin showed 2%, 1 of Green liountain 5%, and a second field of
Green Miountain 50%. tea
‘Tipburn {cause questionable) was noticsable through New England but was
definitely most severe in the southern bart, especially in Connecticut
and Rhode Island.

SPINACIA OLERACZA , SPINACH

Peronospora efi offusa, downy mildew. Severe infection was observed in
_l large Connecticut 3 field. ‘resulting in 5 Pe LOe ose u yo Tt was also
found in 1 field Pita scachueetes. causing a very slight loss. Downy
mildew was less damegjng to fall spinach than usual.

DISEASES OF CEREALS, GRASSES, AND FOKAGE CROPS

AGROSTIS CANINA, VELVET BUNT GRass.

Corticium fuciforme, pink patch. A single observation was made, at
the Kingston, Rhode Island experimental plots where it was causing only

a@ moderate amount of damage.

Sclerotinia homococarpa, dollar spot, was seen but once, at the Kings-
ton, Rhode ‘Island e experimental plots. It was causing a moderate amount
of damage.

-AVENA SATIVA, oats.

Puccinia coronata, crown rust, was observed in several locations in
Vermont and Maine. In many cases damage was severe, as evidenced by

the shriveling of the grain.

Puccinia graminis var. avenae, stem rust, was observed as local out-
breaks in in Vermont and Naine. The presence of the common barberry (Ber-
_beris vulgaris) was peered near one severely damaged ficld in Brook-
ficla, Vermont .

Ustila ago avenae, loose smut, was found in 2 locations in Maine. Dam-
age was slight to moderate. Ts

Ustilago kolleri (U. levis), covered smut. Local occurrences in laine

_ Caused only a slight loss.

140

HORD=UM VULGAR2, BARLBY ie re
Puccinia graminis, stem rust, was found in Newport and. Littleton, Maine,
where it was generally prevalent but causing very slight to slight damage.

Ustilago jenssnii (U. hordei), covered smut, was found in 1 field in
Caribou, Maine, where it was present in very small amounts.

Ustilago nuda, loose smut, also occurred in small quantities in the
ficld at Caribou. |

MEDICAGO SATIVA, ALFPALPA ; :
Pscudopeziza medicaginis, leaf spot, was observed once,, in Maine, caus-
ing very slight ‘damage.
Yellowing due to boron deficiency (diagnosed at the Storrs Station,
Connecticut), was rather prevalent throughout central Connecticut. as
siderable yellowing and some stunting of the plants was evident.

SOJA MAX, SOYBEAN |

Mosaic (virus), with crinkle to rugose symptoms, was present on 24 var-
ieties of edible soybeans in the Kingston, Phode Island test plots. In-
fection ranged from 20 to 90% and was accompanied by marked, stunting of
the plants in certain cases. There was some reduction in yield. liosaic
was present in 1 field planting of edible soybeans in Connecticut and in
several home gardens in Massachusetts, causing some severe stunting and
yield reduction. liosaic was also found in field soybeans in Maine, caus-
ing very slight stunting.

TRIFOLIUM. spp., CLOVER
Erysiphe polygoni, powdery mildew, was generally distributed over New

ingland; causing an unknown amount of loss.

; Pseudopeziza trifolii, leaf spot, was found on red clover in New Hamp-

shire and Maine; it was severe enough to cause damage only at 1 location

in New Wee es | és
Uromyces trifoiii, rust, was found causing slight to moderate damage

at several places in Connecticut, Rhode Island, and Haine.

TRITICUM AESTIVUL, WHEAT

Gibberella zeae (G. saubinetii), scab, was noted in 1 field in Aroos-
took County, Maine, where it was generally distributed but resulted in
only very slight to slight damage.

Puccinia rubigo-vera tritici (P. triticina), leaf rust, was general

and causing slight damage in 1 field in Aroostook County. -

Septoria nodorum, glume blotch, was general and causing Slight damage
a ere ld en Tosatane County.

ZEA MAYS, CORN ay
Bacterium stewartii (Phytomonas stewartii), bacterial wilt, was repor-
ted in 1 Connecticut planting..
Helminthosporium turcicum, leaf blight. Boyd and Sproston report only
traces to very light infections generally in Massachusetts in 1944, con-
trasted with the severe outbreak of the preceding year in that State.
Ustilago maydis (U. zeae), smut, was much more severe than usual in
southern New England in 1943, but was almost nonexistent in northern New

141

England. In Connecticut, damage was slight to moderate. In Massachu-
setts, smut was particularly bad in the early and second plantings in all
counties. Boyd and Sproston reported 1 field observed in Middlesex Coun-
ty on July 208 with 30% of the plants infected and 20% ear infection,
Which was the heaviest loss from smut ever reported in the State. In
Rhode Island, smut was widespread on sweet corn, popcorn, and field corn.
Howard pat tn bes a 5% loss of sweet corn ears a the worst attack of the
last 5 years.

DISHASES Of FRUIT CROPS

AVMYGDALUS PERSICA, PRACH

Monilinia fructicola (Sclerotinia fructicola), brown rot, was found
only in Rhode ‘Island, _ in 1 orchard. The grower reported a considerable
amount of brown rot Since, because of the small crop, the trees were not
well sprayed. This orchardist, at Portsmouth, produced the only crop
of peaches known to the writer. in New England in 1944. He harvested 500
busnels.

Xanthomonas pruni, bacterial spot, was found in Connecticut, Massachu-
setts, and New Hampshire. Where it occurred, infection was fairly heavy
and slight to moderate damage to the foliage resulted.

Winter injury. The severe winter of 1942-44 killed the peach fruit
buds in New England.

FRAGARIA, STRATBERRY

Mycosphaerella fragariae, leaf spot, was recorded in Connecticut,
Rhode Island, Massachusetts, and Maine. Only in Portsmouth, Rhode Island,
was there poe pede defoliation to cause some probable damage.

Root rot (cause undetermined) caused slight damage in 1 field in Bris-
tol County, Massachusetts, and the loss of half the crop in the first
bearing year of a 7-acre field in Hamden, Connecticut.

MALUS SYLVESTRIS, APPLE

Erwinia ar. ylovora, fireblight, was found in Massachusetts and Maine
Only in South ee was there as much as slight damage in Miesaecbueee
in laine, considerable demage was evident in the Acton area.

Glomerella cingulata, bitter rot. Two cases were dserved in Massa-
chusetts., Inl oes Pages the disease caused the loss of 1 tree which
was removed in the fall; in the other case rot caused. 50% loss of Rhode
Island Greening in the pecker

Gynnosporangium clavipes, quince rust, was observed in Massachusctts and
Maine. Danage to Ga Delicious and éolden Delicious in Maine was slight
to moderatc. In Massachusctts, both quince and hawthorn (G. globosum)
rusts wore less damaging than Aeteee

Gymnosporangium junipori-virginianac, apple rust, was found in all of
the New England Statcs. Foliage infcction was sevore in some places but
very little fmit infection was noted even on Wealthy. The disease was

reported to be less prevalent than usual in Rhode Island.

ee

achusetts and southern New Hampshire, although later in the season than

ide

Helminthosporium papulosum, black pox, was observed in 1 orchard each q
in Bristol and Plymouth Counties, Massachusetts. Leaf spots were numer-_
ous, and fruit spots were’ beginning to show on Northern Spy by the sec-
ond “week in September, :

‘Mycosphaerella pomi (Cylindrosporium pomi), fruit spot (Brooks spot),
was reported by G. A. Gries to:be present in Connecticut.

Neofabraea malicorticis, anthracnose, was observed once in Iie ine; no
damage was noted... } : : .

Physalospora obtusa (P. malorum), black rot, frog-eye, was faind in
Connecticut, Rhode. Island, Massachusetts, liew Hampshire, and Maine. In-
fection of the leaves varied from light to heavy. Fruit infection: was
not uncommon even in some well-sprayed orchards. Branch ae were
conion following fireblight in 1 Massachusetts location.

Venturia inaequalis, scab. 194% was one of the most favorable seasons
on record for the development of apple scab in lew England. Commercial
losses in well-sprayed orchards in Rhode Island and Connecticut ranged
from a trace to 40%; on the whole, scab accounted for from 15 to 20% of
the fruits failing to make the No. 1 grade as they otherwise would. In
Massachusetts, commercial losses in Mcintosh ranged from a trace to. 25%
in sprayed ee Seab was present in the southern parts of Veruont,
New liampshire, and liaine in about the same proportions as in southern
New Lngland. The most seriously affected local area in lew ungland
seencd to be through Hero and Grand Isle in northwestern Vermont, where, ‘
in: spite of excessive spraying ,no pr -otective eovering could be weanee ae q
ed, owing: to the heavy rains. The average fruit infection for the area
was 25 to 30%. Throughout New England, losses in unsprayed orchards ‘
ranged from 50 to 100%, and defoliation was practically complete in many :
licIntosh orchards by Septomber LS a ats \ 5,

jnfectious chlorosis or mosaic (virus). One local case was observed
in Connecticut, where the discase was severe enough to cause the partial
defoliation of sevéral acres of trees.

Bitter pit (physiogenic). in Massachusetts losses were about normal,
with greatest damage to Baldwin, Northern Spy, and King, slight losses
on Cortland, and traces on hicIntosh. ‘The disease was very severe in 1
young Baldwin orchard in Rhode Island.

Fruit russet (physiogenic). Some rather severe cases were recorded:
in Connecticut, hassachusetts, and New Hampshire, on Baldwin and Deda en
cious in parenCnieer | | Ng

liagnesium deficiency leaf scorch developed rather extensively in Mass- ‘a

usual. On severely affected Late the’ fruits were badly Stunted and
dropped prematurely.

PYRUS COMMUNIS, PiAR
Fabraca maculata, leaf blight. A single case was observed in Hhode
Island, of ‘slight - ne moderate damage. |

RUBUS sp., RASPBERRY |

iilsinoé veneta, anthracnose, was found in 1 locality in Rhode Island
and 1 in New Papen vee in ae cases it was general in the plantings,
causing slight and moderate damage, respectively.

143

liosaic (virus) was observed causing severe damage in 1 Rhode Island
planting which has since ee removed, and slight damage in 1 Maine
planting.

VACCINIUi. sp., BLUBiuRhY ;

i derosphaera alni var. vaccinii, powdery mildew, occurred locally in
Se eee eu a Columbia, Maine, causing slight damage.

Pucciniastrum goeppertianum (Calyptospora columnaris), rust witches-
broom, occurred locally with slight damage in 1 field in Columbia,
liaine.

Pucciniastrum myrtilli, leaf rust, was general and caused severe dam-

ee oe

age in 7 fields in Franklin and 2 fiélas in Columbia, liaine.

ViTiS sp., GRAPE

Guignardia bidwellii, black rot. Single occurrences with no loss result-
ing were ‘found in Connecticut, Rhode island, and New Hampshire.

Plasmopara viticola, downy mildew, was present on most vines that had

not been killed by late-season frosts in Massachusetts. There were no
losses in yield.

DiS#aSeS OF MISCELLANEOUS PLANTS

AuSCULUS HIPPOCASTANUL:, HORSECHSSTNUT

' Guignardia aesculi, leaf blotch, was prevalent throughout most of New
iugland. Defoliation was most serious in Connecticut and Rhode Island.
Severity gradually diminished toward northern New England.

CATALPA sp., CATALPA

Alternaria catalpae (Macrosporium catalpae), leaf spot, was generally
prevalent in the New Haven, Connecticut, area where it was causing slight
to moderate leaf spotting, .

FRAXINUS spp., ASH |
Puccinia peridermiospora (P. fraxinata), rust, caused severe defolia-
tion of trees in coastal regions.

HELIANTHUS ANNUUS, SUNFLOWER
Brysiphe cichoracearun, powdery mildew, was generally distributed in
i small planting in Hamden, Connecticut, causing no appreciable damage.
Puccinia helianthi (P. Regn ont na Shon sake rust, occurred in the same
planting in Hamden; damage was very slight, if any.

NICOTIANA TaBACUL, TOBACCO

Rhizoctonia sp., sore shin, was found to be general in fields surveyed
in the Connecticut River Valley of liassachusetts, but most infections
were light. Severe infection was found in only 1 field, where 45 to 40%
of the plants were affected and the probable loss was ong,

Mosaic (virus) was generally present in slight to moderate amounts in
the Connecticut River Valley of liassachusetts. An occasional field con-
tained 20 to 40% of the plants infected.

PRUNUS VinGINIANA, CHOKi CHERRY ee ee pik Poult

Dibotryon morbosum (Plowrightia morbosa) , black knot, was peecae Laat
eally and causing ‘slight damage in New Hampshire, ‘Shade Island, and:
Maine.

SONCHUS ARVENSIS, SOW THISTLS aes iy ree ca. |
Yellows (aster-yellows virus), was generally prevalent in Portland,
Maine. ae BAe Hh . Reka, Jat

a RUA

SUMMARY OF PLANT: ee SS SURVEYS TX Na ee IN 1045
Leon J. Tyler

The following: as 8 brief summary of observations made, concerning
plant oe aes in New York State during the perce August 1 eos November
Thy, 1945»

PATHOGENS CAUSING
DISLASES OF VEGETABLE CROPS

ny

ALLIUM CLPA, ONTON:

er ere ee year. — edad
Peronospora destructor was noted: in iene New York counties. i250
Urocystis.¢ epulae was was observed only in. Oswego. County fields (i mckland).

Up to 2% of the bulbs were diseased in some fields sown without treat-
ment .

APTULi GRAVEOLENS var. SuLcE) CEisRy TG Ui pals Me Reine Salita eae
Cercospora apii was generally distributed ‘but the incidence in the TOS
fields visited was low. Pe NG
urwinia carotovora was seen only in 1 Oswego County field where about
2% of. the plants. were destroyed. aes ‘ 3h
Septoria apii was found in almost every celery field Visited in up-
state New York. It was very destructive in some Oswego County fields on
eed. ; .

fle sh : PAs

ASPARAGUS. OFFICINALIS, “ASPARAGUS | shai hie
Puccinia asparagi was. general . in. distribution but prevalence and igh ts
ity were very Low. ce an watts ea ) e : bP Sg
e sTA VULGARIS, BuaT a3
Cercospora deticola’ was everywhere prevalent in garden beets and in
Sraped localities the Sree was very destructive. ap mY

BRASSICA ‘OLERAGLA var. CAPTTATA, CABBAGE
_. urwinia carotovora was generally. distributed | in calbbage-growing | areas,
-eausing a soft rot. of the cabbage head top. One ficld in Nassau County
showed 15% rot of this type. )

145

Fusarium oxysporum f. conglutinans (F. conglutinans) was observed in
Ontario, Wayne, and lionroe Counties; it was destructive in only 1 of the
ficlds visited.

Poronospora parasitica was general in up-statc cabbage fields. and home
gardens, but little damage was dane owing to lateness of its attack.

Phoma lingam was obscrved in widely separated counties. It was -especial-

ly destructive in Cortland County where from 40 to 40% loss occurred in
60 acres set with plants grown from untreated seed.

Plasmodiophora brassicae was general in up-state counties where cabbage
is grown. Prevalence usually was not more than 1 to 2%, but in 1 Cort-
land County field 50% of the plants were attacked. .

Xanthomonas campestris was general wherever cabbage was grown but
prevalence was eae low.

CAPSICUM FRUTESCENS, PEPPER

Gloeosporium piperatum was especially destructive inl Duchess County
field.

Verticillium alboatrum was widely distributed Peter ee unimportant
in 1943.

Virus: tobacco mosaic virus, Marmor tabaci var. vulgare, was generally
distributed but causing little damage.

CUCULMNS MELO, CANTALOUP
Cladosporium cucumerinum was noted once in Nassau County.
Colletotrichum 1 lagenarium was noted infrequently in Nassau County.
Virus: cucumber mosaic virus, Marmor cucumeris var. vulgare, was noted
infrequently in Nassau County.

CUCULIS SATIVUS , CUCUMBER
Cladosporium cucumerinum was noted in central New York gardens and in
Long i: island fields.
Colletotrichum lagenarium was widely distributed but seen infreqeently.
Erysiphe cichoracearum we was general in distribution but caused little
damage.
' Erwinia tracheiphila was present in all fields and gardens visited,
causing much destruction,
Virus: cucumber mosaic virus, liarmor cucumeris var. vulgare, was de-
structive in some Nassau County fields.

CUCURBITA MAXTMA, SQUASH, and CUCURBITA PEPO var. CONDuNSA, SUMMER SQUASH

rysiphe cichoracearum was widespread on winter squash.

Rhizopus nigricans was generally distributed. Considerable destruc-
tion due to this organism was noted in 1 Nassau County field.

Virus: cucumber mosaic virus, Marmor cucumeris var.vulgare, was gener-
ally distributed but appeared 0 have. ‘caused little damage.

CUCURBITA PEPO, PUMPKIN
_brysiphe cichoracearum was generally distributed in Nassau County and
in up-state “home. gardens.

Te Pe
wae ay

ERR ae 2 cea

earn oie

KE

“

ae elit

te
n
ao
2M

oa

Se Bar MOE eigen ee eee ie” ae Iagetn I
ni an OR eg TR Te : ry

ot ae
bic

de

an
we!
-

ae
eT

& ign ~ --

al

=

i ies 8 a Saal on

/

ee) wes
4

Caled:
ee

: 5 ; 1 Wes Oe ay a
a . " - a
EPeea

DAUCUS CAROTA, var, SATIVA, CARHOT : se
Alternaria carotae (Macrosporium carotae) ° was observed causing slight
leaf blight in almost all commercial fields and home gardens, . and was
frequently associated with Cercospora,.
Cercospora carotae (C. apii var. carotae) was almost: always present in

carrot fields “and ga: gardens, causing slight damage.

=

LaCrTUCa SAviVa var, LOUGIFOLIA, ROMAINE

Virus: aster-yellows virus, Chlorogenus callistephi var. vulgaris,
Aster yellows rendered a half-acre field of romaine on Oswego County muck
entirely worthless.

LYCOPERSICON SSCULLNTU, TOMATO i

Alternaria solani was generally distributed over the State. Consider-
able damage was done in victory gazsdens and in commercial fields. In
Wayne County fields the loss was as much as 1 to 5 tons per acre. In
many fields the plants were completely defoliated at the height of the
picking season. A considerable amount of fruit was culled because of
fruit lesions. i ye"

Alternaria tomato was. found only in Suffolk County causing nail-head
spot 5 of the fruit.

Cladosporium fulvum was generally distributed in the tomato~-growing
areas, Much destruction resulted in some Wayne and Ontario County fields.
Colletotrichum phomoides was general over the State. It was very de-

structive in a few fields , observed - in Niagara Cou.ty and in 1 Dutchess
County field. |
Phytophthora infestans ¥ was general throughout upstate New York. Up to
25% of the fruits were attacked in some unsprayed Ontario County fields.
Septoria lycopersici was general over the State, but severe only in
Genesee and Niagara Counties. :
Virus: cucumber mosaic virus, Marmor cucumeris var. vulgare, was rath-
er Widely distributed but was Les in in commercial Preis. being found
more frequently in home gardens.
Tobacco mosaic virus, Marmor tabaci var. vulgare, was general but
damage was moderate.
Double streak, mixture of tobacco mosaic virus and some potato mottile
virus, Miarmor dubium var. ‘vulgare, was general but usually low in prev-
eee

PaSTINaCa SATIVA, PARSNIP

oS eS ee

PHASOLUS LUNATUS, Liisa BEAN
Diaporthe phaseolorum was noticec. aly. in central. New York counties where F
Toner was insignificant. s
Phytophthora phaseoli was observed in 1 field in Suffolk County. Weather
was unfavorable for the development of an epiphytotic. a
Pseudomonas syringae was gonsral over the State but low in prevalence ay
and sé severity. 1

PHASEOTSS YULGARIS, BaAN é

Colletotrichum lindemuthianum was generally distributed over up-state
New York but was destructive only in Iadison, Oneida, and Genesee Coun-
ties...

Husarium spp. were found causing dry root rot of marrow bean, pea bean,
Red Eidney, and snap bean throughout central and northwestern New York.
Usually the disease was found to be more destructive to pea bean than to
Other kinds, especially in Livingston, Monroe, and Orleans Countics where
infection ran up to 50% in some fields. Thirty percent infection was re-
corded on Red Kidney beans in the same area.

Fscudomona 2as medicaginis var - phascolicola occurred gencrally on snap
beans and dry shell beans in os State, but ficld prevalence and severity
were usualiy very slight.

i: Aanthomonas phascoli was generally prevalent in all sections of New
York Stete and caused much damage in the northwestern and ccntral parts.
it was morc destructive than during the past 2 yours.

Bean virus 1, iarmor phaseoli, was prescnt wherever beans were grown.
Prevaleicc usvally varied from a tracc to 12%. From 60 to 60% infcetion
was found in Niagara County, where it was especially destructive to psa
beans and “rench Horticultural beans.

Bean yellow-mesaic virus was generally distributed wherever beans were
grown.

RHEULI REAPOMTICUI!, RHUBARB
Phyliosticta straminella was generally prevalent _on rhubarb but did
not appear destructive to the plants examined.

SOJA MAX. See with forage crops section.

SOLANUM i.LONGSNA, CGGPLAT
Alternaria solani was found causing leaf lesions on eggplant in many
gardens but aid very little damage.

Puomopsis vexans was prevalent in central New York. In some home gar-
dens up to 30% of the fruit was infected.

Ve sPeicillium albo-atrum was generally distributed wherever eggplants

ee a ee

were grown. Up to 50 infection u was noted in some Dutchess County fields.

SOLANU: TUBSROSUL:, POTATO

Alternaria solani was prevalent in all up-state po tato-srowing areas.
Destructive attacks were reported on Houma potatoes in Oswego County and
in some Onondaga County fields.

Corynebactcrium scpedonicum is established in 2/4 of 62 1 New York coun-
tics. its prevalence is known to have beon intensificd by the intro-
duction and use of out-of-state "sclected” sced. In 1 Steuben County
comiereiai ficld of Katahdin up to 20% of the tubers were rotted.
| Bary renckhns dipsaci (Anguillulina dipsaci) was observed only near
Hicksvillc on Long Island. | |

srWinia phytophthora was founifrequently in ccrtain counties where
Out-of-statc secd was plantcd.

Husarium solani f. ee A solani vaz. eumartii) % was [generally
distributed in up-state potatoes. Four out of 25 Gen see County fields
exhibited from 1 to 15% of the plants attacked. |

Heterodera marioni was observed in Nassau County on Long Island.

Phytophthora ‘infestans was widely distributed over the State by August
16 and destructive attacks were noted in muckland potatoes by August 21.
it became destructive in many fields of upland potatoes and to home gar-
dens by September 16. The varieties Sequoia and “ebago appeared to Foster
less destructively affected than Katahdin and Rural. In Steuben County,
tubers secn in the field and in Warehouse bins exhibited from none to
% blight; usually such tuber lots showed 1 to 2%. Long Island potatoes
were. wrostly mature before phe organisia became destructive.

Virus? (calico disease). A diséase cxhibiting symptoms at least simi-
jar to thosc of the calico disease was observed in a few fields in Wayne,
Ontario, Orlsans, Monroe, and Brie Counties. lot more than 1 or 2
plants were Pea during the brief examination of any one field.

SPINzCIa OL:R.Cha, SPINACH 3
Pythium debaryanum, damping-off, was everywhere prevalent in spinach,
coubtless because of unusually favorable weather for the Gisease.

C.uRbaLlS, GRASSES, AND FORAGE PLANTS

AViNA SATIVA, O27S

Puccinia coronata was generally prevaient and destructive in central
and northwestern counties.

Puccinia graminis var. avenae Was generally distributed in very light
amounts in Untario, Livingston, Wyoming, and Genesee County ee.

HORD!UL: VULGAR:., BARLEY

Puccinia anomala was generally distributed in-up-state Hew ‘York and
Was destructive in late varley ficeids.

Puccinia graminis var. hordei was gencraily distributed in western

ounties and was destructive to late barley.

MiDICaGO SATIVa, ALFaLFA
Ascochyta imperfecta was gencral in central New York,
Corynebactcrium insidiosum is general over the State wherever alfalfa
is grown. As.high as 50% infection has been seen in some fields and —
some of theses were 22-year-old stands. _ - 7
Pseudopeziza medicaginis was present in almost all fields. It was 04
found to be. causing sevcre leaf sheding in Cayuga and paps Bid Counties.
Pseudoplea trifolii was noticed only in edison County.. tei ee
Stagonospora meliloti Was gencrally distributed but causing very Littles @
damage. 7 e : eee oY
Stemphylium sarcinaeforme (i/acrosporiu: sarcinaeforme) was overywhore —
prevalont but causing very little damage. | te | dita

SOJa Max, SOYBLaAn iad
Altcrnaria sp. (A. atrans ?) was goneral in distribution,

in victory garden soybeans.

145)

Cercospora sojina was found near Marathon in Cortland County. Appar-
ently this is the first report of its occurrence in New York State.

Peronospora manshurica was generally distributed in central and west-
ern New York. Destructive occurrence was noted on the variety Seneca
in Torypkins County.

Pseudomonas glycinea was widespread and destructive.

Virus: pea virus 1, Mermor pisi, was generally distributed wherever

soybeans are grown. Useeuy not more than 1% of the plants ars affected
but sometimes as high as 15% infection has been found.

TRIFOLIU.. PRATENSE, HED CLOVER

Frome tas trifolii (Dothidella trifolii)was observed in central Ne
Yori. Moderately severe infection was noted on 25% of the plants in
some Cayuga County fields. |

atysiphe polygoni was present in almost every red clover field and was
Causing much destruction in many.

Pseudopeziza trifolii was genemlly distributed over the State. It
causes much shedding of leaves in central New York Counties.

Stemphylium s sarcinaeforme (Macrosporium eS Ee was general
in distribution but was causing, little damage

Uromyces trifolii was general in red sinuee fields. In central New
York some fields were destructively afrected.

Virtus: common pea~mosaic virus, i.armor leguminosarum, was general in
distribution and very severe in many fields.

238 LAYS, CORN

Diplodia zeae, ear rot, was generally distributed in field corn and
caused a loss of probably 2%.

Fusarium moniliforme, ear rot, was emerally GARE ENLed in field corn
but caused little damage.

Gibberella zvae (G. saubinetii), ear rot, Was erent On T2eld corn
but ‘dauage. was insignificant. vials :

Ustilago maydis (U. zeae), ear smut, was generally distributed but
aie low in prevalence and the loss did not exceed Q. 5% far the
state

HRUIT CHOPS

Ai YGDsLUS PLRSICa, Puack

Cladosporium carpophilun was generally distributed in few York peach
areas but inconspicuous because of failure of the peach fruit EOD.

:.Onilinia fructicola was generally distributed in peach-groewing areas,
but because of the alnost complete failure of the crop due to weather
conditions the pathogen was not particularly evident in orchards visited.

Taphrina deroruans (xoascus duformans ) was noted in a few erchards
along Lake Ontario in northwestern New York.

Virus: a-disease virus, Larmor lacerans (yellow-red virosis, X-diseasc).
In the tudson Valley peach area many ox rchards located near cho} cc cherry
exhibic’up to 50 to 75% cisegeed trees,

eae

MALUS SYLVESTRIS, APPL coun
arwinia amylovora was: general but everywhere low VE pre valence and
severity.
Gynnosporang ium clavipes {G. germinale)was peneral iy ay ot eed an
eastern New York apple areas and was more destructive in 1944 than dur-
“ine the past D Picea» ite! sprayed. trees fruit infection varies from ae
to 10%. Pian wt ;
Gymmosporangium juniperi -virginianae was peneral in ee Hudson Valley
area, With mote fruit .infection this year than; last. Up to 15% of the
fruit was destroyed on unsprayed trees. “o
Physalospora obtusa was found. in almost all orchards: lek Was causing
little loss. aoe
Venturia ac was pene rent distributed and everywhere destruc-
tive. The crop in the Hudson Valley was reduced by 10%. “In. Clinton:
and ussex Counties, the crop of-U. Se Hi ene No. 1 apples was reduced __
20 to 25%. “ ARE 2 eS is
PRUNUS aAVIUL:, SWiT CHERRY, AND “Ba Cc} RASUS , - g0uR ‘CHURRY ee
Coccomyces hiemalis was | eceties distribute 2d and destructive in all
sweet and sour cherry-growing regions. Complete ‘defoliation resulted
from the leaf ea as early as ota Pea te the 3 Hudson: Valley area «=

uaa COLLUNIS, PHAR | ng

or was eaten ‘in some Wudeon Veniep se

Gloeodes pomigena was found to be generally distributed in the Badsau
Valley and in some unsprayed orchards it completely runed noe Og the
(sere ly ae

RIBES sp., GOOSuBERRY
luycosphaecrella grossulariae was prevalent and destructive.
Sphae-otheca mors-uvae was prevalent and very destructive in ‘Ontario
County.

RIBES SAU Tr iM, ReD CURHANT
Pscudoveziza ribis was prevalent and destructive in | Ontario Coenen

te ee i ey

plantings. Nn gat

RUBUS spp., BLACKB:RRY ie HAA Og EY ee
Hlsinoé veneta (Gloeosporium venctum) was general and very destructive ~
in soze western New York plantings. | .
Septoria rubi was general but not destructive.

RUBUS OCCID, NTALIS, BLACK RASPBERRY, and RUBUS IDAGUS, RED RASPBSRAY
Agrobacterium tumefaciens was general in distribution but was severe
in only one planting visited.
Didymclla applanata was generally distributed but did not appear to be
especially destructive in 1944. POPE A
Lisinot veneta (Gloeosrorium venotum) was prevalent in Ontario County
plantings but not destructive. | Be

eT ME ON ed ERM SCAR eo

151

Gymnoconia peckiana (G. interstitialis) was notin Ontario County plan-
tings but was not destructive this year.

Septoria rubi (probably Sphaerulina rubi) was generally distributed but
did not occur destructively.

Sphaerotheca humuli was especially prevalent on and destructive to the
variety Lathan.

Verticillium albo-atrum was seen infrequently in Ontario County plan-
tings.

VaCCINIUi: COkYMSBO0SUM, BLUEBERRY

Microsphaera ajJni var. vaccinii. The variety Pioneer appears to be
more susceptible than some other varieties in Oswego County plantings.

Phomopsis spp. Pioneer exhibited more Phomopsis gall than did other
varieties. : Ay.

Virus: blueberry stunt virus. Blueberry stunt is becoming very preva-
lent in Oswego County plantings. Pioneer appears to be more suscepti-
ble than xubel, Jersey Concord, and Rancocas.

Vitis spp., GRAPE
Guignardia bidwellii was generally distributed wherever grapes were
grown but was causing appreciable loss only in the variety. Duchess.
Plasmopara viticola was generally distributed in Ontario, Steuben, and
Yates County vineyards, with much damage being done to the Delaware var-
jety. It Was unimportant in the Hudson Valley grape region this year
Uncinula necator was very destructive in some vineyards in Steuben,
Ontario, and Yates Counties.

SPLECTAL CROPS

HU ULUS LUPULUS, HOP

Uolletotrichum humuli, anthracnose, was general in the hop-growing
aréa. A l-acre | hop yard in Oneida County sustained a 25% loss.

Fumago vagans, sooty mold, was generally distributed. About 1% of the
entire crop was destroyed by this pathogen,

Pscudoperonospora humuli, downy mildew, was general in the New York
hop-groWing area, Attacks during May were destructive because of delay
in operations duc to the wet weather. A considerable loss from this dis-
case was sustained on about 150 acres.

Sphaerotheca humuli, powdery mildcw, was cpiphytotic in Franklin County
but losses Werc low. .

Virus: virus-like disease of hops. From 10 Ae 30% of the hop piants
on 16 acres in Oncida County were destructively affected.

Leon J. Tyler

following is a brief summary of observations made concerning plant
diseases in Pennsylvania during ee olny from August 1 to November
fos is 19 945 e

V..G.TABLE CROPS- | Paw te ks.

ASET.OSCHUS “SCULLANTUS, OKRA. lacrosporium sp. was causing leaf spot
in iiontgomery and Susquehanna County gardens.

ALLIUL: CPA, ONIOU. Stemphylium botryosum (liacrosporium parasiticum)
was observed in trace amounts in Wyoming and Susquehanna Counties, caus-
ing leat break of the onion tops. |

ePIUL..GikVEOLES, CuLcRY. Cercospora apii was observed in amounts ran-
ging from a trace on 25% of the plants in one Cumberland County field +
moderately severe on all plants in one Berks County field. Satie (eee
tovora Was severe in one large Berks County field, and slight in ohe Lan-
caster County garden. Infection by Septoria apil. ranged from trace to
light on most of the plants seen in Cumberland County to severe on reve
plaats seen in Gotaenss County. Virus seatuai hie ac cMee 3% of the plants
in one Luzerne County field.

ASPatL GUS OryviCTksaLIS, ASPsRAcUS. A cuseietiha Sanu Colvaeaee in very
slight amounts in one Bucks County field. Traces of Puccinia asparagi
were noted in a Bucks County commercial field.

Bare VULGE LD, | Baa, Cercospora beticola occurred in lignt to sions
ate amounts in eucie and Dauphin. County fields and. gardens. Eton der

ciency was very severe in 2 Bucks County fields. |

BRASSiC«a OLLRACLA var. BOTRYTIS, CaULIFLOWiR. Alternaria cireinans
(4A. brassicae) was noted in Lioatgomery County, in “trace. amounts.

BRaSSiCs OLERACEA var. BOTRYTIS, BROCCOLI. Alternaria spp. occurred
in slight amounts on most of .the plants seen in a few Iuzeme County .
fields. «a trace of Phoma Lingar: was observed in one Luzerne County
field. a A aS

RaSSiC. OLLRACLA var. Capita TA, CABBAGE. Alternaria spp. were causing
leaf spot in Columbia and Viothebae he Counties but the infection observed
-Was very slight. Phomwa lingam occurred in traces in some Luzerne County
fields. Plasmodiophora brassicae was noted in trace amounts wherever —
cabbage was examined. Xanthomonas campestris was noted in almost every
cabbage field entered but infection was never more than a trace. :

CaPSICUL. FAUTUSCLiIS, PluPPLR. Fusarium sp. was noted causing a trace
of wilt in one Luzerne County ficld. Glocosporium piperatum, usually
foliowed by Alternaria sp., caused severe fruit SPUR in one Luzerne
County ficld:

L.osaic caused by the tobacco mosaic virus was observed in Berks and
Colunbia Counties, infection ranging from a trace to 4%. Slight in-
fections of spotted wilt wore noted in one Luzerne County field. —

Sunscald followed by Alternaria spp. was prevalent in almost every
planting ef peppers seen in ‘Luzerne, Susquehanna, and ‘yorning rheesny
Usually from 5 to 25% of the fruits were destroyed.

- cucusis i710, CATTALOUP. Alternaria cucumerina (i acrosporium sp.) was
— causing light to moderate leaf spott bing in Bucks County fields. Very
’ slight infection with Colletotrichum lagenarium was observed in a Bucks
Hh €ounty field. Light infection by Er Erysiphe cichoracearum occurred on a
few plants noted in Bucks County. Pseudomonas lachrymans occurred in
very slight infections on a few plants in one Montgomery County field.
CUCULIIS SATIVUS, CUCUIBER. A trace of Colletotrichum lagenarium was
noted in one Bucks County field.- Erwinia tracheiphila was very general-
iy distributed at least in the central, southeastern, eastern, and
northeastern parts of the State, infection ranging from a trace to mod-
erately severe. Srysiphe cichoracearum was noted in one liontgomery
County field.
CUCURBITA : Aci A, SQUASH. Light rake eereRCRRE by Colletotrichum lagenar-

ee ee eee we oe

ium was observed in Bucks County. liycosphacrelila citrulls ina was causing
a destructive fruit Spot of white Pack in a Bucks County field. Mod-
erate fruit infection by ihizopus nigricans was observed in Luzerne
County. Occasional plants afrected by the cucumber mosaic virus Were ob-
- served in a luzerme County planting.

_ .. CUCURBITA PEPO, SQUASH. Phyllosticta sp. was causing moderate leaf
spotting on 25% of the. plants in a Berks County field.

' DAUCUS CaROPA, CARLOT. Cercospora. carotac and Alternaria carotae,

_ frequently associated, were found causing slight to moderate leaf 5] Spot=
ting on a trace to 10% of the plants in Bucks, Columbia, and Montgomery
Counties. Heterodera marioni was found ee wee dar ace in one
large Bucks County Field. ~ A trace of Rhizopus nigricans was found in
one Bucks County field. rae

> LACTUCA SATIVA, LETTUCE. A trace of leaf spot caused by Septoria SD.
_ was found in iHontgomery County.

a LYCOPERSICON: USCULPTUM, TOMATO. Alternaria so’ani was prevalent —-

ea

lial bilinear ln
Y dag 33 Seer Gh MS ae Ope
Vos *. “

dU

ee eee

oy wherever tomatoes were grown. . Infection varied from a trace to moderate

- on most plants in the central, southeastern, and eastern counties. Se-
“vere infection was noted in ilontgomery eeinien ,

ae LA trace of Alternaria tomato was noted on a fow plants in Lancaster

_ and Franklin Counties.

Ps - Clasosporiun fulvun was noted on grecnhoussc plants and Was severe in

_ One greenhouse, in Columbia County. On outdoors tomatoes it was severe
in 2 fields in ‘Lancaster County, and a trace was noted in one garden ino

Adams County.

Traces to light amounts of Colletotrichun phomoides were obscrved in
all central, southcastern, and southern counties. ;
Septoria lyeopersici was generally distributcd in central and south-
hte eastern counties but in most casss infection varied from a trace to
only slight on most plants.

_ Xanthomonas vesicatoria was observed in Bucks, Lancaster, and franklin
Counties.” In one Franklin County field 90% of the fruits showed spots
ue to this organism. Only traces were obscrved in the other 2 counties.
The tobacco mosaic virus was ena in distribution but usually low
“a Nleedear ta |

‘Gi a ee... sbeebs

__—

154

Fruit pox (undetermined origin) was noted in Cumberlane Bee. but ap-
peared to be of slight importance.

PASTINACA SATIVA, PARSIIP. Severe infection by Cercospora pastinacae
was observed on 75% of the plants in one Cumberland County planting.

PHASUOLUS LUNATUS, LIMA BEAN. Alternaria sp. caused large circular

leaf lesions and —— severe in one Snyder County victory garden. Pscudo-
monas syringae was generally distributed in fields visited in Luzerne,
Berks, and Columbia County, infection ranging from light to moderately
severs on all plants.

PHASEOLUS VULGARIS, BEAN. Coblebetiichun Jinaemehiaem. usually in
Slight infections, was observed in victory gardens in Ee and north-~
castcrn countics.

A trace of Rsarium spp. causing dry ‘root rot was noted in Bucks County.

Pseudomonas -medicaginis var. phascolicola was Widely distributed, but
not more than a trace vas observed in fields cxamined. :

ahizoctonia solani vas noted in Bucks County but appcarcd to be unin-

a ye ee
pigea ae did not appear pee oe a Ee EGA:

Xanthomonas phaseoli was widely distributed in qe State, infection
varying from a trace to moderately sever on 25 to 100% of he plants in
fields examined.

Bean mosaic (bean virus 1) was widely distributed. Im Dauphin and
Bucks Counties infection varied from 5 +o 157. Apis pee

Yellow mosaic was noticed in gardens and fields throvghout the central
and northeastern counties.

RHUL: REAPOLTICUL, RHUBARB. _Phylisticta straminella was causing a
trace of lear spot on all plants in a Lebanon County planting.

SOJA MAZ. See with forage crops section

SOLANUL. HGLONGESMNA, EGGPLANT. A trace of “Altemaria. solani pocieeen on:

re ee ee me ee re SS

all plants seen in Columbia and Jerks Counties. ~“homopsis vexans caused
slignt leaf spotting in one Luzerne: County fiéld and severe fruit spot
in a field in Bucks County. Verticillium albo-atrum was generally prev-
alent wherever eggplant was seen. |

SOLaANUL: TUBEROSU:, POTATO. Actinomyces scabies was everywhere preva-
lent. but was destructive in only a few fields. Siar

Alternaria solani was widely distributed but no destructive attacks
were found.

(Coxticium- solani) see Pellicularia filanmentosa

Corynebacterium sepedonicum caused widespread destruction at least in
Potter and Warren Counties. The percentage of tubers.attacked usually
ranged from 1 to 6 but one field was seen in which 25h to 50% of the.tu-
bers were diseased. About 30% of the fields visited exhibited some ring
FO. :
A trace of Erwinia phytophthora was noted in Lackawanna County.

Susarium solani fi eumartii (=. solani’ var. cumartii) was widely dis-~
tributed in potato-grow ing areas. A few ficlds in Lackawanna County ex-
hibited from 1 to 3% infection. In Warren County from 0.5 to 1% of the
plants were attacked in fields visited. | .

Pellicularia filamentosa (Corticium solani) was widespread but not par-

ticularly destructive.

ig

a 155

Phytophthora infestans was generally distributed in potato-growing
areas. #rom tuber counts in Potter and Warren Counties at digging time,
it was found that from 1 to 2% of the tubers in some fields exhibited |
blight lesions.

Of the virus diseases, leaf roll was apparently generally aie piped.
Counts in 4 fields in Lackawanna County indicated from 1 to 3% of the
plants attacked. A bare trace of spindle tuber was scen in Potter and
‘Warren Counties. Yellow dwarf was widely distributed but usually not
more than 1% of the nlants were attacked. Giant hill and mouse ear
were observed in Lackawanna County.

CERUALS AND FORAGE CROPS

MDICAGO SATIVA, ALFALFA. Ascochyta imperfecta was widely distribu-
ted. in some Uorthanpton County f ields as high as 50% of the plants
were severcly diseased.

Corynebacterium insidiosum was widely distributed, as shown by its
occurrerice in at least 25 counties and in 79 of 122 fields examined.
infection ranged from a trace to 50% of the plants. A yield reduction
of 20% would appearto bea conservative estimate of the loss sustained.

Pseudopeziza medicaginis was widely distributed all over Pennsylvania.
Infection ranged from a trace on a few plants to moderate on most of the
plants. The heviest infections were noted in eastern and southeastern
counties. :

SOJA& MAxc, SOYBHAK. Alternaria atrans was observed once, in a Snyder
County victory garden. i eee

Fusarium sp. was isolated from diseased roots of plants taken from a
Franklin County field.

A trace of Peronospora manshurica was observed October 22 on 5% of the
plants’ in a field of late soybeans. in Washington County.

Pseudomonas glycinea was widcspread in the State. In Franklin and
Northampton Counties, infection was light on h0% and 100%, respectively,
of the plants.

shizoctonia solani was isolated from the roots of plants taken from
one sranklin County ‘field.

Sphaccloma sp. was identified on diseased soybean plants taken from a
franklin County field. Stem and petiole lesions were presumably caused
by the same funsus.

TRIFOLIUE: PRATSUSE, RED CLOVER. Srysiphe polygoni was generally dis-
tributed, with moderate infcsction insmost fields. |

Stemphyliun sarcinaeforne (liacrosporium sarcinacforme) was noted in
‘Adams, Cumberland, and Northampton Counties, in amounts ranging from a
trace on 10% of the plants to light on 90°. |

Pseudopeziza trifolii was widcly distributed in the Statc. Infection
ranged from a trace of infection on a trace of the plants, to slight
infection on 90% of the plants.

Uromyces trifolii was generally distributed but destructive occurrence
Was not observed.

444 WAYS, CORN. Diplodia zeac (car rot) was generally distributed in
southeastern and ecntral counties. In 27 of 59 ficlds cxamined, car
rot occurred on from 0.5 to 9% of the cars.

“ly aa ee ad Pig oe oS is Ree . . “.@ ae j " ~ 7
Bet.” 2) es ie ' fit eh hers hy oy x he ie oe oe. . Se ‘gh

156 : $ Be i tek eee te

Fusarium moniliforme was widely distributed. It oceurred in 49 ¢ of the |
fields examined, scattered over 8. central +0 coe counties
infection ranged from 1 to 15% of the cars. | tat
Gibberella zeae cc. saubinetii) was observed in % of 59. fields, in.
the southeastern and central parts of the Staté. om 0.5 to 2 of the
cars were arfcctcd. west
Wigrospora sphacrica (Basisporium gallarum)(car rot) was observed in
ll of 55 ficlds in thc southeastern and ccntral parts, on 0.5 to paeeey

thc cars.
Pee; Pcnicillium-Asporgilius complcx was widely dostributed this yoar owing
ae to latc maturity and to mcthods of harvesting. It was found in almost
i all lots of corn and from 0.5 to 50% of thc cars were affected.
a Pythium (? arrhonomancs). A trace was found in 4 of 6 Cumberland Coun-
ae ty Piclds cxamincd.

a

Ustilaso maydis (U. zoac). Trom 0.5 to 3% was found on ears in 25 of
5S “lots. ‘examined. = 5 2 ,

FRUIT CROPS

. APYGDALUS PRSICA, PACH, - Cladosporium carpophilum was observed in
Adams, Cumberland, Franklin, Laneaster, and Snyder Counties;. infection .
varied from a trace to moderate. | ets

Lonilinia fructicola was widely distributed in central, southeastern,
and castern counties. Infection ranged from a trace to eee in .
sprayed trecs, and light to severe in unsprayed or poorly cared-for trees. —
Tee ys iapies appeared most dcstructively affected. a
a Peach yellows (virus, Chlorogenus persicac var. vulgaris). in one Liont- —
Neg goucry County orchard 14% of the trees were affected.
a AMYGDALUS PERSICA var. NECTARINA, NECTASIN:. Cladosporium carpophilum
ak. Was modoratcly severc in one Cumberland County orchard. Lonilinia fruc

Ss pacola. Was Severe in one Cumbcriand orchard. |
mete ' WALUS SYL7SSTRIS, APPLE. Zrwinia amylovora was gencrally distributed
+5 but was Gocumwerive only iu abandoned or poorly managed orchards.

Glocodes pomigena was observed in Lehigh and Snyder Countics. infcc-
tion ranged from scvcrc in unspraycd to none in sprayed trecs. — ee

Gymnosporangium clavipes (G. germinale) was notcd in-Adams, franklin,
BEES Lehigh, and Snydcr Counties, usually in not more than traccs.
vynnosporangium junivorisvirginianac was obscrvced in Adams, Backs , >
franklin, Lebanon, Lehigh, and Snydcr Counties. infection was severe in
aeeayiid trees in Adams County. In other areas it usually varicd from
a trace to slight.
Holminthosporium papulosum was notcd frequently in Adatris, Lehigh, and
Montgomery Countics.
iycosphacrcila pomi was obscrvcd in trace amounts in Bucks ane Lehigh
Countics. Ҥ
3 Physalospora obtusa was observed in Snyder, Soueaes ‘ Lobanon, and
“Bes Lehigh Countics. Infcetion ranged fron a tracc to Severg on unsprayed
a trecs. : eo
Bet Venturia inacqualis was Widcly Lane: with much atid: donc to
rig unspraycd trcocs. ~28 ~2

157

“je

PRUNUS spp., PLUM. Coccomyces prunophorae was moderately severe in a
few Luzerne Count ty orchards. Heat canker (non-parasitic) was moderately
severe on the fruits on all trees in one Luzerne County orchard

PRUIUS spp., CHERRY. Coccomyces hiemalis was general and very destruc-
tive.

RUBUS CECID=SNTALIS, BLACK RASPBERRY, and R. IDAEUS, RED RASPBERRY.
Agrobacterium tumefaciens was severe. a one Snyder cca planting. Didy-

—a

mella applanata was generally distributed in Luzerne, Snyder, Susquehanna,

—_— ==

and Yyoming County plantings; infection was light to moderate. Xlsinoé
Veneta was generally prevalent in Luzerne and Snyder County plantings. —
Septoria rubi (Sphaerulina rubi) occurred in light infections in a few
Susquehanna > and " Wroning County nty plantings.

hiosaic (red raspberry mosaic virus, Larmor rubi) was seen in almost ev-
ery planting visited in Lackawanna and Luzerne Counties. Usually the
percentage of diseased plants was very low.

VITIS sp., GRAPE. Glomerella cinsulata was affecting 1% of the bunches -
in a Lebanon County vineyard. Gui Guignardia bidwellii was observed in Adams,
Lebanon, and Snyder Counties; in terms of bunches affected infection
ranged from a trace to moderate. Plasmopara viticola was observed in
Adams, Lebanon, and Lehigh Counties; infection ranged from a trace to
light on as many as 90% of the plants.

SUMMARY OF OBS URVATIONS ON PLaNT DISUASSS Ti. THs ree J ouRS AY

ee —— ee ne

DE ELAWARS 1 {UARYLAND - AREA 3 sR ae JULY TO. DAC ii BSR ,_ 1943,

age Ae Weal ber

VSGUTABLS CROPS
APIU:: GRAVSOLENS, CELERY
Barly blight (Cercospora apii) was of little economic importance.
Late blight (Septoria apii)was | observed in most plantings causing mod-
erate to severe damage. Cracked stem (non-parasitic) occurred in only
slight amounts in any field. These observations were all made in New
Jersey.

ASPARAGUS CFFICINALIS, ASPaR sRAGUS

Asparagus Aientet ions were examined in New Jersey. In most fields vi-
sited an average of about 2 to 3% of the plants were affected by a stem
rot with which Fusarium sp. was associated. Rust (Puccinia asparagi)
was generally absent in midsummer, but increased during the fall. The
heavist attack observed developed in the vicinity of Woodbury in Glou-
cester County. In some fields about 00% of the plants were affected.
In heavily infested areas parasitization of the fungus by Darluca filum
Was characteristic.

BATA VULGARIS, BEAT
Leaf spot (Cercospora beticol la) was slight to moderate in most fields
in New Jersey. Stands were ver ry poor except in irrigated sections.

BRASSICA OLURACEA var. ACHPHATA, KALE
Yellows: (Fusariun. oxysporum f. “conglutinans) reduced the stand in a

15-acre field in Maryland about - “20 aoS

.

“BRASSTCA 0 OLTRACEA vars APITATA: CABBAGE - Mis og ds
Alternaria leaf spot Hee was not destructive in ‘NewJersy, but “in ;
a large field near Woodville A. brassicae (A. hercul ea) was hee ~ 4
vere damage to outer leaves and sucker - ‘sprout leaves. =
Yellows (Fusarium oxysporum f. conglutinans) was seldom observed to be
causing more- than 0. 5% loss in New Jersey. It was rather common in Mary- —
land victory gardens where care was not used-to sclect resistant varieties.
Black-rot (Xanthomonas campestris) was:gencrally unimportant in both
New Jersey and L&E Varyland. Only occasional ficlds were observed with se-
vere infection. ' .
in liew Jersey, after rains in October, : cracked Weade apne eee
damaged about 10% of the crop being harvested. . :

BRASSICA RAPA, TURNIP ES
White leaf spot (Cereosporella albo-maculans) was causing serious loss
in fields near Newfield and Zlmer in southwestern New Jersey, where 100%
of the plants were affected. It was very common in most : bares pave
in Maryland late in the season. ate a ae
Mosaic (virus) affected 2% of the eoD in the Newfield area of New

Jersey.

CAPSICUM FAUTSSCaNS, PHPPER “his Teed Pat

Alternaria leaf spot (Alternaria solani) was found in one field in New
Jersey in association with the Cercospora spot.

Cercospora leaf spot (Cercospora capsici) was seldom observed in ilew
Jersey. it was noted on scattered leaves in a few fields ini Maryland.
In plantings near Seaford, Delaware, the disease was very severe on the
leaves and some fruit pedicels. pie , aN (Sat | Set

Wilt associated with Fusarium sp. or other organisms was more destruc-
tive than. other diseases in Mew Jersey. All fields visited showed some
wilt, and in many fields from 25 to 30% was observed, while all plantings
would average about 5% of the plants killed. F. annuum was isolated in
some cases. ‘Tilt associated with Fusarium sp. was noted in all fields
Visited in i’aryland also, the average danage being about a of the plants
killed. Some fields showed 5%, one field 20%, and the worst field ob-
served showed 50% of the plants killed. STAR .

Anthracnose! (Glomerella cingulata ) was seldom observed in New Jersey.
in jiaryland from 6 ‘to OF 7 loss of the fruit was noted in 2 fielas.

Bacterial spot (Xanthomonas vesicatoria) was causing about 20% defol-
iation of red peppers in the Vineland section of New J Orsey »

Mosaic and other virus diseases occurred in nearly all fields in Mew
Jersey; were prominent in Delaware; in liaryland about 5% loss was noted
in some fields. .

An undetermined fruit rot was causing about 1% loss in one! Maryland
field. :

Drought caused 10% loss in New Jersey, -in the pepper section where
rows were ridged. |

‘Si SSR asthe Raa
> matt poe f \

Sun scald reduced the erop of salable fruits in New Jersey about 40%.
Loss was Slight in pepper-growing areas in Delaware. In laryland some
was observed in all fields visited and 50% loss was noted in one field
in Anne Arundel County.

CITRULLUS ULGRIS, TATERMSLON Ne .

Leaf blight (Alternaria cucumerina ) Was observed in one field of late
melons near Seaford, Delaware, where nearly all the leaves wore affoc-
ted and many were Killed, wsulting in a large crop of small mclons.

In Maryland, bacterial wilt (Erwinia tracheiphila) caused the death
of 6 to 10% of the plants in one ficld, and was gencrally distributed
in most Jeireih visited.

CUCUR ‘BITA PEPO, PUMPKIN

Choanephora cucurbitarum vas isolated along with Fusarium sp. from dis-
eased roots of wilt-affected plants in Maryland and Now Jersey, but
whether it has any causal relation to the diseasc is not known as yct.

Wilt (Tusarium sp.) wasivyery destructive in both States. . In New Jersey
losses of over 60% were cstimated in some ficlds, and the loss in plants
killed would average 15% for the State. oe eee some ficlds showed
from 40 to 50% of the plants killed. The State loss would average about
10%. In some cases wilt was confuscd with damage caused by the squash
vine. berer.

Downy mildew (Pseudoperonospora cubensis) was found on leaves in one
New Jersey: field, but the fruit was nearly mature and no damage was
apparent.. x

Rootknot: (Heterodera marioni) was severe, affecting about 10% of the

a ae

plants, ina sandy field in Anne Arundel Coun Maryland.

CUCURBITA .PEPO var. CONDSISA, SUMIOR SQUASH
Blossom blight and pio ene ena rot caused by Choanephora cucurbitarum

oer ee we ee ee eee ie ee eee ee ee

was observed in several victory gardens in Maryland. Bacterial wiit
(Srwinia tracheiphila) damaged plants on low land in Maryland. Wilt

(Fusarium isp. ) caused serious damage to most squash plantings in New.

Jersey: and ijaryland. In some fields in Maryland U0% of the plants were
killed.

TPO SORA BATATAS , OWE By sth LPOTAT 6)

Pox (Actinomyces i ipomoeac) was more prevalent than usual in all areas.

Black rot (Ceratostomella finbriata)! was not observed in the field in
laryland at harvest but developed rapidly in storage and loss will ex-
eecd 10%. In iiew Jersey and Delawarc it was causing about 1% and 1.5%
toss, respectively, in fields observed at harvest time.

Stem rot (Fusarium spp.) was observed ohly to a very slight extent in
Delaware, but in lew Jersey and laryland it occurred to some extent in
most ficlds, causing losses averaging 3% in the former and about AY; in
the lattcr. In some ficlds in New Jcrscy from 10 to 40% of the plants

-werc wilted and killed. In Maryland up to 20% infcction was noted

Scurf (lconilochactcs infuscans) occurred in most ficlds in New Jersoy
and Delavare but caused little damagc. In Maryland the discase vas

_ severe in all fields and contributcd greatly to root cracking.

~ ¥ a = _ STS, Ts En eA PgR OCT GA. NTE: RTO UNE Me.

according to Ross W. Davidson (Jour. Agr. Res. 50:8C0O. 1935) this fungus

is an | undoconidio hora, and he makes ¢ = combination 3. finbriata (EL

<F

160

Soft rot (Rhizopus nigricans) developing on the stem end accounted for
about 2% loss in one New Jersey field following a late wet harvesting |
season. Roots from this field would suffer considerable loss in stor-
age. in Delaware this rot was seldom observed at harvest but since the
roots were harvested while full of water, considerable loss may result |
in storage if they are not properly See

Cracking of the roots following rains after the first of October was
frequently noted in New Jersey, causing a loss of about 2%. It was
severe in most Delaware fields where fully 10% or more of the crop was
damaged in this manner. in Maryland it was very severe in low land.

The average loss in this State amounted to 6 to 10%, and some fields
were not dug because of this condition.

Drought reduced the New Jersey crop about 30%, and resulted in the mar-
keting of a larger number of small size swéetpotatoes than usual. In

luaryland also the crop as a whole was reduced about 40% by drought,

and the yield of roots grading U. S. ho. 1 to about 2hfo of normal.

LYCOPERSICON =ZSCULEWTUM, TOLATO

Larly blight (Alternaria solani)was present to a damaging extent on
the foliage in all fields visited in New Jersey. In Delaware-and jiaryland
it caused defoliation of the lower leaves of the.late crop; stem infec-
tion was observed to some extent in Delaware and was abundant in laryland.
A reduction in yield of about A%o occurred in Delaware.

Leaf mold (Cladosporium fulvum) Was observed generally distributed in
one field near Cordova, iiaryland. Outdoors infection by this fungus is
not common in the State.

Bacterial canker (Corynebacterium michiganense ) was observed in one
Maryland field. “he loss in the field averaged 4%, but in some parts ~
of it 50% of the plants were killed.

Fusarium wilt (fusariun Ox vee. ts lycopersici) caused a loss in
Liaryland averaging approximately 5%. It was very severe near Cambridge,
where the average loss was 0% and 35 to 50% of the plants were missing
in parts of some fields. Fusarium wilt and verticilliun wilt (Verticil-
lium albo-atrun) together caused death of about 5% on the average Of
plants in Delavare and New Jersey commercial tomato sections. In New
Jevsey from 16 to 35% of the plants in some fields were killed by one
ofthe other.

Late blight (Phytophthora infe sstans)was noted only in aryland, where
a slight amount was observed on the foliage in 2 fields Jate in the
season, causing no damage.

Bacterial wilt (Pseudomonas sOlanacearuim) was severe in one Maryland
field. | | |

Leaf spot (Septoria lycopersici) caused serious defoliation in some
fields in northwestern New Jersey. Some defoliation was observed in the
Cheswold area of Delaware, with reduction in yield of about 1%. -The
disease caused slight Ae on the sastern Shore and moderate damage in
northern and western liaryland. Some defoliation was noted.

Gray leaf spot (Stemphylium solani) may have caused some of the damage
attributed to early blight in New Jersey. :

hiosaic (virus) occurred in most fields in Delaware but was causing

only slight damage. It was observed in most plantings in iew Jersey also. —

ete PT SRG, eye,

161

Blossom-end rot (physiogenic) was more prevalent than usual in New
Jersey and caused a loss of more than 15%. Late tomatoes in Delaware
and liaryland were badly affected but the disease decreased in severity
after the middle of September. Loss in Delaware was fully 5%, in Mary-
land about 0%. From 30 to 50% of the fruits were affected in some
Maryland fields.

Stem-end cracking of the fruit was observed in the late crop in Mary-
land following the rains after the middle of September.

Drought reduced the late-season crop in New Jersey-and Maryland by 40%,
and was responsible for the large number of small fruits. The early
crop in New Jersey was slightly affected.

PsTROSELINUL: CRISPUM, PARSLEY
Stunt {virus) was found in one New Jersey planting near Elmer.

RADICULA ARMORACTA, HORSERADISH

white rust (Albugo candida), leaf spots caused by Alternaria brassicae
(A. herculea) and Colletotrichun sp., and downy mildew (Pcronospora par-
asitica) were observed in all of the mostly small plantings examined in

New Jersey.

SOLANUL. i-ZLONGENA, GGPLANT

Anthracnose (Colletotrichum atramentariur) ‘was seldom observed in New
Jersey plantings. About &% of the fruits in one field in Anne Arundel
County, Maryland, were affected.

Wilt (Fusarium sp) caused an average of about 6% loss to truck growers
in Liaryland. Wilt due to Fusarium and to Verticillium albo-atrum was
the most ee ore disease “of * egeplants in WNew Jersey. Most fields
contained 1% or more, with an average of about 5%, while in some fields
from 40 to A0% of the plants were wilted. Verticillium was possibly the
more important in this State.

stem canker and fruit rot. (Phomopsis vexans) caused no damage to the
early crop in New Jersey, but loss in.the late crop amounted to 40 to-
50%. Stem cankers caused the death of some plants before frost. In
one field observed in Maryland about September 15, about 26% of the
' plants were killed and 45% of the fruit was affected.

Cracked fruit following fall rains Pexe Lope’ to a severe extent in New
Jersey.

SOLANU!: TUBEROSU:, POTATO

Scab (Actinomyces scabies) was observed occasionally in New Jersey but
was not severe. in Marvland it was practically absent on the late crop
in the lower elevations of the eastern part of the State, but was very
severe in western ijaryland where some varieties averaged from 10 to 15%
deep scab and 15 to 20% surface scab.

Larly blight (Alternaria solani) was generally slight to moderate on
the late crop throughout - the area.

Bacterial ring rot (Corynebacterium sepedonicum) was observed on
Katahdin. potatoes in Garrett County in western iJaryland at harvest, the
_ first record for this part of the State. The disease was introduced
With a carlot of "Select" northern seed that was distributed to over 400

i >

“Was killing about 1% of the plants in a ficld near Scaford, Delaware.

victory gardeners. Tubers infected in the crop from this seed amounted
to about 6%. ee. eas a

Rhizoctonia (Pellicularia. Pianedtass car: ieias solani) caused severe
black scurf on tubers in western haryland. No aerial tubers were ob- ;
served.

Late blight (en eaeNinee antec was “practically absent in most
sections. in New Jersey tuber rot was observed in only one field, of the
Chippewa variety. In western Maryland where rain was plentiful late
blight reduced the crop in unsprayed fields about 25%.

Brown rot (Pseudox mona s solanacearum) was observed to cause slight dam-
age ina field of late “potatoes in Caroline County, liaryland.

Lsaf roll (virus) was serious in the late crop on the sastern Shore of
Maryland, with over 3% of the plants affected. | 3

ee affected the late crop in Delaware and wie seas canl reducing
stands about 40%.

CUR LAILS, GRASSES, AND FORAGE C?0PS
FPAGOPYRU!! SSCULLENTUM, BUCKVWHEAT. A stem rot of undetermined origin

LODICAGO SATIVA, ALFALFA. Leaf spots (Pscudopeziza medicaginis and
Pyrenopeziza medicaginis) caused severe defoliation of the uncut or seed
crop in New Jersey late in the season. New growth showed only slight
leaf spotting with no apparent loss. In Delaware leaf spots caused con-
Siderable defoliation of the lower leaves after the second cutting.

SOJA AX, SOYBEAN. Frog-eye (Cercospora sojina) (C. daizu) was ob-
served to a limited extent in Delaware.. In Varyland slight infection
was noted in 2 fields visited. Bacterial spot (Pseudomonas glycinea)
bacterial pustule (Xanthomonas phaseoli var. sojense) caused about 2%
loss in Delaware and were observed frequently in Haryland.

Drought was scvcre in both Delaware and laryland, reducing the crop
30 to 55%.

SORGHUIH VULGARE var. SUDANENSE, SUDAN GRASS. Jeaf blight (Helmintho-
sporium turcicum) was very severe in all fields examined throughout the
area, drying up the leaves and rendering the crop useless for silage or
hay. | ;
TRIFOLIUI: spp., CLOVER. Powdery mildew ee was very
pronounced by late summer. | |

ZboA T:AYS, CORN. har rots caused by Diplodia zeae and ie
liforme were less common than usual. Loss from Diplodia was about 1.2%
in Delaware and Maryland and did not exceed 2% in New Jersey; loss due
to Fusarium was about 1%.

Stalk and root rot caused by Diplodia zeae was severe in St.ivary's
County, Maryland, where losses averazed about 5h.

Leaf blight (Helminthosporiun turcicun)was of minor importance. It was
observed only in northwestern lew Jersey , very late in the season, and
in northeastern Maryland. ; rat

Smut (Ustilago maydis) (U. zeae) infection amounted to less than 1%
throughout the area. Ear infection was practically absent in Delaware
and New Jersey.

Drought, in Maryland, reduced the yield about 430%.

ra, hin) tat FASE Pe ©, Mt eee

“dua Vays, SWLET CORN. Bar “infection by smut (Usti silago maydis) in Del-
aware appears to be jucreasing. The crop from some fields showed 20% 7
or more affected ace when received at the canning factories.

FRUIT CROPS

ee - AMYCDALUS PERSICA, PACH Ve ;
q Scab (Cladosporium carpophilum) was seldom observed in well-sprayed or-
: chards, but was severe in some poorly managed plantings. Over 50% infec-
_ tion of the fruit, severe shot-hole with defoliation, and some twig in-
_ fection were noted in some liaryland orchards. The variety Lizzie was |
: severely affected in one New Jersey orcnard, evidently not well-sprayed.
Brown rot (jonilinia fructicola)causeé but slight loss in iiaryland and
- was practically absent in Delaware and iiew Jersey. The variety 7. H.
Hale showed most infection in iwarylandg, and orchards with heavy infesta-
_ tions of the oriental peach moth were also most heavily attacked by brown
oo. FOts One block of J. E. Eale near Dover, Delaware showed a loss of 2 Bt
a os
Constriction disease (Phona persicae) was observed in several young and Rays
_ Old orchards in waryland, manifested by a yellowing of leaves on the af- F
_ fected.branches. Tne results from severe stem infection occurring dur-
_ ing the 1941 season are becoming pronounced. :
Bacterial spot (Xanthomonas pruni) was the most destructive disease of he
3 ' peaci Eheak in New Jersey. “The varieties Blberta, Golceneast, Hale- M
haven, J. H. Hale, and Summercrest showed most severely arfected fruits,
bs While none or only slight infection occurred on Golden Jubilec and
_ Beile. The disease was severe in 4% far-separated orchards in Narvland,
_ Varieties showing the greatest fruit injury were Breckett, Champion,
Barly Bilberta, HZlberta, Goldeneast, Goldcnglobe, Halehaven, J. EH. Hale,
_ Late ulberta, Redskin, “Rio Oso Gon, Summercrest, Roberta, Sunhigh, and
' White Hale. Near Dover, Dcolawarc, bacterial ee Was severe on fruits
Of J. H. Hale, Elberta, and Shippers Lato. )
Ras ‘Little peach (virus) was obscrvyed in scattcred eas in New Jcorsey,
a to ‘the extent of about 1%. . Ag
Spray injury in the form of marginal leaf burning was vcory pronounccd . i
in most orchards in _|Dalaware;. this type of injury may also have peen ae
_ associated with drought injur. Severe spray burn was notcd in one nen
<3 iaryland orchard whcerc summcr-oil uscd on apples drifted: across. :the af
_ peach bleck. In this Statc aiso, espocially scvcre arscnical injury
= was notcd on: Salwey and Krumacll in onc instanec, where 5% of the fruit f
a was damage and 60% of the leaves were lost. 4
_ ‘Freezing of the fruit buds by spring frosts was responsible for about a
85% reduction in the crop in Delware, and 75% reduction in iaryiand. .
On the Kastern Shore and ‘in southern | Maryland frost caussod 96% reduc-
_ tion tm the crop; in the mountain areas of western Maryland, on the other
' hand, the crop was about d0% of normal. pe hes

; oes geese 2 duc oe winter eae was observed on 50% of the trees

alls RUG, Pies ace iN

[tds

+ ee eee

164

EiALUS SYLVESTRIS, APPLE

Fire blight (arwinia amylovora) was not active during the summer or ...
fall. Jonathan and Wealthy showed some injury in ! uryiand.

Bitter rot (Glomerella cingulata) was of very slight importance through-
out the area. In lew Jersey it was observed mostly on Grimes Golden and
Golden Delicious fruits. In Delaware it was practically absent in or-
chards visited except in one block of the Stark variety near Cheswold
in which about 10% of the fruit was affected. In scattered orchards in
Maryland, Grimes Golden showed 10% fruit infection, iaiden Blush 2%,
Winter Banana a trace, Nero 25, and Black Twig a ao

Cedar rust (Gymnosporangium juniperi-virginianae) was severe on leaves
of Rome Beauty in New Jersey. In Maryland it was more prevalent on the
leaves than usual, but the fruit remained comparatively clean;.on York
imperial 50% eo aoe of the leaves was often observed whereas Jonathan
showed only 1% infection. iiostly slight leaf infection was noted on
nome Beauty although in one orchard 40% was observed.

Black pox (Helminthosporium papulosum) was sévere on Rome Beauty fruit
from trees showing twig symptoms of measles in Maryland, while Gor Cee
ium fuckelii was isolated from such affected twigs.

Fruit spot (liycosphaerella pomi) was observed in one orchard in north-_
eastern Maryland.

Black rot (Physalospora obtusa) leaf infection (frog-eye) was nore
common than usual in ilaryland. It appeared most frequently on York In-
jSserbe Ue A056 of the leaves of this variety were affected in one orchard.
Yellow Transparent, Northwesteri. Greening, and Winter Banana were lightly
affected. One block of Nero showed 2% loss from fruit rot.

scab (Venturia inaequalis) was practically absent or very light on the
fruit in most of the area. Larly season leaf infection was also light,
but a considerable amount developed on leaves late in the season, par-
ticularly on Delicious, Grimes Golden, Rome Beauty, Stayman Winesap, and
York imperial. in bponcee. Lew Jersey moderately severe infection was
observed on lcIntosh and Stayman Winesap, and to some extent om Deli-—
cious, fruit. , ;

neoteee injury was severe and resuited in small fruit that dropped off
early.

Late blossoming was observed August 25 in a neglected orchard near
Cheswold, Delaware. Leaves were few and there was no fruit on the trees.
Spray pee resulted in. considerable leaf marginal burning in several
orchards in iiaryland. Some fruit injury was observed on Gano and York

iiperial in two orchards.

RUBUS BP, RASPBERRY

In raspberry plantings observed in j‘aryland, spur blight (Didymella
applanata) was generally distributed; about 10% of the canes. were af-
fected by anthracnose (L1lsinoé veneta) ; a slight amount of cane blight
(Leptosphaeria coniothyrium) < occurred in commercial plantings; verti-
cilliun wilt (Verticillium albo-atrum) was responsible for most of the
dead canes. .

165
SPECIAL CROPS

NICOTIANA TABACUM, TCBACCO

In Maryland granville wilt (Pseudomonas solanacearum) was observed in
2 fields, one. of Maryland Medium Broadleaf, and the other of Burley type.
Losses amounted to 25-30% of plants killed. Mosaic (virus) was more
severe than usual; average number of plants affected was about 20%.
Ringspot (virus) was light, resulting in about 1.5% plants affected.
Drought injury (weather) reduced the total crop 40%.

PLANT DISEASES IN OHIO DURING 1943

M. KR. Harris

During the 1943 growing season, Chio weather was somewhat abnormal. The
spring was late. Precipitation was higher than normal which resulted in
soil too wet to cultivate until as much as several weeks after the usual
planting dates, In the middle and latter part of the growing season there
was a scarcity of rainfall in the central and southern portions of the
State resulting in some crops, such as corn and soybeans, ripeming some-
what prematureiy. However, the lack of rainfall late in the season made
possible the harvesting of relatively disease-free corn and soybean crops.

VEGETABLE DISEASES

ALLIUM CEPA, CNICN

Onions were danaged by hot wet nooner Whichiresti ied in 2, scald’ of
the bulb tops. Later, soft rot bacteria completed the breakdown. Pink
root caused some loss where the fungus (Phoma terrestris) yas present in
the soil, Smut (Urocvstis cepulae)} was largely controlled by, proper.
treatuents at planting time.

APIUM GRAVEOLENS, CELERY. Early blight (Cercospora apii) of cdory was not ser-
ets Witte Anlieu{Septoria a apii}) caused some injury where fields were not
properly sprayed. Yellows (Fusarium oxysporum f. apii) was not an eco-
nomic factor in celery production this year due largely to the planting
of resistant varieties. |

ASPARAGUS OFFICINALIS, ASPARA GUS. In some plantings, rust (Puccinia
asparagi) is becoming a serious problem. Among growers, the opinion seems
to be that resistant plants are gradually becoming susceptible.

BRASSiCA OLERACEA var. CAPITATA, CABBAGE. The yellows disease (Fusar-
ium oxysporum f. conglutinans) of cabbage was not damaging, owing largely
to the planting of resistant varieties. Blackrot Ganthomonas campestris)
was quite a factor in some fields and caused 4 4% loss over the envire
State. Club root (Plasmodi.ophora brassicae) persists in a few places and
caused a O. 5% loss in cabbage growing areas. :

CUCUNIS MELC, CANTALGUP. Cantaloups were attacked by the anthracnose
Brganicm (Goltetotrichan: lagenarium) much less than last year. Bacterial
wilt (Erwinia, tracheiphila) was mich more prevalent than last year and
caused a 5% loss. Fusarium wilt (Fusarium sp.) was no more severe than

persici) was a faetor in tomato production only locally where it caused

monas phaseoli and/or Corynebacterium flaccumfaciens) caused a 0.5% re

- . i 4 “ 4 ‘ i ¥ k y Z
| . P are i caf + f =a + Be e

a : . i on it aay " ‘abel es he or ( Na
; .: =a .. PRY \ + 2

‘ $ ‘ Bo re, ‘ ¢ K2 ;

| = Ny : ea ay rv: a vg

. aie AA OS é al ‘
- t fi F 2 ry ~ ee = $3.
3 \ S Neadt t Ler ' Ry

in an average year, causing a traée:6f damage. Leaf spot (Alternaria
cucumerina) and mosaic caused only a trace of loss. Bie:

CUCUMIS SATIVUS, CUCUMBER. -Anthracnose (Colletotrichum lagenarium)
caused a. 1% loss on cucumbers. Bacterial wilt it (Erwinia tracheiphila.)
was more severe, causing a 3% loss. ‘here was a trace of angular lear
spot (Pseudomonas lachrymans) in a few fields. Mosaic. is becoming quite
severe .on some varleties of cucumpers, reducing the pick by more than
half. Over the State this disease caused a 4% loss.: —

DAUCUS CAROTA, CARROT. Leaf blight (Cercospora carobae and Alternaria
carotae) of carrots was no more severe than usual and caused a 6% reduc- .
tion of the crop.

LYCOPERGTCCE ESCULENTUM, TOMATO. Tomatoes were attacked ‘te early
blight (Alternaz “la solani) early in the season during weather favorable
toe the disease, “Losses up to 90% were seen.in some fields, but over the
entire season enly 1% loss was sustained. Leaf mold (Cladosporiwa ful-
vun) while quite general in its distribution caused only 0.5% damage t to
the crop. Anthracnose fruit spot (Coiletotrichum phomoides) was severe.
in spots and destroyed 7% of the State crop. A trace of wiit (Fusarium
oxysporum f, _lyco persici) was noted. Blossom-end rot was not very pre-
valent this oast séason. In some greenhouses it is a serious problem. ~
Bacterial cenker (Corynebacterium michiganense) was most often found on
plants brouzht in from southern states which were delayed in being plant-
ed. There was a 1% loss from this disease. Leaf spot (Seotroia lyco- -

a reduction in yield up to 754 ina few fields. The lateness of the
season was not favorable to the development of leaf blight. There was:
a trace of wilt (Verticillium sp.) but the cool summer reduced the amount
of this trouble. There was a 1% loss from virus diseases over the State
but individual fields ran as high as 100%. | oe
PHASECLUS VULGARIS, BEAN. The bean crop was reduced 2%, by anthracnose.
(Colletetric srichum lincemuthianum). Powdery mildew (Erysiphe cl yeoni ) did
eae Gamaze generally but “isolated fields in the northern part of .the
State were severely damaged late in the season. Bacterial blight (Xantho-

duction in the crop and was favored by wet weather early in the season.
PISUi SATIVUM, PEA.. The pea crop was reduced 5% by seed decay and root
rot ¢aused by Fusarium sp. and fvored by wet soil early in the season.
Sot LANUL } sSLONCHT VA; EGGPLANT. Eggplant fields were severely damaged by
wilt (Verticilli Lum es) and over the State generally there was a 10% loss.
SOLANUM TUBEROSUM, POTATO. Potatoes were damaged to a moderate degree
by scab (Actinomyces scabies) ard there was a 1% loss. Early blight
(Alternaria solani) was more prevalent than usual this past year and re-
duced the crop by 2.5%. In three fields of the State bacterial ‘ring rot-
Corynebacterium sepedonicum) was known to occur. The source of the dis-
ease was infected seed. On muck areas scu’f and stem rot (Pellicularia
filamentosa) (Corticum: solani) did a slight amount of damage. Here and
‘there a trace of blackleg (Erwinia phytophthora) was found. “Wilt (Fusar-
ium spp, ) was about as prevalent as usual and the loss was ©.5%. Late
blight early in the season promised to be serious but. weather. unfavorabl €
to its development later in the season reyiced the loss. to a trace. The

167

ee (Phvtoohthora infestans) was found near Columbus late in July.
The virus diseases exclusive of leaf roll reduced the crop by 1%. Leaf
roll was more severe and caused a 4% loss. Insect injury due to leaf
hoppers was more severe than usual and was estimated at &%.

CEREAL DISEASES

AVENA SATIVA, OATS. On oats there, was a trace of leaf blotch (Helmin-
thosporium avanae) this past season. A trace of halo blight (Pseudomonas
coronasaciens) was found in the nortnwestern part of the State. Leaf
rust (Puccinia coronata) was general and reduced the crop by 1%. Traces
of steim rust (Puccinia graminis var. avenae) were found in widely scatter-
ed localities. Loose smut (Ustilago avenae) was general and caused a
0.5% loss while covered smut (Ustilago See eS Was more severe and re-
duced the yield by 1.0%.

HCRDEUi VULGARE, BARLEY. On barley a trace of ergot (Claviceps pur-
purea)was found. In four fields a trace of mildew (Erysiphe graminis)
occurred. In the southern part of the State scab (Gibberella zeae) was
cbserved in 4 fields and in one it had damaged the heads severely. A few
traces of blotch (Helminthosporium spp.) were seen. Leaf rust (Puccinia
anomala) was fairly prevalent but caused no loss. Stem rust (Puccinia

raminis) likewise was scattered but not severe. Loose smut (Ustilago
nuda) reduced the crop by 1.0% and covered smut (Ustilago jensenii) by 2%.

SECALE CEREALE, RYE. Ergot ee urpurea) on rye was severe —
in spots causing as high as 25% loss in isolated fields but over the
State generally reduced the crop by 1%. Scab (Gibberella zeae) in one
field infected 30% of the heads but averaged only a trace for the State.
Traces of leaf rust (Puccinia rubigo-vera var. secalis) and stem rust
(Puccinia graminis) were seen. In one field a trace of stem smut (Uro-
cystis occulta) was present.

TRITICUM AESTIVUM, WHEAT. A trace of anthracnose (Colletotrichum
graminicolum) was seen in Ashland County. One field showed traces of
powdery mildew (Erysi iphe graminis tritici). Scab infection was general
and frequently severe. Percentage of heads infected with the fungus
(Gibberella zeae) ran as high as 85 in some fields and for the State
generally the loss was 12%. Stem rust (Puccinia graminis) was of general
distribution and caused a 2% loss while leaf rust (Puccinia mbigo-vera
var, tritici ) was less severe and reduced the crop by 1%. A trace of
glume blotch (Septoria nodorum) was found in four fields. There were
traces of bunt (Tille tia levis) fairly common over the State but loose
smut (Ustilago tritici) was much more general but not an economic factor.

Z#A mwAYS, CORN. The corn crop was generally fairly free of discase.
Ear rot (Dinvlodia, Gibberelia and other fungi) was most coimon in the
northern part of the State and reduced the crop by 0.8%. There was a
trace of stalk rot caused by these same orgenisms. In the south half of
the State, leaf blight (Helminthosporium turcicum) was quite prevalent
but develooed late in the season and caused only 1% loss. There was a
trace of Stevart's wilt disease (Bacterium stewartii) im tield- corn big
sweet corn showed an average loss of 3%. Smut (Ustilago maydis) reduced

the field cérn crop by 0.6%.and sweet corn by 2%. -— ,

FIELD CROP DISEASES

VULGARIS, SUGAR BEET. On sugar beets, leaf spot (Cercospora |
beticola) caus Se a i loss mee would have been much heavier if Tosist-
Many fields were lost in tne seed-
ling So pecause of various fungi ,causing a black root condi ti on aided
By wet weathcr.

MEDICAGU SATIV4, ALFALFA. . Alfaifa is grown in the western and neeeean
parts of the State. The wilt and root rot disease (Corynebacterium
insidiosum) is severe in many-fields and reduces the crop annually vy 5%.
Leaf spot (Pseudopeziza medicaginis) is present in every ficld but does
very lit va Gamage. | Be uF ae

NICOTIANA TABACUM, TCBACCC. Tobacce is a minor.crop in Chio. In one :
field a trace of angular leaf spot (Pseudoionas angnlata) was seen. Black —
root rot (Thielaviopsis basicola) reduced the crop by 4%. Traces of downy
mildew (Peronospora tabacina) and waldtare ‘(Pseudomonas tabaci) were =,
present. in é very few fields.

SOJA HAY, SCIBEAN. Soybeans were piowtee late over much of the State |
but due to very favorabte weather late in the season matured pe
crop. Frog-eye spot was common over the State but severe in only a. few.
frelds. % reduced the crop-by 0.5%. There was a trace of nod end heme
blight (Diaporthe soiae). “Anthracnose (Glomerella glycines) cut the yield
by 6.1%. tildew (Percnesvera manshurica) at one time in the season ap-—
peared to be ‘on the verge” of a severe outbreak. put. finally damaged
crop by only 1%. Various virus and mosaic: diseases™ were widely scattered.
"Bud blight" was the most severe. The ioss from ali viruses is estimated
at 1%. Bacterial pustule (Xanthomonas phaseoli var. sojensé ) se, oresent
in every field examined but seldom was serious and caused a for: the
State estinuated at 2 fe Vee

FRUIT DISEASES -
ANMYGALUS PEESICA, “PEACH. On peaches, there was a trace of scab (Clado- ~
sporium car bo69hi Lum) which is less than im an average year. There was:

at least a 25 Loss from brown rot (ionilinia fructicola) in the orchard.

Ae Sarapons much more by the time the fruit was used. Bacterial blight

as oruni), leaf curl (Taphrina deformans), canker (Valsa leuco-
ap Bake virus diseases (little peach and yellows) were ali i ee

as uraces but did no appreciable damage, ~— é cp

PRAGARIA SPP., STRAWBERRY. Strawberries were Teseked with leaf spot
(liycosphaerelia fragariae). but no appreciable damage was done. ~Tn* some” |
plantings traces of red stele (Phytophthora: fragariay were observed. Root
rots caused by various fungi - favored by poor entee conditions iiled Se 3
of the State's vlants. | | eS

MALUS SYLVESTRIS, APPLE. On yale) there was very much less fire: ;

. blight (Erwinia amyl Lovora) than in an average year and no danase was done
Bitter rot “(Glomerelia ia ‘cingulata) was much more prevalent in southern ey
Uhio than in an average year. Damage was C. 5%. Tne usual trace of cedar —
rest (Gymnosporangium juniper i-virginianae) was present ina nunber ee E

rea ae

a wo fo ot acolbine GBs tn eae vied 9) blather hl) he 9 ae Sei
al 94 piesa Ne? auger ” ; afr) ’

169

commercial orchards. In southern Ohio, pox disease (Helminthos»orium
papulosum) was more prevalent than in an average year but no appreciable
damage over the State generally was recorded. Here and there a trace of
Brook's spot (liycosphaerella pomi) could be found. Blotch (Phyllosticta
solitaria) could be found where re spraying was not done proverly. There
was an early severe leaf infection of black rot (Physalospora obtusa)

in southern Ohio which resulted in statewide damage of 0.3%. Scab
(Venturia inaecualis) was severe and favored by weather conditions early
in the season. The total loss for the State was 10%.

PRUNUS SPP., CHERRY. Cherry leaf spot (Coccanyces hiemalis) was more
severe than usual during the past season and defoliated trees which were
not sprayed. In some commercial orchards weather conditions prevented
spraying at the proper time and in such orchards some defoliation re-
sulted. The loss over the State was estimated at 1%. There was a trace
of brown rot (Monilinia fructicola) when the fruit was ripening.

PRUNUS SPP., PLUM. On plums there was a trace of bacterial spot (Xan-
thomonas pruni). Brown rot, with the aid of insect damage, was severe
and destroyed | 12% of the crop.

PYRUS COMRIUNIS, PEAR. On pears, traces of black spot (Fabraea maculata),
fire blight (Erwinia amylovora), and scab (Venturia pyrina) were observed.
Fire blight was less common than other years while black spot was seen
more often.

RUBUS SPP., RASPBERRY. Raspberry cane blight (Leptosphaeria coniothy-
rium) was more prevalent than in an average year but did no appreciable
damage. About 2% of nursery plants were found infected with crown gall
(Agrobacteriwa tumefaciens). Anthracnose (Elsinoé veneta) took a heavy
toll in sane plantings and damaged the whole State to the amount of: 8%.
Virus diseases were found on C.5% of the plants observed.

VITIS SPP., GRAPE. On grapes, the black rot fungus (Guignardia bid-
wellii) was very destructive and in many home vineyards which were not
sprayed the crop was a total loss. Commercial vineyards that received 2
or more eat sprays were fairly free from the trouble. The State loss
was 10%. trace of both downy mildew (Plasmopara viticola) and powdery
mildew (Uncinvla necator) were seen but did no appreciabie damage.

-R. C. Baines

This report was prepared in collaboration with R. M. Caldwell, C. T.
Gregory, and R. Ww. Samson of the Purcue University Agricultural Experi-
ment Station and Arnold J. Ullstrup, of the Division of Cereal Crops and
Diseases, U. S. Bureau of Plant Industry, Soils, and Agricultural Engi-
neering. Specific recognition for the information presented is made by
“mame under each disease.

PROBABLE INFLUENCE CF RAIN ON THE DEVELOPMENT OF
DISEASES CN CROPS IN INDIANA DURING 1943.

The rainfall during May in central and northern Indiana was aporoximate-

)

0

Seiya et ey

te)
3
G
e
2
es

Apr-May Sane-duly Aug Sept, Oct-Nov,
Figure 1.

Inches of rain and mean temperature in
northern, central, and sduthern Indiana
during the months of April to November,

19436

Legends.

actual rainfall |.

average (56 years) rainfall ;

ne ere fis eae ie Be arty fre) eee ae THs cn Ry Seg tat: . f

ly 2-1/2 times the average amount (see Figure 1). From June to Septen-
ber, inclusive, the rainfall in central Indiana departed only slightly
from the averaze, while in northern Indiana it was slightly more than the
average amount. The rainfall was considerably below the average during
Gctober in northern Indiana and during Cctober and November in central
Indiana.

Tn southern Indiana the rainfall during May was 1-1/2 times the aver-
age amount and in June and July approximately the average precipitation
occurred. However, during the remainder of the summer and in the fall
the Ss in this area was much below normal.

ebundant rainfail during May conditions apparently were ex-
Bee onally favorable for the development of wheat scab (Gikberella zeae)
and apple scab (Venturia inaequalis).

The normal and above-normal rainfall from June through Scptcmoer in
central and northern Indiana was favorable for the develonment of oustule
spot (Xanthomones phaseoli var. sojense) and downy mildew (Peronospora
manshurica) cf soybeans, late blight “Phytophthora infestans) of potatoes,
leaf-spot (Seotoria lycopersici) of tomato, leaf- spot (Cercospora zebrina)
of red clover, cherry leaf-spot (Coccomyces hiemalis), leaf-blizht (Hel-
mintnosoorium turcicum) of corn, appie scab, etc.

in southern indiana the rains were somewhat spotted during tne summer
and certain areas, especially the southwest corner, were very dry. The
leaf-spot diseases and some fruit-rots, such as bitter-rot of an: see were
not very prevalent nor severe in southern Indiana.

The below-average rainfall during Gctober and November in Indiana ap-
peared to check the spread of most diseases. Thus, very few sotato tu-
bers were infected with late blight, even in fields in which the foliage
was blighted severely, and the percentage cf corn ears thet were infected
Witn Diplodia zeae was below normal.

tee OF VEGETABLES

ALLIUiH CEPA, ONION
Erwinia carotovora (soft rot) was common on dried onions. In home
gardens considerable rot was evident at harvest, especially on white
Bermuda onions, end losses ranged from 16 to 60%. A trace.of soft rot
was found in comercial fields of onions on muck soils in northern
Indiana. losses ranged from 2 to 4% in topped and cured onions according
tof. Gi. paanes.
Phoma terrestris (pink root rot). Onions on soil on which a muber of
crops of onions had been grown in the past usually were affected slightly
to severely with pink root rot. No attempt was made to interpret the |
degree of infection as reduction in yield, although it is assuaed that ae
severe infection and killing of the rects must affect detrisentally the
size of the bulos. -- R. C. Baines
Urocystis cepulae (smut). A trace odcurred on young onions., This dis-
€ase apparently is controlled satisfactorily by seed treatments according
foec.. T, Gregory.

ot * i phd ee i be Pyh Pa nA Ss ; Vs ; afl rah
us as Te ey a Ne ta es LM ; : me ‘1
= ; ‘4 i - “ Vig i y * f re Be saya ; ath y wi ‘

APIUM GRAVEGLAG HS, CELERY ae
Cercospora apii (carly blight). occurred zererally on ce ery end caused

severe injury in -in northern. Indiana. - The estimated loss was_20%.° A trace

of celery affected with Fusarium oxysporum f. apii (Fusarium yellows) was

cbserved. Varieties resistant. to the disease are usually grovm. Sep-
toria sp. (late blight) caused’ a trace of infection and “ees - 6.

Gregory.

BHTA VULGARIS, BEET

Actinomyces scabies eee caused 5%-loss in marketable beets in one
field in northern Indiana according to Re W. Samson. The loss for the
State is: olaced at a trace.

Cercospora beticola (leaf spot) Seeiered on practically all beets and
very likely caused 2 to 5% loss in yield. -- R. ©. Baines and C. T.
Gregory.

BRASSICA CLERACEA var. ACHPHALA, KALE He :
Fusarium oxvsporum f. conglutinans (yellows). Between 5 and 20% of
the plants in market garden piantings- were affected with yellows, which ©

“resulted in anproximately 1C% loss for the State. -- C. T. Gregory —

BRASSICA OL=RACHA var. CAPITATA, CABBAGE
‘Erwinia carotovora (bacterial soft rot) caused a head rot in the field
in early sumer in northern Indiana. The vrevalence and severity of this
disease appeared to be due to the frequent heavy rain (see rainfall map,
figure 1. he loss is estimated at 54 by C. T. Gregory and R. C. Baines.
Fusarium oxysporum f. conglutinans (yellows). Between a trace and 5%
of yellows-affected plants occur in most fields. Resistant verieties are
usually grow. The tees loss is aacaalee to be 24 by C. @. Gregory

and R. C,. Beines, :

Plasmodiophora brassicae (clubroot). In 2 fields in northern Indiana
approximately 75% of the plants were infected, resulting in 50% loss.
The estimated loss for the State was a trace. -- C. T. Gregory and: Re iGs
Baines. : 3

Xanthomonas campestris (black rot). A trace occurred in a few of the

a
fields observed by\R. CG. Baines and'@.°T. Gregory.

BRASSICA PEKTi YSIS, CHINESE CABBAGE 3

Xanthomonas campestris (black rot). In a half-acre planting near
Indianapolis 15% of the plants were infected severely. The average loss
from this disease for the State is about 1%. -- C. T. Gregory.

CAPSICUM FRUTESCENS, PEPPER

Xanthomonas vesicatoria (bacterial spot). In a few fields this disease
reduced the foliage by 5%. The average loss in yield (including fruit
infection) was about 0.5%. |

Mosaic (virus). In a few plantings 50% of the olants were infected,
and the average loss in yield in the State is estimated at 5%.

Sun scald (nom-perasitic). The: loss of fruit from sun scald is esti-
mated at 10%. -- C. T. Gregory and R. C. Baines.

P13

CICHCRIUM ENDIVIA, ENDIVE
Aster yerrens Ete occurs in nearly all plantings and the loss is
estimated at 5%. -~ C. T. Gregory.

CITRULLUS VULCARTS, WATERMELON

Alternaria cucumerina (leaf blight) occurred in most plantings and
slight defoliation and 0.2% (estimated) reduction in yield. -- R. C.
Baines and .C. T. Gregory.

Colletotrichum lagenarium (anthracnose). Slight to moderate infection
of the leaves occurred in most plantings. Severe infection of tne fruit

cccurred Jate in the fall in nortnern Indiana. The average estimated

Loss from anthracnose was 0.5%. -- R. ©. Baines.
Fusarium oxysporum f. melons (wilt). A trace occurred in occasional
plantings cf susceptible varieties. -- R. C. Baines and C. T. Gregory.

Pythium sop. (blossom-end rot) occurred in all of the fields eianinee

and the estinated average loss was 5%.

CUCUF:IS MELO, CANTALOUP

Alternaria cucumerina (leaf blight) occurred rather generally over the
State and caused about 1% loss. es

Colletotrichum lagenarium (anthracnose). Slight to moderate infection
eccurred on the leaves in central and northern Indiana. In sovthern
indiana the reinfall was deficient during the summer and practically no
anthracnose was found in that area. It is estimated that anthracnose:
caused 6.2% loss for the State.

Erwinia tracheiphila (bacterial wilt) was of general occurrence in the
State and cavsed an estimated 5% loss.

Fusarium oxysporum f..melonis (Fusarium wilt). Ina few fields in
southwestern Indiana between 106 and 15% of the plants were infected
severely. — The Bes loss for the State was Sead to be C.l%. --
R. C. Baines and ©. T. Gregory.

CUCUMIS SATIVUS, CUCUMBER

Hrwinie tracheiphila (bacterial wilt) was of general occurrence in the
State. The percentage of piants infected in the different fields ranged
from 5 to 50,and the average estimated loss was 10%. -- R. C. Baines and
C. T. Gregory.

Heterodera jmarioni Beni). in occasional greenhouses nematcdes
caused approximately 20% loss. The estimated loss in yield for the State
was O. Libe =. T.,Gregory.

DAUCUS CARCTA, CARRCT
Alternaria carotae (leaf blight) was of general prevalence and caused
an estimated reduction in yield of 5%. -- R.. CS. Baines and C. T. Gregory.

IPOMOEA BATATAS, SWEETPOTATO

Actinomvces sp. (soil rot) occurred in 20% of the sweetnotato fields
in Indiana. In 15% of the fields only a trace was noted; however, in 5%
of the fields approximately 21% of the fleshy roots were infected. slight-
ly to moderately. Soil rot caused aoproximately 0.2% loss in yield and
quality in Indiana,

7 ~ . 3 5 * use ty BN
eat v ‘ 3 f 7 Soe :
’ » } y, y ‘ *f. is bal
y } i ‘ ey aes meinen : sea hitde ; ys
i ; bir od a) IS, 4 ms : ik Saha i
Cy Mie ie Sat oe
¢ »: \“%. f ae Wt : \

Ceratostomella. See Endoconidionhora. PRAT Slee Oe ea

Diaporthe batatatis (dry. rot) was found.in storage houses on an OC
casional root. This disease caused no appreciable loss in Indiena.

Endocconidiovhora fimbriata (Ceratostomella fimbriata) (black rot). A
trace of black rot was found in 10% of the fields at harvest, but none
was seen on rocts examined in storage during the winter. peas aro
yield in indiana from black rot was a trace.

Fusarium oxvs.orum f. batatas. Stem rot or wilt was the most serious
and widesores ad disease of sweetpotatoes in southern Indiana in 19/3. Tt:
occurred in 90% of the fields examined, and from a trace to 33% of the
plants were infected severely and killed or badly stunted, while the
yield from moderately infected plants was reduced about ian The aver
reduction in yield due to wilt in the State was about 10% .

Some sweetootatoes ai fected with fusarium surface rot were found in att:
lots exauined in storage houses during December, totaling about 0.5% of
the roots in storage. In occasional lots about Cy arena al swe eetnotatoées
were discarded because of surface rot. ;

Pythium ultimum (mottle-necrosis and ring rot). A trace of mottle
necrosis occurred on Yeliow Jersey sweetpotatoes in 10%. of the fields.

In storage oily a trace of ring rot. was opserved. ~ ;

Rhizopus nigricans (soft rot). In one lot of sweet potatoes stored in:
tight, poorly ventilated baskets approximately 3% of the roots were in- .
fected. The average was about G.5% of the sweetpotatoes in storage in-
fected. ae Pca:

Sclerotium bataticola (charcoal rot). Occasional roots infected with.
this fungus were found in storage. -- R. C. Baines

LACTUCA SATiVA, LETTUCE

Botrytis cinerea (gray mold). A trace was found on the first planting
in a few greenhouses. In subsequent plantings from a trace to 5% (aver-
age 0.5%) less occurred ih all of the greenhouses. -- C. T. Gregory and
H. CG. Baines.

Sclerotinia sclerotiorum (drop). In occasional greenhouses a few in-
fected plants were observed during December. -- R. C. Baines and C. T.
Gregory. ) |

Brown blight ? (virus aueabay Lettuce in 2 apnennetee at Tndian-
apolis and in 1 at Evansville showed from a trace to 3% infection with a
transmissible virus disease (R. “I. Samson, PDR 28(6):°203, Mar. 15, 19Ah):
that produces syinptoms somewhat similiar to the brown blight disease de-
scribed by I. C. Jagger (Phytopath. 30: 53-64, 1940). The affected plants
usually were not marketable. -- R. C. Baines, C. T. Gregory, and R. WW.
Samson.

“Aster: yellows (virus). An occasional infected plant was found in a

. greenhouse, near ivansville.. -- R. C. Baines

Mosaic (virus). Usually from 1 to 5% of the plants in époehhonnee are
infected with mosaic. However, the value of the infected plants was not
lowered and the disease apparently caused no loss. -- C. T. Gregory and
R. C. Baines. | fel ee

7

rats 0 ucla sch cl sik nt aes alias ae aa a kA reais Al Ra he el
via CA Ae ‘ * ;

175

LYCOPERSICCH ESCULENTUM, TChATO

Aiternaria solani (stem canker and early blight). Stem cankers on
recently transplanted tomatoes caused approximately 2% reduction in stand
and yield. Frequent rains during May and June in Indiana delayed plant-
ing and favored the development of this disease on the young plants. The
delayed planting in Indiana necessitated, in many cases, the growing of
the seedling for a longer time in the plant fields in the southern States
under crowded plant conditions, which are usualiy favorable for tne de-
velopment of collar rot or stem cankers.

During the growing season carly blight caused appreciable defoliation
in many fields and reduced the yield for the State about 3%. -- 2. W.
Samson and Rh. C. Baines.

Cladosporium fulvum (leaf mold) occurred in traces in about half of
the greennouses in Indiana. -- C. T. Gregory.

Colletotrichum phomoides (anthracnose). During August and Seotember
anthracnose of ripe, fiecld-grown fruit was particularly abundant in
central and northern Indiana. The loss of fruit and the reduction in
quality of the fruit produced amounted to about 2% for the State. --

R. Wis Sanson and R. C. Baines.

Corynebacterium michiganense (bacterial canker) occurred in traces
in.a few fields. The almost exclusive use of certified seed for. the
production of olants for the commercial canning acreage has zreatly re-
duced the prevalence cf this seed-borne disease. -- R. W. Samson and
R. C. Baiiies.

Fusarium oxysporum f. lycopersici (fusarium wit}. ...n-oceasional
fields from 3G to 40% of the plants were affected with wilt.. The aver-
age loss in yvicld caused by this disease in ficid-grown tomatoes in Indi-
ana is estimated at 2%.

In greenhcuses fusarium wilt resulted in losses up to 25% with an

estimated average loss of 1%. -- C. T. Gregory and R. C. Baines. :

Phytophthora parasitica (buckeye rot). A trece of fruit wes affected
by buckeye rot during 1943. In a few cases it caused from 30 t o 10%
loss of fruit in victory garden plantings. --.R. C. Baines and [Re ie
Samson,

Pseudomonas solanacearum (bacterial wilt) was particularly prevalent
on late-plantec transolants, which had been grown in the southern States
(see Alternaria solani). The percentage of plants infected ranged from
a trace to 60% and the average loss for the State was C.5%. -- R. ‘ie
Samson.

Septoria Il-coversici (leaf spot). A severe epiphytotic occurred
generally in Indiana, except for the dry southwestern corner of the State.
During August and September tomatoes were defoliatel50 to 90%, and it
was estimated that the yield and value of the fruit in the State was re-
duced 20%. -- x. ©. Baines and R. W. Samson.

Xanthomonas vesicatoria (bacterial spot). In central and nortnern
indiana the bacterial spot disease occurred on leaf-stems and fruit in
approximately 1/3 of the fields. The estimated average loss in yield for
the State was 1%. -- R. C. Baines and R&R. W. Samson.

Heterodera marioni (rootknot). A trace of rootknot occurred on toma-
toes ina few fields. The transplants used in these fields had been

grown in the southern States! -+ R. W. Samson. at =

In occaszonal greenhouses nematcdes caused from 3 a Le loss in yield.
The estimated avcrage loss of greenhouse-growm ee Wes Osl%. -=
Girt. Greg POR sig |

Aster yellows. (virus). A anes of the Serene: plants in a few fields
were infected with what is thought to be aster yellows. -- HR. \/. Samson
and R. C. Eaines. ;

Mosaic (virus), in field-grown tomatoes caused an average loss of Ge 5%
in yield for the State. -- R. W. Samson and R. C. Baines.

Between 30% and 5C% of the plants of the spring crop in most green-
neuses in Indiana were infected with mosaic. The average. estimated Loss
in yield was 5% -- C. T. Gregory.

Single-virus streak (virus). In one greenhouse establishiaent near
Terre Haute GC% of the early winter crop were infected scverely with
single-virus streak (caused by a strain of the tobacco mosaic virus) and
the yicld evidently was reduced from 10 to 15% in this BOBS ss Re” Gag
Baines, C. T. Gregory, and R. W. Samson. ~

‘ PHASEOLUS LUNLTUS , LIMA, BEAN. _ |

Xenthomonas phascoli (bacterial blight) was prevalent on lima beans
and frecucntly ebout 10% of the foliage was blighted. The reduction in
yield was probably 3 to 4%. -- C. T. Gregory and R. C. Baines. a

PHASEOLUS VULGA{IS, GREEN BEANS
Fusarium solani f. phaseoli (root rot). In many garden plantings
fusarium root rot caused a slight reduction in stand. The decrease in
yield during 1943 was estimated to be 0.2%. -- C. T. Gregory aid i. Us
Baines. ,
Xanthomonas ohascoli (bacterial blight) caused severe loss in wicld -
of an occasional garden planting; however, the average loss in yield was
a trace. -- R. C. Baines and C. T. Gregory. : 3

RAPHANUS SATIVUS, RADISH _ |
Aphanomyces raphani (black root). Radishes in the vicinity of Lafay-

ette frequently were affected severely. -- - C. Baines. |.
Pellicularia filamentosa (Corticiun vagum) 6tem rot). In greenhouses

ee ee eee

near Indianapolis, .radishes were infected hay ~~ C. T. Gregory.

SCLANUM iELCEGENA, EGGPLANT ais tay
Verticillium albo-atrum (wilt). In a few plantings from 50 to 90%

of the plants were infected. The loss for the State was estinatcd to be

1% of the yield. -- R. C. Baines and C. T. Gregory. Maat

SCLANU!: TUBBRROSUM, POTATO Rest
Actinomyces scabies (scab). Between 15 and 70% (average 33%) of the
“ potatocs grown on muck soil were affected by scab and approximately 4%
goon. of the tubers were infected severely (culls). It is estimated that the
bo reduction in grede and loss\of marketable potatccs amounted to 6% of
the of the value of the crop. -- R.-C. Baines and R. Y. Samson.
Alternaria solani (early blight) was prevalent during the sumer in ©

im. Fy} ier ete) ee oe y —

177

most fields but did not result in appreciable infection and defoliation
until fall. The yield was reduced about a trace. -- R. W. Samson and H.
C. Baines. '

Corticium. See Pellicularia.

Erwinia carotovora (bacterial soft rot) caused a trace of loss when
the potatoes were graded soon after digging. -- R. W. Samson and R. C.
Baines.

“Pellicularia filamentosa (Corticium vagum) (stem rot) was favored by
the cool wet weather following planting in the spring, and causcd about

2% loss in stand. -- R. W. Samson.
ee infestans (late blight) was prevalent on the foliage in
all late-.22 uring fields in northern Indiana. Ina few ficlds the vines

were blighted severely. However, the dry weather and soil during Scp-
tember appearcd to be unfavorable for the infection of the tubers and
the development of rot. In a few late fields from 1 to 8% of the tubers
were rotted. The estimated averege loss from late blight in Indiana was
C.2%. -— R. Cs Baines and C..T. Gregory.

Viruses (all viruses but chiefly leaf roll and spindle tuber). From
a trace to 1 to 2% of the plants were usually infected. The cstimated
average loss for the Statc was 0.2%. -- R. W. Samson.

DISEASES OF CEREALS, GRASSES, AND FORAGE CROPS

AVENA SATIVA, SPRING OATS

. Soring oats in Indiena generally were infected severely with Puccinia
coronata (crovm rust), which reduced the yield about 10%. Pyrcnoohora ~
avenae (Helininthosporium aveneec) (leaf hotels) was of generel occurrence
in Indiana. Usually infection was slight. It was estimatcd that leaf
blotch resulted in an average reduction in yicld of 0.5%. Ustilago
avenae (loose smut) and U. kolleri (covered smut) occurred in most fields
to some extent, and usually about 0.5% of the panicles were smttcd. It
is estimated that the average reduction in vield wes 0.5%. -- R. M. Cald-.
well.

HCRDEUM VULGARE, WINTER BARLEY

Gibberella zeae (scab). Barley, which is grown chiefly in the south-
ern half of Indiane, usually wes infected slightly with G. zcac. The
average estimated loss in yield from scab was 5%. -- R. ie Caldwell

Puccinia anomala (leaf rust). Berley was affected slightly with leaf
rust, and the yield was reduced a trace as a result of this diseasc. --
R. M. Caldvell,

Puccinia graminis var. tritici (stem rust). A trace occurred on bar-

ley and no adparent loss in yicld resulted from this disease. -- R. Me
Caldwell. :

Ustilago jensenii (covered smut) . A trace of infection resulted in
a trace reduction in yield. -- R. C. Baines.

Ustilago nigra and U. nuda (loose smut) generally occurred in moderabe
infections which reduced the yicld aoproxinately 2h. -- R. M. Caldwell.

. ores eee

178

MEDICAGO SATIVA, ALFALFA

Pseudomonas medicaginis (bacterial wey: From 10 to 20% of the
alfalfa plants in a number of fields in northwestern Indiana were in-
fected and killed.’ The actual, Loss" in hay was minimized by the cultural
practice of interplanting the alfalfa with timothy or some otner thay!
ErasSa, = fi. On F euce.

psec ue tee medicaginis (leaf spot) was abundant on the first cutting
throughout the State and on the second cutting in northern Inciana. The
estimated reduction in yield of the first cutting was 5 to 10%: -- BR. C.
Baines.

* (Secale 2 see below);
SOJA MAX, SOYSHA} sic

Cercospora ote (C. daizu) (frog-eye leaf spot) was prevalent in
central and southcentral Indiana. In this area from 70 to 10C% of the
leaves in a quarter of the ficlds were infected severely and tne yield
was reduced about 10%. A trace was observed in northern Indiena. South-
western Indiana was unusually cry and ee wore nearly free from lear
Spot diseases.:' The loss in yield from "frog-eye" for the State is esui-
mated at a trace. -- R. C. Baines and . T. Gregory.

Cercosporina kikuchii (purple spot of soybean seed). From 1 to 3% of
the soybeans in occasional fields in central and northern Indiana were ~
affected severely with the purple spot disease. There was no avparent
erap loss. =-- Rw,_C... Baines.

Diaporthe sojae (pod and stem blight). Very little of this disease was
observed in 1943. A trace was found in a few fields at harvest, but no
Significant loss resulted. -- R. C. Baines and C. T. Gregory.

Fusarium oxysporum f. tracheiphilum (wilt) was observed in 2 fields, and
apparently this disease.at present is not widespread in Indiana. In
Shelby County 1C% of the plants of the Manchu variety.in a siall variety
planting were killed prematurely and about 0.5% of the plants in a 20-acre
field in Hendricks County were killed. The loss for the State was a

traces, —=.G. 71. (Gregory, and hh. Cs<cBaines,.
Glomerella giycines (anthracnose). During September a trace developed;

chiefly on the stems, in most fields, but the disease resulted in little
or no damage as the plants were nearly mature at the time of its appear—
anes: ==_ Ho OL Barnes and CG. T. Gregouy.

Peronospora manshurica (downy mildew) occurred in about 60% of.the soy-.
bean fields examined. infection was especially abundant in central and
northern Indiana, and sparse in southwestern Indiana. Ina few fields
between 50 and 100% of the leaves were infected severely.: Considerable
etiolation of the’ infected leaf area occurred, but only slight necrosis.
The reduction in yield from most fields was a trace; however, in occasion-
al fields it appeared that the yield was reduced by 2 to 3% at least. --
R. CG. Baines and C. T. Gregary.

Sclerotiwna bataticola (charcoal rot). A trace was found in one field
in Sullivan County by C. T. Gregory.

Xanthomonas phaseoli var. sojense (bacterial pustule or blight). The
bacterial oustule or blight disease was very prevalent on soybeans in
central and northern Indiana, while in southwestern Indiana soyveans were
free from or affected by only a trace of this disease. Approximately 5%.

*SECALE CERGALE, RYE

A trace of Claviceps purpurea (ergot) occurred in 1943. Generally rye
was infected slightly ee Puccinia rubigo-vera var. secalis (leaf rust),
and a trace resulted. -- R. Mm. Caldwell.

_— |) =

yo

of the fields were nearly free from infection, 45% were affected slight-
ly, 30% moderately, and 20% severely. In the fields classed as moderate-
ly affected from 40 to 90% of the leaves usually showed moderate infec-
tions, while in fields that were severely affected from 60 to 90% of the
leaves showed severe infection. |

This disease induced little or no defoliation of the varieties grown
in indiana, but caused considerable yellowing and necrosis of the infec-
ted leaf area. In the moderately affected fields the yield probably was
reduced 1 to 5%; and in severely affected fields from 5 to 10%. Thus,

the yield 25 the State was reduced 3 to 4% by this disease. -- R. C.
Baines and ©. T. Gregory.

Mosaic (virus). A trace of mosaic was found in occasional fields. ==
R. C. Baines and R. W. Samson.

Streak or bud blight (virus). This disease is caused by the tobacco-
ringspot virus or a virus that has somewhat similar properties. The dis-
ease causes the abscission of biossoms and young: pods, the blasting of
beans in the pod, brown blotches arid streaks on the pod, mosaic symptoms
on the young leaves, and usually dark streaks in the pith of the inter-
nodes. Plants infected when still young mature few or no beans.

R. W. Samson observed this disease on vegetable soybeans in Indiana in
1941. He deterimined that the disease was caused by the tobacco-ringspot
virus (PDR 26(17): 382, Sept. 15, 1942). In 1942, Folke Johnson observed
the disease on field soybeans in Ohio, and confirmed the identification
of the causal virus (PDR 27(2):86-87, Feb. 1, 1943). During 1943, from
a trace to 1% of the plants in many fields were infected with streak in
Indiana. In occasional fields from 5 to 10% of the plants were infected.
The yield from infected plants ranged from none at all to 60% of that
from healthy plants, depending presunably on the stage of maturity of the
plant at the time of infection.

At this time not very much is know regarding the sources of infection
and the mode anda rate cf spread of the disease in soybean fields. The
development of this disease should be followed closely in the future and,
if necessary, iweasures taken to prevent any serious spread or increase. --
R. C. Baines and C. T. Gregory.

SORGHUM VULGARE var. SUDANENSE, SUDAN GRASS
Heliinthosporiun turcicum (leaf blight). Sudan grass was severely in-
fected and it was estimated that the feed value was reduced 30 to 40%. --

Re Os baines,

TRIFOLIU': PRATEKSE, RED CLOVER

Cercospora zebrina (leaf spot). Red clover generally was infected
moderately to severely with C. zebrina. The average reduction in yield
and quality of hay was estimated at 10%. -- R. C. Baines.

TRITICUM AESTIVUM, WINTER WHEAT

Gibberella zeae (scab) occurred in epidemic severity on wheat in Indi-
ana in 1943. ‘heat in the southern half of the State was infected severe-
ly and in a few fields a 50% loss in yield resulted. In the northern
half wheat was affected slightly to moderately and losses ranged from 1 to

1a,

21% (average 10%) of the grain. The average loss in yield and grade of
wheat due to scab was estimated to be 17% for the State. -- R. M. Cald-
well and. Rk, C. Baines.

Puccinia eraminis var. tritici (stem rust). A trace of infection and
loss occurred in south-central Indiana. -- R. M. Caldwell.

Puccinia rubigo-vera var. tritici (leaf rust) was moderate and es
ly distributed over Indiana. The average loss in yield and cuality was
estimated to be 5% for the State. -- R. M. Caldwell.

Septoria nodorum (glume blotch). Slight infection occurred in local
fields of wheat in southern Indiana. The loss was a trace. -- R. Me. Cald-
well.
Septoria tritici (speckled leaf blotch). Slight, fairly general infec-
tion occurred in Indiana in 1943. This disease was more prevalent than
usual and caused a trace of loss. -- R. Mi. Caldwell.

Tilletia foetida (T. levis), (bunt). A slight amount, of intecctxon.as
bunt occurred in occasional fields; the resultant loss was a trace reduc-
tion in yield. -- R. M. Caldwell

Ustilago tritici (loose smut) occurred generally over the State and
caused an estimated average loss of 5% in yield. -- R. M. Caldwell.

A root rot of undetermined cause occurred in occasional fields and was
serious especially in wet areas. The estimated loss was 1%. -- R. il.
Caldwell.

A trace of wheat mosaic (virus) occurred in limited and local areas. --
Re Mi, Caldwell,

ZEA MAYS, CORN

Bacterium stewartii (bacterial leaf blight). Nearly all of the corm
fields in Indiana were affected slightly or moderately with bactcrial
lear blight An occasional field was affected severely. It was esti-

res Oe

mated that iagees ranged from a trace up to 1% in severely affected fields.

-- R. Cs. Baines and A. J. Ullistruo.

Diplodia zeae (ear rot and stalk rot). Diplodia ear rot was less pre-
valent than normal. Between 1 and 3% of the ears in 16% of the fields
were infected, The estimated loss in yield for the State from this rou
was 0.2%.

Diplodia stalk rot was found in all of the fields examined and between
1 and 65% (average 27%) of the stalks were infected severely. This dis-
ease occurred late when the corn was dented well. Ina few fields in-
fection occurred when the grain was immature and caused a slight reduction
in yield... -~ BR. C., Baines, and A. J., Vlistrup.

Gibberella nee (fusarium ear rot) occurred in 84% of the ficlds.
Between 1 and 9% (average 2.8%) of the ears were infected slightly. The
loss in sound peck from this rot was estimated at a trace. -- R. C.
Baines and A. J. Ullstrup.

Gioberella zeae (Gibberella ear rot) was more prevalent than average
and was distributed generally over the State. From 1 to 4% of the ears
in 40% of the fields were infected. Approximately 0.8% of all the ears
were infectcd with G. zeae, which resulted in about 0.4% reduction in
sound corn,

ft appears likely that the increase in Gibberella ear rot over other

181

years was caused by the abundance of inoculum from scabby grain fields.--
R. G. Baines and A, J. Ullstrup. .

Helminthosnorium turcicum (leaf blight) was very severe on corn in the
east-central area of Indiana, and this area of severe infection was larg-
er than in 1942. Local fields in central and northern Indiana also were
infected severely, Severely blighted leaves were killed preiaturely and
resulted in inany chaffy ears; also, there was appreciable reduction in
the quantity and quality of fodder. No accurate estimates of decreases
in the yield of grain were obtained; however, it is believed that leaf
blight in severely infected fields reduced the yield by 10%, and for the
State 0.5% loss is probable. -- A. J. Ullstrup and R. C. Baines,

Hormodendron sp. (kernel rot). In occasional fields a black rot of
individual grains, caused by Hormodendron sp., occurred, There was no
appreciable loss in Ble from this disease. -- R. C, Baines and A, J.
Ullstrup.

Nigrospora sphaerica (cob rot) oecurred in 12% of the fields examined
and caused only § a- peace of reduction in yield for the State. -- R. C.
Baines,

Penicillium spp. (ear oor Penicillium rot nearly always followed ear-
worm injury and caused a trace of loss in most fields. -- R. C. Baines.

Physalospora zeae Stout (leaf and stalk rot). Sparse lesions ceused by
P. zeae occurred on leaves and at the bases of the tassels in occasional
fields in the southern half of Indiana. The imperfect stage, liacrophoma
zeae Tehon & Daniels, was found associated with the perithecia of P, zeae.
There was no anpreciable loss from this ches So - -- A. J. Ullstrup and
R, C. Baines, )

Physoderma zeae-maydis (brown spot). Corn in the Ohio drainage area
was infected slightly to moderatcly with P. zeae-maydis, but there was
no appreciable damage, -- A. J. Ullstrup and R. C. Baines,

Puccinia sorghi (rust). Occasional scattered fields throughout Indiana
were infected slightly to moderately, No apparent loss in yicld result-
ed. =- Rk, ©. Baines, :

Ustilago maydis (smut) was much less prevalent than normal and caused
no appreciable lcss. The maximum percentage of infected plants in a
field was 3. -- R. C. Baines and A. J. Ullstrup. .

Seedling blights (caused by Diplodia zeac, Fusaria, etc. ), eaused no
important losses during 1943. Corn planting was delayed oecause of wet
weather during May and the seed germinated and grew rapidly when planted.

Corn was injured severely by root worm in scattered areas of the State
and the injured plants frequently were affected by an undcteriined bac-
terial stalk rot. There appeared to be a close relationship between the
insect injuries and the stalk rot. -- A. J. Ullstrup.

DISEASES OF FRUIT CROPS

AMYGDALUS PERSICA, PEACH. In southern Indiana an occasional fruit af-
fected with brown-rot (Monilinia fructicola) was observed, The dry ©
weather during July and-August apparently was unfavorable for the develop-
ment of this disease. A trace of leaf-curl (Taphrina deformans) occurred,
In most orchards from slight to moderate becterial spot (Xanthomonas pruni)

developed on the fruit and leaves and caused a trace of loss” ‘in the *
State. -- R. C. Baines. .. =

FRAGARTA, STRAWBERRY. Mycosphaerella fragariae fear enoe ls Sera
berries in Indiana generally were infected slightly to moderatcly. Oc=
casional commercial fields of strawberries were infected moderately with
Phytophthora fragariae (red stele) and a number of home garden plantings
were infected, severely. Severely infected plants. produced fow or no
oo age es. -- R. C. Baines. fr

[ALUS SYLVESTRIS, APPLE. Giomerella cingultata. (bitter-rot). During
hen and August a few apples affected with bitter rot were observed ina
few orchards in southern Indiana. “This disease did not increase during
August and Sentember, evigene because of unfavorable moisture conditions.
The loss was a trace. pick

Gloeodes nomigena (sooty biokant: A trace to 1% of the ‘apne were af-
fected moderately with socty blotch in a few orchards in southern Indi -
ana, Tnere was no appreciable loss.

Gymnosporangium clavipes (G. germinale) (Schw. ) eet (quince rust).>
trace of Delicious apples infected severely with quince rust were ob-
served in a few orchards in southern Indiana. -

Gymnosporangium juniperi-virginianae (apple rust). From a trace to 5¢
of the leaves and fruit were infected with the apple rust fungus-in or-
chards in central and southern Indiana. The loss of fruit in the State
“from this disease was a trace. prs Pie

Helminthosporium papulosum (black pox). In one orchard near Seymour,
Indiana, Grimes Golden apples on a number of. old trees were infected
severely with Helminthosporium.papulosum.

Phyilosticta solitaria (blotch). In a number of orchards in southern
Indiana Dutchess apples-were infected severely. The loss in grade and
quality was estimated to have amounted to 3% of the vals of the crop.

. Physalospora obtusa (black-rot, frog-eye). On apples in Indiana frog-
eye leaf-spot was of general occurrence. Infection ranged from a trace
to slight and apparently caused a slight reduction in vield. ‘A trace of
fruit infected with P. obtusa was observed in all of the acne =
ined.

Venturia inaequalis (scab). Scab infection of apples’ was more severe
in 1943 than di during the past 4 years. The climatological conditions
during the spring were favorable for the epiphytotic development of this
disease in many orchards. Fruit infected with scab ranged from a trace
to 100%. The differences in the degree. of scab infection in the orchards
appears to be caused chiefly by differ neces in the amounts of primary ~~ 2@
ascosporic inoculum, and the timeliness and thoroughness that the appli= ~~
eations of fungicides were made. It is estimated that scab caused a 104%

loss of crop and a 10% loss in grade or value, total loss 20%. -- R. C.
Baines, ;
PRUNUS AVIUM, S'TEET CHERRY Coccomyces hiemalis (leaf-spot).
caused severe defoliation. -- se: C. Baines. |
PRUNUS CERASUS, SCUR CHERRY. Coccomyces hiemalis (leaf-snot). Sour
cherry trees were severély defoliated by €. hiemalis. -- R. 0. Baines. -
PRUSUS spp.,.PLUM.. Plus in Greene and Lawrence Counties were infec-

ted severely with C. prunophorae (leaf spot’) and defoliated soderately.
Xanthomonas pruni (bacterial spot) was severe on hybrid (Zurovean x
Americana) plums 1 near Lafayette. -- R. C, Baines.

183

— +) a.

RIBES SATIVUM, RED CURRANT. Mycosphaerella grossulariae (leaf spot):
Currant leaves in Tippecanoe County were infected moderately with slight
defoliation resulting. -- R. C. Baines.

RIBES UVA-CRISPA, GCOSEBERRY. Mycosphaerella grossulariae (leaf spot).
Gooseberries in Tippecanoe County, Indiana, were defoliated severely and
the yield and quality reduced possibly 10%. -- R. C. Baines.

RUBUS sp., RASPBERRY. Elsinoé veneta (anthracnose). During 1943,
the new raspberry canes were infected severely ‘with anthracnose. It is

estimated that this disease caused a 5% loss in crop. -- R. C. Baines.
Sphaeruvlina rubi (leaf-spot). Raspberries in Indiana were infected

severely with S. rubi and frequently were nearly defoliated in September.
The cron is estimated to have been reduced 5 to 10% by this disease. --
2. C, Baines.

Non-parasitic, low winter temperature. During the winter of 1942-1943
raspberry ‘canes were injured severely by low temperatures. in many cases
the injured canes produced new leaves, blossomed, and then died before
the berries matured. The injured canes frequently were infected by
Leptosphaeria coniothyrium. The loss of crop was estimated at 30 to 50%
(average 40%). -- R. C. Baines. .

VITIS: LABRUSCA, GRAPE. Guignardia bidwellii (black-rot). Grapes
that were not thoroughly sprayed were infected moderately to severely |.
with G. bidwellii. The losses ranged from a trace to LO% (average 10%).--
R. C. Baines.

DISEASES OF SPECIAL CRCPS

BETA VULGARIS, SUGAR BEET. Cercospora beticola (leaf spot) was com-
mon on sugar beets in northeastern Indiana and between 50 to 60% of the
leaves were infected severely. The loss in yield is estimated at 10%. --
R. C. Baines. : ES

MENTHA PIP@RITA, PEPPERMINT. Peppermint on the muck soils in northern
Indiana was infected from a trace to severely with Sphaceloma menthae
(anthracnose). The yield of oil-of-peppermint from the occasional severe-
ly infected ficlds was reduced approximately 50%, and the average reduc-
tion was estimated at 5%. -- R. C. Baines... --

WENTHA SPICATA, SPEARMINT. The second growth of the "Scotch! variety
of spearmint generally was infected severely with Puccinia menthae (rust)
in northern Indiana. The infection developed too late to affect the
yield of oil from the first cutting appreciably, but evidently weakened
the plants seriously and thus rendered them more susceptible to cold
injury during the winter.

Severe infection with Sphaceloma menthae developed on the second.
growth of the "scotch" variety in about. 75% of the fields in northern
Indianay -- 2. C. Baines. ~

18h

DISEASES OF CRNAMENTALS

ANTTRRHINUM MAJUS, SNAPDRAGON. Phyllosticta antirrhini (leaf spot)
occurred in an occasional greenhouse and caused a trace of injury.
Snapdragons in most greenhouses were affected with a trace or slight
amounts of Puccinia antirrhini (rust), which caused no appreciable
loss. -— C. I, Gregory. ry

Verticilliun albo-atrum (wilt). In occasional
greenhouses: in Indiana 5 to 10% of the Pia were infected with Verti-
ciilium albo-atrum. The loss for the State was a trace. -- C. T. Greg-
orys

CHRYSANTH Si UM sop., CHRYSANTHEMUM. “In occasional plantings out-of-
doors 50% of the plants were infected severely by Aphelenchus aus
(foliar nematode). -- C. T. Gregory.

Septoria chrysanthemella (leaf spot). Frequently from 5 to 10% of
plants outdoors were moderately infected. However, there appeared to be

only a trace of damage. -- C. T. Gregory and R. C. Baines.

Verticilliun albo-atrua (wilt). From C.5 to 10% of the plants fre-.
quently were infected. The average loss was about 1%. -- C. T. Greg-
Ory.

DIANTHUS CARYOPHYLLUS, CARNATION. Between 2 and 20% (average 5%)
the plants in a few greenhouses were infected by Fusarium sp. (branch
rot)... The. est:mated loss. for thesState was ‘14: — "rom 1 to 104 of. aae
plants in greenhouses were affected by Pellicularia filamentosa (Corti-
cium vagum) causing stem rot, end. the estimated average loss was 2%.

Uromyces caryophyllinus (rust) affected between a trace and 10% ot
greenhouse plants, mostly in moderate infections. The loss in the State
from rust was a trace. -- 0. T. Gregory.

GLADIOLUS so >., GLADIOLUS. Varieties such as Picardy appeared to be:
especially suscentible to corm rot caused by Fusarium oxysporum f.
gladioli. From/a trace to 20%, average 0.5%, of the corms were infec-
ved, ==. He. Baines and’ C.. 7. Gregory.

A trace of scab caused by Pseudomonas marginata was observed py C. T.
Gregory.

LATHYRUS ODORATUS, SWEET PEA. Cccasional greenhouse plantings of
sweet peas were infected siightly by Erysiphe - polygoni (powdery mildew)
which caused a trace of loss. Rhizoctonia solani (root rot) occurred
frequently on sweet peas in greenhouses 5 and usually reduced the stand by
10%. -- C. T. Gregory.

PELARGONIU:! spo., GERANIUM. Botrytis cinerea (gray mold) occurred
commonly on geraniums in greenhouses and caused a trace of loss. Pseudo-
monas erodii (bacterial leaf spot) was prevalent ‘ on geraniums in green-

185

houses. From a trace to 100% of the plants were infected moderately.
The average loss in value of the plants was estimated to be from ] to
2%. -- C. T. Gregory.

PHLOX spo., PHLOX. Erysiphe cichoracearum (powdery mildew) was pre-
valent on phlox and impaired the ornamental value of this. plant. --.R. C.
Baines.
>» ROSA spp. cult., ROSE. Roses in all of the greenhouses examined were
infected slightly to moderately with Diplocarpon rosae (black spot). It
was estimated that the disease caused an average loss. of 2%. Leotosphae-
ria coniothvrium (cane blight) occurred in most greenhouses and from 2 to
10% (average 4%) of the canes were killed. Sphaerotheca humuli (powdery
mildew) occurred in traces in all greenhouses but caused no anparent loss.
However, rambler roses outdoors were infected severely. -- C. T. Gregory.

TULIPA spp., TULIP. Botrytis tulipae (botrytis blight) was of general
occurrence and used 1 to 24 loss. -- R. C. Baines and C. T. Gregory.

PLANT DISEASES AND RESULTING CROP LOSSES IN ILLES 1943

R. C. Baines

This report was prepared in collaboration with G. H. Boewe of the
Iilinois State Natural History Survey, Section of Applied Botany and
Plant Pathology; H. W. Anderson, A. S. Cabby, Benjamin Koehler, ii. B. Linn,
and D. Powell, of the Illinois Agricultural Experiment Station; and Wi. B.
Allington, of the Division of Forage Crops and Diseases, U. S. Bureau of
Plant Industry, Soils, and Agricultural Engineering. Specific recogni-
tion for the information presented is made by name under each disease.

DISEASES OF VEGETABLE CROPS

ALLIUH CEPA, CNION
Phoma terrestris (pink root rot) appeared to be of general occurrence
on onions in northern Illinois. Frequently from 5 to 30% of the roots
were infected, The crop loss resulting was estimated to have been 1 to
2%. Very little infection by Urocystis cepulae. (smut) developed on
young onions in northern Illinois. Seed treatment appears to be effec-
tive in controlling this disease and generally is used. -- ij. B. Linn.

BETA VULGARIS, BEET

Cercospora beticola (leaf spot) was of Sa eas occurrence, usually in
moderate amounts. It appeared to cause a 4 to 5% average loss in yield.
-- li. B. Linn and 2. C. Baines.

BRASSICA OLERACHA var. CAPITATA, CABBAGE ;

Fusarium oxysporum f. conglutinans (yellows). In a few fields in
northern Illinois about 3C% of the plants were infected severcly and
failed to mature marketable heads. The average loss in the State from
yellows was about 1%, according to M. B. Linn.

Phoma lingam (black leg). A half-acre field near Peoria was a commutes

ci

‘ae
Lv
,

Say oR

i ee ee ee ee ee eee ee
Moor hat each cog roa dice SP a

“4 cs - iy My % < ; fy: fee Ta Ab eZ #0 k ie ; ve =
186 En Bae tn. ePoee eter Mer stir g a ty

loss due to black teen The average loss eaused in the State was a
trace. -- x. CG. Baines and M. B. Linn. |

CAPSICUM FRUTESCENS, PEPPER ©

Fusarium sp. (wilt). In an acre planting near Sterling, approximate-
ly 5% of the bell pepper plants were affected severely. The loss in this
field from wilt amounted to about 5%. For the State it was a trace. --
M. B. Linn and &. C. Baines.

Xanthomonas vesicatoria (bacterial spot). Fruit and leaves of bell
peppers in a 3-acre field near Rock Falls were slightly affected. The
loss from this disease appeared to be a trace. -- R. GC. cee and lie Be
Linn.

Tobacco 0saic Ea Approximately 5% of the bell ee Dlants in
a 3-acre planting near Rock Falls were infected moderately with the
tobacco-mosaic virus. The loss in this planting amounted to about 3%;
for the State it was a trace. -- M. B. Linn and R. C. Baines.

Blossom-end rot (physiogenic) occurred in all pepper plantings examined,
and resulted in an estimated 5% loss for the State. -- R. C. Baines and
ivan bak eae

CICHORIUi” DIVE 2 ENDIVE

Betrreen 3 and ay of the plants in a 1/5-acre planting near Tcoria were
infected severely with aster yellows (virus). The loss for the State
was a trace. -- M. B. Linn and R. C. Baines

CETRULLUS VULGARIS, WATERMELON
‘Colletotrichnum lagenari (anthracnose). Moderate to severe infection
of the leeves caused appreciable defoliation in most plantings. The
average loss caused by anthracnose in Illinois was between 5 and 10%.
Fuserium oxysporum f. mclonis (wilt). In a few fields near Havana-and
Thomas, from 25 to 90% of the vines were severely affected or killed by
wilt. The average crop loss from wilt in Illinois was 10%. —
es sp. (blossom-end rot) occurred in all of the ficlds cxamined
nd the estimated average loss was 10%. -- R. C. Baines and M. 5. Linn.

CUCUHIS BELO, CA“TALCUP are

Fusarium oxysporum f. melonis Cian “In a 5-aere field near Havana
approximately 2% of the plants were infected severely or killed by wilt.
The average loss in the State was a trace. -- R. C. Baines and H. B. Linn.

CUCUMIS SATIVUS, CUCUMBER pat he :

Erwinia trecheiphila (bacterial wilt) was of general distribution in
Tljinois and caused an estimated average loss of 3 to 5% in yicld. --
M. B,. Linn.

Z

CUCURBITA PEPO var. CONDENSA, SUMMER SQUASH

Choanephora cucurbitarum (blossom blight and fruit rot). In a garden
near Uroana, occasional’ young squash fruits were rotted by this organism,
according to li. B. Linn.

187

DAUCUS CARCTA, CARROT

From a trace to slight infection with Alternaria carotae (leaf blight)
occurred in most carrot plantings, and a trace of Cercospora carotae
(leaf blight) occurred in occasional plantings. In a few fields in Cook
County 30% of the plants were infected with the aster yellows virus; the

yield in these fields was reduced from 1 to 2%. -- M. B. Linn

IPOMOEA BATATAS, SWHETPOTATO |

Actinomyces sp. (pox or soil rot). Slight infection of from a trace
to 10% of the sweetpotatoes was noted in occasional fields. . Average yield
and grade was reduced a trace. -- R. C. Baines. |

Ceratostoiella. See Endoconidiophora.

Endoconidiophora fimbriata (Ceratostomella fimbriata) (black rot).
Sweetootatocs in a few fields at the time of digging showed from a trace
to slight amounts of black rot. However, in storage houses during Decem-
ber a few lots contained 30 to 60% of the roots severely affected, and
about 10% of the lots contained from 4 to 6% of affected roots... The
estimated average loss from black rot was about 1%. -- R. C. Baines.

Fusarium oxysporum f. batatas. (Stem rot or wilt) occurred in half of
the sweetpotato fields in southern Illinois. In occasional ficlds in
Union County 30% of the plants were infected severely or killed, In
about 10% of the fields, from 10 to 15% of the plants were infccted severe-
ly; and in 20% of the ficlds less than 1% of the plants were infected. - -
R. C. Baines ana G. H. Boewe.

Fusarium surface rot affected from a trace to 0.5% of the swectpotato
lots examined in storage houses during the latter part of Decomber. --

R. C. Baines,

Monilochactes infuscans (scurf). A few affected roots were found in
a_ftield an Union County. -- R. C. Baines.

Pythiuim ultimo (ring rot) caused losses in storage houses ranging from
0.5 to 5% and averaging about 1%. -- R. C. Baines.

Rhizopus nigricans (soft rot) affected from a trace to 1% of the stored
sweetpotatoecs. -- R. C. Baines. ©

Ssclerotiun bataticola (charcoal rot) was found on occasional sweet-

potatoes in storage. -- R. C. Baines.
fiosaic (virus). Most fields were free eran mosaic. <A few. infected
plants were found in one field in Union County. -- R. (C. Baines.

LACTUCA SATIVA, LETTUCE
Approximately 5% of the lettuce plants in an outdoor planting near
Rast St. Louis were infected with aster yellows (virus). -- li. B. Linn.

LYCOPERSICON ESCULENTUM, TOMATC

Alternaria solani (early blight). Tomatoes in most plantings were af-
fected slightly wit with the leaf spot, which caused a trace of reduction
in, yield. ~- R. C.. Baines and M. B. Limn.

Cladosporiwa fulvum (leaf mold). Tomatoes in a greenhouse near Ster-
ling were inoderately infected, with about 2% loss in yield. -- M. B. Linn.
Colletotrichum phomoides Ca achost) was moderately prevalent during

August and Sept ember on ripe ficld-grown fruit. Loss of fruit and re-

: : “e yee indy + is fons why REALE
; ¥ i ars Me Se pe ¥ 4 Ween He Dar r ‘i
18 & m 7 cs 1 ‘ ; Neen My % x (Seis fee Nee my
“ , oe bere ye i,
: er eho ’ iy Et

“duction in quality was estimated to be between 1 and 2%. -- R. C. Baines
and M.B. Ginn. % | eve aue es ts
Corynebacterium michiganense (bacterial canker). eg Fo vohbueee:
affected with bacterial canker were observed in Illinois ia 1.94, Seas
By Bw Leon
Hise nion cefeponin eee Peace (wilt) was especially scrious in
mark: et-garden plantings of tomatoes, and between 1C and 30% of the plants
were infected scverely. In the acreage planted for canning about 1% of

the olants were affected scverely and produced little or no fruit. “in a
greenhouse near Bloomington approximately 30% of the spring crop was lost
as a result of fusarium wilt. -- R. C. Baines and M. B. Linn.

Phytoonthora parasitica (buckeye rot) affected 20% of “the friitk: on one
first. clusters to ripen in occasional early plantings. The Joss for the
olLare, Wasa” trace. =—M, B. Linn, . ue

Septoria lycopersici (leaf spot) caused moderate to severe defoliation
during Aug ust and September in central and northern Illinois. The aver-
age loss in yicld was estimated at 5%. -- R. C. Baines and ii. B. Lim.

Aster yellows (virus). An occasional tomato plant was ge oe
aster yellows during 1943. -- M. B. Linn and R. C. Baines. Aesth

Mosaic (virus). Tomatoes grown in the field and in greenhouses fre-
quently were infected with mosaic. This disease was very prevalont on
tomatoes in victory a The average loss in rk is estimated ate

1%. -- Wi. B, Linn and R. Cy Baines.
In occasional greenhouses between a trace and 1% of the eee plants
were infectcd with the cucumber mosaic virus. -- M. B. Linn. SUR

Leaf roll (physiogenic). Tomato plants in victory gardens, and. especial-
ly staked plants, frequently were affected scverely with this. non=para- |

sitic disease according a x B. Linn. sa 12s 1 ga

PHASEOLUS LUNATUS , LIMA BEAN 4

‘Gerticium,. .Sec Pelliculariay:

Fusarium solani f. phaseoli (root rot) occurred in traces in most - ima
bean plantings. -- M. B. Linn.

Fusarium sp. (d0d rot). In commercial ficids in northern Illinois be-
tween 1 and 24-of the pods that were in contact with the soil were rotted

by Fusarium so. -- M. B. Linn and R. @3 Baines. __ | : |
Pellicularia filamentosa: (Corticium vagum). Bow oiaeine were infooten
and kilicd in most plantings. -- M. B. Linn.

Xanthomonas phaseoli (bacterial blight) caused 100% loss in a 30-acre ie
ficld of lima beans grown for canning in northern Illinois, The average
estimated loss for the State is 10%. -- M. B. Linn and R. C. Baines.® 9

Mosaic (virus) infeeted a few plants in most plantings, but no apprecta= ay
ble loss resulted. --'M. B. Linn and R. C. Beines. AM

PHASEOLUS VULGARIS, GREEN BEANS
Fusariui solani f. phascoli (root rot). Serious losses fren root rot —
were rather local although this, disease is widely distributed. in T1li-..
nois. A 5-acre fidd of carly-planted beans near East: St.Louis was in-
fected. severcly. and was abandoned. The avera Age Loss in the. Stato was. ae “ae
urace. ~<UMiy: Be ohanme Aieeutenk Ue Dr NS :

a a
~ sh oe ad

189

Pseudomonas medicaginis var. phascolicola (halo blight) occurred in
traces in occasional plantings of green beans. -- M. B. Limn.

Xanthomonas nhascoli (common bacterial blight) was scvere in occasional
plantings; howcvor, most plantings were free or showed only a tracc. The
loss for the State was.a trace. -- M. B. Linn and R. C. Baines.

Mosaic (virus). Plantings were free from mosaic or only occasional
plants were affected. -- M. B. Linn and R. C.’ Baines.

PISUi SATIVUM, PEA

Aphanomyces cuteiches (root rot) occurred in trace amounts on peas in
victory and home gardens. Mycosphecrella sp. (blight; Asochyta leaf and
pod spot) occurred in traces in occasional plantings. Seed decay and
post emergence damping-off, of undetermined cause, frequently resulted in
serious reductions in stand of peas in garden plantings. -- ii. B. Lim.

SCLANUM MELCONGENA,. EGGPLANT

Phomopsis vexans (fruit rot). In a market-garden planting near Rock
Falls, 25% of the fruits were infected severcly and rotted by P. vexans.--
M. B. Linn and:R,- €.. Baines.

Verticillium albo-atrum (wilt) was of general occurrence in Tilinois
and from 5 to 100% of the plants usually were infected severcly or kill-
ed. The average estimated loss from wilt was 40% of the yicld. -- R. C.
Baines and M, B. Linn

SCLANU:!: TUBERCSUM, POTATO

Actinomyces scabies (scab). Potatoes in Illinois usually were affected
slightly to moderately with scab. -- R. C. Baines, G. H. Bocwc, and M. B.
Linn, |

Erwinia phytoohthora (E. atroseptica) (black leg) was cspecially ser-
ious on carly-planted potatoes in the East St. Louis area, tice Peake
averege loss was 5%. The loss for the State was a trace. -- i. B.. Linn.

Phytophthora infestans (late blight). During the first half of Sceptem-
ber the foliage of potatoes in northwestern Illinois frequently was in-
fected slightly to severely with P. infestans. Late blight was especially
prevalent in Jo Daviess County and was more prevalent and scvere on un-
sprayed than on sprayed potatoes.

Very little rot developed on the tubers even in fields in which the
foliage was moderately infected. The dry weather during the latter part
of September and during October evidently was unfavorable for infection
of the tubers and the development of rot. -- G. H. Boewe, R. C. Baines,
and M. B. Linn,

Leaf .roll (virus) frequently affected 30% of the plents when common
seed wes used. It is estimated that leaf roll caused a reduction of 5%
in the yicld of potatoes in Illinois. -- M. B. Linn.

Hopperburn (leafhopper)., Leafhoppers were very abundant and caused
serious damage to potatoes in Illinois. It is estimated that in eat
gardens the yield was reduced 50% and in commercial fields 20%,
hopperburn, -- hi. B. Linn and G. H, Boewe

1: <

: AVENA SATIVA, ‘onrs

Puccinia coronata (crown rust) was very prevalent and severe during
1943. By harvest time, 100% of the oat plants were infected, except in
fields of resistant varieties. The infcction was especially severe in
the northern and western counties and in an area in the east-central and
south-central part of Illinois. From a trace to 41% (average 14%) of
the leaf arca of the plants was occupicd by the rust pustules. Fora
more detailed revort see PDR 27(17): 31,6- B47; AGS. |

Puccinia graminis var. avenae (stem rust). Cats generally were aftees
Led with) 4 ites to Pepe anounts of ‘stem rust, which apparently caused
an average loss of 1% in yield.

Ustilago avenae (loose smut) occurred in 80% of the 52 ficlds that
were examined in Illinois. From none to 14% (everage 3.2%) of the pani-
cles were smutted. The highest level of infection occurred in the 2
tiérs of counties. across the northern part .of Tllinois.. Phe everage
loss in .yicld from loose smut was about 1%.

Ustilago kolleri (U. levis) (covered smut) occurred in approximatcly
33% of the 5 at Tae that weru examined and in: amount s ~ anging from a.
trace to 9% (average C.6% of the panicles smutted). -- G. HE. Bogue.

HORDEUM VULGARE, BARLEY

Puccinia anomala (leaf rust). Barley generally was infected slightly
by PR. anowalea in Illinois during 1943. Between a trace and 7% of the
leaf area was affected by rust pustules.and 0.5% loss in yicld resulted,

Puccinia greminis var. tritici (stem rust) was light and occurred only
in the northern 2/3 of the State. It’ caused no apnea loss in yield.
er barley in 11 tLinois ain ogAa,

Ustilago jensenii (U. hordei) (covered smut) occurred only in the
southern third of Illinois, the winter barley region. The infection was

light and spotty. In one ficid 3% of the heads were smutted.

Ustilego nuda and other species (loose smut) occurred throughout une
nois in emounts ranging from a trace to 1%. -- G. H. Boewe.e

MEDICAGO SATIVA, ALFALFA

Cercospora: zcbrina (leaf soot) occurred generally, in slight ainounts:.

Pseudopezize medic medicaginis and Pyrenopeziza medicaginis (leaf spots).
Usually alfelfa in Illinois.was affected slightly to moderatcly with

both of these leaf spot diseases and slight defoliation resulted. --
G. H. Boewe. |

SECALE CERBALE, RYE
Puccinia rubigo-vera var. secalis (leaf must} occurred as slight infec-
tions in most ficlds. Urocystis oc occulta (stem smut) was not observed in
Illinois during 1943. Ustilago tritici (loose smut) apparently did not
eccur in Illinois during 1943,+- G.JHo.Boeewe.

et eee Fn ee et ee ee a en ee

Yor ee ae eee

+ ae. ey we ie ve Leet Le een SS tia” ty es Ee
Me oe eo oe eee x 7}
Ps Beige Sigel S ae ,

191

SOJA MAX, SOYBEAN

Cercospora sojina (C. daizu) (frog-cye leaf spot). Soybeans in occa-
sional ficlds in southern Illinois were infected slightly or moderately.
Cnly a trece was observed in a few fields north of Urbana. The loss for
the State wes estimated at a trace, -- G. H. Boewo and W. B. Allington.

Dianorthe sojac (pod and stem blight). At harvest soybeans zencerally
were infected scoverély with D. sojac. However, infection occurred late
in the develosment of the soybeans and caused slight reduction (C.5%) in
yicld. -- iJ, B, Allington, G. H. Boewe, and R. C. Baines.

Glomerella glycines (anthracnose). During the fall soybeans in occa-
sional ficlds vere infected slightly; however, the seeds were well-matured
at the timc of infection and the yield apparently was not impaired. --

W. B. Allington and R. C. Baines.

Peronosz0re manshurica (downy mildew). Soybeans in Illinois were af-
fected slightly to moderately with downy mildew. - The vericty Illini ap-
peared to be very susceptible. The average estimated rcduction in yield
was a trace, ~-- W. B. Allington, G. H. Roewce, and R. C. Baincs.

Xanthomonas phaseoli var. sojense (pustular spot). All of the standard
varicties of soybeans in Illinois were infected slightly to moderately
with X. phascoli var. sojense which very likely caused a 3 to 4% reduc-
tion in yicld. -- W. B. Allington, G,. H. Boewe, and R. C. Baincs.

Mosaic (virus) infected from 2a trace to 2 or 3% of the plants in many
ficlds. -- %. B. Allington and G. H. Bocwe. :

Streak or bud blight (tobacco ringspot virus) was distributed widely
in Illinois. Usually about 1% of the plants were infected, but in oc-
casional ficlds in central Illinois 5C% cf the plants showcd scvere symp-
toms of this discase and the yicld was reduced approximately 25% in these
ficlds. The everage estimated reduction in yield from bud blight in
Illinois was 1%.

_, Streak or bud blight is a discase of apparently recent occurrence,
which is capable of causing serious crop losses. Occurrence of the virus
on soybean was first reported from Indiena in 1941 by R. W. Samson (see
above, page 179. During 1943, this disease of soybeans wes widespread in
Hitinois and Indiana. Little is known concerning infection sources or
metnod or rate of dissemination and the disease should be watched closely
to prevent possibdle serious spread. -- W. B. Allington, G. H. Boewe, and
R. ©. Baines.

“ildfire, a bacterial disease caused by an undetermined orgenism, oc-
curred in scattered fields over the State. In many fields the infection
was slight, and cither general or occurring in small local arces. In one
ficld soybeans in 2 small area were infected severely. The loss from
this disease during 1943 was slight. -- 'Y. B. Allington and G. H. Boewe.

TRIFCLIUE | RATENSE, RED CLCVER

Cercospore ze prina (leaf spot) occurred generally in moderate to severe
infeetions, the average reduction in yicld and quality of the hay bcing
estimated -t 10%. -- R. C. Baines.

TRITICUM AESTIVUM, WHEAT
Gibberclla zcae (scab) occurred in epidemic severity on wheat in T1li-

nhois during 1943. In the northeastern part between 6.5 and 2.9% (aver-

age 1.9%) of the wheat spikelets were infected with G. zeae. In southern

-in the central end southern Tllinois arcas. Losses in yicld from leaf
blight verica from a trace to possibly 2h -- B. Koehler, R. C. Baines,

oS

and eastern Titinens from 0, Pi FON of coh Or ag) of ‘tho , epleneee!
were infected severely. Sceab was espe cially sévere in the large central
part of the State, and losses in yield in this area ranged from 3 to 1%
(avernge 11%). For.a. more detailed report see PDR 27(14):271, 1943.

Puccinia graminis var. tritici (stem rust). Wheat throughout most of
Illinois was infected very slightly. In most fields. from 60 to 100% of
the -culms | were affected with a trace to slight stem rust at hervest. —
However, in one ficld in Whiteside County and one field in Fulton County
9.7 and 8.0% of the stem area of the upper internodes were affected by
rust, respectively. The infection in the State as..a whole was eos and
thc loss was probably 1%.

Puccinia rubigo-vera var. tritici (leaf rust) occurred in all of the
ficlds exemincd, and from a trace to 26% (average 9.3%) of the leaf area
of the plents was: destroyed by the rust pustules... The rcduction in yield
possibly was ee proportional to the leaf area destroycd. Sce also
PDR 27(17): 346, 1943.

Tilletia pos da. (T. levis ) (bunt) occurred in only 2 of the 41 fields
of wheat that were examined in Illinois during ee In tuese 2 ficlds
G29 and: 2% of tho heads were smutted.

Ustilago tritici (Loose smut). Infection: was general and slight belies
most of Tliinois, except in2 small areca in the east-central art,
which the level of infection wes much higher than in the romeinder af the
State. . The percentage of heads smutted and the loss ‘in -yicld ranged
from none ito 27% and averaged 2.6%. For detailcd information regarding
the amount of loose smut in aifter ent areas of Illinois sce PDR 27(17)
343, 1943. -- G. H. Boewe.

ZHA MAYS, CORE ae
Asvergillus sp.-(ear rot). An occasional ear infected with Aspergillus
sp. occurred: in about 8% of the fields examined. -- G. H. Boewe and R. C.
BPI Sh: ne, :
Bactcriun stewartii {bacterial wilt, bacterial leaf blight). Generally
the carly-plented sweet corn was affected slightly by wilt. The amount
of inoculun wes low in the- spring, because of low winter tempcrature, but
increased during the summer end caused severe leaf blight of ficld corn

and G. H. Boece.
Cephalosvorium acremoniun. ue other causes (black ‘rites Corn -af~
fected with the black-bundle disease or exhibiting a somewhat similar —
diseased condition occurred in 43% of the fields. This discase was espe=
cielly prevelcnt in southern Illinois and corn in a few ficlds was’
ly damaged. The average loss in yield for the State was about 5%. -
G. H. Bocwe, R. C. Baines, and B. Koehler. Sy
Diplodia zcac (stalk rot and ear rot). Diplodia. stalk. rot occurred
n all ficlds examined and ranged from 1 to 71% of the stalks infected
severely. Infccted stalks in most fields had produced ears with well-
matured grain. However, grain produced on infcctcd plants appcared not
to be quite so well filled as that produced by apparently healthy plants. 4
In some ficlds ‘losses of 10% in yield occurred, and the average estimated 5

193

loss was 4%.

Dinlodia cer rot oecurred in 46% of the fields examincd and up to 5%
of the cers wore infected. The average loss in yicld for the Stete was
1.5%. _ The nercentage of ears infected with D. zeae was.less than occurs
in most years and it appeared that the low rainfall during Scptember and
October was unfavorable for the spread and development of this rot. --

Ge ou. Bocwe,~H. C. Baames; and B. Kochler.

Fusarium spo. (fusarium ear rot) occurred in all ficlds oxemined and
on 12% of the cars. This rot usually followed car-worm injury and gen-
erally only the tips of the ears were affected. The estimatcd average
loss in yiclda was 1%. --G. H. Boews, R. C. Baines, and B. Kochler.

Gibberella zeae (Gibberella ear rot) occurred in 38% of the ficlds
and on 0.5% of the ears. The loss due to the ear rot and to stalk rot
was cstimated to be 1%. -- G. H. Boewe, R. C. Baines, and B. Kochlcer.

Helminthosvorium turcicum (leaf blight). From a trace to slight in-
fection occurred on corn in many ficlds. One field in Christion County
was severcly affected end: the yicld reduced about. 10%. The loss in
yield for the Stete was a’trace. -- B. Koehler, R. C. Baincs, and G. H.
Boewe.

Nigrosporea sphacrica (cob rot) eccurred in 19 % of the ficlds and on
0.6% of the cars. The estimated average loss in yield was 6.2%. -- G. H.
Boewe, R. GC. Baines, and B. Kochler.

-Penicilliua so. (ear rot) occurred in 87% of the fields, on 6% of the
ears. This rot usually followed ear-worm injury and generally occurred
at the tips-of the ears. The estimated avcrege loss in yicld was C.2%.--
G. H. Boewe, Rk. €. Baines, and B. Kochler.

Puccinia sorghi (rust). Gccesional scattered ficlds in northern [11i-
nois were infected slightly to moderately. No apparent loss in yicld
resulted. -~ Rs C. Baines and G. H. Bocwe.

Pythium arrhenomanes and other fungi (root rot). Root rot was unusual-
ly prevalent on carly-planted swect corn and ficld corn and possibly
was faevorcd by the high soil moisture and low temperature during this
period. The root rot in many cases did not kill the plants, but caused
them to be barren. Many market-garden plantings were reodlantcd because
‘of poor stands and weakened plants. The cstimated reduction in yicld of
field corn wes 5%. -- B. Koehter. : .

Rhizopus nigricans (car rot). An occasional slightly infected car oc-
curred in 11% of th¢e ficlds examined. Thcre-was no apparcnt loss. --

G. H. Boewe end R. C. Baines. a tee ge

Sclerotium bataticola (charcoal rot). In occasional corn ficlds in
southern Jilinois from a trace to 26% of the plants were affected ‘sevcre-
ly with charcoal rot. The average loss in yicld in Illinois was a trace.

G. H. Boewe. 7

Ustilago imaydis (smut) was much less prevalent than normal. From none
to 15% (everage 2.5%) of the stalks were infected, usually slightly. In
50% of the ae between a trace and 9% of the ears were siutted. The ©
est.mated everage loss in yicld from smut was 1p. -—- G. H. Bocwe, R. Ce
‘Baines, and B. { ae.

19h | ate Bee ch
DISEASES OF FRUIT CROPS ge

AMYGDALUS PERSICA, PEACH. A ipa ice of Cladosporiua carponhilun em
occurred on peaches in southern Tllinois during 1943..-= D. Powell, G. baie
Boewe, H. .. Anderson.

Monilinia fructicola (Sclerotinia fructicola) (brown ae Blossom
blight wes severe in one planting of Red Bird peach trees in southern
Illinois and possibly also occurred in other orcherds. In most. orchards ~
in southern Illinois 1% of the fruit was affected by the fruit.rot. --

D. Powell, G. H. Boewe, and R.: Cs Baines.

Taphrina deformans (leef curl) occurred in trace amounts. -- G. H.
‘Boewe and D. Powell . , :

Xanthomonas pruni Wye cheraad spot). Moderate to scvere infection of:
peach leaves occurred in most orchards, resulting in 30 to 40% defolia-
tion in many cases. Approximately 10% of the fruit was. infected slights

y. =- D. Powell, G. H. Boewe, H.: Ws Andersons- and -R..G, Baines:

FR: RAGARTA, STRANBERRY. Strawberries generally were infectcd slightly
to moderatcly with Mycosphaerella fragariac (leaf spot), which did not
appear to cause any Avant reduction in yicld. Phytophthora fre-
gariae (red stcle) was very prevalent during the spring of 1943, cspe-
cially on stra bebeies planted on heavy poorly drained.soil. The high
rainfell during Mey apparently was f> vorable for its develooncnt. The
highly resistant varictics Pathfinder and Abérdeen were infecbod sede
ly to severely when plented on poorly drained soil infested with the or-
ganism.'-- A. S. Cdby. | |

WALUS SYLVESTRIS, APPLE. A traec of Erwinia smylovora (fire blight)
-eccurred on apples in Tilineis during 1943. -- H. W. Anderson end D.
Powell. ue

Glomerclla cingulata (bitter rot). Golden Delicious, ae Gouem
and Jonathen applcs in southern Illinois were infected severely. The
percentage. of fruits infected in different orchards ranged from a trace

to 100. The variations in the severity of bitter rot in.different orchards

apperently were caused by differences in the quantity of initial inoculum
present in the. ore ards and in the thoroughness and timeliness of fungi-
cidel applications: £6 control the disease. The estimated < overage Loss:

of fruit ccuscd by bitter rot in Illinois was 1%. -- He We Anderson, D..°

Powell, G. H.. Boewe, and,/R. C. Baines.

Glocodes pomigena (sooty blotch) affected a trace of the fruit in most
orchards. -~ R. C. Baines, D. Powell, and He vy, Anderson.

Eymosporens. aa clavipes (G. germinele) (quince rust). An occasional |
(trace) Delicious, Rome Beauty, or Winesap apple was infccted .severcly.--
H. W. Anderson, D. Powell, and.R. C. Baines.

Gymnosporangiun juniperi-virginianae (apple rust) was very severe in
local areas in southern Illinois in which cedar trees are numerous: and
rust nas been noted in the past. In one orchard that received sprays of
wettable sulfur from 90 to 100% of the foliage and 1/:% of the fruit OL
Jonathan trees were infected severely. The foliage and fruit of Rome
Beauty trees usually were infected moderately. The average estimated loss
for the State from apple rust was 1%. -- H. W. Anderson, D. Powell, Gs. H.
Boewe, and R. C. Baines. |

195

Phyllosticta solitaria (blotch) was severe on Duchess and Yellow
Transparent annles, which are pianted extensively in southern Illinois.
Blotch was also severe on the few Northwestern Greening and “Jinter Bana-
na trees that usually occur in the small orchards scattered over [ilinois,.
Between a trace and 100% of the fruit was infected severely, Ina few
presumably well-sprayed orchards 70% of the fruit was infected. The

-average estimated loss caused by blotch on these 4 very Spe ae la var-
ieties was 20%, -- D. Powell and H. W. Anderson.’

Physalosvora obtusa (black rot, frog-eye). Frog-eye leaf spot was of
general occurrence on apples in Illinois. Infection ranged from a trace
to slight and apparently caused a slight reduction in yield. Black rot
was more prevalent in southern Illinois than in the northern part. Ap=
proximately 10% of the Gano and 2% of the Jonathan fruit in southern
Illinois were infected. The estimated average loss from black rot in the
‘State was 3%. -- D. Powell, G. H. Boewe, H. %. Anderson, and R. CG. Baines.

Venturia inaequalis (scab) was more prevalent and severe during 1943
than normally. In poorly-sprayed orchards 100% of the leaves and fruit
were infected severely, and in well-sprayed orchards from a trace to 18%
of the fruit was infected. It was estimated that 15 to 20% of the fruit
was affected, and that the average monetary loss to the growers was 10%
of. the value of the crop. -- D Powell, G. H. Boewe, H. ‘YY. Anderson, and
R. C,. Baines,

PRUNUS CiRASUS , SOUR CHERRY. OE ee sour cherry trees were severely
defoliated by Coccomyces hiemalis (leaf spot) and trees that had been
sprayed to control the disease usually were infected and cefoltated
moderately. -- G. H. Boewe and R. C. Baines.

Cecasional fruits were infected with Monilinia fructicola (Sclerotinia

fructicola} (brown rot); however, no appreciable loss resulted, -- G. H.
boewe. | | |

*PYRUS CChSiUHIS, PEAR. A trace of fire blight (Erwinia amvylovora) oc-
curred on pears in 1943. -- G. H. Boewe.

RUBUS sp., BLACKBERRY. Occasional olantings of blackberries in south-
ern jilinois were infected severely with Gymoconia peckiana (G. inter-
stitialis) (orange rust). The Alfred variety aopeared to be very sus-
ceptible and the Eldorado highly resistant. -- A. S. Colby. 3 |

RUBUS sp,., RASPBERRY. Agrobacterium tumefaciens (crown gall) occurred
in most plantings of raspberries in Illinois. Usually the plantings
were infected slightly to moderately. Black raspberries usually were
more severely infected than red raspberries. -~- A. S. Colby

Elsinoé veneta (anthracnose). Young raspberry canes usually were in-

fected moderately to severely. -- D. Powell, G. H. Boewe, and R. C. Baines.

Raspberries generally were infected severely with Sphaeruline rubi
(leaf spot), which caused severe defoliation by early fali. The loss in
yield caused b, leaf spot was not known; however, it appears that early
defoliation weakens the plants and makes them more susceptible to injury
from low temperature. -- A. S. Colby and R. C. Baines.

- Virus diseases, chiefly mosaic. Occasional plants infected with mosaic
occurred in a few plantings. -- A. S. Colby.

VITIS spp., GRAPE. A severe outbreak of Cryptosporella viticola (dead
arm) occurred in the Tllinois Experiment Station vineyard at Urbana and

“i ef
Pe, Eee ee ee

Iliinois during 1943. -- D. Powell

196

in occasional vineyards over the State. The dicenae ain aeEls Jad beee!
spreading in the Experiment Station vineyard for abort 3 years. The
spring of 1943 was very favorable for the spread of the disease and
lesions occurred on the current year's shoots of the 56 varieties in the
vineyards. Differences in varietal susceptibility ogecurred. The dead
arm or dieback phase of this disease was not so aburdant or cvident as
the lesions on the new growth. See also PDR 17(12/13): 245- id -1943.

H. A. Anderson and A. S. Colby.

Grapes generally were infected moderately with Gui nipnaedia pidwellid
(black rot) in Illinois. -- H. W. Anderson, D. Powell, G. H. Boewe, R. C.
Baines, and A. S. Colby.

Very little Plasmopara viticola (downy wiidew Ev Stone on grapes in

| BLANT DISEASES IN TCHTGAN DURING 1943

M. R. wees

The weather in’Michigan during the first part of the 1943 season was
very unfavorable to agriculture. Rainfall was heavy and continuous for
much of the fore part of the summer. As a result crops were a month
late in starting and in many instances were not planted at all. The
acreage of some crops such as sugar beets was very drastically reduced.
As the summer advanced the weather improved and these crops that were
planted began to make a satisfactory growth. However frost in many parts
of the State was a week to 10 days earlier than usual and made the sea-
son for crops which freeze easily rather short. After a ccld beginning the
fall season was very favorable for the maturity and harvesting of crops
and such things as soybeans and corn dried out well. This resulted in |

|

a

better yields than ara been anticipated for most late crops»

—_

—

VEGETABLES

:
tant :
: .

ALLIUIi CEPA, ONION. ° Onions were not damaged by downy mildew (Perono- |
spore. destructor ) because the weather was too variable to permit devel-
opment of the disease. * Pink root (Phoma terrestris) did considerable e :

damage but came so late in the season that it did not reduce the crop.
There was considerable scald due to hot sun cooking the bulbs. Smut was
found but treatment of the seed at planting kept the fungus (Urocystis
cepulae) from doing much’ damage.

ARIU:: GRAVECLEES , CELERY." Celery was infected with early blight .
(Cercospore apii) and ey the State generally there was a 4% loss. Yel- —
lows (Fusarium o: oxysporum apii) (F. apii and F. apii pallidum) was not —
a factor in celery aoe te this year owing to low soil temperatures. —
Late blight (eras apii-graveoLentis) caused a 6% loss over the State
gencrally and was favered: by a wet cool season. Ae

BRASSICA CLERACEA var. CAPITATA, CABBAGE. Cabbage yellows (Fusarium
oxysporum f. conglutinans) was responsible for a 3% loss over the State

197

generally but the loss was greatly reduced by the use of resistant
varictics. In some fields where susceptible varieties were planted the
loss was total.

CUCUMIS i HELO, CANTALOUP. CantalLoups were severely infected with an-
thracnose (Colletotrichum lagenarium) in some fields and over the State,
generally loss. was 10%. In some fields the disease was partially con-
trolled by spraying. Macrosporium leaf spot (Alternaria cucumerina )
also caused a 10% loss. Traces of mosaic (virus) were found but no ap-
preciable damage -was caused.

DAUCUS CAROTA, CARROT. Carrots were as a rule a healthy crop but inthe
Detroit market garden area there was some defoliation:caused by leaf
blight: (Alterna: aria carotae) (Macrosporium carotae).

LACTUCA SATIV, Se LETTUCE Lettuce over tne state generally was severe-
ly affected with the aes yellows virus. There was a great prevalence
of the insect vector. Many fields were a complete loss and it is esti-
mated that for the State generally 75% of the crop was lost.

LYCOPERSICON ESCULENTUM, TOMATO. Tomatoes were adversely affected by
poor weather conditions earlier in the season. Early blight (Alternaria
solani) was present on plants imported from the southern states. Canker
(Corynebacterium michiganense) (Aplanobacter michiganense) was also found
on plants coming in from nurseries in the southern States. Anthracnose
(Colletotrichum phomoides) was severe in some fields causing damage to
the- fruit. It. reduced ae crop over the State erate) by 5%. Fusarium
wilt (Fusariun oxysporum f Lycopersici) caused a 1% loss. There were
traces here and there of iiiagsoncend rot (physiogenic) and mosaic and
spotted wilt (viruses). In the Victory gardens around Detroit blight
(Septoria lycopersici) was severe in spots and caused a 1% reduction of
the crop. a

PHASEOLUS VULGARIS, BEAN. Beans in some of the market gardens around
Detroit were severely infected with anthracnose (Colletotrichum lindemu-
thianum). About 2% of the total crop was lost. Bacterial blisht (Xan-
thomonas (Phytomonas) phaseoli and Corynebacterium (P.) flaccunfaciens)
Was severe on Black Valentine, Bountiful, and Plentiful varieties in
market gardens and reduced the crop by 2%.

SOLANUM TUBERCSUM, POTATO. The potato crop of Michigan was reduced
by scab Pictinomyces scabies) by approximately 10% last season, larly
~ blight (Alternaria solani) was not severe and caused a 2% reduction of
the crop. A trace of ring rot (Corynebacterium (Bacterium) sepedonicum)
was found in a few fields. Black leg (Erwinia phytophthora) (HE. atro-
septica) was favored by weather conditions and caused a 1% loss to the
crop. Traces of fusarium wilt (Fusarium oxysporum) also favored by
weather conditions, were noted. It is estimated that damage caused by
leafhoppers was sufficient to cause a 25% reduction of the crop. In some
fteids this insect caused a total loss. Late blight ‘(Phytophthora infes-
tans) was present in many fields but owing to variable weather conditions
‘during the latter part of the season it never became serious. The esti-
mated loss is only C.35% for the entire State although individual fields
showed as high as 80% loss. Scurf (Rhizoctonia solani) caused a 1% loss
to the crop. A trace of purple top wilt caused by aster yellows virus »
Was seen in one field. Traces of the virus diseases, leaf roll, mosaic,

ge SR

—_ . =
Sa te NALS ce ie elena
gs es Bani - reese tea

et) ay Sa
MRT etree ir

nore wanehuriea) at one time during the latter part of the season ap-

wera var. tritici) (P. ee ag by 2%.

198

spindle tuber, and yellow dwarf, were observed but these did no apprecia- —
ble damage.

FIELD CROPS

AVENA SATIVA, OATS.. A severe leaf rust (Puccinia coronata) infection
of oats reduced the crop by 20% during the past season. A iiichigan hy-
brid strain of high yielding qualities was severely affected by the rust
for the first time this season. Loose smut (Ustilago avenae) and covered
smut (Ustilago kolleri) ) (U. levis) each reduced the oat crop yield by
Cizs .

BETA VULGARIS, SUGAR BEET. Sugar beet leaf spot (Cercospora beticola)
caused a loss of 0.2%. The acreage of sugar beets in the State was
drastically reduced by poor weather conditions at the time of planting.
As a result various root-rotting fungi damaged the young plants and it is
estimated that the total damage from these fungi was 10%.

HORDEUM VULGARE, BARLEY. Barley head blight (Gibberella zeae) (G.
saubinetii) reduced the yield by 10%. Blotch (Helminthosporium sativum)
caused 0.5% loss. There was a trace of stem rust (Puccinia graminis) in’
some fields. Loose smut (Ustilago nuda) and covered smut (Ustilago
jensenii) (U. hordei) each caused a 0.1% loss.

MEDICAGO SATIVA, ALFALFA. Alfalfa fields were generally infected with
wilt and root rot (Corynebacterium insidiosum) (Phytomonas insidiosa) and
there is some loss each year in at least half of the fields in the State.
It is estimated that the yearly loss is 5%. Damage amount ing to a trace
is caused by leaf spot (Pseudopeziza medicaginis).

SOJA MAX, SOYBEAN. Soybeans in Michigan were planted late and con-
sequently matured late. Frost caught many late fields. A trace of frog-
eye spot (Cercospora-sojina) (C. daizu) was found in many fields. Ina
few fields a trace of pod and stem blight (Diaporthe sojae) was seen but
no damage was noted. :. Likewise anthracnose (Glomerella glycines) was
found on a plant here and there in a few fields. Downy mildew (Perono-

peared to be about to cause: some damage but never developed beyond a
trace in most fields. In many fields an occasional plant showing virus
symptoms could be seen but no seriously infected field was seen. Bac-
terial pustule (Xanthomonas phaseoli var. sojense) was by far the most
common disease seen and no field appeared to be completely free from it.
It is estimated that it caused a leaf fall reducing the crop by 2%.
TRITICULM AESTIVUM, WHEAT. Wheat head blight (Gibberella zeae) (G.
saubinetii) caused a 10% reduction in the yield of that crop. Stem rust
(Puccinia graminis) reduced the yield by 3% and leaf rust (Puccinia rubigo-

MISCELLANEOUS HOSTS |

FRUIT CROPS. Owing to restrictions on travel by the experiment station
staff, no very extensive observations were made on fruit diseases. It
was noted that brown rot (Moniliria (Sclerotinia) fructicola) and leaf

Lg

spot (Coccomycés hiemalis) each reduced the cherry crop by 10%. Brown
rot-was also severe on peaches causing a 10% reduction of the crop while
peach canker (Valsa Leucostoma) killed 5% of the peach trees. Apple scab
(Venturia inaequalis) was severe in many of the State's orchards and
caused a loss of 10% over the State generally.

MENTHA spp., MINTS. The growing ef mint croos is an imsortant indus-
try in tiichigan. Diseases cf mints may be serious. Anthracnose on
peppermint (Spnhaceloma menthae) was not severe but traces were present.
Winter-injury killed about 15% of the plants last winter when the snow
melted and a severe freeze followed. Wilt (Verticillium sp.) killed
about 5% of the crop. Rust (Puccinia menthae) is severe some seasons and
sthis year affected late cuttings. In one field it reduced the crop by
20% but generally was present only as a trace.

PICKA sp., SPRUCE. Among the forest-trees rust (Chrysomyxa cassandrae)
on spruce was very severe in many locations in tne north central part of
the State, On some trees as much as 30% of the needles were infected.

PLANT. DISEASES CBSHRVED IN WISCONSIN IN 1943

Edwin E. Honey and R. EF. Vaughan

VEGETABLE DISEASES

ALLIUM CEPA, ONION. Neck rot {Rotrytis sp.) was less important than
usual, owing probably to good weather at-harvest time. The usual scat-
tered traces of anthracnose (Colletotrichum circinans) were observed.
Smut (Urocystis cepulae) as usual, was scattered in distribution, being -
found only on soil long used for growing onions.

APTUM GRAVEOLENS,-CELERY. The usual slight amounts of early blight
(Cercospora apvii) and moderate amounts of late blight feepeore apii)
occurred. Stem canker due to boron deficiency is decreasing since srow-
ers have been ee Tne boron for its control.

ASPARAGUS CFFICINALIS, ASPARAGUS. Rust (Puccinia asparagzi) was of
slight importance, as usual. The resistance of the Washington varieties
is not complete.

BETA VULGARIS, GARDEN BEET. Leaf spot. (Cercospora beticola), although
less prevalent than usuai, was observed in various gardens, and in var-
ticular in Dane County and central Wisconsin where it was present but not
destructive during the August dry period. Scab (Actinomyces scabies) a
and damping-off (ihicactoni a and/or Pythium) were of the usual slight
-importance, Hore internal black spot due to boron deficiency was noted
than occurred during the preceding year, although boron for soil treat-
ment,is generally available to canners in affected regionse

BRASSICA Cai PESTRIS, RUTABAGA. A greatly expanded acreage planted to
rutabagas was accompanied by an increase in prevalence of black rot
(Xanthomonas campestris). Internal spot due to boron deficiency is being
eee ee by the use of boron in fertilizer and is decreasing in impor-
ance,

6h ek, Od ae

es ral

‘s. = oe a

5

‘5% a <<
Cent ea aa tLe ee ee
Phe sa See Tei a 2, ee

; ' j eek oe 4

i \ \ a OAS | wit

; ; f ‘ ,
200 5 Sy, . uh),

BRASSICA OLERACEA var. BOTRYTIS, BROCCOLI and CAULIFLOWER. Black rot
(Xanthomonas campestris) was noted to a slight extent as usual on both.
‘erops. Yellows (Fusarium oxysporum f. Cos EBACE SiS was of the usual

slight local importance on cauliflower.
| ee CLERACEA var. CAPITATA, CABBAGE. Leaf spot (teen cir-

cinans) (A. brassicae), yellows (Fusarium oxysporum fe conglutinans), and
black leg (Phoma lingam) were scattered in occurrence and of slight in-
portance to the crop as a whole, as usual. Dry hot weather favored the
development of yellows in the Racine area of southeastern Wiscoisin. —
Much more club root (Plasmodiophora brassicae) than usual was observed.
Black rot (Xanthomonas campestris) was more prevalent in some areas than
during the year before: The disease was conspicuous in the Outagamie
County area in northern Wisconsin, while less was noted in the vicinity
of Racine.- Host of this trouble is traceable to lack of rotation or to
use of plants from infected seedbeds. Bsa Wor

A mosaic (virus) that is being investigated by Dr. J. C. ‘ialker and-
his associates, occurred in scattered localities. ,

CAPSICUM FRUTESCENS, PEPPER. Bacterial leaf spot (Xanthomonas vesi-
catoria) was .scattered in distribution.

-CUCUMIS MELO, CANTALOUP. Scattered infections of leaf blight (Alter-
Aiea cucumerina) and downy mildew (Pseudopercnospor a cubensis) were
noted, but dry 7 weather prevented significant eam he reduction
in acreage planted to cantalouns gave a better chance for crop rotation
with a consequent decrease in amount of anthracnose (Colletotrichum
lagenariun) from the preceding year. Mosaic (virus) occurred in scat-
tered infections and was of slight importance as usual.

CUCUMIS SATIVUS, CUCUMBER. Leaf blight (Alternaria cucumerina) scab
(Cladosporium cucumerinum), anthracnose (Golletotrichum lazenarium), bac-
terial wilt (Srwinia tracheiphila), and angular leaf spot (Pseudomonas
lachrvmans) were of average importance or somewhat less. “Powdery mildew
(Erysiphe cichoracearum) was observed in Portage County. Mosaic (virus)

occurred locally in moderate amounts. In Portage County in central Wis-
-consin, frost injury that occurred in the early part of June when the
plants had about 5 leaves, was evident nme August as brown necrotic: areas
‘on, the leaf ‘edges. .

DAUCUS CARCTA, CARROT. Leaf blight (Cercospora carotae) was generally
distributed but was held in check by hot dry weather and only the lower

eaves were affected. Yellows (aster yellows virus) was general in oc- .
currence and of moderate importance.

LYCCPERSICC! ESCULENTUM, TOMATO. Early blight (Alternaria solani) and
leaf spot (Septoria lycopersici) were general in occurrence, but dry }
weather during the summer and also, in the case of Septoria, the increased ©
use of mulching, resulted in less loss than average. Dusting for control ~
is not recommended for Wisconsin conditions and little is done. Anthrac-
nose (Colletotrichum phomoides) appeared in scattered locations late in 4
the season. ‘silt (Fusarium o oxysporum f. lycopersici) was noted in a field ©
near a ereenhouse. Specimens of fruit affected by buckeye rot (Phytoph-
thora parasitica) were received from Polk and Taylor Counties in northern
Wisconsin Se ptember 1. A considerable amount of blossom-end rot (physio-
genic) occurred in the Racine area which was affected by drought; else- ~~
where, a reasonable amount of rainfall resulted in less blossom-end rot

201

than usual. |

Leaf mold (Cladosporium fulvum) was more prevalent on greenhouse toma-
‘toes than usual because of delay in heating the houses. Rootknot (Hete-
rodera marioni) was observed only in greenhouses.

PASTINACA SATIVA, PARSNIP. Leaf spot (Cylindrosporiun pastinacae) »
(Phvllacnora pastinacae), was observed in farm and victory gardens in
Dane and Columpia Counties. Yellows caused by the aster yellows virus
was reported from Door County.

PHASEOLUS VULGARIS, BEAN. . No disease was recorded as. very important.
The bacterial blights (Pseudomonas medicaginis var. phaseolicola and
Xanthomonas phaseoli), anthracnose (Colletotrichum lindemuthianum), dry
root rot (Fusarium solani £. phaseoli) (F. martii | phaseoli), stem canker
“(Rhizoctonia sp.), rust (Uromyces phasecli var. typica), and mosaic (virus)
were observed to occur in the usual prevalence or less.

PISUM SATIVUM, PEA. Root rot (Aphanomyces euteiches) is a very important
disease of peas in Wisconsin; it occurs generally where peas are grown
and affects all varieties. In 1943 an increase in prevalence from the
normai was due to the reuse of infested soil and to favorable wet weather;
however, there was less than in 1942, Wet weather also favored general
eecurrence and increased amounts of bacterial blight (Pseudomonas pisi),
and anthracnose (Colletotrichum pisi), and also the ascochyta blignts
(Mycosphaerella pinodes, Asco ochyta pisi, and A. pinodella), of which M.
pinodes was most important. Mo cases of fusarium wilt (Fusarium oxysporum

pisi race 1) (F. orthoceras var. pisi) were seen; since resistant
varieties are used where the soil is known to be infested this disease
has become unimportant. Fusarium root rot (F. solani f. pisi) also was
of slight importance and less prevalent than usual. Near wilt (F. oxy-
sporun f. pisi race 2), on the other hand, was more abundant than during
the preceding year. Powdery mildew (Erysiph polygoni), downy mildew
(Peronospora pusi.), and blotch (Septoria pisi) were of slight importance
as usual. The vi virus diseases mosaic and streak caused moderate damage.

SOLANUM MELONGENA,EGGPLANT. Occasional plantings of this crop were
noted. Dry weather held the blight due to Phomopsis vexans in check and
it caused very ieewLe Frule rou, occurring mostly asa leaf snot.

SOLANUM TUBEROSUM, PCTATC. Scab (Actinomyces scabies) is a major-dis-
ease of potatoes in Wisconsin, and in 1943 was even more imoortant than
usual, Dry weather while the crop was maturing favored its development,
and infection in some fields ranged up to as much as 85%; for the State
loss is estimated at 4%. The varieties Russet Rural and Russet Burbank
were resistant. |

A marked increase in amount of bacterial ring rot (Corynebacterium
sepedonicum) over the precedin ng year was evident. It is not generally
distributed in the State, occurrence, being limited to scattcercd locations.
Vine symptoms were obscured by the prevalence of late blight and hopper-
burn. Up to 50% field infection was observed, while the loss for the
State was a trace.

Late blight (ehykbowenons infestans), while less damaging than in 1942,

“was more prevalent than usual. Infection was general excépt in the
drought area of southeastern Wisconsin. Elsewhere in the State wet weather
until the latter part of June favored vine infection. Drought and high

‘
¥
aw
.. 4

Re HR, Se

(

og)
a Freht aad
ee tee

eS

- oa

Zi 1 eee >
ra cee ,
Pee AS ako
att “2

we

ha Oe Oe A»
7
ae

Si capa

OE aren

we a c
es

Sear
wih

| temperatures after June 20 checked the development of the disease, al- Pi
though in northern Wisconsin local rains resulted in some damage from —

Ge phytophthora) “were noted, while rhizoctonia (Pellicularia fila-

Rural, Chippewa, Katahdin, Sebago, and Warba, while Green Mountain and

spindle tuber were average in‘ prevalence, while less yellow dwarf was

Stee g

‘ye Net ae
ir tae a

amounts in scattered locations.

‘and caused a trace of loss. Much less sun scald developed than usual;

pebundant and severe.

202 . seme es ae tee Ata A)

5 sid

tuber rot. liuch more use was made of copper’ sprays and dusts than usual,
but the amount of spraying was limited by availability of machines. Re-
duction in yield due to ‘late blight amounted to 5%; tuber rot caused LS
loss, 4
Other diseases, of ae importance, that were more prevalent than usual —
were wilt caused by Fusarium avenaceum and silver scurf caused by Spondy-
locladium atrovirens. Loss from wilt was estimated at a trace.
Average amounts of early blight (Alternaria solani), and black leg.

ow (Cox ‘ticium vagum) was less prevalent than usual. These diseases
ordinarily are unimportant.
Of the virus diseases, mild crinkle mosaic was locally distributed and
caused moderate damage,~as:usual. Resistant varieties grown include

Triumph are susceptible. Leaf roll, spindle tuber, and yellow dwarf are
scattered in occurrence and of minor importance; in 1943 leaf roll and

noted than usual. Sebago and Katahdin. are susceptible to the curl type
of leaf roll, and Sebago is resistant to yellow dwarf. Spindle tuber is
prevalent in rundown stocks of Chippewa. ~

The increased application of sprays and dusts-resulted inj,less hopper-
burn due to leafhoppers than usually occurs. This trouble was most pre-
valent in the Uroue tsar southeastern part of the State. Loss was
estimated at G,5%.

Spindle sprout and sprain (both undetermined) were noted in te

Discoloration of tubers tone cooking (physiogenic) gevetai toa
less extent than usual. = eye :

Injury from frost occurring ‘before harvest was. spotted in cistribution

loss was practically none.

_ TRAGOPOGO!: PORRIFOLIUS, SALSIFY. Yellows caused by the aster yellows
virus was oovserved on salsify in Door County, where the disease was

DISEASES. OF CEREALS, GRASSES, AND FORAGE CROPS :

AGROPYRON REPENS, QUACK GRASS. Diseases observed are ergot (C laviceps
purpurea ) in Dane and Waupaca Counties; and powdery mildew (Erysiphe _
graminis), tar spot (Phyllachora graminis), and See ee (Puccinia Eat
graminis) which were all of general occurrence.

AGROSTIS ALBA, RED TOP. Leaf rust (Puc¢cinia rubigo tees and brown
stripe (Svolecatweenah graminis s) occurred generally.

AVENA SATIVA, OATS. Traces of loss were recorded from bacterial blight
(Pseudomonas ccoronafaciens),; crown rust (Puccinia coronata), stem rust
(Puccinia graminis), and loose and covered smuts (Ustilago avenae and U.

kolleri). The generally grow variety Vicland is resistant to both rusts
and both smuts.

203

BRO:US TIMERS, SMOOTH BRCME GRASS. Ergot (Claviceps purpurea) vas
observed in Dane and Waupaca Counties. Bacterial spot (Pseudomonas
coronafaciens var. atropurpurea), leaf scaid (Rhynchosporium secalis)
-and leaf spots caused by Helminthosporium bromi, Selenophoma bromigena,
and Septoria bromi, were general in distribution. |

CENCERUS PAUCIFLCRUS, FIELD SAND BUR. Head smut (Sorosporium synther-
ismae) was collected in Columbia County in August and September.

HORDEU!H VULGARE, BARLEY. Ergot (Claviceps purpurea) was abwndant in

regions where quack grass was present, and caused a trace of loss. Leaf
spot, stem blight, and head-blight due to Helminthosporium sativum and
H, teres were. severe, and the resultant loss is estimated at 5%. Loo

<=
~ se ww
smut (Ustilago spp.) caused a loss of 0.5%. Covered smut (U. jensenii

gramineum), leaf rust (Puccinia anomala), stem rust (Puccinia graninis),
or scorch (Rhynchosporium secaiis). 7

LINUM USITATISSIMUM, FLAX. Pasmo (Mycosphaerella linorum) (Sphaerella
‘linorum) caused a trace of loss; none was recorded from other diseases.

MEDICAGC SATIVA, ALFALFA. “During a survey in Cctober (PDR 27(21):

566, Oct. 22, 1943) the known range of bacterial wilt (Corynebacterium
insidiosum) in the State was extended northward. Indications were that
this disease and winter injury were the main conditions responsible for
dying out’ of alfalfa stands after 2 or 3 years.

Cf other diseases observed leaf spot (Pseudcpeziza medicaginis) was most
general, although yellow leaf blotch (Pyrenonsziza medicaginis) was more
severe in certain fields. Downy mildew (Peronospora trifolioru), leaf
spot (Pseudoplea briosiana), rust (Uromyces striatus) and yellows (leaf-
hopper injury) were also present. .

MELILOTUS spp., SWEETCLOVER. Stem blight and leaf spot (Cercosvora
meliloti}, blight (Mycosphaerella lethalis), downy mildew (Peroncsnora
trifoliorma), and root rot (Phytophthora cactorum) were less prevalent.
than in 1942.

PHLEUM PRATENSE,- TIMCTHY. Brown stripe (Scolecotrichum sraminis), stem
rust (Puccinia graminis var. phlei-pratersis), and stripe smut (Ustilago
striaeformis) were recorded. |

POA PRATEMNSIS, KENTUCKY BLUEGRASS. Claviceps purpurea,
inis, Helminthosporivum vagans and Septoria sp. causing Le
due to Puccinia poae-sudeticas and P. rubigo-vera, and st
Ustilago striacformis occurred in the usual amounts.

SECALH CEREALE, RYE. Traces of loss were recorded from ergot (Clavi-
ceps purpurea), anthracnose (Colletotrichum graminicolum), scab (CGibbe-
rella zeae), and stalk smut (Urocystis occulta). No loss was caused by
either stem rust (Puccinia graminis) or: leaf rust (P.. rubigo-vera var.
secalis).

SEEARTA spp., FOXTAIL GRASS. Leaf spot (Piricularia grisea) wes noted
on both S. lutescens, yellow foxtail grass, and S. viridis, green foxtail
grass. Head smut (Ustilago neglecta) occurred on S. lutescens.

_ SOQJA MAX, SOYBEAN. Nore downy mildew (Peronospora manshurica) was
evident than usual. Bacterial blight (Pseudomonas glycinea) caused damage
amounting to a trace on the crop cut for hay. Bacterial pustule (Xantho-
monas phaseoli var. sojense) occurred in the usual slight importance.

20) | . ae aly ee

Mosaic (virus) was Less prevalent than usual and caused a trace of loss,
At least 2 tynes,-a mottling type and a dwarfing type, were cvident.
Mendota was very resistant, vegetable Wee Sener ety were susceptible,
and EKtum was very susceptible. -

SORGHUi: VULGARE, SCRGHUM. Covered smut (Sphac selotheca be te caused
a trace of damage.

SCRGHUM VULGARE, var. SUDANENSE, SUDAN GRASS. Diseases recorded, all
of general occurrence and in the normal amounts, were anthracnose (Col-
wetooiehen graminicolum) , leaf blight (Helminthosporium turcicum), bac-

rial spot -(? seudomonas andropogoni), rust (Puccinia purpurea), and
Saas mut. (Sphacelotl Sphacelotheca sorghi).

TRIFOLIUM sop., CLOVER. Diseases occurred in about average amounts.
On red clover, ie pratense, powdery mildew (Erysiphe polygoni), northern
anthracnose (Kabatiella. caulivora), and black. stem (Phoma trifolii) are

most important, the last-named being especially severe in late summer and
early fall. iiinor diseases include leaf spot (Cercospora zebrina), sooty
blotch (Cymadothea trifolii), bacterial leaf spot (Pseudomonas eves eo)
ee trifoliorum), leaf spot (Stemphylium sarcineaforme), and rust
(Uromyces trifolii var. fallens). Stemphylium jeaf spot and rust are
most prevalent late in the season.

Sooty blotch occurs on white clover, T. oe as well as red one

TRITICUM AESTIVUM, WHEAT. Losses from leaf rust (Puccinia rubigo-vera
Wars _ftiticina ) and stem rust (P. graminis var. tritici) were estimated
at 5% and C.5%, respectively. Foot rot (Helminthosporium sativum), scab
(Gibberella zeae), bunt (Tilletia spp.), and loose smut (U Istilago + tritici }
caused traces of loss. :

ZHA MAYS, CORN. Information on diseases of corn was contributed by
P.-E. Hoppe. . :

Bacterial wilt (Bacterium stewartii) was of slight importance, as usual.

Har rots and stalk rots generally. were less prevalent than in 1942 or _
the average year. This was true.of. ear and stalk rot caused by Diplodia
zeae and by Fusarium sp., ear rot caused by Gibberella zeae and by Nigro-
spora sphaerica, and kernel rot due to Penicillium ssp. ~The low incidence
of Fusarium ear rot was associated with minimum damage from ear worm. Dry
conditions at the siiking period resulted in a minimum amount of ear in-
fection by Gibberella.zeae in the southern part of the State.

The seediing blight due to Gibberella zeae was of the usual slight
importance,

Incidence of rust (Puccinia sorghi) was average, the disease being’
generally distributed but causing little damage. "

Smut (Ustilago maydis) was less prevalent than usual. Certain sweet
corn varieties are more susceptible than others.

Losses from smut.were estimated at a trace to 1%; other loss estimates
were a trace each from Nigrospora ear rot and Gibberella ear rot.

ease?
test su:

205
DISEASES OF FRUIT CROPS

FRAGARIA spp., STRAWBERRY. Leaf scorch (Diplocarpon earliana), leaf
spot (Mycosphaerella fragariae), and blackroot associated with Low tem-
peratures occurred generally.

MALUS SYLVESTRIS, APPLE. Crowngall (Agrobacterium tumefaciens) oc=
curred to the usual extent in nurseries.

Fireblight (irwinia amylovora) infection was favored by the succulent
wood growth induced by favorable rains and more occurred than during 1942
or than usual. Wet weather in May and early June also favored the devel-

opment of apole rust (Gymnosporangium juniperi-virginianae) and scab
(Venturia ee ee and both were more severe than usual, although not
more prevalent than during the preceding year. Scab was the major disease
in all orchards. Ascospores were mature on April.28, which is later than
usual. The main period of ascospore discharge was from May 24 to June 4,
and infection was first noted June 8.

Black rot (Physalospora obtusa) occurred in the usual anounts, mostly
in old neglected trees in southern sections.

Dry weather at harvest time resulted in reduced amounts of the minor
diseases fly speck (Leptothyrium pomi), biétch (Phyilosticta solitaria),
and core mold (Alternaria sp. and Fusarium sp.).

Bitter pit (physiogenic) also was less troublesome than usual.

Frost damage from low temperatures at blossoming time was much less de-
structive than during 1942; the Loss being estimated at a trace. About

the average amount of winter-killing occurred.

PRUNUS CERASUS, SOUR CHERRY. Leaf spot (Coecomyces niemalis) is one
of the most important factors affecting production of this important
fruit crop in Wisconsin. During 1943 as in the preceding year, weather

_/favored its development and it was more prevalent than usual. The peak

of ascospore discharge was reached early, during blossom.
Favorable weather also resulted in above-normal infection by both brown

rot fungi, Monilinia laxa and. M..fructicola. The presence of M. laxa

in Wisconsin, where it was first observed in 1941, has been reported | by
G. Ws Keitt-et al. (Phytopath. 33:1212, Dec. 1943). ‘Previously this
fungus was not known to occur in this country outside of the Pacific
Coast area. Observations so far have been limited to Door County. The
spur blight caused by M. laxa was of great importance in some orchards

where as many as 75% of the s aes were killed. Early Richmond was more

susceptible than Montmorency. M. fructicola occurred locally, prinarily
as a blossom blight. In-some orchards 80% of the blossoms were affected.

Cherry yellows (virus), another disease of major importance in Viscon-
sin, increased in prevalence over both the preceding year and % une aver a Be
year.

Necrotic Peres (virus) is reported from Wisconsin for the eee time,
although it has been recognized as a distinct trouble since about 1934
but not well understood.

An increased amount of winter killing was related to poor leaf spot
control in 1942. Some frost damage was noted.

PRUNUS spp., PLUM. Scab (Cladosporium carpophilum) was less prevalent
than in both the preceding and the average year. Black knot (Dibotryon
morbosum) occurred in normal amounts. Although moisture conditions

206 a Rage NOTE DES I on Va mt ee . a cesta

early in the season favored brown rot (Monilinia fructd cols), ater eo
weather resulted in no more than average and less than in 1942. Plum
pockets (Taphrina pruni) occurred to the usual extent on susceptible
anericana olums. .Bacterial spot on the leaves (Xgathomonas pruni) oc-
curred in scattered locations. : -

PYRUS COMMUNTS, PEAR. Pears are not a commercial crop in ‘Tisconsin.
Fireblight (Bry rwinia amylovora ) and scab (Venturia pyrina) were both more
severe than usual. ae) iin ts:

RIBES GROSSULARIA, GOOSEBERRY. Rust (Cronartium ribicola) occurred as
usual; it is important. in connection with distribution on white pine.
Rust (Puccinia grossulariae) was more prevalent than usual; it occurs
locally and is most severe near marsh-grass. Anthracnose (Pseudoneziza
ribis) and powdery mildew (Sphaerotheca mor s-uvae) — occurred in the usual
amounts. : ¢ a

RIBES SATIVUR, “RED CURRANT. Rust (Cronartium ribicola) was scattered
in occurrence; it is of slight importance on red currant but serious in
connection with infection of white pine. It was also observed on eulti-
vated R. odoratum and R. nigrum, but it has not been observed on R. alpin-
um nor on ‘Viking currant. Antaracnose (Pseudopeziza ribis) was normal
‘in occurrence.

RUBUS spp., BLACKBERRY. Rust ne: a peckiana) is the limiting
factor. in blackberry growing; there was more than usual in 1943. Anthrac-
nose (Elsinoé veneta) also showed an increase in prevalence over nermal.
Crowngall (Agrobacterium tumefaciens) and mild mosaic Geese) occurred |
to the usual extent. On wild blackberry sooty blotch (Gloeodes pomigena)
and fly speck (Leptothyrium pomi) were noted.

RUBUS SpD-; Ee ee Anthracnose (Elsinoé veneta) was normal in oc-
currence, , Me ae

RUBUS spp. RASPBERRY. Cn black raspberry, anthracnose (HZlsinoé veneta)
occurred in average amounts. t was favored by wet weather early in the
season but dry weather prevailed from the latter part of June. aa

On red foe crowngall (Agrobacterium tumefaciens), spur blight
(Didymella applanata), anthracnose {Flsinoé veneta), orange rust (Gym-
noconia peckiana) (G. interstitialis) were of normal prevalence, as was
mosaic (virus)... eee ee

VACCINIU spp., CRANBERRY. False blossom (virus) is general in cran-
berry bogs. Leafhoppers,. the insect vector, were more abundant than in
1942 but control with pyrethrum prevented the development of more than
the average amount of false blossom, although there was more than in the
preceding year. Storage rots due to Penicillium spp. and other fungi
were average in occurrence,

VITIS spp., GRAPE. Dry weather at Meee. prevented black rot (Gui vig-
nardia bidwellii) from developing in more than normal amounts, and there
was less than last year. Downy mildew (P Plasmopara viticola) also was
normal in prevalence and less important fhan in Sard: Wild varieties
are susceptible to downy mildew.

207
DISEASES OF SPECIAL CROPS

BETA VULGARIS, SUGAR BEET. Tip root rot (Avhanomyces sp.) was less
prevalent than usual, an occasional rotted beet being observed ina few
Pci ds. sm

Leaf spot (Cercospora beticola) was much less important than usual. It
was severe in an occasionai field, but in most it- occurred in traces or
not at all. Dry weather late in the season and cool nights were not con-
ducive to its spread.

Root rot (Phoma betae) was of less importance than usual; traces were
observed in scattered fields. :

Crown rot due to-Rhizoctonia solani and Pythium sp., altnough more com-
mon in occurrence than usual, caused only slight loss. Ina few fields
damage to the roots was appreciable; elsewhere it amounted to only a,
trace. infection of petioies and leaves occurred very generaily but dam-
age was light in most fields examined.

Heart rot due to boron deficiency was iess troublesome than usual al-
‘though more was observed than in 1942. The condition appeared very late
in the seascii and became most prevalent in the dry southeastern part of the
State cast end south of Lake Winnebago. Late rains in most areas were un-
favorable to its development.

HELIANTHUS AKNUUS, CULTIVATED SUNFLOWER. Powdery mildew (Erysiphe
cichoracearum) occurred to the usual slight extent. Rust (Puccinia
helianthi-mollis) was generally less common than last year, except in
northern sections with greater rainfall.

NICOTIANA TABACUM, TCBACCO. Infcrmation on tobacco diseases was con-
tributed by James Johnson.

Much less blackfire (Pseudomonas angulata) than usual occurred in fields;
the disease was conspicuous by its absence except in one section in the
vicinity of Rio in Columbia County. It was rare in seedbeds also.

A new outbreak of wildfire (Pseudomonas tabaci) was found this year in
the northern tovacco district of the State, on isolated farms in Vernon
and Crawford Counties. Infection was heavy in some fields. Wecurrent
infection was noted in Rock County.

‘Black root rot (THielaviopsis basicola) occurred to the same extent as
last year, which is less than usual. The loss caused was estimated at 5%
from reduction in’ yield and 10% in grade. The use of resistant varieties
is very general.

Damage from mosaic (virus) was less than usual. The disease occurred
to some extent in most fields and high percentages of infection were ob-
served in scattered fields. Loss was estimated at 1% from reduction in
yield and 2% from lowered quality. Streak (virus) was of slight impor-
tance, as usual, although it was generally distributed and more occurred

than in 1942, High percentages of infection were noted on the borders
of occasional fields.

Potash hunger due to potassium Leaps was less damaging than usual.
This trouble is not important in relation to yield but the low potash

content reduces quality of the crop.

Brown roct rot (cause undetermined) was scattered in distribution.
There was a slight increase this year in the use of "sod fields" with
resultant brown root rot. As many as 50% affected plants were observed
in some fields. The reduction in yield was estimated at 1%.

No frenching (cause undetermined) was scen in 1943.

The crop was generally late in development. The cool wet spring de-
layed transolanting.

DISEASES CF ORN ANENTALS AND MISCELLANECUS PLAN TS ee

A comprehensive report on forest tree diseases has been given in piss
Plant Disease Reporter (28(6):172-180. Mar. 15, 1944).
AGRIMONTA sp. Pucciniastrum agrimoniae, rust, was common in Langlade
County in August.
ALTHAEA RCOSEA, HCLLYHOCK. Very few specimens of. Puccinia nave
rust, were seen in 1943. . 3 :
AMARANTHUS RETROFLEXUS, PIGWEED. Aibugo bliti, white rust and Gloeo-
sporium amarenthicola, anthracnose, were common during August in Green
Lake County and elsewhere. ;
ANTIREHINUL MAJUS, SNAPDRAGON. Puccinia antirrhini, rust, Serine as
usual in greenhouses, and late in the season in most gardens. . 5 .
ASCL#°TAS SYRITACA, MILKWEED. Yellows caused by the -aster yellows virus —
was observed in Door County. te | BMC:
ASTER MACROPHYLLUS, BRCAD-LEAF ASTER. Colcosporium solidaginis, rust, ~
was gencrally distributed and common in September. Septoria atropurpurea, -
leaf spot, was common on Madeline Isiand in Ashland County in September. ~
_ CALLISTEPHUS CHINENSIS, CHINA ASTER. A severe infection of Coleosporium™
solidaginis, rust, was noted in Langiade County. Fusarium oxyspcrum f. é
_ callistephi (F. conglutinans var. callistephi), wilt, was scattered in
distribution and less important than usual. Aster yellows (virus). was
generally distributed as usual. ia en ooh
CELASTRUS SCAWDENS, BITTERSWEET. Ramularia celastri, leaf SPC Mea
common in Columbia County. |
CHRYSANTHEMUM sp. a undetermined species: ‘Of Coleosporium was sent in
from Langlade County. Erysiphe cichoracearun,. pee mildew, was more
evident than usual. |
CONVCLVULUS sp., BINDWEED. Puccinia PEN Ng rust, was general and
_ abundant curing August.
: CORYLUS CORNUTA, BEAKED HAZEL. Gloeosporium coryli, leaf spot, was
scattered in occurrence. It was observed eoaneeee in Wood and Adams ~

mM Counties.

Ly | DAHLIA snp. Mosaic (virus) was scattered in occurrence and less im-
portant than usuai. Commercial growers pull out infected plants as soon

ge as symptoms are noted.

DELPHINIUM spp., LARKSPUR. Botrytis sp. ae blight was mobovanna
dant than usual owing to wet weather early in the season. Infection by
Pseudomonas delphinii, black ‘spot, was checked by drought almost as soon
ay: as it appeared. Rape ERI |
Be EPILOBIUM ANGUSTIFOLIUM, FIREVWEED. Pucciniastrum pustulatum, rust,
Bi was common throughout the State. It was noted cape cially ony sade ae.
Island in Ashland County.

GAULTHERTA PROCUMBENS, WINTERGREEN. Gloeodes pomigena, sooty blotch,

. and Leptothyrium pomi, fly speck, were general in occurrence. r
“a GLADIOLUS spp. Pseudomonas marginata, scab, and Septoria gladioli,. -

hard rot, were normal in 1 prevalence; scab was generally distributed while —
hard rot was noted in scattered locations. Xanthomonas gummisudans, bac=
terial spot, was more prevalent than usual in the local areas where it
occurred. Less mosaic (virus) than usually occurs was noted in scattered
plantings. A general increase, from the normal amount and from that

CO a ee
pais Pre a
ee onus th, tas

7 Lhe

4;

ain
i) i
>

>
<
ee

- ae

209

noted last year, of whitening due to thrips injury seems to be associated
with the reduction in the use of bichloride of mercury for treatment The
better growers will resume the use of bichloride if it can be obtained.

HELIANTHUS sp., WILD SUNFLOWER. Puccinia helianthi, rust, was collect-
ed in Marathon and Dane Counties in August.

IMPATTENS BIFLORA, JEWELWEED. Ramularia impatientis, leaf spot, was
collected. in Columbia County in August.

TRIS spp. Didymellina iridis, leaf spot, occurred in local arcas in
average amounts, although less than in 1942. Erwinia carotovora, root
rot, was scattered in distribution and less important than usual.

LILIUM spp. Botrytis sp. causing blight of regal lily (L. rcegale) was
favored by wet weather and more developed than usual although not more
than last year. Mosaic (virus) was not serious.

MENTHA sp., ‘ILD MINT. .Puccinia menthae, rust, was collected in Green
Lake County in August. Septoria menthicola, leaf spot, was collected in
September on Madeline Island in Ashland County.

PABONIA sp., PrECNY. Botrytis sp., blight, occurred to the same cxtent
as in 1942 which was more than usual. Wet weather in the carly part of
the season favored its development. Dry hot weather later in the season
reduced the prevalence of Cladosporium paconiae, leaf spot, and Erysiphe
cichoracearum, powdery mildew. Heterodera marioni, rootknot, was of the
‘usual slight importance in scattered locations.

POLYGONUM sp., SMARTWEED. Ustilago utriculosa, head smut, was collected
in Waupaca County in August.

POTENTILIA MONSPELIENSIS, CINQUEFOIL. Ramularia arvensis, leaf spot,
was collected in Green Lake County in August,

ROSA spp.e, ROSH. Agrobacterium tumefaciens, Be aT was local in
distribution, iereahinn being largely confined to greenhouse plants.
Diplocarpon rosae, black spot, was of less than normal importance, dry
weather at the critical period preventing the usual amount of infection.
Phragmidium sp., rust, was scattered in distribution as usual. ‘Wild type
rose varieties are susceptible. Sphaerotheca pannosa, powdery mildew,
occurred locally in the usual amounts. Rugosa varieties showed resistance;
Dorothy Perkins and Paul Scarlet were susceptible.

RUBUS PARVIFLORUS, THIMBLEBERRY. Septoria rubi, leaf spot, was collect-
ed on Madelinc Island, Ashland | ae in September.

SYMPHGRICARPOS ALBUS, SNOWBERRY. Glomerella cingulata, anthracnose,
was scattered in occurrence and less abundant than usual. Severe fruit
and leaf infection by Sphaceloma symphoricarpi, scab, was observed in
tit County in August.

*. TAGETES spp., MARIGOID. Yellows (aster virus) was observed in Door
County where yellows on asters was quite severe.

TARAXACUM OFFICINALE, DANDELION. Ramularia taraxaci, leaf spot, was
common in august. Sphaerotheca humuli var. fuliginea, powdery mildew,
occurred generally.

-TULIPA sp., TULIP. Botrytis sp., blight, was favored by wet weather in
the early part of the season and more occurred than normally. The usual
amount, in scattered locations, of breaking due to virus was. noted.

_* SYRINGA VULGARIS, LILAC. Microsphaera alni, powdery mildew, was
general in distribution and normal in prevalence.

Tan W. Tervet

Of possibly greatest interest in the plant disease situation in Minne-
sota in 1943 was tne development of large pustules of stem rust (Puccinia
graminis var. avenae Race 8) on the hitherto resistant oat varieties,
Vicland, Tama, etc., that derived their resistance from the Richland var-
iety. If race $ of P. graminis avenae increases in population in the 4
future, there need be little expectation that the oats of Richland parent— ~
age will have any advantage in stem rust resistance over the varieties such
as Gopher, hitherto grown in Minnesota. Stem rust was of little importance
on wheat and barley. A moderately heavy epidemic of crown rust (Puccinia
coronata) caused some reduction in yield but the intensity of the disease
was much less than in the heavy epidemic of i941.

An unusually heavy epidemic of the diseases associated with Helmintho-
sporium sativum and Helmirthosporium spp. occurred on barley. Seedling
blight and root rot were generai; heavy leaf and pee and head
blight reduced yields appreciably. Scab (Gibberella zeae) (G. saubinettii)
was heaviest in the southern part of the State. The pasmo disease, _ 4
(Mycosphaerella linorum) (Sphaerella linorum) of flax reached unusual de-
velopment, the most severe epidemic of this disease being recorded.

Late blight (Phytophthora infestans) on potatoes was less severe than in
1942 but was more prevalent than in most recent years. On rutabagas, leaf
spot (Alternaria brassicae) (A. herculea) was common, and many of the
roots in storage were infected.

Leaf-infecting pathogens were common on many hosts in 1943, bacterial
leaf blight on oats and barley being very conspicuous. Lack of critical
and experimental evidence on the losses resulting from most of such infec-
tions makes estimations of losses a matter of opinion.

VEGETABLE CROPS

BRASSICA CAMPESTRIS, RUTABAGA. Alternaria brassicae (A. erelileats
Alternaria leaf spot and dry rot. Alternaria leaf spot was common in north >
central section of the State. Dry rot of the roots was seen in warehouses —
in Beltrami and Pine Counties. Fusarium sp., dry rot, was seen only in i
one warehouse in Beltrami County. Phoma lingam , black leg, was not.
abundant and loss was a trace. Loss from Xanthomonas campestris (Bacterium

“"

4

ee

\
The writer acknowledges his indebtedness for the assistance given to
him during the course of the survey by E. C. Stakman, J. Jd. Christen-
sen.) Ma Be Moore, C.J. Hides Geri. Christensen, E. G. Sharvelle and
Miss L. M. Dosdall of the University of Minnesota.

i

ea ke

‘gampestre), black rot, was especially severe in. Pine POUnE Ys about 15%
being estimated,
BRASSICA OLSRACEA var. CAPITATA, CABBAGE. Fewer reports. ah Xanthomonas

campestris (Bacterium campestre), blackrot, were received in 19E3 than in
previous years, Loss was a_ trace, ak is average...
Only a trace of Fusarium oxysporum f. conglutinans, yellows, was seen.

“Most commercial varieties grown are resistant. Phoma lingam, black leg,
_ caused a trace of loss. Plasmodiophora brassicae, elubroot, is present
in the principal cabbage regions of the States i Loss of 1% in 1943 is
average. ; iN

CUCU.LS at CANTALOUP. Only occasional infected plants by Erwinia
tracheiphila) (Bacillus tracheiphilus), bacterial wilt, were seen. The
estimated loss from Colletotrichum lagenarium, anthracnose, of 2% is about
~ average but is less than for the.2 preceding years. The loss from Fusarium
oxysporum f. melonis (F. bulbigenum var. niveum f. 2) is about the same as
in previous years. Growers do not grow melons on land known to be. infected.
Loss from mosaic (virus) was limited to a trace.

CUCUMES SATIVUS, CUCUMBER. The estimated loss of 1% from Erwinia
tracheiphila), bacterial wilt, was about average. An average loss (5%)
was estimated from mosaic @rtrusk.

LYCOPERSICON ESCULENTUM, TOMATO. Colletotrichum phomoides, anthracnose,
appeared late in the season. Phytophthora infestans, Ss, Late blig zht, was -much
less prevalent than in 1942, only nly slight Loss occurring. yee lyco-

rsici, leaf spot, in the1943 epidemic again was heavy, an estimated lo loss
of 10% resulting. | 3

.Catface (non-parasitic) was seen most commonly in the vicinity of the
Twin Cities, near Owatonna and Faribault in Southern Minnesota. The high
soil moisture levels in the early summer of 1943 favored the. development
of leaf roll (non-parasitic). Mary inquiries were received | about. this
disease, but losses appeared to be siight.-°
. PHASEOLUS VULGARIS, BEAN. Less anthracnose (Colletotrichum Lindeimthi-
anum) was seen in 1943 and loss was negligible. Less bacterial blight
(due to Pseudomonas spp. and Xanthomonas spp.) developed in 1943 than in
the previaus vear.

PISUM SATIVUM, PEA. each blights (Ascochyta pisi, A. pinodella,
and Mycosphaerella pinodes), were noted. Very little Sur ; (Fusari ium oxy-
sporun f. pisi race 1) (f.. orthoceras var. pisi) was observed, for “ost
varieties grown are resistant. Near wilt (Fusarium oxysporum f. ioea.
race 2) (F. oxysporum f. 8) has been reported by canning companies as be-
coming increasingly important. Somewhat less poe blight (Pseudo-
monas pisi) developed than in 1942.

SOLANUM * TUBEROSUM, POTATO. -The prevalence of Actinomyces scabies, com-
mon scab, in 1943 was about average, the disease remaining as one of the
major potato problems in the State. A heavy epidemic of Alternaria solani.
early blight, on the foliage occurred generally throughout- the State, be-
ing most severe apparentiyv on the lighter soils in the northern part of
the Red River Valley. Occasional lots of tubers were heavily infected
with tuber rot but loss from this phase of the disease was slight. Rejec-
tion of fields for certification was principally: because of Cornyebacterium
orem, bacterial ring rot, but infection in these fields was light.

~

cei Fe
os a Sat

1 \ ? 4 yang i" Ac At +
i r - " Sad _ a a; P, f
‘ ~ Fa oe A re : ma
. ; 3 = ‘ 4 Ta ow 2 for a rr Caen
> : > > oa ocd 2 > f HE Saba
s : ' x : ; anc’ # a = 2 Pe
A Py

rae es
= oe ase Ie

at ta &

Common stock is not infects inenoeed but actual oss is lights: a
Erwinia phytophthora (E. carotovora), black leg, was severe, Pellicularia
filamentosa, (Corticium solani), black scurf, was less prevalent than usual.
-While Phytophthora infestans, late blight, was much less imoortant in 1943 ~
than in 1942, it still was more prevalmt than in an average year. Loss

from late blight was light. Loss from all virus diseases including leaf
roll, mosaic, and spindle tuber, was average. Purple top wilt was most —
prevalent east of the Red River Valley and especially around Grand Rapids. —

CEREALS, GRASSES, AND FORAGE CROPS

GRAMINEAE, (VARIOUS GRASSES). Claviceps purpurea, ergot, was found on
many grasses throughout the State, commonly on Agropyron repens, and-
Bromus inermis, and not infrequently on Phleum pratense. _ Infection was |
heavier than in recent years,

AVENA SATIVA, OATS

Fusarium sppe, Helminthosporium avenae, and other fungi, seedling blight
and root rot, were comuon or oats in 1943 but losses are not known.

Pseudomonas (Phytomonas) coronafaciens, hala blight, was more prevalent
in 1943 than in most years, the disease being very common ear in the
season. No estimate of loss was attempted.

Puccinia coronata, crown rust, occurred-in a moderately heavy epidemic
in agis but losses were much less than in 1941, when the grain was shrivel-
led from the heavy rust attack. A 3% reduction in yicid was estimated.
Vicland and Tama were resistant, Gopher and Minrus very susceptible.

Puccinia graminis avernae, stem rust, was more prove. Lent than in an aver-.
age vear, Viclana, Tama, and Nakota were resistant, although large pus
tules, indicating susceptibility to rust, were found on oats whose stem-
rust resistance was derived from Richland. Gopher was very susceptible.

Ustilago avenae, loose smut, and U. kolleri (U. levis), covered smut. .
Loss from the smuts remained at the same level as in recent years. Vic= >")
land, Tama, and Nakota. were resistant, and Gopher susceptible. ; ,

BROMUS INERMIS, BROME GRASS PUA GEES ERE a EO |
Pseudomonas (Bacterium) coronafaciens var. atropurpurea, chocolate spot, —

sia the most serious disease of brome grass in 1943. Selenophoma bee

gena, leaf spot, was much less evident than in recent oars a

DACTYLIS CLO:ERATA, as “ORCHARD CRASS
Colletotrichun graminicolum, ‘anbhracnone was. less common Pere in Whe

HORDEULE VULGARE, BARLEY
Jlaviceps we ergot, was common pat not taporbenie
Fusarium spp., head blight; seedling blight and root rot;
Givberella zeae UG. saubinetii), seab; seedling blight and root rot;
Helminthosporium spp.,-head blight; toe ee blight, root rot; 3
Seab and head bL blight -- A general infection of scab and néad- baht re-
duced yields more than in an. average year, the estimated reduction in

yield from these diseases being 13%. Loss from scab was heaviest in the

aL

southern half of the State, while head blight, resulting from infection by
Helminthosporium sativum, was found more generally throughout the State.
Head blight, resulting from infection by Fusarium spp., occurred only in
‘the northern part of the State.

Any attempts to distinguish between the losses to’barley from head blight
resulting from infection by Gibberella, Helminthosporium, and Fusarium
would be purely a matter of conjecture when readings are based on field ob-
servations, Accuracy in determining the proportion of blight due to any
specific organism can only be obtained by adequate analysis of the seeds
for microflora,

Seedling biight and root rot -- Seedling blight and root rot, resulting
from the planting of seeds heavily infected with Gibberella zeae, Helmin-
thosporium spp. and Fusarium spp. and Fusarium spp., was more widespread
and destructive in 1943 than in most years. Especially good response (in
stand and yield) resulted from fungicidal treatment of the seed.

Stem blight and foliage blotch. <A very severe epidemic of stem blight
and leaf blotch occurred throughout Minnesota in 1943, the disease being
much more serious than in previous years. Helminthosporium spp. (particu-
larly H. sativum) were chiefly responsible for the infections. Al] varie-
ties grown were susceptible. Reduction in yield was estimated to be about
Th.

Helminthosporium gramineum, leaf stripe. Average loss (a trace) from
leaf stripe was reported. Barbless and Glabron were resistant, Velvet and
Peatland being susceptible.

Puccinia anomala, leaf rust, was general but damage was slight. Barbless
and Velvet were susceptible.

Rhynchosporium secalis, scald, was present but apparently did not cause
any loss.

Ustilago jensenii, covered smut. Loss from covered smut was recorded as
trace. Barbless remained resistant.

Ustilago nuda, loose smut. While loss from loose smut was recorded ag
trace, the disease appears to becoming more common. Barbless, Velvet, and
Glabron were susceptible, Trebi resistant, and Peatland resistant in the
field but not when artifically inoculated.

Xanthomonas (Phytomonas) translucens, bacterial blight, was general
throughout the State.

LINUM USITATISSIMUM, FLAX

Colletotrichum linicolum, Helminthosporium spp., Fusarium spp. and
Rhizoctonia spp. causing seedling blight and root rot are of moderate
importance in Minnesota and loss (estimated at 0.5%) in 1943 was average.

Fusarium oxysporum f. lini, wilt, is now of slight importance in Minne-
sota, the loss of 1% in 1943 being average. Some of tne newer rust-resis-
tant varieties, such as Viking and Bolley's Golden, are moderately suscept-
ible to wilt. wT Fan

Melanpsora lini, rust, was less severe in 1943 than in many previous
years, and was serious only in the northern part of the State. The recent-
ly developed variety, Koto, hitherto rust-resistant in field plots, was
attacked very severely at the Crookston Station of the University of
Minnesota. Other varieties, such as Bolley's Golden and Viking, retained
their resistance to rust.

21h

liysphacrella linorum, pasmo. In 1943, the most severe epidemic of
pasmo occurred. While the disease has been recognized for 27 years in
the United States, this is the first year that losses from. pasmo have
been heavy. While the loss unquestionably was heavy, exact figures on
the extent of the effect in yield are difficultto obtain, The yellow
flaxes suffered more than the brown-seeded varieties, Viking and Bolley's
Golden being very susceptible.

POA PRATENSIS, BLUEGRASS
Calonectria graminicola and Typhula itoana, snowmold, was common in

the Twin City area on lawns, and was ae reported from south-east Minne-
sota. Loss from this disease was relatively light in 1943, no heavy out-
break having occurred in Minnesota since 19h1. |

Helminthosporium vagans, leaf spot and crown ret, was common in July
and August on lawns in Twin City area, and was seen on specimens submitted
from southeastern part of the State. Reports indicated some loss to blue-
grass pastures from this disease.

Puccinia poae-sudeticae, leaf rust, was much less Pee Ee 2 than in the
preceding 2 years. None was seen in pastures; it was observed only where
bluegrass was uncut.

SECALE CEREALE, RYE
Less Claviceps purpurea, ergot, than usually developed, was seen.
Infection by Puccinia rubigo-vera var. secalis (P. dispersa) wes light
and no loss is reported.

Rye stem rust, Cuccini a graminis var. secalis) was found only near bar-
berries.

SOJA MAX, SOYBEANS

Pre-emergence damping off and seedling blight due to Pythium sp. and
probably other fungi is common on certain vegetable varieties to the ex-
tent that it is not possible to get satisfactory stands of some-varieties,
including Etum, Giant:Green and some others, at University Farm, St. Paul.
Other vegetable varieties, including Bansei and Chusei, have given good
stands. sjost oll and hay types are relatively resistant to seed decay.

While Xanthomonas phaseoli var sojense, bacterial pustule, is common, |

it did not cause any appreciable loss in 1943 and was much iess destructive
than in 192.

Mosaic (virus) was ne common in SS A varieties.
SORGHUM VULGARE var. SUDANENSE, SUDAN GRASS

Pseudomonas holci, bacterial spot, occurred in most sudan grass fields
but no apparent loss resulted. x his:

TRITICUM AEST IVUM, WHEAT

Alternaria sp., Helminthosporium spp., and bacteria, black point, was
most common and injurious on durum varieties and was as prevalent as-in
previous years.

While loss from Claviceps purpurea, ergot, did not exceed a trace, in-
fection was not uncommon. Thatcher in the common wheats and Mindum in the

215

durums were the most susceptible of the commonly grown varieties.

Gibberella-zeae (G. saubinetii), scab was very destructive in the corn
area, from central Minnesota south, a 10% reduction in yield occurring.
Thatcher and Mindum were very susceptible, and Minturki was the most re-
sistant wheat.

Cver much of the State, environmental conditions in the spring were un-
favorable for good root development, with the result that seedling blight
and root rot due to Heimi iminthosporium spp., Fusarium spp., and other Fungi
Imperfecti, were more severe than in an average year. A reduction in
yield of 5% was estimated.

Puccinia graminis var. tritici, stem rust, caused very little loss, most
of the wheat varieties grown being resistant.

Infection by Puccinia rubigo-vera var. tritici (P. triticina), leaf rust,
was on about the same level as in most recent years, a reduction in yield
of 5% resulting. Thatcher was very susceptible, and Rival and liindum the
most resistant,

Scattered infections of Septoria tritici, leaf blotch, were seen. The
disease was common at the wheat breeding nursery at Waseca in south-east
Minnesota, marked differences in the susceptibility of different lines of
wheat being observed.

infection by Tilletia foetida (T. levis) and Tilletia caries (T. tritici)
bunt, remained on the same level as in recent years, a trace of loss being
reported,

Very little Ustilago tritici, loose smut, was seen.

Xanthomonas translucens var. undulosa, . black chaff, was not uncommon.

ZEA MAYS, CORN |

Diplodia zeae and Fusarium spp. and othér Fungi Imperfecti, stalk rot,
ear rot, seediing blight and root rot. Stalk rot was somewhat more severe
than in 1942, a loss in yield of about 2% resulting. Infection was general
and marked differences in the amount of disease in different fields was
observed, liuch of the loss in yield resulted from stalk breakage.

Very little ear rot developed, loss being less than in an average year.

The poor seed crop of 1942 gave poor stands and weak plants in 1943.
The estimated loss of 10% reduction in yield is much higher than is nor-
mally found in ilinnesota. Seed treatment resulted in marked improvement
in the stand and vigor of the plants.

The 2% loss in yield from Ustilago maydis (U. zeae), corn smut, repre-
sents an average loss for Minnesota. Many of the new hybrids are more
resistant than old hybrids or standard varieties.

FRUIT CROPS

FRAGARTA spp., CULTIVATED STRAWBERRY. Dendrophoma obscurans, leaf
scorch, caused no loss. Fusarium spp., Rhizoctonia sp. and probably other
fungi, root rot, is most usually associated with winter injury making any
- 6sbimate- of fs difiveuie: Mycosphaerella fragariae, leaf spot, was
Somewhat inore common in 1943, but loss was negligible.

Lat

A. Se

216

MALUS SYLVESTRIS, APPLE. Erwinia amylovora, fireblight, was very pre-
valent in home orchards on Wealthy but of minor Sel in commercial
plantings :

eeriaoenin oe coe juniperi-virginianae, apple-cedar rust, ina heavier
than average attack caused much disfigured fruit in Hennepin and Ramsey
Counties,

Venturia inaequalis, Soop affected almost a fruits in many unsprayed
orchards, and many fruits in some well-sprayed orchards. The epidemic was
rather more severe than in most years. a

A fruit russetting, which always occurs to some extent on Haralson, was

very prevalent on that variety in 1943. .

PRUNUS spp., PLUMS AND CHERRY-PLUM HYBRIDS. Coccomyces hiemalis, leaf
spot, is coimon on plums and cherry-plum hybrids. The disease appears in
late July or August, causing some defoliation. -

A heavier than average epidemic of brown rot blossom blight due to
Monilinia (Sclerotinia) fructicola, caused severe injury to the plum
cherry variety Cka and tc sand cherries in 1943.

RIBES sp., CURRANT. Sphaerotheca mors-uvae, powdery mildew, was severe —
on tne Red mare variety of currants in nursery stock in Southern iiinnesota.

RUBUS Pes ASPBERRY. Elsinoé veneta, anthracnose, was somewhat more
revalent oe cia. Sphaerulina ra Probl, leaf spot, was more orevalent in
43 than in recent years.” LOss Trot mosaic (virus) is light, most new

pees being relatively free from this disease. -

MISCELLA-ESGUS HCSTS

' BETA VULGARIS, SUGAR BEETS. je teocemeee cochlioides, damping-off and
root rot of sugar beets continues to spread in the beet area of southern
Minnesota, and already is, or is becoming, a serious hazard in the produc-
tion of sugar beets in McLeod, Sibley, Blue Harth, Waseca, and Faribault
Counties. In Blue #arth County, 400 acres of beets were severely injured,
with a probable reduction in yield.of 40%.

Cercospora beticola, leaf spot, was found in all sugar beet areas of the
State but did damage only in the southern beét area. Infection in the Red
River Valley was light and late. ;

- Damping off as a result of infection by Phoma betae is rarely scen.

Loss from Rhizoctonia solani causing damping-off and root rot is slight. ~
DELPHINIUi:i spo. Pseudomonas (Bacterium) delphini, leaf spot, was report-
ed once in 1943. tahoe )
GAILLARDIA sp. Entyloma polysporum, white smut, was reported once in

1943 ,in the same city park in which the disease was found in 1942. |

HEDERA sp., IVY. Ocdema (cause unknown) was reported once in 1943; tiny
galis, very numerous and conspicuous developed on a house plant.

IRIS sp. Heavy infections by Bacterium tardicresens, bacterial leaf
blight occurred on some varieties and this disease is becoming troublesome
in nurseries, Botrytis convoluta, Botrytis rhizome rot, was observed only
in St. Paul area, with slight damage to the rhizomes. Very little Hetero-
sporium gracile, leaf spot, was seen in the St. Paul area.

LILIUM spp. Very little blight caused by Phytophthora, Spe developed in
1943 compared with the heavy epidemic of previous years. Lilium regale
and L. tenuifolium are the most susceptible species.

217

PAEONIA sp. Very little Botrytis paeoniae, blight, developed in St. Paul
area compared with the heavier infection in 1942. Occasional infections
by Phytophthora sp, causing blight, were reported.

PETUNIA so, One report was received of a house plant infected by Oidium
Sp., powdery mildew.

PINUS RESINCSA, RED PINE. Ten percent of an 8-year old stand of red
pine planted in an area of Red Lake Indian Reservation, Beltrami County, :
was dying of root rot. Site and soil was said to be very good. The root
systems were very small and .ntirely parasitised by Armillaria mellea. A
similar dying of red pine was Revenue’ by the Soil Conservation Service
from their nursery at Winona.

ROSA sp. Fewer reports of Phragmidium speciosum, rust, were received
than in recent years.

SYRINGA VULGARIS, LILAC. Phytophthora sp., blight, was reported once
in 1943.

SULLIARY CF PLANT DISEASES OBSERVED IN IOWA DURING 1923

T. We Bretz

The following summary of estimates on the plant disease losses in Iowa
for the year 1943 is based principally upon the information provided by
the various State and Federal pathologists working in this territory. Ow-
ing to the rather late start of the Emergency Plant Disease Prevention
Project, this summary would not be possible without the willing assistance

of these men and the writer is duly grateful for their help. It should

ee
ay

be borne in inind that this report is, of necessity, a record of the final
crop loss estimates for the State as a whole and does not contain the
trend of the plant disease situation during the growing season, nor the
relative severity of the various diseases in different sections of the.
State.

The weather during the growing season was unusual in several respects.
Whereas the precipitation and temperatures during April were about normal,
May was unusually wet and the temperatures were below the average. The
remaining months were characterized by precipitation and temperatures
slightly above average. These conditions are perhaps reflected to some
extent in the increased destructiveness of the root necrosis pathogens, as
weli as in certain other instances in which diseases were noticeably more
serious than during the past few years.

VEGETABLE DISEASES

ALLIUM CEPA,- ONION

Krwinia carotovora, soft rot, and Pseudomonas alliicola (thought to be
the causal agent of the "undetermined neck rock" reported from Towa in PDR
Vol. 27, No. 16, p. 337, 1943) were estimated to have accounted for a com=
bined loss of 25% of the crop. It is difficult to determine the extent of
the losses caused by these organisms individually, since P. alliicola field

a

SEES Creme ata st .
pe oe om aor Siete 4 ba :
5.
=

Be nash ase

. fe —
nee
Panay

tes
in +

ron

eres
Sage

rs Sh a Re Rea as se
A ge PN ey ee ee
oe it ae! > ee
‘ i i) led menaten Nic
. z i at :

to

Sex

Wma
ee.
.

erates tee mae
Wipe are

ae aa!

oe ey
as

infection is commonly followed by the soft rot bacterium under storage,

- APIUM GRAVEOLENS, CELERY

* the prevalence of 2 leaf spots, Cercospora apii os blight), accounting |
for 10% loss, and Septoria apii (late blight y ac account for 10%, loss.

~
=

leg) and Plasmodiophora b brass: cae (club root}, were each So eee for

Pi ae: aie te baer Peis ca cle 15t Re ie “
f << “ = cain. wis e Br e rh. " t

= a 4 : f t “ ¥ : v«
a 8 yal 3 fr 7 : 7 7 m % ‘ , —_ -, r Pn’ se @ J

conditions. ; «
Urocystis cepulae, smut, varied in “importance in different localities,

but for the entire crop, was responsible for no more than a trace of dam- —
age. ;

It was estimated that 20% of the celery grown in Towa was lost due to

ASPARAGUS CFEICINALIS, ASPARAGUS 7 | e
Puccinia asvaragi, rust, was the only disease of importance observed
during the season; it caused an Bee abed 2% reduction in yield.

BRASSICA OLERACHA var. CAPITATA, CABRACE
No excessive losses due to disease were reported for this crop.
Ba Ee see ee ope Erwinia carotovora (soft rot), Fue

See Sige ee

(wire haat Peronospora parasitica ee oe phoma Lingain (black-

a trace of damage.
Pythium spp., damping-off, was estimated to have been Pesven as for
a 2% loss.
Xanthomonas campestris, black rot, accounted for the greatest loss, an
estimated 5%.

CITRULLUS VULGARIS, WATERMELON |

Colletotrichum lagenarium, anthracnose, was the most serious disease of
watermelons this past season. Premature death of the vines due to foliage
infection, plus fruit infection, accounted for an estimated 25 loss of
ane CCODs

Fusarium oxysporum f. niveum, wilt, was held in check by the use of
wilt-resistant varieties, but was responsible for a 5% loss. |

Pythium aca as blossom-end rot, caused an estimated 2% reduction ~
in yield. nies |

Pythium spp., ‘dainping-off, reduced: the yield approximately 5% by de-
creasing the stand.

iosaic, (virus), wa s responsible for a trace of damage.

CUCUMIS MELO, CANTALOUP
Alternaria cucumerina (Macrosporium cucumerimum), leaf blight, was
severe and caused an estimated 5% reduction in yield. e
Colletotrichum lagenarium, anthracnose, as with watermelon, was respon=
sible for the greatest loss in cantaloups. Leaf infection, which caused —
Ce death of the vines, as well as fruit infection, reduced the crop
Erwinia ee ae pacherter wilt, resulted in a 5% ieate f
Fusarium oxysoorum f. melonis (F. bulbigenum var. niveum f. 2), wilt ©
resulted in a 5% loss.

219

Pythium spp.; canierne eae through its effect on stand, reduced the
ait approximately 3%.
fosaic (virus) accounted. for a trace in reduction in yield,

DAUCUS CARCTA, CARROT
Erwinia carotovora, soft rot, was estimated to have caused a 5% loss in
yield.
Xanthomonas carotae, bacterial gee was observed but considered to be
of minor importance, causing a trace of damage.

IPOMCEA BATATAS, SWEETPOTATO +
Endoconidio»hora (Ceratostomella) fimbriata, black rot, was considered
to be a disease of minor importance and caused an estimated loss amounting

to a trace of the crop.

Fusarivun SUNG f. batatas (F. batatatis and F. hyperoxysporum),
stem rot E (wilt), continued to be the major disease in the field as in for-
mer years, causing an estimated 10% loss.

. Fusarium oxysporum (surface rot) and Pythium ultimum (mottle necrosis)
each accounted for a trace of damage.

Rhizopus nigricans, soft rot and range rot, was the most important dis-
ease in storage, accounting for a 15% loss.

Internal breakdown, pnysiological, accounted for a loss amounting to a
trace .of the harvested crop.

LYCOPERSICON ESCULENTUM, TOMATO

Alternaria solani, early blight, was prevalent in most plantings to a
rather limited extent and was estimated to have accounted for a eats of
damage.

Fusarium oxysporum f. lycopersici (F. bulbigenum var. eae wilt.
The increased use of wilt-resistant varieties tended oe keep po the
losses from this disease, estimated to be 1%.

Phytophthora infestans, late blight, was observed. in a few isolated
plantings late in the season, but caused no appreciable Mosse fh trace, Of
damage was reported. “os

Septoria lycopersici, blight, was the most prevalent and serious disease
of tomatoes, resulting in much defoliation by late summer. In many in-
stances the disease did not, become well established, however, until after
the fruit had set and was BLUEL Ey The loss due directly to this disease
was estimated at 10%.

Xanthomonas vesicatoria, bacterial spot, was present in most of the
—. tomato acreages but caused relatively little loss, an estimated
0.5

Fruit rots, were caused by miscellaneous fungi one bacteria, ~following
injuries to the fruit. Sunscald, resulting from defoliation due to Sep-
toria blight, was undoubtedly an important forerunner of much of this de-
cay. At least 25% of the fruits rotted in the fields.

Mosaic (virus) was reported from various parts of the State, but in no
instance was it particularly serious, An estimated 2% loss was attributed
to it.

Blossom end rot, physiogenic, was prevalent early in the season on the

220

fruit of the first clusters set, but considering the entire. season it was
not a seriovs problem, causing a 1% reduction in yield.

PHASECLUS VULGARIS, BEAN

Colletotrichum lindemuthianum, anthracnose, was the most prevalent and
destructive disease of beans, reducing the yield an estimated 10%.

Uromyces phaseoli, rust, was of minor importance, causing only a trace
of damage,

Xanthomonas phaseoli, bacterial blight, was prevalent and serious in
some plantings, causing an average reduction in yield of 5%.

Mosaic (virus) was common but not a serious problem, accounting for an
estimated l% loss.

PISUiM SATIVUM, PEA.

Except for the root rots, the pea was not affected by any disease toa
serious degree,

Aphanomyces sp., Fusarium sp., Pythium sp., and. Rriroctones solani, as
well as other pathogens causing root rot, were Seek to have caused
a. 5% loss in the pea crop.

. SOLANUM TUBEROSUM, POTATO "> © ’

An estimated 146.7% of the potato ¢rop was lost due to ndbenseet

Actinomyces scabies, scab, was responsible for a 10% reduction in yield.
Its severity veried from field to field. Some fields were vractically
scab-free; in others practically all tubers showed scab’lesions.

Alternaria solani, early blight, was observed to a limited extent in
most of the potato acreages but was of minor importance, causing a trace
of damage,

Erwinia phytophthora (E. carotovora), black leg, did not appear to be
of major importance, accounting for 0.5% loss.

Fusarium solani f. eumartii, Fusarium wilt, was observed affecting an
occasional plant, causing a trace of damage.

Phytophthora infestans, late blight, again occurred in epiphytotic pro-
portions on the imck-land potatoes in northern Iowa. The severity of the
‘outbreak depended to a great extent upon the effectiveness with which the
fields were protected by means of spraying. Fields that were well spray-
ed showed little loss, but poe sprayed or unsprayed fields in many
instances shoved as much as 50% reduction in yield. For the State, in-
cluding all situations, it was estimated that the loss amount ed to 16%
of the crop.

Rhizoctonia solani, black scurf, varied greatly in feted from field
to field. An estimated 6% loss was attributed to it, somewhat more than
last season,

Seed piece decay, various organisms responsible, eausee an estimated
loss of 1%. |

Leaf roll (virus) was fairly common and caused an estimated 2% teak.

Mosaic (virus) was thought to have reduced the yield 2%.

Spindle tuber (virus) was fairly prevalent and caused an estimated re-
duction in yield amounting to 3%.

Other viruses probably reduced the yield an additional 2%. Tipburn and

a a
ieee eed

Pease = is! et 2 : ; eee | oan eel

hopperburn ‘were general and in some fields destructive, causing an aver-
age loss estimated at h&.

“> - DISEASES OF CEREALS, GRASSES, AND FORAGE CROPS
AVENA SATIVA, OATS oF

The-é¢stimated losses in the oat crop due to all diseases bag to
33.2%, distributed as follows:

Fusarium sp., foot rot, 1%.

Gibberella’ zeae (G. es eed tied: scab, a trace.

Helminthosserium avenae, leaf spot, a trace.

Pseudomonas coronafaciens, halo blight, 1.5%.

Pythium spp., root necrosis, 10%. This is somewhat higher than in pre-
vious years and is probably accounted for by the favorable conditions for
development of Pythium early in the season. .

Puccinia coronata, crown rust, 10%. This was a ‘favorable season for
rust developnent , which accounts for a higher loss than was experienced
the preceding season, despite the gréater use of the available rust-resis-
tant oat varieties (Boone, Tama, Control, and Marion).

Puccinia graminis var. avenae, stem rust, 5%, which is considerably more
than in previous years.

Ustilago avenae, loose smut, 1. sd. a: eeaueneed as compared with previous
years, probably accounted for by the wider use of the new oat varieties
which are somewhat smut-resistant.

Ustilago kolleri (U. levis), covered smut, 0.5%.

5 Sees physiological, 0.5%.

Leaf spot, physiological (?), 3%.

BROMU S sppe, BROMEGRASS

The yield of bromegrass, was reduced an estaincwee 42;:7% because of
disease,

Claviceps purpurea, ergot, accounted for 1% of this odedasé*

Pseudomonas coronafaciens var. atropurpurea, bacterial gpot, reduced
the yield an estimated 1.5%.

Puccinia graminis, stem rust, caused a trace of apie

Pythium sppd., root necrosis, accounted for the greatest seduction in
an estimated 33%.

Stagmogpora sp., purple leaf spot, was estimated to be responsible for

a 5% loss.

Xanthomonas translucens, bacterial streak, was Rucenaible for a 3%
loss.

Phyllody, (cause ?), caused a trace of damage.

HORDEUM VULGARE, BARLEY
- Diseases were estimated to have reduced the yield of bares 10.9% in
spite of an otherwise favorable season for this crop.

Eiemcens purpurea, ergot, was more prevalent than in the past and ac-
counted for a eek of damage. ae

Erysiphe grami var. hordei, bucudeny cde was observed buf con-

sidered to be ae minor importance, the loss resulting amounting to a
trace,

Ph ea pi one! ae Pes a aes SO a Re ee 3
222 | ss ca

Gibberella zeae (G. saubinettii), scab, was somewhat more prevalent
than in the preceding 3 years, causing an estimated: 3% reduction in yield.

Helminthosporium gramineum, stripe, as in former paeoansy was present —
but accounted for only a trace of damage.

Helminthosporium sati.vum, spot blotch, was an éeéptiohanty serious
problem and i including the the seedling blight phase of this disease, was esti-
mated to have reduced the yield 25%. Extremely heavy nodal infection was
observed, resulting in the death an the leaf sheaths before the plant was
in the boot stage of development.

Helminthosporium teres, net isk was observed and estimated to have
resulted in a loss amounting. to a trace of .the crop.

Helminthosporium sp., Fusarium sp.« and QOphiobolus sp., foot rots, ap-
peared to be of less importance than in former years, accounting for a
0.2% reduction in yield.

pees anomala, leaf rust, was estimated to have reduced the yield
lh.

Pee teen enanceeet stem rust, reduced the yield an estimated 0.5%.

Puccinia. rubigo-vera var. tritsici (P. triticina), wheat leaf rust, was
of negligible importance on barley reducing the yield a trace.

Pythium spp., root necrosis, favored by the weather conditions, was
estimated.to have accounted for a loss of 8%.

Ustilago intermedia, intermediate smut, was somewhat more common and
reduced the yield approximately 0.5%.

Ustilaao jensenii {U. hordei), covered smut, was the least prevalent of
the smuts and caused a reduction in yield amounting to a trace.

Ustilago nuda,-loose smut, was the most serious of the smuts and account-
ed for an estimated 2% reduction in yield.

Xanthomonas translucens, bacterial blight, was considered to be of minor
importance, the loss resulting from this disease amounting to a trace.

LINUM USITATISSIMUM, FLAX

Diseases accounted tor an approximate reduction in yield amounting to
one-third of the crop. .

‘ Cok#etotrichum linicola, anthracnose, accounted for a trace of damage.

Fusarium oxysporum f. lini, wilt, was of relatively little importance
as a result of the wide use use of the wilt-resistant Wari abies An estimated
1% 1éss was attributed to this disease.

Melampsora lini, rust, was estimated to have eee" a 0.5% loss.

Mycosphaerella (Sphaceciaa) linorum, pasmo, was prevalent and moderately
severe, causing a 5% loss.

Pythium spp., causing root necrosis and damping-off, was the most ser-
ious disease problem and accounted for the greatest loss, an estimated

25h.

MEDICAGO SATIVA, ALFALFA
- It was atime that the yield of alfalfa was reduced about one-third
_as a result of the prevalence of certain diseases.
_ Cercospora medicaginis, leaf ache was common and accounted fez an
estimated 1% loss.

Corynebacterium insidiosum, avy ‘was: the oat destructive. aipeane ob=
served, accounting for a 20% reduction in yield. ist

223

Peronospora trifoliorum, downy mildew, was considered to be of minor
importance, causing a trace of damage.

Pseudopeziza medicaginis, leaf spot, was common and severe, causing an
estimated 6% loss,

Pyrenopeziza medicaginis, yellow leaf blotch, was estimated to have re-
duced the yield h%.

Uromyces striatus, rust, was observed but was considered to be of minor
importance, causing a trace of damage.

PHLEUM PRATENSE, TIMOTHY

Puccinia graminis var. phlei-pratensis, stem rust, was considered to be
of minor importance, causing a loss amounting to a trace of the crop. c

Scolecotrichum graminis, leaf stripe, was the most prevalent and destruc-
tive of the timothy diseases, causing an estimated 1% loss.

Ustilago striaeformis, stripe smut, was of minor importance, accounting
for a trace of damage.

Xanthomonas translucens var. x, bacterial leaf spot, was observed and
estimated to have accounted for a trace of damage.

POA PRATENSIS, BLUEGRASS
Erysiphe graminis, powdery mildew, was responsible for a trace of damage.
Puccinia graminis, stem rust, caused an estimated Ee toss.
Septoria oe leaf spot, caused a trace of damage.

SECALE CEREALE, RYE

This crop appeared to be relatively free of destructive diseases.

Claviceps purpurea, ergot, was more prevalent than in former years,
causing an estimated 1% loss.

Puccinia rubigo-vera var. secalis (P. dispersa), leaf rust, was pre-
valent and accounted for a 2% reduction in yield.

Puccinia graminis, stem rust, was of minor importance, a trace of dam-
age being reported.

Ustilago sp., smut, caused a trace or damage.

Xanthomonas translucens var. secalis, bacterial blight, was observed
but considered to be of minor importance, causing a trace of damage.

SOJA MAX, SOYBEAN

Diaporthe sojae, pod and eaieiene was reported from all sections of
the State and was present in a high percentage of the fields, but the
actual damage caused by this disease was estimated not to exceed 0.5%.

Glomerella glycines, anthracnose, was found in all sections of Iowa but
in relatively few fields, usually occurring on plants affected by some
other disease and in a poor state of vigor. Only a trace of damage was
attributed to this organism.

Peronospora manshurica, downy mildew, appeared rather late in the grow-
ing season in a limited number of fields and probably affected the yield
to a negligible extent. A’trace of damage was recorded.

Pseudomonas glycinea, bacterial blight, was prevalent in practically all
fields. The amount of leaf area involved by the lesions was relatively
small, however, and the disease was thought to have reduced the yield an

estimated 0.5%.

R
oe 2 - ower

r " r : Bi vad . ‘i ban \ § | ; | i ie
ue | aie REECE a A a

lent than _ Tae year, was not particularly serious except in localized

Pythium spp., root necrosis, was probably responsible oe a , Limited re-_
duction in stand, but owing to the thick seeding practiced in planting 4
this crop, the loss was largely compensated for by the increased vigor. of
the remaining plants. An estimated loss of 1% was ‘attributed’ to this
disease.

Rhizoctonia solani, Pen ‘As in the case of root nee oe “the
loss in stand due to this disease was not necessarily reflected in a
corresponding decrease in yield, and a 1% reduction in yield was recorded.

Septoria glycines, Septoria leaf spot, was observed early in the growing
season but did not persist as an important factor in limiting Viste being”
responsible for an estimated 0.5% reduction.

Xanthomonas phaseoli var. sojense, bacterial oaebules This undoubtedly —
was the most prevalent and serious disease of soybeans. It was observed
in all fields in every section of the ‘State, causing much leaf spotting
and some defoliation. It was estimated to have caused a Lose in yield
amounting to 24, an ea:

Bud blight was widely distributed throughout the State. The percent-
age of plants affected in individual fields varied froma trace to 100%
and the severity of the disease was correspondingly varied. Relatively
few fields were observed in which there was a serious reduction in yield
and for the State the loss did not exceed 1%.

Mosaic (virus) was observed in a relatively small percentage of the
fields and in only a few instances did it appear that there was a marked ~
reduction in yield resulting. A loss to the extent of a trace was record=—
ed for this disease. |

The late planted fields and eels planted to late-maturing varieties
were hit by frost, particularly in the northern counties, before the crop gy
was ed papeen, resulting in an estimated 2% reduction in yaetd

SCRGHUM VULGARE, SORGHUM
Pseudomonas holci, bacterial spot, was common but of minor importance,
causing a trace of damage. j
Sphacelotheca sorghi and S. cruenta, kernel smuts, eee for an
estimated 1% reduction in yield.

TRIFOLIUM PRATENSE, RED CLOVER

Erysiphe polygoni and Cymadothea trifolii, powdery mildew and sooty |
mold, respectively, each accounted for a trace of damage.

Pseudomonas syringae (P. trifoliorum) , Pseudopeziza. 1A ag oe ef Ds a a and
Stagonospaa. sp., the leaf spotting organisms, caused a combined loss
estimated at 3%.

Mosaic (virus) was responsible for a trace of damage.

TRITICUM AESTIVUM, WHEAT
Gibberella zeae (G. saubinetii), scab, was unusually severe on winter :
wheat, causing a 12.5% reduction in yield. It was less destructive than q
last season on the spring wheat, however, causing a 5% loss. a
Puccinia graminis var. tritici, stem rust, although somewhat more prevem

areas, causing loss ranging from a trace to 25%. It was estimated to have
reduced the average yield of winter wheat 3%, and of spring wheat me ae
trace.

225

Puccinia rubigo-vera var. tritici (P. triticina), leaf rust, was the
most destructive disease observed and was somewhat more severe than usual
on the winter wheat, causing a 10% loss. It apneared to be less serious
than last season on the spring wheat, reducing the yield 15%.

Pythium spp., root necrosis, was somewhat more prevalent and serious than
in previous seasons, causing an estimated 10% loss in the winter wheat
crop. | , |
Septoria tritici, speckled leaf blotch, was of minor importance, causing
a 1% loss in the winter wheat and a trace of damage in the spring wheat.

Tilletia foetida (T. laevis) and T. caries (T. tritici), bunt, caused a
trace of damage. |

Ustilaso tritici, loose smut, appeared to be no more destructive than
in former years, accounting for a 2% and a 0.5% reduction in yield in the
winter and spring wheats, respectively.

Xanthomonas translucens var. undulosa , black chaff, was observed on
winter wheat but was considered to be responsible for only a trace of
damage,

ZEA MAYS ver. IDENTATA, FIELD CORN

much of the corn was subject to very unfavorable weather early in the
season, which was reflected to some extent by a general increase in the
amount of root necrosis due to various pathogens. The other diseases
“were not noticeably more serious than in previous seasons, except for an
increased prevalence of Gibberella ear rot.

= ences acremonium, black bundle, was observed and caused a
trace of daiage,

Diplodia zeae, root necrosis, was prevalent and caused a 2%é loss. The
dry rot phase of the disease accounted for an estimated 5% reduction in
yield.

Fusarium spp., dry rot, was prevalent, particularly following corn ear-
worm damage, but was considered to have caused only a trace of damage.

Gibberella zeae (G. saubinetii), caused an estimated 5.6% loss. The
root necrosis phase of the disease accounted for a 2% reduction; the stalk
rot phase 1% and the dry rot of ears, 2.6%.

Nigrospora oryzae, dry rot of ears, was prevalent, particularly on
secondary ears, but was of minor importance on primary ears, causing an
estimated 0.5% loss.

Puccinia sorghi, leaf rust, was common in all sections of the State but
in no instance did it occur in destructive proportions. A trace of dam-
age was reported.

Pythium spp., root necrosis, was prevalent and destructive, causing an
estimated 10}, reduction in yield.

Ustilago zeae, smut, was prevalent in all fields in varying amounts,
causing an average decrease in yield estimated at 3%.

ZEA MAYS var. RUGOSA, SWEET CORN

| Bacterium stewerti, bacterial wilt, was of minor importance, ee a
trace of damage.

Diplcdia zeae, stalk rot, was generally prevalent and destructive, caus-

et ing an estimated 5% loss.

Puccinia sorghi, rust, was prevalent but caused only a trace of damage.
Ustilago zeae, smut, was the most destructive disease observed, account-
ing for an estimated 8% reduction in yield.

AMYGDALUS PERSICA, PEACH . ee Pe
Cwing to the lack of adequate means of applying protectants in the
farm and home orchards, combined with the favorable weather conditions
for disease development, the losses are somewhat higher than in previous
years.
Cladosporium carpophilum, scab, was generally prevalent. and reduced ae
yield an estimated 3%. ->*’ a
Monilinia (Sclerotinia) fructicola, »rown rot, was the most serious ;
disease problem encountered arid caused an estimated 15% reduction in viclag
Sphaerotheca pannosa var. persicae, powdery mildew, was observed but |
considered to be of minor importance, causing a trace of: damage.
Taphrina defcormans, leaf curl, appeared to be somewhat more pronounced
this season than last, reducing the yield an estimated 2%.
Zantnomonas primi, bacterial aaa was quite destructive, causing an
estimated 5% loss.

FRAGARTA, STRA\IBEI
Botrytis sp.,; pet eainee cactorum,.and Rhizoctonia sp., causing field ~
fruit rots, were prevalent and accounted for tne greatest disease es
an estimated 1C%.
Mycosphaerella fragariae; leaf ney was also more eeeuaione than in
previous years and reduced the yield an estimated: 1%. seve ie a
Sclerotinia sclerotiorum, crown rot, was of minor. imporbance, accounting |
far O.5%° loss. 4
Mosaic, virus (?), (thoughtto be different from June yal owe has pees
observed, but was RE to be of minor importance and responsible for |
only a trace of damage. The late spring freezes were “estimated to be
“responsible Pores, LOZ loss in yield. ie
MALUS SYLVESTRIS, APPLE i ster: 3
Approximately one-third of the apple crop was estimated to have been de-
stroyed by diseases the past season. Most of this loss occurred in the ‘
farm and home orchards where means: protection from disease was not ~
practicable. ; ! eee
Erwinia amylovora, fire blight, was generally prevalent in all plantings
and caused an estimated 24 loss. . . : > ) Soaaaa i eae
‘Gloedes nomigena, sooty blotch, was of rather minor importance and ~
reduced tne yield about 0.5%. :
Glomerelia cingulata, bitter rot, was ihe common and accounted Ge only
a trace of damage. | 7
Gymnosporangium juniperi- virginianae, cedar-apple rust, was. common on
the s susceptivle varieties and caused an estimated 2% reduction in yield.
Nummularia discreta, blister canker, was not serious, causing an eat
mated 0.5% loss. ;
Phyllosticta solitaria, blotch, was not generally prea eae and ‘caused

oe

only a trace of dam damage. ee aa
Physalespora obtusa, black rot, was somewhat more serious than in 1 pre=
vious seasons ais and accounted for 5 L@ reduction-in yield. / Kee

227

Venturia inaegualis, scab, “was the most destructive disease, especial-
ly in unsprayed or poorly sprayed, orchards, causing a loss estimated at
15%.

Winter injury was estimated to have reduced the yield 10%.

PRUNUS spp., CHERRY ‘gf

Owing to the fact that few cherries are grown cammercially in this
State and that farm and home orchards are generally not adequately pro-
tected from disease, tne losses from controllable diseases are rather
high.

Coccomyces hiemalis, leaf spot, was the most destructive disease, ac-
counting for much early defoliation. it was estimated to have reduced
the yield eae
es than in aoe Seana Peele. for an Eanes ‘Yo? loss.

Monilinia (Sclerotinia) fructicola, brown rot, appeared to be less ser-
ious than in former years, causing a 1% reduction in yield.

The late spring freezes were of importance in reducing the set of fruit
and accounted for an estimated 10% loss.

PRUNUS spp., PLUM

Dibotryon morbosum, black knot, was observed but was of minor importance,

causing a trace of damage.
Monilinia (Sclerotinia) fructiccla, brown rot, was generally prevalent

and a serious problem, accounting for an estimated 10% reduction in yield.

Taphrina pruni, plum pockets, was estimated to have reduced the yield
lo :
Xanthomonas ni, bacterial biight, was prevalent and serious, caus-
—— see
a 10% loss.

RiBES spp., CURRANT AND GCCSEBERRY

Cercospora angulate, leaf spot, was orevalent and caused an estimated
2% loss.

Cronartium ribicola, Huropean currant rust, was present in scattered
localities, accounting for a trace of damage.

Mycosphaerella grossulariae, leaf spot, was generally distributed and
caused a 2% loss. |
-Puccinia grossulariae, cluster-cup rust, was observed in scattered
locations, causing a trace of damage.

Sphaerotheca mors-uvae, powdery mildew, was prevalent and accounted
for an estimated 2% loss.

RUBUS spp., RASPBERRY :

Agrobacteriun tumefaciens ens, crown gall, was present in some plantings
and accounted for a 1% -ioss.

Elsinoé veneta, anthracnose, was the most prevalent and destructive
fungous disease observed, in some instances destroying practically the
entire stand. . For the State it was estimated to have caused a 7% loss.
— Gymoconia pees (G. interstitialis), orange rust, caused a loss
estimated at lh.

Tae ties
Bh od :
Pgs A Ae

p

prevalent and estimated to have caused 5% damage.

‘ e tae a ee Re Ciel 3 ; Sa ‘ ary often \
; , di
I ‘ ' > _ ee ae o. 3% t
: + pes! te Gye rd,
28 a Pe ae Se ae
: » 7 z 5d “ aha oe Nath ol nied te iin vo ees

Leptosphaeria: coniothyrium cane. blight, was Bonereaty distributes, |
counting for an estimated 3% loss.
Mycosphaerella rubina, leaf spot, was ee but not serious, causing
only a trace of damage. 4
Septoria rubi, leaf spot, was common and eceentcd for a 3% reduction in
yea
Vinter injury was estimated’to have caused a 1% loss.
Mosaic, (virus), was prevalent and destructive, accounting for an esti- ©

mated 7% reduction in yield. : 4

=

VITIS spp., GRAPE a
Owing to the ai eficulty in keeping the vines adequately protected be- —
cause of the frequent precipitation, the losses in this crop were consider-
ably greater than in previous years. 4
Guignardia bi a black rot, and Plasmopora viticola, downy mildew, —
were each estimated to have caused a 5% LOSS. a
The late spring freezes were thought to have reduced the yield an addi- 4
tional 5%.

DISEASES OF MISCELLANEOUS HOSTS

BETA VULGARIS, SUGAR BEET. Disease losses accounted for 45.4% of the
Erop, . ah 3

Actinomyces scabies, scab, was respcnsible for only a trace of damage.
hanowyces cochlioides, root rot, favared by soil conditions conducive ~
to its developinent, caused an estimated reduction in yield amounting to
20%. : :

Cercospora beticola, leaf spot, was favored by the moist weather and
accounted for a 12% loss of the crop, somewhat higher than in previous
S€asonse ee)

Phoma petae, root rot and leaf spot, each accounted for a trace of damage,

Pythium sop., damping off, was estimated to be responsible for a 10% a
loss, somewhat above the average of past seasons. . a

Rhizoctonia solani, oe rot, was more severe than usual, causing an
estimated 3% loss. -

Savoy disease (virus) Uceemwed for a trace of damage.

HELIANTHUS ANNUUS, SUNFLOWER. Erisyphe cichoracearum (powdery mildew)
and Puccinia helie ec vak (rust), were generally prevalent and each accounted
for an estimated 2% loss. | eA gate 4

JUNIPERUS VIRGINIANA, REDCEDAR

Gymnospore. ngium juniperi-virginianae, rust, was common but accounted
for only a trace of damage. . &

Phomopsis sp., blight, appeared to be an increasingly important disease ~
and was observed affecting.many nursery plantings. An estimated 5% of —
this nursery stock was considered to be affected to the extent that even
after pruning, the trees would have no sale value.

mOSA spp., ROSE. Agrobacterium tumefaciens, crowngall,.was estimated to

ar hh

be responsible for a loss. Dae be Dinlocarvon rosae, Beal spot, was gen-@

et ee ee ee ee

eral, the severity varying with protect: ive measures applied. It was esti-=
mated to have caused a 5% loss. Spha erotheca humuli and: Se pannosa were —

eae

chr ough Gurion. sti
imomonia lace, leat: ‘spot, was severe

32

Nd