CRANBERRY DISEASES

A Thesis submitted to the Faculty of Graduate
Studies of the George Washington University
in part satisfaction of the requirements
for the degree of Doctor of Phi-
losophy, June, 1906.

BY

CORNELIUS LOTT SHEAR, B. S., A. M., Ph. D

WASHINGTON, D. C.
1907

This thesis was defended publicly ,.'

r

By CORNELIUS LOTT SHEAR, B. S., A. M., University of
Nebraska, in doctorate disputation, Monday, May 28,
1906.

Before FRANK H. KNOWLTON, Ph. D.

JOHN R. MOHLER, A. M., V. M. D.
MERTON B. WAITE, B. S.

Professor ALBERT MANN, Ph. D., presiding.

But. •nV*Bur*aa ot PlSnt'lruiuStVy, U. S. Dept. of Agriculture.

PLATE I

CRANBERRY SCALD.

A. HOEN 4 CO., LITH.

U. S. DEPARTMENT OF AGRICULTURE.

BUREAU OF PLANT INDUSTRY— BULLETIN NO. 110.

B. T. GALLOWAY, Ckitf of Bureau.

CRANBERRY DISEASES

BY

C. L. SHEAR,

//

PATHOLOGIST IN CHARGE OF INVESTIGATIONS OF
DISEASES OF SMALL FRUITS.

ISSUED OCTOBER 10, 1907.

WASHINGTON:

GOVERNMENT PRINTING OFFICE.
1907.

BUREAU OF PLANT INDUSTRY.

Pathologist and Physiologist, and jOhicf of Bureau, Beverly T. Galloway.

Pathologist and Physiologist, and Assistant Chief of Bureau, Albert F. Woods.

Laboratory of Plant Pathology, Erwin F. Smith, Pathologist in Charge.

Investigations of Diseases of Fruits, Merton B. Waite, Pathologist in Charge.

Laboratory of Forest Pathology, Haven Metcalf, Pathologist in Charge.

Plant Life History Investigations, Walter T. Swingle, Physiologist in Charge.

Cotton and Tobacco Breeding Investigations, Archibald D. Shamel, Physiologist in Charge.

Corn Investigations, Charles P. Hartley, Physiologist in Charge.

Alkali and Drought Resistant Plant Breeding Investigations, Thomas H. Kearney, Physi-
ologist in Charge.

Soil Bacteriology and Water Purification Investigations, Karl F. Kellerman, Physiologist
in Charge.

Bionomic Investigations of Tropical and Subtropical Plants, Orator F. Cook, Bionomist in
Charge.

Drug and Poisonous Plant Investigations and Tea Culture Investigations, Rodney II.
True, Physiologist in Charge.

Physical Laboratory, Lyman J. Briggs, Physicist in Charge.

Crop Technology Investigations, Nathan A. Cobb, Expert in Charge.

Taxonomie Investigations, Frederick V. Coville, Botanist in Charge.

Farm Management Investigations, William J. Spillman, Agriculturist in Charge.

Grain Investigations, Mark A. Carleton, Cerealist in Charge.

Arlington Experimental Farm, Lee C. Corbett, Horticulturist in Charge.

Sugar-Beet Investigations, Charles O. Townsend, Pathologist in Charge.

Western Agricultural Extension Investigations, Carl S. Scofteld, Agriculturist in Charge.

Dry Land Agriculture Investigations, E. Channing Chilcott, Agriculturist in Charge.

Pomological Collections, Gustavus B. Brackett, Pomologist in Charge.

Field Investigations in Pomology, William A. Taylor and G. Harold Powell, Pomologists
in Charge.

Experimental Gardens and Grounds, Edward M. Byrnes, Superintendent.

Vegetable Testing Gardens, William W. Tracy, sr., Superintendent.

Seed and Plant Introduction, David Fairchild, Agricultural Explorer in Charge.

Forage Crop Investigations, Charles V. Piper, Agrostologist in Charge.

Seed Laboratory, Edgar Brown, Botanist in Charge.

Grain Standardization, John D. Shanahan, Expert in Charge.

Subtropical Laboratory and Garden, Miami, Fla., Ernst A. Bessey, Pathologist in Charge.

Plant Introduction Garden, Chico, Cal., August Mayer, Expert in Charge.

South Texas Garden, Brownsville, Tex., Edward C. Green, Pomologist in Charge.

Cotton Culture Farms, Seaman A. Knapp, Lake Charles, La., Special Agent in Charge.

Editor, J. E. Rockwell.
Chief Clerk, James E. Jones.

INVESTIGATIONS OF DISEASES OF FRUITS.
SCIENTIFIC STAFF.

M. B. Waite, Pathologist in Charge.

P. J. O'Gara, W. S. Ballard, and F. W. Faurot, Scientific Assistants.

C. L. Shear, Pathologist in Charge of Investigations of Diseases of Small Fruits.
George F. Miles, Lon A. Hawkins, and Mrs. Anna K. Wood, Scientific Assistants.

W. M. Scott, Pathologist in Charge of Orchard Spraying Demonstration Work.
James B. Ilorer and T. W. Ayres, Scientific Assistants.
110

2

LETTER OF TRANSMITTAL

U. S. DEPARTMENT OF AGRICULTURE,

BUREAU OF PLANT INDUSTRY,

OFFICE OF THE CHIEF,
Washington, D. C., April 26, 1907.

SIR : I have the honor to transmit herewith, and to recommend for
publication as Bulletin No. 110 of the series of this Bureau, the
accompanying technical paper entitled " Cranberry Diseases," by
Dr. C. L. Shear, Pathologist in Charge of Investigations of Dis-
eases of Small Fruits.

This paper contains the first full account of the fungous parasites
of the cranberry and the diseases they produce. It also gives suc-
cessful methods of preventing the diseases.

The illustrations which accompany this paper are considered
essential to a full understanding of the text.
Respectfully,

B. T. GALLOWAY,

Chief of Bureau.
Hon. JAMES WILSON,

Secretary of Agriculture.
110

239382

CONTENTS.

Page.

Introduction ! 9

Previous investigations ' 10

The most serious diseases 12

Blast _- 12

Scald 13

The fungus (Guignardia vaccinii Shear) causing blast and scald 14

Pycnidial form 14

Ascogenous form 15

Cultures of Guignardia vaccinii 16

Pycnidial form 16

Ascogenous form 17

Conditions or factors determining the production of the ascogenous

form 19

Dormant condition of the fungus 21

Time and manner of infection 22

Treatment 24

Applications to the soil 24

Improving the condition of the plants 24

Selection of resistant varieties 25

Application of fungicides 25

Rot 26

The fungus (Acanthorhynchus vaccinii Shear) causing the rot 27

Ascogenous form 27

Appressoria 27

Relationship of the fungus 28

Cultures of the fungus 29

Treatment 30

Anthracnose 30

The fungus (Glomerella rufomaculans vaccinii Shear) causing an-

thracnose 31

Conidial form 31

Ascogenous form 31

Appressoria, or chlamydospores 32

Cultures of Glomerella rufomaculans vaccinii 32

Factors determining the production of the ascogenous fructifica-
tion 33

Relationship of the fungus 33

Dormant condition of the fungus 34

Treatment 35

Hypertrophy 35

The fungus (Exobasidiwn oxycocci Rostr.) causing hypertrophy 36

Relationship to other Exobasidii — 36

Treatment... , 37

110

5

6

CONTENTS,

! * : • • '«? i .* •*£' ' / Page.

Less important diseases _'.i^ii_-J__lil 37

Fungi attacking the fruit 37

Synchytrium vaccinii Thomas 37

Pestalozzia guepini vaccinii Shear 38

Pestalozzia </uepini Desm 39

Helminth osporium inaequalis Shear 39

Gloeosporium minus Shear k 40

Sporonema oxycocci Shear 41

Arachniotus trachyspermus Shear 41

Septoria longispora Shear 42

Sphacroiicma pornorum Shear '. 42

. Phyllosticta putrefaciens Shear 43

Anthostomella destruens Shear 43

Penicillium glaucum Link 43

Leptothyrium pomi (Mont) Sacc.? 44

Fungi occurring on the leaves or stems 44

Venturia compacta Peck 45

Sclerotinia oxycoccl Wor?_^ 45

Discosia artocreas. (Tode) Fr : 40

PlagiorhaMus oxycocci Shear 40

'Sporon&tna pulvinatum Shear 40

Rhabdospora oxycocci Shear 47

Leptothyrium oxycoccl Shear 1 47

Ceuthospora (?) lunata Shear 47

Valsa delicatula C. & E 48

Cladosporium oxycocci Shear 48

Plectrothrix globosa Shear 48

Chondrioderma simplex Schroet 48

Epicoccum 49

Diplodia 49

Chaetomium 49

Oospora 49

Macrosporium 49

Preventive and remedial measures _• — 49

Regulation of the water supply 49

Destruction of diseased vines 50

Selection and breeding of resistant plants _ — 50

Application of fungicides 50

Bordeaux mixture 51

Preparation and application 52

Cost of spraying 53

Summary ^

Bibliography of cranberry diseases 55

Description of plates 58

Index 61

110

LLUSTRATIONS.

Page.
PLATE I. Cranberry scald, showing different stages in the progress of the

disease Frontispiece.

II. Fungous parasites of the cranberry. Figs, 1 to 14. — Guignardia

vaccinii. Fig. 15. — Pestalozzia guepini vaccinii 60

III. Fungous parasites of the cranberry. Figs. 1 to 9. — Glomerella

ritfoniaculans vaccinii. Figs. 10 and 11. — Gloeosporium
minus. Figs. 12 to 22. — Acanthorhynchus vaccinii GO

IV. Fungous parasites of the cranberry. Figs. 1 to 7. — Venturia

compacta. Figs. 8 to 11. — Anthostomella destruens. Figs. 12
to 14. — Septoria longispora. Figs. 15 to 17. — Synchytrium

vaccinii. Figs. 18 to 22. — Arachniotus trachyspermus 60

V. Less important cranberry fungi. Fig. 1. — Sphaeroncma ponio-
rum. Figs. 2 and 3. — Plagiorhabdus oxycocci. Figs 4 to
9. — Helminthosporium inaequalis. Fig. 10. — Phylloitticta pu-
trefaciens. Pigs. 11 and 12. — Ceuthospora (?) lunata. Figs.
13 to 15. — Lcptothyrium poim (V). Fig. 16. — Fungous spores
associated with Leptotliyriwn pomi (?). Figs. 17 to 20. —
Sporoncnia c.vi/coccL Figs. 21 to 24. — Rhabdospora oxycocci.
Figs. 25 to 28.—8poronema puivinatum. Figs. 29 to 33. — Lep-

totliyrium oxycocci 60

VI. Cranberries destroyed by blast and scald 60

VII. Cranberry Exobasidii. A and B. — Etrobasidium vaccinii. C

and D. — Exobasidium oxycocci 60

110

B. P. I.— 286.

CRANBERRY DISEASES.

INTRODUCTION.

The American cranberry (Vaccinium macrocarpum) has been in
cultivation for seventy-five years or more. The wild plant in its
native habitat does not appear to be affected to any very noticeable
degree by fungous parasites. Up to the present time only five species
of fungi, according to the published host indices, have been reported
as occurring upon this plant. It is generally the case, however," that
the longer a plant is in cultivation and the greater the area covered
by it the more numerous and serious are its parasites, since the con-
ditions and opportunities for their development and distribution be-
come much more favorable. This is true of the cranberry. At the
same time, this plant by selection, cultivation, and growth under
rather abnormal conditions has apparently become somewhat weak-
ened and more susceptible to disease.

The cranberry is distributed from Newfoundland southward
through the Alleghenies to North Carolina and westward into Wis-
consin. It is also cultivated in a few localities on the Pacific coast,
in Oregon and Washington. The native cranberry of that region is
regarded by some botanists as a variety of Vaccinium oxy coccus.'1 (°)

The diseases of the cranberry are most serious in the southern sec-
tions of its area of cultivation. The losses from the various maladies
are heaviest in New Jersey and decrease as one proceeds northward
through Long Island, Connecticut, and Massachusetts, being least of
all in. the bogs of Nova Scotia. There is also comparatively small
loss from disease at present in Wisconsin and on the Pacific coast.
The annual crop of the United States approximates 1,000,000 bushels,
valued at about $2,000,000. The loss from disease is estimated to
average about 10 per cent, or $200,000 each year. From a careful
study of the matter is seems probable that the climatic conditions are
chiefly responsible for the greater amount of loss in the southern
localities. The long, hot summers of the southern region seem to
be unfavorable to the production of the most hardy cranberry plants

o The serial numbers used in this paper refer to the bibliography which will be
found on pages 55 to 57.

3525— No. 110—07 M 2

9

10 CRANBERRY DISEASES.

and at the same time most favorable for the development of the vari-
ous parasitic fungi which attack them.

Several serious diseases have been found to be prevalent. They have
nearly all, however, been heretofore included under one name by
cranberry growers. All softening of the fruit, accompanied by more
or less discoloration, has been called " scald " or " rot." This was
quite natural, as the . differences in the appearance of fruit attacked
by the different parasites are so slight that it is difficult to distinguish
between them by external examination.

There is no accurate record, so far as we have been able to discover,
as to when the cranberry diseases first became sufficiently serious to
cause much loss. Mr. J. J. White read a letter before the Cranberry
Growers' Association in 1873 showing that the scald was known
twenty years earlier, i. e., 1853. The diseases have probably spread
more or less gradually as the fruit has become more widely cultivated.

PREVIOUS INVESTIGATIONS.

Cranberry scald was a frequent subject of discussion at the early
meetings of the New Jersey Cranberry Growers' Association,2 which
was organized in 1869 and is now called the American Cranberry
Growers' Association.

In 1874 Dr. Thomas Taylor, Microscopist of the Department of
Agriculture, was sent by the Commissioner of Agriculture, at the
request of the American Cranberry Growers' Association, to investi-
gate the so-called cranberry " scald," which had for some years caused
a great amount of loss on some of the New Jersey cranberry bogs.
Doctor Taylor 3 published several articles giving accounts of his obser-
vations and studies. He concluded, as a result of his work, that
the primary cause of the trouble was an excess of acid in the soil and
water. He also believed that excessive heat and drought were impor-
tant factors, causing a fermentation to take place in the fruit. He
observed fungous filaments in the rotten or scalded berries- but did
not consider this fact of much importance.

Taylor 5 says (Monthly Report, Dept. Agr., 1875, 446) : " I am
convinced that the scald and rot, so called, -of the berry may arise
from dissimilar causes, although chemically considered they are
practically the same, viz, the conversion of their starch into grape
sugar, a fermentable substance affording a nidus for the growth of
fungi."

It will be seen from this quotation that the presence of a fungus
was not considered the cause of the disease, but rather a secondary
matter. Taylor believed that the trouble might be remedied by
some application to the soil which would correct its acidity and pre-
vent the fermentation in the fruit. In accordance with this sug-
110

I'UKVIOUS INVESTIGATIONS. 11

gestion a considerable variety of substances ivas tried by the cran-
berry growers, including lime, copperas, salt, and sulphur. Little
or no benefit, however, seems to have been derived from these appli-
cations, and the diseases continued to cause serious loss, varying
somewhat in different seasons as the climatic and other conditions
chanced to be favorable to their development or otherwise.

Schroeter,8 in 1879, in discussing a sclerotium disease of the fruit
of Vaccinium myrtillus, mentions the American cranberry disease
which had been described by Taylor and expressed his belief that the
trouble was due to a parasitic fungus, either the same or one similar
to that which he found in Europe. He had seen no specimens, how-
ever. Supposing the disease to be due to Sclerotinia, he recom-
mended the application of lime and suggested flooding the vines just
before the spores are formed.

Woronin 9 in 1888 in treating of Sclerotinia oxycocci refers to the
cranberry disease of the eastern United States and suggests that it
is caused by this fungus. This opinion was not based on an examina-
tion of specimens, however, but on Doctor Taylor's accounts of the
disease. If the disease were caused by Sclerotinia he thought it
could be eradicated by collecting and burning all the mummied
berries.

Xo species of Sclerotinia has yet been found on cranberries in the
East so far as known, but, as will be seen later, one has been found
in Wisconsin.

In 1889, Dr. Byron D. Halsted,10 of the New Jersey Experiment
Station, undertook a study of the cranberry diseases, arid as a result
published a bulletin and several briefer reports on the subject.
Doctor Halsted 8 recognized the parasitic nature of the disease, and
described and illustrated, without name, the twro stages of the fungus
which produces cranberry scald. On account of his finding fun-
gous hyphse in the stems and roots of plants bearing rotten or scalded
berries, he concluded that the parasite infested the soil and perhaps
gained entrance to the plant, in part at least, by way of the roots. He
consequently thought that remedies should be directed chiefly toward
the improvement of soil conditions,11 though later he recommended
spraying with a solution of ammoniacal copper carbonate.12 In his
later publication13 he says: "It seems well established that the
fungus infests all parts of the plants and may enter the berry by
means of the filaments which grow from the stem directly into the
green berry, or by spores lodging upon the surface, the germ threads
penetrating the fruit." Doctor Halsted 10 also investigated the cran-
berry gall disease, which will be referred to later.

Some work on cranberry diseases has also been done at the Wis-
consin Agricultural Experiment Station. This will be referred to
later in discussing the diseases,
no

12 CRANBERRY DISEASES.

Ill 1901, at the urgent request of the American Cranberry Growers'
Association and in cooperation with the New Jersey Experiment
Station, a study of cranberry diseases on behalf of the Bureau of
Plant Industry was commenced by the writer. Both field and labo-
ratory investigations have been continued since as the pressure of
other duties would permit. Careful studies were first made of the
field conditions, and laboratory and greenhouse studies have been
made of the diseases found and the fungi producing them.

THE MOST SERIOUS DISEASES.

Cultures of the fungi found in diseased berries soon showed that,
instead of a single disease, the term " scald " as used by cranberry
growers includes at least three distinct diseases of the fruit — scald,
rot, and anthracnose — caused by three different fungous parasites,
Guignardia vaccinii Shear, Acanthorhynchus vaccinii Shear, and
Glomerella rufomaculans vaccinii Shear. Besides the diseases which
affect the more or less mature fruit there is another, commonly called
u blast," or sometimes " blight," by the cranberry growers, which
attacks the very young berries about the time the blossoms fall,
causing them to turn black and shrivel up. There is also a disease
which causes hypertrophy of the axillary leaf buds, and thus ex-
hausting the vitality of the plant prevents the production of fruit.
The most important diseases of the cranberry are those mentioned.
Besides these there are a number of diseases of minor importance
which will receive briefer consideration.

BLAST.

As already mentioned, the blast attacks the flowers and very young
fruit, which shrivels up and becomes covered with the pycnidia of
the parasite (PL II, figs, la, 16). It frequently happens that as
much as one-half of the crop on some bogs or portions of bogs is
destroyed in this manner. The disease is caused by the pycnidial
form of Guignardia vaccinii Shear.24 The blasting of young fruit
had been observed for many years by cranberry growers, but appar-
ently the fungous nature of the disease was not known. There
is, of course, some blast, or blight, of blossoms and of very young
fruit due to other causes, as imperfect fertilization or injury by
storms, frost, or insects, but by far the greater part of the blasted
fruit on New Jersey cranberry bogs is due to the above-mentioned
fungus.

Whitson, Haskins, and Malde15 mention a cranberry "blight"

which occurs in Wisconsin, killing the blossoms and very small fruit.

This trouble, according to the writers mentioned, has been attributed

by growers to hot weather. The results of their experiments were

no

SCALD. 13

contrary to this theory. They concluded from their trials with
several fertilizers that the blight depended largely upon the vitality
of the vines. Plats treated with phosphates showed least blight.
In conclusion they say : " The agent of destruction of these blossoms
is probably a bacterial or fungus growth which takes place only
under a devitalized or weakened condition.'' Having had no oppor-
tunity to make a study of the blight, or blast, in Wisconsin, we are
unable to say how much of it may be due to Guignardia vaccinii,
which produces the blast, or blight, in the East. From the fact that
this fungus occurs in Wisconsin and destroys more or less of the
fruit, it is highly probable that some of the blight, or blast, is also
caused by it. The " blossom blight " is also mentioned by Whitson,
Sandsten, Haskins, and Ramsey.10 They state that a treatment for
blight of three applications of Bordeaux mixture produced an
increase of 30 per cent in the crop of fruit over that on adjacent
vines not treated. This would seem to indicate that the disease is of
a fungous nature.

SCALD.

The term u scald " is one which has been in general use among
the New Jersey cranberry growers for a long time. It originated
as a result of a view previously held by many growers that the
softening of the diseased fruit was due to an actual scalding of the
berry, caused by the hot sunshine when the berries were wet.

A condition somewhat resembling the effect of the fungus does
sometimes occur when berries have been overflowed and covered
with water for half a day or more during hot weather, but injury
of this kind is infrequent and unimportant.

The first indication of the attack of the scald fungus upon the
cranberry is the appearance of a minute, light-colored, watery spot
upon its surface. This, under favorable conditions, rapidly spreads,
usually in a concentric manner, until finally the whole berry becomes
soft (PI. I). Frequently the diseased area is marked by con-
centric dark-colored rings. This, however, is not always the case,
and is not especially characteristic of this disease, as it sometimes
occurs in the case of the cranberry rot. In very rare instances only
a small, light-colored sunken spot is produced upon the berry, the
fungus by some unknown cause having been retarded or entirely pre-
vented from further development. In such cases we occasionally find
the pycnidia of the scald fungus present, as illustrated by Doctor Hal-
sted 10 in his work on cranberry scald. Ordinarily, however, there
is no indication on the surface of the fruit of the presence of a
fungus, except for occasional dark blotches or brownish zones, as
mentioned above. Berries which are attacked before they are half
grown usually shrivel up and become blackened and covered with
no

14 CRANBERRY DISEASES.

the pycnidia of the scald fungus (PL II, fig. 1, &, and PL VI). This
form of the disease is called blast, as already described.

The disease also affects the leaves, occasionally causing an irregular
reddish brown spot, covering a portion of the leaf, and bearing
pycnidia or perithecia of the fungus. These spots are of very infre-
quent occurrence. Where the disease has been severe for a number
of years the plants are completely killed, and the dead, brown leaves
still hanging to the vines are usually covered on the under surface
with the minute fruiting bodies of the parasite (PL II, fig. 1).

Cuttings the first year or two after planting and before fruiting
are sometimes seriously attacked by Guignardia vaccinii, which
causes the leaves to turn yellow and fall and finally kills the plant.
Some of the other cranberry fungi are also associated with this
injury, but the greater part of the damage is apparently due to the
scald fungus.

THE FUNGUS (GUIGNARDIA VACCINII, SHEAR) CAUSING BLAST

AND SCALD.

Scalded or rotten berries so rarely show any fruiting forms of
fungi that it is necessary to determine their presence and identity
by careful microscopical examination and cultures. A microscopic
study of the softened tissues of scalded berries at once reveals the
presence of an abundance of fungous hyphse. These hyphse when
transferred to culture media grow readily and frequently produce
the fruiting forms of the fungus. This fungus, Guignardia vaccinii
Shear,24 which has been found upon blasted berries, upon the leaves
of scalded vines, and isolated in numerous cases in pure cultures
from scalded fruit, has been grown in the laboratory for several
years.

Whitson, Sandsteri, Haskins, and Kamsey16 state that the cran-
berry scald in Wisconsin is caused by an unnamed species of Rosel-
linia. We have never found any fungus of this genus associated
with cranberry scald or any other disease of the cranberry in Wis-
consin or elsewhere. The only cranberry fungus which at all resem-
bles Rosellinia is Anthostomella destruens Shear, which has been
found only once in our investigations, and then in New Jersey. The
true scald fungus (Guignardia vaccinii} has, however, been found in
Wisconsin berries. There are two stages thus far known in the
course of its development, a pycnidial and an ascogenous stage.

Pycnidial form. — The pycnidia are minute, black, membranous,
globose receptacles, 100-120^ in diameter, provided with a minute
apical, sometimes slightly prominent ostiole, or mouth. When oc-
curring on the leaves they are situated beneath the epidermis, usually
on the under side, and are slightly erumpent, with the minute ostiole
no

THE FUNGUS CAUSING BLAST AND SCALD. 15

exposed. In most cases they are thickly and evenly distributed over
the sui'face of the leaf, except for the infrequent occasions when only
a portion of the leaf has been killed by the fungus (PL II, figs. 1 and
2). Mature pycnidia contain great numbers of pycnospores, bearing
at their apexes a rather inconspicuous appendage consisting of
granular matter, which appears to be embedded in a somewhat gelat-
inous substance. They are borne on short, simple sporophores 10-15 ^
long. These pycnospores are hyaline, obovoid, with the apex fre-
quently truncate, and measure from 10.5 to 13.5 by 5 to 6 ^. The
appendage is usually about the length of the spore, or somewhat less,
and curved (PL II, fig. 3, «, 6, c). At maturity these pycnospores
are expelled from the pycnidium in a small gelatinous tendril or
threadlike mass, being held together by the gelatinous substance of
the spore appendages as Avell as the free gelatinous matter which
appears to be produced within the pycnidium and forms a thin layer
about the pycnospore.

Ascogenovs form. — The ascogenous perithecia are much less fre-
quently found than the pycnidia. The perithecia resemble the pyc-
nidia very closely in form, size, and other characteristics (PL II,
fig. 10). In fact it is almost or quite impossible to determine, in the
absence of asci or pycnospores, to which form a particular fruiting
body may belong. The perithecia seem to have a denser, somewhat
more opaque wrall than the pycnidia, and they contain oblong, or
somewhat clavate, short-stipitate, or sessile asci, the spore-bearing
portion varying from 52 to 60 by 9 to 12 ^ the total length being GO
to 80 fji (PL II, fig. 11). The asci contain eight hyaline, or, when
old, slightly yellowish brown, short elliptical or subrhomboid asco-
spores, having the contents rather coarsely granular (PL II, fig. 12).
They vary in size from 13 to 16.5 by 6 to T/x. No paraphyses have
been found. The characters of the ascogenous form of this fungus
seem to agree most nearly with those of the genus Guignardia and
correspond very closely to the black-rot fungus of the grape (Guig-
nardia ImJwellii (Ell.) V. & R.). The pycnidial stage of Guignardia
bidwellii, as described and illustrated by Viala 18 and others, differs
from the pycnidial stage of the cranberry scald fungus in scarcely
any particular except in the absence of the spore appendage. A
recent careful study of fresh pycnidia of (Guignardia bidweUii shows
that its pycnospores also bear a similar appendage. It is, however,
shorter and less easily distinguished than that of Guignardia raccinii,
and soon disappears in mounted specimens. The appendage in the
case of the cranberry fungus is very constant and characteristic.

The cranberry scald fungus is rather generally distributed through-
out the cranberry-growing sections of this country. Pycnidia have
been found on either leaves, flowers, or fruit in West Virginia, New
no

16 CRANBERRY DISEASES.

Jersey, Massachusetts, Nova Scotia, Wisconsin, and New York, and
perithecia in New Jersey and New York.

CULTURES OF GUIGNARDIA VACCINII.

Over 200 cultures from hyphae, pycnospores, and ascospores have
been made upon artificial media of various kinds. The first cultures
of the fungus were niade from hyphae taken from the interior of
scalded berries. The berries were first thoroughly washed and
soaked in a 1 to 1,000 solution of corrosive sublimate (HgCL). and
a portion of the pulp containing the fungous hyphae was transferred
with sterile needles to the culture medium.

The following culture media have been used: Cylinders of pota-
toes and of beets ; steam-sterilized and dry-sterilized cranberry leaves
and cranberry fruit; cranberry agar and cranberry gelatin, pre-
pared by adding various proportions of cranberry juice to agar and
gelatin; beef agar and sugar-beet agar; corn meal saturated with
cranberry agar; corn meal saturated with cranberry gelatin; malta
vita saturated with cranberry agar, and corn meal saturated with
distilled water. It appears to grow equally well upon acid and
neutral media.

We have had the greatest and most uniform success in the use of
corn meal and water sterilized in an autoclave for about fifteen min-
utes. The fungus also grows readily on corn meal saturated with
cranberry agar, corn meal saturated with cranberry gelatin, and on
potatoes. It grows more slowly and less luxuriantly on most of the
other media tried.

Pycnidial form. — Cultures producing the pycnidial form have been
made from the pulp and skin of diseased fruits in thirty-eight differ-
ent cases and from leaves in two instances. This form has also been
grown from pycnospores. The mycelium in all cases is at first thin,
floccose, and white. In a few days it becomes denser and takes on a
bluish gray color. As the culture gets older the hyphae spread con-
centrically and the mycelium loses its bluish tint and becomes grayish
brown. Pycnidia begin to appear in four to eight days, and mature
pycnospores can usually be found in -twelve to eighteen days. The
pycnidia form a more or less continuous layer on the surface of the
somewhat felty subiculum formed by the mycelium. They are fre-
quently inconspicuous on account of the velvety surface growth of
hyphae, with which the mycelial layer is covered. In the majority of
cultures made from hyphae taken from diseased berries only pycnidia
are produced, and in many instances the culture has all the character-
istics of growth and appearance of Guignardia vaccinii, but is either
entirely sterile or produces sclerotia-like bodies resembling pycnidia
externally but containing no spores,
no

CULTURES OF GUIGNARDIA VACCINII. 17

Ascogenous form. — Cultures producing both pycnidia and asci have
been obtained in five cases by transplanting the fungous hyphae from
diseased berries, and in three cases from affected leaves, to culture
media.

The first successful culture was made from decaying fruit obtained
in the Washington market. The source of the fruit is unknown, but
it was probably from New Jersey. The culture was made on March
31, 190'2. The berries used were softened; the skin was light colored
and watery and showed small dark-colored blotches of fungous
hyphap on the inner surface. Two cultures were made from one of
these berries by transferring portions of the pulp containing the
hypha? to flasks of cranberry agar and corn meal. The cultures were
kept in the laboratory at the ordinary temperature, which varied
from 16 to 25° C. The course of development and appearance of
the fungus were the same as in the cultures producing pycnospores
only, as previously described. Mature pycnidia were produced in
about twelve to fifteen days, and at the end of twenty-two days a great
abundance of ascogenous perithecia was found. There is nothing
in the macroscopic appearance of a culture bearing ascogenous
perithecia to distinguish it from one bearing only pycnidia. The
ascogenous perithecia are practically identical in appearance with the
pycnidia. In mature and old cultures the color of the mycelium
becomes dark brown, or almost black, and the pycnidia or perithecia
become more exposed on the surface of the subiculum or crustlike
stroma.

The second successful culture of the ascogenous form was made
January 20, 1903, by transferring a portion of the skin of a diseased
berry showing darkened spots to a flask of water-saturated, autoclaved
corn meal. The course of development was the same as in the culture
just described. Many bodies resembling pycnidia were produced at
first, but all examined were apparently sterile. Later, in addition
to these sterile bodies, ascogenous perithecia of Guignardia were
found.

The third successful culture, of ascogenous perithecia was made
December 23, 1903, from diseased New Jersey berries, which had
been kept in ordinary storage in an unheated building in the Depart-
ment. These berries showed the ordinary appearance of scalded
fruit, and the cultures were made by transferring sections of diseased,
berries which had been washed and soaked in a solution of corrosive
sublimate to flasks of sterilized corn meal. An abundance of fertile
pycnidia was produced, and at the end of nineteen days perithecia
containing mature asci were found.

The fourth successful culture was also made at the same time as
the last mentioned, and from fruit from the same source, treated in
the same manner.

3525— No. 110—07 M 3

18 CRANBERRY DISEASES.

The fifth successful culture from diseased berries was made May
10, 1904. The berries Avere received from Cranmoor, Wis. They
were softened and shriveled and showed definite black spots 011 the
surface. After washing and soaking for three-fourths of an hour
in corrosive-sublimate solution, sections of the diseased portion, in-
cluding the skin, were transferred to large tubes of sterilized corn
meal. About one month later ascogenous perithecia of Guignardia
were found in this culture. Several other cultures made at the same
time upon the same culture medium and from fruit having the same
appearance produced only pycnidia. Transfers made from cultures
producing asci to sterile potato cylinders have produced the ascoge-
nous form as quickly and 'abundantly as when grown on corn meal.

Besides the successful cultures just described, which have been made
from diseased berries, we have, in three instances, obtained from
cranberry leaves pure cultures bearing both pycnidia and asci.

On March 23, 1905, cultures were made by placing in flasks of
sterile corn meal leaves which had been first soaked for about onp
hour in a 1 to 500 solution of corrosive sublimate and then cut in
two pieces. These leaves were taken from vines which had borne
very badly scalded fruit during the previous season. The vines were
collected on November 29, 1904, and kept in an ice box from that
time until the cultures were made. The leaves were of 1903 growth
and were to all external appearances healthy and free from fungi.
Leaves taken from this collection in March, 1906, still produced plenty
of good pycnidia and ascogenous perithecia. The course of develop-
ment of the fungus in these cultures was identical with that described
in the other cases. Pycnidia were produced in abundance in about
fifteen days, and at the end of twenty-nine days ascogenous perithecia
were found in three of the cultures.

From these original cultures many others have been made by trans-
fer. Four generations have been grown in this way, producing both
pycnospores and ascospores in each. After this the fungus appeared
to have lost its vitality and did not grow well. In other cases it
developed both spore forms for one or two generations only.

The fresh pycnospores of this fungus germinate and grow readily
in water, in a dilute solution of sugar and water, and in ordinary
culture media. Spores placed in a drop culture of sugar water in the
laboratory began to show signs of germination at the end of two days.
The germ tube usually arises from the side of the pycnospore, first
forming a slight enlargement, which rapidly elongates into a germ
tube and soon begins to branch (PL II, figs. 4 to 9). At the end of
four days many of the germ tubes have attained considerable length.
The tube occasionally arises from the basal end of the spore (PL II,
fig. 6), but we have never seen it arise from the apical end, where the
no

THE PRODUCTION OF THE ASCOGENOUS FORM. 19

appendage is borne. The mycelium now grows more rapidly and soon
assumes the color and other characteristics mentioned in the descrip-
tion of the macroscopic appearance of cultures of the fungus.

The appendage of the pycnospore, as seen upon immature spores,
consists of a hazy, hyaline, finely granular, gelatinous mass, equaling
the spore in diameter (PI. II, fig. 3). A little later it becomes some-
what elongated, curved backward, and more or less appressed on the
side of the spore. As the spore matures the appendage becomes still
narrower and free from the side of the spore, but even at maturity it
is usually somewhat curved. In old cultures which have passed
maturity and in which all the spores have been set free, the append-
age is frequently wanting and seems to have been dissolved or
disintegrated.

No signs of a conidial form of the fungus have been found in any
of the numerous cultures made, either from the mycelium or spores.
No chlamydospores have been found in cultures, but what appear to
be such are found in old berries destroyed by the fungus. Sterile
pycnidia or perithecia are frequently found, especially in poorly
developed cultures. These are sometimes solid and sclerotoid, with
the interior cells lighter colored, and are about the same size as the
pycnidia and perithecia.

CONDITIONS OR FACTORS DETERMINING THE PRODUCTION OF THE
ASCOGENOUS FORM.

The reasons for the rare occurrence of ascus-bearing forms in cul-
tures of what are undoubtedly ascomycetous fungi have always been
obscure, and it has usually been found impossible to produce the
ascogenous fructifications with much frequency or certainty.

The w^ork of J£lebs19 and others upon the effect of various nutrient
and other substances upon the production of sexual fructification,
especially in the alga?, has suggested the possibility of such factors
having a determining influence on the production of the ascogenous
stage in this fungus. While our experiments in this direction have
been comparatively few, there has been no indication that the compo-
sition of the culture medium is of particular importance in this
respect. When once an ascus-producing race, strain, or generation
of the fungus was obtained it grew almost equally well upon different
culture media, such as steamed corn meal, cranberry gelatin and corn
meal, cranberry agar and corn meal, and potatoes.

The effect of variations in temperature has also been tried upon
a series of pycnospore-producing cultures made from the same
original pure culture. Cultures in flasks on corn meal were kept
in the laboratory, where the temperature varied from 20° to 26° C.
Others were kept in a thermostat at- a temperature of 30° C. Others
110

20 CKANBERRY DISEASES.

have been kept in a refrigerator at a temperature of about 3° C.
The cultures kept in the laboratory made the most rapid and vigorous
growth of mycelium, those in the thermostat and refrigerator grow-
ing about one-half as fast. All these cultures finally produced
pycnidia, but no signs of asci were ever found.

Experiments have also been tried to determine the effect of differ-
ent quantities of moisture. The fungus was found to grow more
rapidly on a rather wet medium, but there is no indication that this
influences the production of the ascogenous stage of the fungus.

Other experiments were tried to determine the effect upon the
growth and development of the fungus of varying the amount of
available air and the evaporation by plugging the culture flasks more
or less tightly. Little or no difference was noticeable in the growth
in these flasks, and only pycnidia were produced.

The work of Blakeslee 20 on Mucor and the factors controlling the
production of zygospores in that and related genera has suggested
the possibility that the sexual or ascogenous fructification might
arise from the union of different races or individuals. The few
experiments we have made along this line, however, have been
unsuccessful.

It has been thought by Brefeld 21 that ascus formation may depend
upon the time of the year, or possibly the period of development of
the fungus in its host. Our investigations, however, are not conclu-
sive in regard to these points, so far as they concern Guignardia
vaccinii. Cultures have been made from fruit and leaves taken
almost every month during the year, and it will be noted that cul-
tures which produced the ascogenous stage of the fungus were made
in January, March, May, and December. Many other cultures, how-
ever, made during these same periods and from leaves and fruit in
which the fungus had presumably passed through approximately
the same period of development were either sterile or produced
pycnidia onlv. While we have no cultures made from material taken
during the summer which have produced ascospores, this may be
due to the fact that comparatively few cultures have been made from
leaves or fruit during that season.

In regard to the bearing of the duration of development of the
fungus upon the production of asci, we have no means at hand of
determining, except by mere conjecture, the age of the fungus which
may be present at any particular time in the tissues of cranberry
leaves or fruit, not knowing positively when the infection took place
and the germ of the fungus entered the plant. All the evidence at
hand, however, points toward June and July as the time.

As a result of our work, we are led to the belief that there is some
inherent potentiality in the mycelium of the fungus in certain strains,
no

DORMANT CONDITION OF THE FUNGUS. 21

races, or generations which causes it to produce the ascogenous stage
whenever conditions for its growth are favorable, i. e., on favorable
culture media without special reference to their exact composition
or environment or on the leaves of its natural host. Whether this
potentiality depends on some preceding union of nuclei from dif-
ferent or the same individuals, or some equivalent stimulus, we are,
of course, unable to say. It appears possible, however, that there
may be such a factor concerned.

DORMANT CONDITION OF THE FUNGUS.

Leaves and berries which, so far as can be discovered by external
examination, are perfectly sound are very frequently found to con-
tain the fungus. Leaves perfectly normal in appearance, taken from
vines growing in diseased areas, have been thoroughly washed and
soaked from fifteen minutes to two hours in a solution of corrosive
sublimate, 1 part to 500 parts of water, in order to destroy any
fungous spores which might possibly be present upon their surfaces.
These leaves were then placed in sterile, moist chambers. After a
period of eight to twelve days an abundance of the pycnidia of
Guignardia raccinii was found to have developed upon the leaves, and
in some instances these were followed by the ascogenous form of the
fungus. Berries apparently perfectly sound and healthy have also
been treated in the same manner, and in many cases the characteristic
decay of the fruit has followed. Cultures made from the pulp of
these berries have produced the fruiting forms of the Guignardia.

So many experiments of this kind have been tried that we feel
convinced that the fungus must be present within the tissues of the
leaves and berries referred to in a dormant or more or less inactive
condition. It does not seem possible that any spores could resist the
action of the corrosive sublimate solution used. Tests which have
been made show that the spores of Guignardia vaccinii are killed
by being immersed in a 1 to 1,000 solution of corrosive sublimate for
five minutes. A great number of microtome sections of leaves and
fruit supposed to contain the dormant form of the fungus have been
studied. It has been found very difficult to demonstrate the presence
of the fungus and to determine its form, chiefly, perhaps, on account
of unsatisfactory results in differential staining.

In case of the berries, carefully stained sections have shown what
appear to be cells of fungous hypha? just beneath the epidermis. In
both leaves and fruit the fungus seems to be able to exist in the
tissues in a more or less inactive or dormant condition while await-
ing an opportunity for further development; such opportunity is
apparently afforded by any conditions which weaken the cranberry
plant and also by those which are favorable to the growth of the
no

22 CRANBERRY DISEASES.

fungus, such as sufficient heat and moisture. If a similar condition of
affairs should prove to obtain rather generally among similar para-
sitic fungi, as seems to be possible from observations and experiments
made with other cranberry diseases and several anthracnoses on
different hosts, it will have an important bearing upon the results
and conclusions derived from ordinary infection experiments in
which plants have been used which were not grown from uninfected
seed under conditions which would preclude possible infection at
any time previous to their use. It would also have an important
bearing upon the value of inferences regarding the time of infection
based upon the time of the outbreak of the disease.

It has been supposed that in the case of diseases such as the black-
rot of the grape the time of its external destructive appearance fol-
lowed within a short period after the germs of the disease had entered
the tissues of the plant. In other words, it has been taken for
granted that as soon as a germ tube gains entrance to the tissues of
its host it proceeds to develop under normal conditions and soon pro-
duces its characteristic injuries. On the contrary, however, it seems
much more probable that there is no regular period of incubation,
but that the development of the parasite depends largely upon the
conditions surrounding it and its host. If the host plant becomes
weakened in any way or if the conditions of heat and moisture are
especially favorable for the fungus its development may be rapid and
continuous, but if these conditions do not obtain the fungus may
remain in an inactive or dormant condition, or its development may
be very slow or intermittent and in some cases perhaps entirely sup-
pressed. Many illustrations of this condition can apparently be
found among foliicolous pyrenomycetes which develop their fruits
so abundantly during the winter on old fallen leaves. There is no
evidence, so far as we know, that infection of these leaves takes place
during the winter. The scanty observations which have been made
indicate rather that the mycelium is present in the leaves when they
fall, though there is no outward indication of its presence.

TIME AND MANNER OF INFECTION.

We have been unable thus far to discover exactly when and in what
manner infection of the leaves and fruits takes place. The pycnidial
form of the fungus may be found within from ten to fifteen days
after the water with which the vines are usually flooded during the
wrinter has been removed. This appears to be about the normal
period required for the development of the pycnidia when the growth
of the fungus is regular and continuous, as shown by its growth and
development in pure cultures. The pycnidia appear first upon old
leaves of vines which have apparently been weakened or killed by the
no

TIME AND MANNER OF INFECTION. 23

disease. A great number of pycnospores are also produced about the
1st of July upon the very small blasted berries. These are probably
the chief source of the infections which follow. The pycnospores may
also be found more or less abundantly during the whole season upon
old dead and dying leaves, especially of those vines which have been
cut and broken.

The ascogenous form is apparently not of very frequent occur-
rence. It has been collected occasionally on old leaves from June to
November, but, judging from the small quantity found, it does not
seem probable that it is a very important factor in the general dis-
tribution and spread of the disease. Ascospores in most pyreno-
mycetous fungi appear to be produced normally in late winter and
spring. The abnormal conditions under which the cultivated cran-
berry is grown — the plants being generally flooded with water from
November until May — prevent the production of the fruiting forms
of the fungus during that period. We have found by laboratory ex-
periments that the fungus does not develop upon leaves when they are
kept immersed in water. Twigs with leaves from vines bearing very
badly scalded fruit have been kept in water in the laboratory for
months without any external indication of the development of the
fungus, wrhile leaves from the same plants kept in moist chambers
developed Guignardia in abundance. In the early stages of our inves-
tigation various inoculation experiments were tried, both in the field
and in the greenhouse, using plants which were presumably free
from disease, judging from the external appearance of the vines and
berries. The results of these experiments have, however, since been
shown to be valueless on account of the quite general occurrence of
the fungus in leaves and fruit which appeared normal and healthy,
as already pointed out. In order, therefore, to make conclusive infec-
tion experiments it is necessary to grow plants from seed in sterile
soil under conditions which will prevent possible infection from any
'source except artificial inoculation. Thus far we have been unable
to do this, owing to the fact that great difficulty has been experienced
in germinating seeds and growing satisfactory plants in the green-
house. From field observations made in connection with our spray-
ing experiments it seems very probable that infection of the young
leaves takes place very early in the season, soon after the water is
removed from the bog and as soon as the first generation of pycno-
spores is produced upon the old dead and fallen leaves. There are
also observations and facts which seem to indicate that infection of
the berries generally takes place when they are rather young. This
is self-evident of course in the case of the blasted fruit, which is
destroyed when it is very small. Attempts to infect mature or nearly
mature fruit in the laboratory have in all cases been unsuccessful,
no

24 CRANBERRY DISEASES.

Fresh pycnospores have been placed in drops of water upon fruit
kept in sterile moist chambers, but without any noticeable result.
The spores germinate, but are apparently unable to penetrate the
epidermis of the fruit. That infection of the foliage and fruit in-
stead of taking place in whole or in part by way of the roots and up
through the stems, as supposed by Doctor Halsted, arises from exter-
nal sources seems to be proved by the very satisfactory results of
spraying experiments and by the observations already recorded. Sev-
eral tips of vines bearing leaves, collected September 15, which had
been thoroughly sprayed during the season, were carefully washed
with corrosive sublimate and placed in sterile moist chambers. A
few fungi developed in a very few of these leaves. Other leaves,
collected at the same time from adjacent vines which had not been
sprayed, were treated in the same manner. These were found to be
completely infested with fungi, and the pycnidia of Guignardia de-
veloped in abundance on almost every leaf.

A considerable quantity of fruit which had been sprayed was
treated in the same manner as the leaves already mentioned. As a
result, 1,200 sprayed berries picked on September 18 showed on
October 18 but 9.8 per cent of diseased fruit, while the same number
of unsprayed berries from the same source kept under the same con-
ditions in the laboratory for the same period showed 38.1 per cent
of diseased fruit. The only explanation of these results in the light
of our present knowledge of the effect of Bordeaux mixture is that
most of the spores of the fungus had been destroyed by the spraying
and therefore did not gain entrance to the leaves and fruit.

TREATMENT.

Applications to the soil. — Acting upon the supposition that the
cranberry- scald was primarily due to unfavorable soil conditions or
to fungi attacking the plant by way of the root system, chemicals
or fungicides to be applied to the soil were suggested as a remedy
by Doctor Taylor,4 and later they wrere tried by Doctor Halsted.11
Lime, plaster, salt, sulphur, copper sulphate, and iron sulphate were
tried in different quantities. No decided benefit is reported to have
resulted from these applications.

Improving the condition of the plants. — It is a' matter of general
observation that the cranberry scald is much more serious on certain
bogs or portions of bogs than on others. The conditions obtaining in
the soil and water of these diseased areas no doubt have much to do
with the prevalence of the disease. The factors concerned are so
complex, however, that it is difficult to demonstrate satisfactorily
exactly what they are and which are of greatest importance. The
experience of various growers appears to show that the control of the
no

TREATMENT. 25

water supply is an important factor. The cranberry plant is natu-
rally water loving and grows in its wild condition in the sphagnum
bogs of deep swamps. When it is cultivated in open meadows and
without a constant and sufficient water supply it quite naturally
becomes weakened and susceptible to disease. In order to keep the
plants in a thrifty condition the water supply should not only be
sufficient but well controlled, so that the moisture may be kept near
the surface during the growing season. In many cases there are local
soil conditions which interfere with the healthy growth of the plants.

The practice of applying a thin layer of sand to the surface of the
bog every few years is quite general in Massachusetts and is believed
to tend to keep the plants in a thrifty and vigorous condition. In
New Jersey this practice is not so common and the beneficial results
where it has been tried do not seem to have been so apparent as in
Massachusetts. The practice of sanding, since the sand would cover
all the fallen diseased leaves and many of the old dead vines, would
tend to prevent the development and spread of the spores and might
prove beneficial in this way, if in no other. It is also desirable as a
sanitary measure to rake out and destroy all dead and dying plants.
The fungus Guignardia vaccinii produces its spores in great abund-
ance upon such plants, and these, therefore, serve as a source of dis-
tribution for the parasite. All such dead and diseased matter should
be destroyed by burning, preferably in the fall of the year.

Selection of resistant varieties. — It has been frequently observed
that even in the most diseased areas of cranberry plants there is an
occasional vine bearing fruit which appears to be free from disease.
It seems probable, therefore, that by the selection and propagation
of such plants a variety might be produced which would show a
very considerable degree of resistance to. this disease. As the cran-
berry is generally reproduced by cuttings, the propagation of a re-
sistant variety would be simpler and more likely to succeed than
in the case of plants propagated by seed.

Application of fungicides. — As already stated, Doctor Halsted 1X
recommended spraying with ammoniacal copper carbonate. He also
reports 4 trying several fungicides, including Bordeaux mixture and
potassium sulphid, making two applications of each. No benefit
from these applications was observed.

After determining the parasitic nature of the cranberry scald,
the relationship of the parasite, and the probable manner of infec-
tion, it seemed reasonable that the disease should be prevented by
the proper use of fungicides. In our first experiments the ammonia-
cal copper carbonate solution, potassium sulphid solution, and Bor-
deaux mixture were used. As very little benefit was apparently
derived from the use of the two fungicides first mentioned, later
352o— No. 110—07 M 4

26 CKANBEKKY DISEASES.

experiments were made with Bordeaux mixture only. In the spray-
ing work of 1904 2r> the results showed an average of 21.7 per cent of
diseased fruit on the sprayed plats, while on the unsprayed check
plat there was an average of 76.8 per cent diseased. The circum-
stances under which this was done were such, however, that the appli-
cations could not be made at proper intervals. During the next
season (190526) the work was done more thoroughly and the results
were far more satisfactory. As a result of five applications the
sprayed plats averaged 2.36 per cent of rotten berries, while the un-
sprayed check plats averaged 92.6 per cent of rotten fruit. The
6-6-50 formula for Bordeaux mixture was used and 4 pounds of
resin-fishoil soap were added. It was found that the plain Bordeaux
mixture did not spread properly over the surface of the fruit and
foliage, and also did not adhere well. In order to correct these
defects the soap was added and was found to give most satisfactory
results. The cost of spraying as done in these experiments averaged
from $15 to $20 per acre, the mixture being applied at the rate of
4 barrels, or 200 gallons, at each application. Success in preventing
this disease by spraying depends largely upon the care and thorough-
ness with which the preparation is made and .applied. In our last
experiments the 5-5-50 formula was used, and with thorough work
it has been found to give as satisfactory results as the 6-6-50 mixture.

ROT.

The term " rot " is here applied to a decay of the cranberry caused
by a fungus which we have recently described as a new genus and
species (Acanthorhynchus vaccinii Shear).24 The appearance of the
fruit attacked by this disease is not sufficiently peculiar or character-
istic to satisfactorily distinguish it from scald or anthracnose by its
external or internal appearance. The rot first appears as a small,
light-colored, soft spot on the berry, finally softening and destroying
the whole fruit. In the later stages of its development it very fre-
quently produces small, dark-colored blotches on the inner surface
of the skin. So far as has been observed, the fungus never produces
spore-bearing fructifications upon the berries. The only way in
which this disease can be positively diagnosed is by making a culture
from the mycelium of the fungus taken from the interior of the
affected fruit.

The disease attacks the leaves also, but the fungus is very rarely
found in a fruiting condition except on those which have fallen to
the ground. Judging from the frequency with which this fungus
appears in cultures made by transplanting the fungous hypha3 from
decaying berries, the injury caused by it is second only to that pro-
duced by the scald. Though this disease is most frequent and destruc-
no

THE FUNGUS CAUSING THE BOT. 27

t i Y(> in New Jersey, it has also been found in West Virginia, Massachu-
setts, Wisconsin, and Nova Scotia.

mi: FUNGUS (ACANTHORHYNCHUS VACCINII, SHEAR) CAUSING THE ROT.

The fungus producing the rot dift'ers in several respects from any
species which we have been able to find described. The rarity of its
occurrence in a fruiting condition in the field probably accounts for
its not having been discovered before. It has been found occasion-
ally in considerable quantity on fallen leaves of diseased vines, and
frequently appears on apparently healthy leaves from diseased
vines which are kept in a sterile moist chamber for a week or two. It
grows readily on various culture media and produces an abundance
of ascogenous perithecia.

Ascogenous form. — The perithecia are ordinarily sparsely scat-
tered over the under surface of the leaf, being buried beneath the
epidermis, which is very slightly elevated and punctured by the short
neck and ostiole (PL III, fig. 12). They usually vary in diameter
from 300 to 400 /*. The short neck of the perithecium is beset with
black, nonseptate spines 50 to TO /x long by 8 to 9 ^ thick at the base.
These black spines are a constant and characteristic feature of the
fungus, occurring in all of our cultures, as well as under natural
conditions (PL III, fig. 13). On leaves the perithecia are somewhat
depressed globose, but in artificial cultures, where there is no
pressure from above as there is in the tissue of the host, they are
somewhat pyriform. The wall of the perithecium is membranous or
submenbranous in texture and consists of a single layer of cells. The
asci are clavate, short-stipitate, and range in size from 136 to 180 by
30 to 48 p.. They are accompanied by rather stout, sepate paraphyses,
occasionally branched near the end and varying in dimensions from
200 to 340 by 5 to 8 /x. The ascospores are somewhat biseriate or
irregularly uniseriate. They are hyaline until almost mature, but
finally assume a pale yellowish brown color. In shape they are
oblong elliptical, and the protoplasm is densely granular. They vary
in size from 27 to 36 by 12 to 20 p.

Fruiting specimens on leaves have been collected in May, July,
August, September, and October, and have been found in Nova
Scotia, Massachusetts, New Jersey, West Virginia, and Wisconsin.

No conidial or pycnidial form of this fungus has ever occurred in
any of our numerous cultures, and no such form has been found asso-
ciated with it in nature under such circumstances as to suggest a
genetic relation.

Appressoria. — A rather remarkable body is produced by the germ
tube of the germinating spore. This is a more or less disciform,
dark-colored, rather opaque organ, with an irregular, rather deeply
110

28 CRANBERRY DISEASES.

lobed margin (PL III, fig. IT). It has been found upon the surface
of leaves which bore mature perithecia, but was first found on the
smooth surface of the upper portion of culture flasks where spores
of the fungus had germinated. It is produced at the end of a short
germ tube, arising from the ascospore, and its primary function is
evidently that of an apressorium or holdfast.

Appressoria were first described and so named by Fisch 37 in 1882,
as found in Polystigma. A little later Frank 38 described the same
thing and also the similar productions occurring in Gloeosporium
lindemuthianum. These bodies have usually been called chlamydo-
spores. Meyer,39 De Bary,40 Bu'sgen,41 and, more recently, Hassel-
bring,42 have discussed these organs and their formation and func-
tion. Their production has generally been regarded as due to chemi-
cal or contact stimuli and lack of nutriment. The organs which are
produced by Acanthorhynchus vaccinii differ in form from any of
those described by the authors just mentioned. They have been
found, as already stated, on the sides of glass culture flasks and upon
the surfaces of cranberry leaves. They are produced in a few hours
from fresh spores discharged against and adhering to the cover of a
petri dish. These appressoria when transferred to culture media
soon germinate and produce an abundance of ascogenous perithecia.
They have also germinated on the covers of petri dishes where they
have formed. This would appear to indicate that they possess a
reproductive function not depending necessarily upon their connec-
tion with the surface of the host plant. When produced upon the
surface of a cranberry leaf, the small irregular projections about the
margin of the disk appear to attach themselves firmly, apparently by
dissolving and forming small shallow cavities in the surface of the
epidermal wall. A germ tube arises near the center, or sometimes
toward the margin of the appressorium, and penetrates the surface
of the leaf, usually in the sections we have studied entering through
a stoma (PI. Ill, figs. 21, 22). Sometimes the 'germ tube does not
appear to penetrate the leaf at once, but sends out several superficial
brownish filaments upon the surface of the leaf, as shown in Plate
III, figure 20. These appressoria have been frequently found upon
fallen cranberry leaves during the summer. They are sufficiently
large to be easily observed, and are so firmely attached to the leaves
that they are not readily removed.

Relationship of the fungus. — Acanthorhynchus is evidently closely
related to certain Sordariaceous fungi, especially such genera as
Sordaria and Hypocopra. The perithecia and spores are somewhat
similar, and the spores are forcibly discharged from the asci at
maturity, as in those genera. In Acanthorhynchus the whole mass
of eight spores is thrown in some cases as much as 10 centimeters or
no

THE FUNGUS CAUSING THE EOT. 29

more, and, being embedded in a gelatinous matrix, they adhere to
any object with which they come in contact. As the spores mature
the protoplasm surrounding them becomes denser and forms a sort of
secondary membrane (PI. Ill, fig. 14, c). The ascus has a character-
istic apex which suggests that of Hypocopra, as described by Zopf 43
and also by Griffiths,44 though in Acanthorhynchus it does not turn
blue upon the application of iodin and does not show the peculiar
thickenings observed by Zopf. The mass of protoplasm surrounding
the spores reaches to the apex of the ascus and is attached there. In
the case of some asci from which the spores have been discharged a
small caplike portion remains, which suggests that the ascus may rup-
ture about the apex. In other cases, however, the spores seem to have
been discharged through the apical pore or the ascus has been split
longitudinally from the apical pore. It has been impossible to differ-
entiate or to positively distinguish a secondary membrane about the
mass of gelatinous protoplasm in which the spores are embedded,
but the manner in which it holds together would signify that there
may be an outer layer functioning as a secondary membrane.

Cultures of the fungus. — Cultures of this fungus were first obtained
from mycelium found in the interior of rotten berries. These cul-
tures were made by transplanting the mycelium as described in the
case of Guignardia vaccinii. Perfect perithecia and asci have been
produced in forty different cultures made from diseased berries.
In a number of instances a mycelium apparently identical with that
of Acanthorhynchus has appeared, but no perithecia were ever
formed. The fungus grows and reproduces most readily on corn
meal, corn meal agar, and cranberry agar and corn meal. A few
mature perithecia have been formed on steamed sweet potato cylin-
ders. The fresh ascospores sometimes germinate quickly in moist
air and produce appressoria in a few hours. In most cases in which
spores have been observed to germinate, appressoria have been
formed. The spores very rarely germinate in culture media.
They germinate in damp air or water on glass and also on
cranberry leaves. In pure cultures the fungus first forms a branched
white mycelium, which spreads concentrically from the point of
origin, forming a rather close white layer, which continues to
spread until the whole surface of the culture medium is covered.
Soon the mycelium begins to assume a dirty, ochraceous color, which
becomes quite uniform and is soon followed by the appearance of the
dark perithecia of the fungus. These, when full grown, give a dark
cast to the surface as they become uniformly distributed throughout
the yellowish layer. As in case of other ascogenous forms Avhose
natural mode of growth is within the tissues of their host, the peri-
thecia in cultures are more or less covered with fungous hyphse, with
no

30 CRANBERRY DISEASES.

the exception of the short neck, which protrudes above the surface
of the mycelial subiculum (PL III, fig. 13). The fungus grows best at
ordinary laboratory temperatures, varying from 20° to 26° C., and
the mature perithecia are produced iri from fourteen to thirty days.
As in the case of Guignardia, and for the same reasons, we have been
unable to determine yet at what time infection of fruit and vines
takes place. Appressoria have not been observed on diseased berries,
but, as already stated, they have been found on leaves, with the germ
tube penetrating the tissue. The fungus is found in a fruiting condi-
tion on the cranberry bogs soon after the water is removed from the
vines in the spring. It is therefore probable that infection of the
young leaves begins about this time.

This fungus also evidently has the power of remaining in a dor-
mant or inactive condition in the leaves and fruits, as is shown by the
development of the fungus in apparently normal and healthy leaves
and fruits wThich have been disinfected and kept in moist chambers in
the laboratory. That the original infection is from external sources
is shown by the presence of appressoria on the leaves, the germ tubes
of which have been found entering the tissue (PL III, fig. 22).

TREATMENT.

What has been said in regard to the treatment of cranberry scald
applies equally well to the rot. The two diseases almost always occur
together, and Bordeaux mixture applied in the same manner as for
scald has given satisfactory results.

ANTHRACNOSE.

Anthracnose is a disease not heretofore reported as affecting the
cranberry. As is the case in most other diseases to which this name
is applied, it is due to one of the fungi which have been called Gloeo-
sporium. The ascogenous stage of the fungus having been produced,
it is found to belong to the genus Glomerella and has been named
Glomerella rufomaculans vaccinii Shear.24 Like the scald and rot,
this disease is at all times difficult, and usually impossible, to diag-
nose by a macroscopic examination of the diseased berries. The
berries from which wre have isolated the fungus which causes this
disease have not been uniform in appearance. In one case the berry
was very soft and light colored, while in other cases the fungus did
not seem to have developed so rapidly and the portion of the fruit
affected by the disease was not so soft. Acervuli sometimes develop
on the diseased berry, but usually they do not. Judging from the
infrequency of occurrence of this fungus in cultures made from
affected berries, the disease is much less injurious than the rot or
no

THE FUNGUS CAUSING ANTHRACNOSE. 31

scald. It appears, however, to be widely and generally distributed
throughout the cranberry growing regions of the eastern United
States.

THE FUNGUS ( GLOMERELLA RUFOMACULANS VACCINII, SHEAR) CAUSING

ANTHRACNOSE.

Two species of Gloeosporium have already been described as occur-
ring upon species of Vaccinium, but their relation to the fungus
causing this disease is doubtful. This parasite has been grown in
pure cultures, producing both the conidial and ascogenous forms.

Conidial form. — The acervuli are rather small, scattered over the
under or upper surface of the leaf and sometimes occurring upon old
berries which have been destroyed by the fungus. The epidermis is
usually somewhat dark colored immediately above and about the
mass of conidia. At maturity the epidermis ruptures and the conidia
form a light, flesh-colored, waxy mass upon the surface. They are
hyaline or subhyaline, as observed under the microscope, and oblong
elliptical, or sometimes slightly smaller at one end, varying in dimen-
sions from 12 to 18 by 4.5 to 6 /x (PL III, fig. 2). The conidiophores
are simple, tapering upward, and from 15 to 20 /x long. The conidia
germinate readily in water or ordinary culture media. The mode
of germination and growth agrees with that of other species of
Gloeosporium, as described by Stoneman,45 Clinton,46 and others,
except that no septum is formed in the conidia so far as observed.
This conidial form has been found on berries from several localities
in Massachusetts, and also on leaves from New Jersey which were
soaked in corrosive sublimate 1-1,000 and kept in a moist chamber
for from one to two weeks. It has also been obtained in cultures
made from diseased fruit from Wisconsin, Massachusetts, and New
Jersey.

Ascogenous form. — This stage of the fungus has not been found
on the cranberry plant either in the field or in moist chambers, but
has been grown in cultures from leaves bearing the fungus, and also
from ascospores. The perithecia are membranous, subglobose or
slightly pear shaped, usually somewhat buried in a felty subiculum
or pseudo-stroma when growing on corn meal and forming a continu-
ous layer over its surface (PI. Ill, fig. 6). In old cultures they fre-
quently become closely packed and form a more or less opaque stra-
tum. The asci are clavate, sessile, or short stipitate, and measure 60
to 72 by 10 to 12 /A (PL III, fig. 7, a, £, <?), and are sometimes accom-
panied by what seem to be evanescent paraphyses (PL III, fig. 9).
The ascospores are somewhat irregularly biseriate, oblong elliptical,
and occasionally slightly inequilateral or curved. They are hyaline
no

32 CRANBERRY DISEASES.

at first, but when fully mature become pale greenish yellow. They
vary in size from 9 to 18 by 5 to 7.5 /* (PL III, fig. 8).

Appressoria^ or chlamydospores. — In badly decayed berries and in
old pure cultures the irregular dark-colored bodies have been found
which have been called chlamydospores by some authors and appres-
soria by others (PL III, figs. 4 and 5) . The work of Fisch,37 Frank,38
Hasselbring,42 and others seems to show that the primary function
of these organs is that of an appressorium. In the case of the
cranberry anthracnose, at least, they may also function as repro-
ductive bodies. Some of those found in the interior of a decayed
berry (PL III, fig. 4) were carefully transferred to culture media
and were found to germinate and produce a luxuriant growth of
mycelium and conidia. It has been urged that they show no pro-
vision for distribution, as spores or reproductive bodies should.
When produced in the interior of berries, however, the}7 appear to
show even less possibility of functioning as appressoria. The bodies
as found in fruit and old cultures are somewhat variable in form
and appearance, but agree in general with those produced upon the
germ tubes arising from conidia. The light-colored spot frequently
observed and regarded by some as a germ pore is quite as frequently
wanting in the cases we have observed. Though probably primarily
functioning as appressoria, these bodies under certain conditions
appear to serve the purpose of a resting spore or chlamydospore.

Cultures of Glomerella rufomaculans vaccinii. — Cultures made
from berries affected with anthracnose and from leaves have in most
cases produced conidia only, but in four instances the ascogenous
stage was also produced. The berries were from Massachusetts, New
Jersey, and Wisconsin.

Cultures have also been made from leaves containing mycelium as
well as from conidia and ascospores. The growth in all cases is
essentially the same in appearance. The conidia germinate readily,
sending forth one or more germ tubes, which soon begin to branch
and then form a rather dense pure white mycelium. This on steril-
ized corn meal spreads rapidly until the surface of the medium is
covered with a compact layer of the fungus. On poured plates of
beef agar the growth of the mycelium is much less luxuriant.
Acervuli of conidia begin to appear in three or four days, and these
are frequently followed by the formation of dark-colored bodies
resembling the fundaments of perithecia. These bodies, however,
have never produced mature asci on agar cultures.

The germination of the ascospores and the subsequent growth and

development of the mycelium are essentially the same as in the case

of the conidia. Cultures from ascospores on poured plates of beef

^agar only produced conidia and what appeared to be young perithe-

110

THE FUNGUS CAUSING ANTHRACNOS$. 33

cia, but no asci were ever found. Transfers made of germinating
ascospores from such poured plates to flasks of sterilized corn meal
produced ascogenous perithecia in abundance in about ten to twelve
days. In the case of one culture made from a diseased berry, very
few conidia were ever formed, but an abundance of the ascogenous
form was present after eighteen days. We have not as yet succeeded
in growing the ascogenous form in pure cultures from single conidia.
Little opportunity, however, has been given for making such cultures
from the ascus-bearing form, on account of the few conidia produced
by it. Besides beef agar and corn meal, the fungus has been grown
upon cranberry agar and com meal, and also upon potato cylinders.
Although the fungus appears to grow best on corn meal or cranberry
agar and corn meal, there is nothing to indicate that the culture
medium is the determining factor in the production of the ascogenous
stage of the fungus. As in the case of the scald fungus, Guignardia
vaccinii, the important factor seems to be some particular potentiality
of the mycelium or spore from which the culture is made.

Factors determining the production of the ascogenous fructifica-
tion.— Previous successful attempts of the writer and others to pro-
duce asci in various forms of Gloeosporium have indicated that there
is a much more important factor involved than the culture medium or
conditions of light, temperature, and moisture. Whether the near-
ness or remoteness of origin of the conidia from an ascogenous form
is of importance has not yet been satisfactorily determined. The
successful cultures made by Miss Stoneman 45 were from conidia
taken from acervuli produced upon the different hosts of the species
studied. In such cases, of course, there is no means of determining
the ancestry of the conidia used.

Relationship of the fungus. — The ascogenous forms of the numer-
ous anthracnoses known have very rarely been recognized or reported
as occurring under natural conditions. It is probable, however, that
some of the pyrenomycetous fungi which have been described under
the genera Physalospora or Phomatospora, or perhaps under other
closely related genera, are really the ascogenous forms of species
of Gloeosporium. The very close relationship of many of the species
described under these genera and the want of any very striking or
peculiar characteristics of the known ascogenous forms of Gloeospo-
rium make it difficult to determine with certainty from purely mor-
phological characters the generic identity of these organisms. The
name Glomerella has been proposed for these fungi by Spaulding
and von Schrenk.47 This name, however, may have to be abandoned
if it can be demonstrated that ascogenous forms heretofore described
under an older valid generic name are really stages in the develop-
ment of congeneric species. The question of specific distinctions in
no

34 CEANBEERY DISEASES.

this genus is very perplexing. The differences in the morphological
characters of the ascogenous fructifications are quite as slight and
unsatisfactory for separating species as the differences which occur
in the conidial forms. This has been clearly shown by the studies of
Shear and Woods.35 Various inoculation experiments made with the
conidial forms occurring on different hosts have seemed to indicate
that they will pass readily from one host to another. Most such
inoculation experiments appear to us inconclusive, particularly in
such cases as those given by Halsted 14 and others, in which transfers
of conidia were made from one mature fruit to another by inserting
the conidia in the fruit. These experiments may perhaps be more
correctly interpreted as indicating that the fruit upon which the
fungus grows successfully in such an inoculation experiment is
simply a satisfactory nutrient medium for the fungus. In order to
demonstrate the possibility of the various forms being passed from
one host to another as actual parasites, it would be necessary to make
the inoculations on the living and actively growing parts of the
plants. This has been done in one case, at least, by Sheldon,48 in
which he successfully inoculated stems and leaves of growing sweet
peas by applying conidia from the bitter-rot (Glomerella rufomacu-
lans (Berk.) Spauld.' & von Schrenk) of the apple. Whether other
forms will show equal ability to pass from one host to another as
active parasites remains to be determined.

Dormant condition of the fungus. — We have found by experiments
similar to those described in connection with the account of the
scald fungus, Guignardia vaccinii (p. 21), that the mycelium of the
cranberry Glomerella may remain in an inactive or dormant condition
in the tissues of the living fruit of the cranberry for a considerable
time. Whether the fungus is really inactive or not it is difficult to
say. It at least does not give the slightest local external evidence of
its presence. Berries which were, so far as could be determined by
external examination, perfectly sound and free from fungi, were very
thoroughly soaked and washed in a 1-500 solution of corrosive sub-
limate. Such leaves and berries when placed in warm, sterile, moist
chambers developed typical cases of anthracnose. On the leaves
treated in the same manner numerous acervuli have appeared,
and cultures made from the mycelium found in the decayed fruits
mentioned above have produced the conidia in pure cultures. Inoc-
ulation experiments, made by applying fresh conidia to the surface
of cranberries and apples placed in warm moist chambers, have been
without definite results. It seems that in the case of this fungus, as
well as Acanthorhynchus and Guignardia, the spores do not pos-
sess the power of penetrating the epidermis of the fruit after it has
reached maturity. Infection apparently occurs earlier in the season,
no

HYPERTROPHY. 35

but the exact time and manner has not yet been determined for want
of plants known to be entirely free from disease.

TREATMENT.

From the beneficial results of spraying cranberries where this dis-
ease was known to be present and also from the success obtained in
preventing other diseases caused by similar fungi, such as the bitter-
rot fungus of the apple,49 it appears probable that thorough spray-
ing with Bordeaux mixture will prove a satisfactory treatment.
The disease so far as now known is always associated with scald or
rot, and the treatment recommended for those diseases will be suffi-
cient for this.

HYPERTROPHY.

The fungus (Exobasidium oxy cocci Rostr.) causing hypertrophy is
only known at present from Massachusetts. In 1906 it destroyed a
considerable part of the crop on several cranberry meadows in that
State and caused considerable alarm. It is apparently somewhat
erratic in its behavior. On one meadow it attacked almost every
plant on a part of the bog, while some other portions were almost free
from it. The variety known as Matthews seemed to be especially
susceptible to the disease.

The disease first makes its appearance on flooded bogs soon after
the water has been removed in the spring, which is usually about the
middle of May or a little later. The axillary leaf buds, which usually
remain dormant, are attacked by the disease and produce short shoots
with rather close, enlarged, swollen, and distorted leaves which are
pink or light rose colored (PI. VII, C and D). The colored Iwper-
trophied leaves, being close together, bear a slight superficial resem-
blance to a flower of some sort. This appearance has led some per-
sons to call these diseased shoots " false blossoms." This is mislead-
ing, as it suggests some reference to the flowers of the cranberry,
which are not included in this peculiar malformation.

Most of the affected plants are attacked before the blossoms have
developed, thus preventing the production of fruit. Shoots whose
buds are attacked later in the season after the blossoms have opened
or fallen (PL VII, D) also usually fail to develop fruit, as the vital-
ity of the shoot is apparently exhausted by the fungus. Besides the
fruit-bearing shoots, ordinary vegetative shoots or runners are also
affected in the same manner (PL VII, C).

No opportunity has been afforded to examine plants which had
suffered from this disease the previous year, but the injury to the
affected plants and the lowering of their vitality are so evident that
the production of fruit the succeeding season would probably be far
below normal even though the disease did not recur upon the plants,
no

36 CEANBEKRY DISEASES.

THE FUNGUS (EXOBASIDIUM OXYCOCCI, ROSTR.) CAUSING HYPERTROPHY.

In this, like all Exobasidii, the mycelium of the fungus infests
the tissue of the leaves and stems, producing the hypertrophied con-
dition described above. The basidia are elongate clavate, and are
produced at the extremities of the hyphas. They emerge on the
surface of the affected part of the host and produce usually four
basidiospores at the ends of short, slender sterigmata. The spores
are usually somewhat fusiform, slightly curved, and hyaline, measur-
ing 14 by 3.5 fji. They proceed to grow soon after falling and may
be seen in old specimens in different stages of germination. From
one to three transverse septa are usually formed, after which a germ
tube arises from either or both ends, which produces conidia somewhat
resembling the basidiospores, but smaller. The fungus, when mature,
gives a fine, gray, powdery appearance to the surface of the distorted
parts of the host.

Relationship to other Exobasidii. — This species, so far as it has
been studied, agrees in morphological characters with Exobasidium
vaccinii (Fckl.) Wor. The spores of Exobasidium vaccinii are,
according to Saccardo, 5 to 8 by 1 to 2 /x. This, according to
Woronin,9 Richards,59 and others, is an error, as the basidio-
spores usually range from 14 to 17 by 3 /*. The error possibly arose
from the confusion of basidiospores with conidia, which are fre-
quently present, especially in specimens which are getting old.

The typical form of Exobasidium vaccinii occurs on Vaccinium
vitis-idaea, producing hypertrophied spots on the leaves. No record
has been found of the occurrence of hypertrophied shoots on this
host similar to those found on cranberry plants. Rostrup 51 seems
to have been the first to describe this form. In 1883 he reported it
as occurring on Oxy coccus palustris in Denmark. His description
accords exactly with the specimens we have found on the cranberry
plant. He says he could not find the two forms, i. e., the one pro-
ducing spots on the leaves, typical Exobasidium vaccinii, and the one
producing hypertrophied shoots, Exobasidium oxycocci, on the same
plant, but the two were found in the same locality in one instance.

An Exobasidium also occurs on cranberry plants in Massachu-
setts, which produces spots on the leaves like those produced on
Vaccinium vitis-idaea, and agrees also in all microscopical characters
with Exobasidium vaccinii (Fckl.) Wor. (PL VII, A and B). No
specimens of the two forms could be found on the same plant or
in the same vicinity. No cross-infection experiments with these two
forms have been tried on these hosts so far as known, and as the
observations already made seem to indicate the probability of their
no

LESS IMPORTANT DISEASES. 37

being separate species, we shall retain for the present the two names
as already used.

Richards 59 reports infection experiments with the Exobasidium
producing spots on leaves of Andromeda and the one forming large
inflated galls on the same host. He succeeded in producing the leaf-
spot form by using spores from the gall-producing form which was
named Exobasidium andromedae by' Peck.03 This suggests the pos-
sibility of the interchange of other forms, and it is hoped that further
work may be done in this direction.

Exobasidium oxycocci occurs in greatest abundance in May and
June. It has also been collected as late as September, when occasional
fresh specimens were found at Brewster and Pleasant Lake, Mass.

TREATMENT.

Little, if anything, so far as can be learned, has been attempted
in the way of controlling diseases caused by Exobasidii, as they
have rarely assumed economic importance. As definite knowledge in
regard to time and manner of infection is lacking, it is difficult to
recommend treatment. It is possible that spraying with Bordeaux
mixture may be beneficial, and experiments in this direction are
planned for the coming season, when it is also hoped to secure more
knowledge of this fungus.

LESS IMPORTANT DISEASES.
FUNGI ATTACKING THE FRUIT.

8ynchytrium vaccinii Thomas. — This fungus was first described
from New Jersey specimens by Dr. Fr. Thomas,5'5 of Germany, in
March, 1889, under the above name. When first discovered it threat-
ened to do serious injury to the New Jersey cranberry bogs. It was
first found in 1886 upon a bog near Browns Mills, N. J. Doctor
Halsted,10 of the New Jersey Experiment Station, gave an account
of the disease in 1880, and called the parasite the cranberry gall
fungus. The fungus attacks the leaAres and young stems as well as
the flowers and fruit, forming great numbers of small, reddish,
gall-like swellings upon their surface (PL IV, figs. 15 and 16). Sec-
tions of these galls show the fructification of the fungus embedded
near their center (PL IV, fig. 17). The fungus consists of a scanty
vegetative mycelium producing globose sporangia, which finally
develop a mass of swarm spores within. The sporangia rupture and
the spores are then set free. These swarm spores are motile and well
adapted to distribution through the water. At the time this fungus
was found at the place mentioned a considerable portion of the
plants on one side of the cranberry meadow was affected and the
no

88 CRANBERRY DISEASES.

complete destruction of the vines was threatened. So far as known
the only measure taken to prevent the disease was the withholding
of the water during the winter, as it was believed that the disease was
distributed chiefly by the water. This plan seems to have proved
successful, as the disease disappeared entirely within a few years.
When the affected bog was recently visited it was impossible to find
a trace of the fungus present on the vines or to learn of its occurrence
anywhere in the region since. It seems to have entirely disappeared."
Similar sudden appearances of new parasites have been observed. No
entirely satisfactory explanation of such phenomena has yet been
given. Their sudden disappearance is less common. This fungus is
not restricted to the cranberry plant, but has been found on several
other ericaceous plants. Specimens on the following hosts collected by
Doctor Halsted in New Jersey are preserved in the pathological col-
lections of the Department : Gaultheria procumbens, Cassandra caly-
culata, Kalmia angustifolia, Azalea viscosa, Clethra alnifolia, and
Gaylussacia sp. It may be expected to appear again if the condi-
tions for its development and spread should happen to be favorable.
Since its discovery in New Jersey it has been found as far north as
Newfoundland, but has not been reported as doing harm to the cran-
berry, except in the case mentioned.

Pestalozzia guepini vaccinii Shear.22-r-This fungus has been
isolated in eight instances from diseased cranberries. It is also
frequently found on the leaves of the cranberry plant. The effect of
this fungus upon the berries, like that of some other parasites, is not
sufficiently characteristic to enable one to recognize it by an examina-
tion of the fruit. Hence we are unable to determine how much injury
is caused by it. The indications are, however, that it does not do
nearly as much damage as the other parasites already described. It
is much more frequent upon the leaves than upon the berries and
may be found upon the recently fallen leaves during the summer. It
also develops very frequently on leaves apparently free from disease
when they are placed in a sterile moist chamber.

The acervuli of the fungus are formed beneath the epidermis and
are sparsely scattered over the leaf (PI. II, fig. 15). As the fungus
matures the epidermis ruptures and the spores collect in dark masses
or spread out and form a thin layer upon the surface about the
acervuli. The corridia are elliptical and somewhat inequilateral and
usually four-septate (PL II, fig. 15, <z, 5). The three central cells are
dark colored and usually guttulate. The septum below the upper cell
is usually darker than the others. The two terminal cells are hyaline,
and the apical one is furnished with three to four filiform setae,

° Since this was written the disease has again been reported as occurring this
season in New Jersey.
HO

LESS IMPORTANT DISEASES. 39

varying from 22 to 35 /x in length. The basal cell also has a short
hyaline appendage 6 to 12 /A long.

This fungus is quite generally distributed in the cranberry-growing
regions. Specimens have been obtained from West Virginia, New
Jersey, Wisconsin, Massachusetts, and New York.

Pestalozzia guepini Desm. is given by Farlow and Seymour60 as
occurring on the cranberry, but a study of that species indicates that
our plant is a variety at least, as indicated, and may perhaps be
found to be a distinct species.

The spores of this fungus germinate readily under ordinary labo-
ratory conditions in water or culture media. The germ tube almost
invariably arises from the basal cell of the spore (PL II, fig. 15, c, d).
Occasionally two germ tubes arise, one from each side of the basal cell
(PL II, fig. 15, d). The germ tube grows rapidly and soon begins to
branch, forming a nearly white mycelium. This covers the culture
medium with a thin, rather compact layer. About the time acervuli
begin to form, a faint pinkish tinge appears. Acervuli and spores are
produced in about ten to twelve days. The acervuli first appear as
dark-colored dots. Spores are produced in enormous numbers and
spread about the acervuli in irregular black masses.

This fungus has been grown from leaves and fruit from different
sources on different media and under different conditions for several
years, but no other spore form has ever been found. Where the
growth of the fungus is very luxuriant, abnormal spores are pro-
duced, which bear four or five and rarely six appendages, sometimes
much longer than usual, and branched.

This fungus is common and widely distributed, but so far as our
knowledge goes does not attack the fruit with sufficient frequency to
cause much loss. It is much more common on the foliage and may thus
injure the plants affected. It has been found to be present in leaves
which showed no external signs of disease, as has already been noted
in the case of Guignardia vaccinii and some of the other cranberry
fungi.

There is reason to believe that where the disease is present it can
be controlled by the usual treatment with Bordeaux mixture.

Helminthosporium inaequalis Shear 24. — This fungus has been
obtained in cultures made from diseased cranberries from New Jer-
sey. These cultures were made November 8, 1905, by carefully trans-
ferring the fungous hyphse from the pulp of affected berries to flasks
containing sterilized corn meal. There was nothing in the external
appearance of these berries to indicate that the injury was due to
other than the usual rot or scald fungi. The first growth of the
mycelium was nearly white, but very soon assumed a light, smoky
color, and finally became a dark, smoky brown. The whole surface

110

40 CRANBEKRY DISEASES.

of the medium was covered with a thick, loose layer of much-branched
hyphse. The vegetative hyphse frequently form strands of several
filaments closely united (PL V, fig. 8).

The fertile hypha? were distributed over the surface and bore
conidia at the apex as well as at the sides (PL V, fig. 4). These
conidia are somewhat elliptical and usually conspicuously inequilat-
eral (PL V, figs. 5, 6, 7). They are thick walled and from three to
five celled at maturity, all but the terminal cells, which are hyaline,
being of a deep-brown color. The conidia measure from 18 to 36 by
8 to 14 /*. In old cultures tufts or clusters of erect, slender, irregular,
somewhat branched, hard, black bodies 5 to 15 millimeters in length
are formed in great abundance, covering the surface of the culture
(PL V, fig. 9). These appear to be of a sclerotoid nature. They have
never been found to bear fructifications of any sort. When broken
up and pieces are transferred to culture media, the mycelium grows
and soon produces conidia. So far as known this fungus is of infre-
quent occurrence and probably causes very little injury. It has not
been found in a fruiting condition upon fruit or vines in the field.

Gloeosporium minus Shear.24 — Besides the Gloeosporium (Glomer-
ella rufomaculans vaccinii), already described as causing' the cran-
berry anthracnose, another has been found which has been published
under the above name. Only the conidial stage is known. All
efforts to produce an ascogenous form have thus far failed.

The aceryuli are amphigenous, small, and scattered, and do not
form a definite discolored spot on the leaf so far as observed. They
sometimes occur upon the berries. In such cases the epidermis is
dark colored above and about the acervulus. The conidia are dis-
charged through a rupture in the epidermis and form a pale pinkish,
glutinous mass. They are oblong-elliptical or subcylindric and some-
times inequilateral or somewhat clavate (PL III, fig. 11), and are
usually guttulate when fresh. They vary in size from 6 to 9 by
3 to 4 p. and are borne on simple, slightly tapering sporophores one
and a half to two times the length of the conidia. No seta3 have been
observed in any of the acervuli.

The conidia of this species are only about one-half as large as
those of Glomerella rufomaculans vaccinii and show no great amount
of variation, either under natural conditions or in cultures. This
species is perhaps closely related to Gloeosporium myrtilli Allesch.,
which has conidia 6 to 10 by 1.5 to 3 /*, and occurs on Vaccinium
myrtillum in Germany.

This fungus wTas first found on cranberries offered for sale in the
Washington market in April, 1902. It has also been found on
cranberry leaves from New Jersey and has been isolated from other
leaves from the same State. It is apparently of comparatively rare
occurrence and perhaps of little importance as a disease producer,
no

LESS IMPORTANT DISEASES. 41

Sporonema oxycocci Shear.-4 — This excipulaceous fungus has been
found on cranberry leaves from various localities. The pycnidia are
imperfectly developed, the upper portion being thin and disappearing
toward the center of the disk (PL V, fig. 18). They are dark brown,
scattered or gregarious, pulvinate, covered by the epidermis, and
measure about 50 to 100 ^ in diameter. They rupture by a longi-
tudinal or irregularly triangular slit (PL V, fig. 17). The spores
are continuous, hyaline, cylindrical, obtuse, borne on very short ovoid
sporophores, and measure 17 to 19 by 3 to 4 ^ (PL V, figs. 19 and 20).
In cultures the range of variation in spore measurement was some-
what greater, being 15 to 20 by 3 to 4 /*.

Specimens have been obtained from Carver and on Cape Cod,
Mass., and Martinsville, Me. ; also from near Belleplain and Whites-
ville, N. J., the dates ranging from June to September.

This fungus has usually been found on dead or dying cranberry
leaves, but in one instance it was found in a diseased berry which was
obtained in the Washington market. The berry had a soft, slightly
discolored spot. After thoroughly washing and soaking the berry
in corrosive sublimate solution, a portion of the diseased pulp and
skin of the fruit was carefully transferred to a flask of sterilized
corn meal. Normal pycnidia of the fungus developed upon the
portion of the skin of the berry in the culture. The mycelium
spread to the culture medium and formed a rather compact thin
layer, at first whitish, then dark grayish green, and finally dark
grayish brown and somewhat mouse colored. In about a month
mature pycnidia were formed about the sides of the flask. The so-
called pycnidia are incomplete and consist in the culture of dense,
dark, pulvinate masses depressed at the center where the pycnospores
are borne and somewhat overgrown by loose hyphse from about the
margin. Frequently instead of normal spore development the sporo-
phores became lengthened and formed irregular stout hyaline fila-
ments about twice the length of the spore. The single instance in
which this fungus has been found in the fruit shows that while it is
capable of injuring the fruit, it perhaps does very little damage at
present.

Arachniotus trachyspermus Shear.23 — This fungus was first iso-
lated from a very badly diseased berry from New Jersey which had
been kept from September until April 11. The berry was very soft
and light colored. The same fungus has also occurred twice on the
surface of decayed fruit which had been kept in a moist chamber for
a considerable period.

In pure cultures the fungus first forms a fine, thin, white mycelium,
which is soon followed by the development of minute arachnoid
snowy -white perithecia (PL IV, figs. 18 and 19), which are 325 to
no

42 CRANBERRY DISEASES.

425 fji in diameter and consist of slender, thin-walled, unarmed
hyphaB, forming an anastomosing arachnoid layer about the mass of
asci. The asci are globose or subglobose, very thin walled, and 7 to
8 p. in diameter (PL IV, figs. 20 and 21). The ascospores are ovoid,
light lemon yellow in mass, echinulate-roughened, and measure from
3.25 to 4 by 2 to 2.5 /* (PL IV, fig. 22). The asci are very closely
packed together and borne upon the tips of the very slender and
scantily branched filaments of the ascogenous hyphse. It is not until
the ascospores are fully mature that the color and rough surface are
readily recognized.

The species is closely related to A. candidus (Eid.) Schroet., but
differs in having rough, faintly colored spores. A minute, greenish,
conidial form resembling Penicillium occurred in all the old cultures
of this fungus. These cultures were apparently pure and free from
contamination, and it seems quite probable that this represents the
conidial stage of this Arachniotus. We have, however, been unable
as yet to satisfactorily demonstrate this by other cultures made from
ascospores and conidia. This fungus has not been found fruiting in
the field, and is probably of no great pathological importance.

Septoria longispora Shear.24 — This fungus has been collected three
times in New Jersey — twice upon cranberry leaves and once upon a
fruit. It has also been grown in ten cases in cultures from cranberry
leaves. The pycnidia are scattered over the surface of the leaf or
fruit and seated beneath the epidermis. They vary in size from 120
to 250 p in diameter (PL IV, figs. 12 and 13). No definite spot or
discolored area seems to be 'formed. The pycnospores are very long
and slender and curved, varying from 150 to 240 ^ by 3 to 4 /* (PL

IV, fig. 14). When straightened they reach 300 /* long. They are
borne on simple slender sporophores 6 to 9 //, long. The length of the
spores seems to separate this species from any other Septoria de-
scribed, as they are twice as long as those of any species heretofore
known. This fungus appears to attack the fruit but rarely. It has
been found only in New Jersey, and is apparently of infrequent
occurrence.

Sphaeronema pomorum Shear.24 — This fungus has been found but
once: It was obtained in a culture made by the transfer of hyphse
from the interior of a diseased berry taken from a lot of sprayed fruit
from New Jersey. It has been kept growing on culture media for a
long time. The fungus first formed a thin white layer upon the
culture medium, and this was soon followed by the development of
numerous pycnidia quite evenly scattered over the surface of the
mycelial layer, giving it a dark appearance. The pycnidia are
membranous or subcoriaceous, globose or subglobose, 120 to 200 p
in diameter, and provided with a slender neck about 80 /* long (PL

V, fig. 1). The pycnospores are hyaline or pale greenish yellow in
no

LESS IMPORTANT DISEASES. 4

mass, oblong or subcylindric, and measure from 5 to 10 by 3 to 6 ^
(PL V, fig. 1, «). This fungus has not been found upon either leaves
or fruit in the field, and appears to be of rather rare occurrence.

Phyllosticta putrefaciens Shear.24 — This fungus has been obtained
in two cases in cultures made from the hyphse taken from the
interior of decayed berries. The berries were picked from the
sprayed plats at Whitesville, N. J., and kept in the laboratory about
a month. The berries showed no external appearances which would
indicate that the disease was different from that produced by rot or
scald fungi.

The pycnidia are gregarious, membranous, globose, or subglobose,
and vary from 75 to 150 //, in diameter (PI. V, fig. 10). The spores
are faintly yellowish in mass, ovoid or oblong-ovoid, and measure
from 4 to 6 by 2 to 3 /x (PI. V, fig. 10, a). In the cultures the fungus
first produced a thin, white, floccose mycelial layer over the surface of
the medium. This gradually became thicker and then produced a
layer of black pycnidia. What appears to be the same fungus has
been found on leaves from Massachusetts. A fungus closely resem-
bling this one has also been collected in Massachusetts on cranberries
which had been destroyed by the berry worm. The spores were
slightly larger and the ostiole different. This fungus presumably is
the pycnidial stage of some ascogenous fungus, but no such form has
appeared in any of the numerous cultures which have been made.

Anthostomella destruens Shear.24 — This fungus has only been
found in one instance, when it was obtained from a diseased berry
grown in New Jersey. The culture was made November 2 by trans-
ferring the fungous hyphse from the interior of the berry, as in the
other cases mentioned. A white mycelial layer was first formed, and
this was soon followed by the development of black perithecia more
or less overgrown by the white filaments of the mycelium. The peri-
thecia are membranous or submembranous, globose, and 350 to 450 //,
in diameter (PI. IV, fig. 8). The asci are cylindric or cylindric-
clavate and vary from 150 to 225 by 14 to 18 ^ (PL IV, fig. 9). No
paraphyses have been found. The ascospores are dark brown, ellip-
tic, uniseriate, and 16 to 24 by 10.5 to 12 /* (PL IV, fig. 10). This
fungus has not been found fruiting in the field and is apparently of
rare occurrence. None of the cultures made from ascospores has
shown any other spore form. The plant is perhaps rather closely
related to Anthostomella picacea (C. & E.) Sacc., which has been
found on Vaccinium, but it is easily separated by the size of the asci
and spores.

Penicillium glaucum Link. — This fungus occurs frequently on old

diseased fruit when it is kept in a sterile moist chamber. It grows

especially upon the old calyx of the flower and the apex of the fruit

and has been isolated from the pulp of decayed fruit.. In cultures and

no

44 CRANBERRY DISEASES.

on decaying fruit it occasionally produces the coremium form. The
fungus probably does not cause decay of the fruit, except where the
skin has been injured to permit its entrance.

Leptothyrium pomi (Mont.) Sacc. ? — Occasionally about picking
time there appear on cranberries minute black fungous specks or
spots having an appearance identical with that of the " fly speck "
or fruit speck of the apple. Microscopical examination shows that
these spots consist of thin, dense, superficial, dark-colored, short-
celled, rather thick-walled hyphse. When old the spots are slightly
convex, and when examined in cross section show a somewhat lighter
colored compact cellular mass closely attached to the epidermis of the
fruit (PI. V, fig. 15). Specimens kept for a long time in a moist
•chamber have never shown any indication of spore formation. A
study of these specks in different stages of formation shows that they
arise from a germinating spore. An anastomosing, dark-colored,
thick- Availed mycelium is formed (PL V, figs. 13 and 14), which
continues for some time to increase in size and thickness until it
reaches the condition shown in Plate V, figure 15. A careful ex-
amination of the surface of berries bearing these specks revealed
the presence of three different kinds of fungous spores- (PI. V, fig. 16,
«, &, and c). Those shown at ~b and c were rather frequent. The form
shown at a is the only one which was found germinating, and as
remains of similar spores were found connected with the very young
specks we are led to think that they are produced by these spores.
We have no means of knowing to what genus of fungi any of these
spores belong. Those shown at c bear a strong resemblance to
Cladosporium.

So far as we have been able to learn, no one in this country has
found any spores produced by this fungus. We have attempted to
grow the plant in culture media, but without success. Labrella pomi
Montagne 5G was described as follows : " Macula nulla, peritheciis
ellipticis minimis rugosis nitidis, sporidiis globosis." In view of
the mention of globose spores in the description and our scanty knowl-
edge of the original plant, it is rather doubtful whether the plant
we are dealing with is that described by Montagne.

This fungus has only been seen from one locality, Parkdale, N. J.
It does not seem to injure the fruit except that it renders it unsightly.
Thorough spraying will probably prevent its appearance.

FUNGI OCCURRING ON THE LEAVES OR STEMS.

Several of the species of fungi already described as attacking the

fruit are also found on leaves or stems. The following species have

been found only on the leaves or stems of the cranberry. So far as our

present knowledge of these goes, they do not cause sufficient injury

no

LESS IMPORTANT DISEASES. 45

to be of great economic importance. Their future behavior can not
be foreseen, however, and they may bear some direct relation to each
other or to the other parasites which may prove important.

Venturia compacta Peck.54 — This fungus has been before reported
upon the cranberry by Professor Peck, who found it in New York.
It has also been collected, according to Ellis, in Maine, and by
Halsted in northern New Jersey. We have found it on cranberry
leaves from Nova Scotia, and also from Massachusetts, New Jersey,
and Wisconsin. Fusicladium has been demonstrated to be the conidial
stage of certain species of Venturia, but no such conidial form has
been found in connection with this species. Cladosporium oxycocci
Shear has been found associated with it, but nothing is known as to
the relation between the two forms.

This fungus shows considerable variability, especially in the group-
ing of the perithecia and the production of spines, the size and shape
of the asci, the presence or absence of paraphyses, and the arrange-
ment of the spores. The perithecia are usually aggregated in rather
dense clusters, but are occasionally solitary (PL IV, fig. 1). The
spines may be few and arranged about the ostiole or more numerous
and scattered over the upper half of the perithecium (PI. IV, figs.
3 and 5). They vary in size from 30 to 60 by 6 /x. The asci are
usually swollen at the lower end (PI. IV, fig. 6), but are frequently
cylindrical (PI. IV, fig. 4). They vary in size from 48 to 66 by
9 to 12 ju,. The spores are very constant in size and shape, measuring
14 to 18 by 4 to 6 //,. It was at .first thought that the extreme forms
might be separate species, but a study of more material shows all
sorts of intermediate conditions. Schweinitz 57 has reported Venturia
cincinnata Fr. on Vaccinium macrocarpum from Pennsylvania. An
examination of Schweinitz's specimen indicates that jt is Venturia
compacta Pk. Fries's 58 species was found on Vaccinium oxycoccus,
and so far as the description goes scarcely differs from our plant,
except that the perithecia are said to be solitary. We have been
unable to find a specimen of Fries's species in his herbarium, and it
is perhaps doubtful whether the two species are the same. It seems
rather probable, however, that such is the case.

This fungus seems to be comparatively rare except in Massachu-
setts, and though a parasite it evidently does little damage. It is
not known to attack anything but the leaves. However, from the
habits of its near relatives, which cause the serious scab diseases of
other fruits, it may perhaps sometimes attack the fruit of the
cranberry.

Sclerotinia oxycocci Wor?9 — The Monilia form of a fungus closely
resembling this was found upon the young leaves and tips of cran-
berry plants sent from Wisconsin in July, 1905. This fungus has
no

46 CRANBERRY DISEASES.

not been reported heretofore upon the American cranberry, though
different species of the genus attack various species of Vaccinium in
Europe and do considerable damage to the fruit. Under favorable
conditions for its reproduction and distribution this fungus might
prove a very serious enemy of the cranberry, and it is quite important
that steps should be immediately taken to eradicate it whenever and
wherever it is found.

The ascogenous stage of this fungus has not yet been found here,
though it probably occurs in the locality from which the conidia
were obtained. The conidia are borne in chains and measure 12 to 20
by 10 to 12 p (PL IV, fig. 23). They agree in all particulars with
Woronin's description and figures, except in the size of the spores.
In his description Woronin gives 25 to 28 by 16 to 22 //, as the meas-
urements.

Discosia artocreas (Tode) Fr. — This fungus has been found on
cranberry leaves from Cranmoor, Wis., which had been kept in the
laboratory in a moist chamber. Other specimens have been ob-
tained on leaves from near Whites ville and Jamesburg, N. J., from
Wareham and Brewster, Mass., and from West Virginia. The speci-
mens collected in the field were found in September and November.
This fungus has usually been regarded as a saprophyte and probably
does no particular injury to the cranberry plant.

Plagiorhabdus oxycocci Shear.24 — This interesting fungus, which
it has been necessary to refer to a new genus and species, was found
on cranberry leaves collected near Carver, Mass., in May, 1906. The
pycnidia are scattered, slightly erumpent, covered by the epidermis,
125 to 190 fj. in diameter. The wall is not regular and well developed,
but is thicker and denser above. The interior is either simple or
somewhat chambered, but opens through a single ostiole (PL V, fig.
2). The pycnospores are hyaline or faintly colored in mass, and
are borne on slender, simple sporophores (PL V, fig. 3). They
measure 8 to 11 by 3 /x and are borne obliquely on the sporophore,
which is abstricted at its base and remains as an appendage (PL V,
fig. 3, «), which is 10 to 15 by 0.75 /*. This species is closely related
to Plagiorhabdus crataegi Shear,24 which is found on the fruit of
Crataegus. It would therefore not be surprising if the species occur-
ring on the cranberry should also be found upon the fruit.

Sporonema pulvinatum Shear.24 — This fungus has been found
upon cranberry leaves in three instances — once on leaves collected in
New Jersey in November, 1905, and once on leaves from Olympia,
Wash., collected in October; also upon leaves from West Virginia
collected in June and kept in a sterile moist chamber. The pycnidia
are simple, dark brown, pulvinate, formed within the epidermis, the
outer wall of which adheres to their surface. They are 300 to 420 /*,
no

LESS IMPORTANT DISEASES. 47

in diameter Iby 100 to 150 //, thick, and sometimes collapse from above
(PL Y, fig. 25). No signs of an ostiole have been seen, and the
manner in which the pycnidium ruptures is not known. The spores
are pale greenish yellow in mass, continuous, subelliptical, and some-
what curved, 6 to 8 by 2 to 2.5 /*. They are borne on simple, taper-
ing sporophores about twice the length of the spores (PL V, figs. 27
and 28). The pycnidia bear a close resemblance to immature speci-
mens of Lophodermium melaleucum (Fr.) De Not., and it may be
the pycnidial stage of this or the closely related Lophodermium
oxycocci (Fr.) Karst. This fungus is closely related to Sporonema
epiphylliim (Fr.) Shear24, but has larger pycnidia and smaller
spores, which are less curved and without a pseudoseptum.

Rhabdospora oxycocci Shear.24 — This fungus has been found on
leaves still adhering to old cut vines collected in September and
November near Whitesville, N. J. The pycnidia are formed beneath
the epidermis on the under side of the leaf and are quite evenly dis-
tributed over its surface. They are depressed-globose, slightly
erumpent, and somewhat cushion shaped, 150 to 225 ^ in diameter.
The wall consists of two layers, wThich sometimes separate, the inner
collapsing and expelling the spores (PL V, figs. 21 and 22). The
ostiole is plain or slightly depressed and the epidermis above the
pycnidia is blackened and transformed by the fungus. The pycno-
spores are hyaline, narrow cylindric-fusiform, and slightly curved.
They show one or two septa or pseudosepta at maturity and measure
20 to 26 by 2 to 3 //,. The sporophores are slender and branched
(PL V, figs. 23 and 24). This fungus has not yet been found
attacking the berries.

Leptothyrium oxycocci Shear.24 — This fungus has been collected
several times on living and dead leaves.0 It was first sent from
Pierceville, Mass., by Mr. H. J. Franklin, May 22, 1906. The pycni-
dia are dimidiate, scattered, irregular, black, erumpent, subsuperfi-
cial, collapsing and rupturing irregularly, or breaking free about the
base, 160 to 250 ^ in diameter (PL V, figs. 29 and 30). The wall of
the pycnidium shows a more or less parallel series of cells in its struc-
ture (PL V, fig. 31). The spores are hyaline, fusiform-elliptic, uni-
septate, 10 to 15 by 2.5 to 3 p and borne on slender, tapering sporo-
phores (PL V, figs. 32 and 33).

Ceuthospora (?) lunata Shear.24 — This fungus has been collected
several times on dead and dying cranberry leaves. It was first found
by the writer near Wareham, Mass., in September, 1902. It has also
been collected at Carver and Onset, Mass., and near Whitesville, N. J.
The pycnidia are scattered, depressed-pulvinate, slightly erumpent,

ffl Since the above paragraph was written, this fungus has been found on old
mummied fruit at the same place where the other specimens were collected.
110

48 CRANBERRY DISEASES.

200 to 375 //, in diameter, irregularly chambered within and bearing
a single prominent ostiole, through which all the chambers empty
(PL V, fig. 11). The walls are subcoriaceous and irregular in thick-
ness. The sporogenous hyphae form a dense, compact, intricate layer,
the ultimate divisions of which are somewhat dichotomous and bear
the short, elliptic, inequilateral, or slightly curved, simple, hyaline
spores, which are T to 9 by 3 to 3.5 /x (PL V, figs. 12 and 12, a}.

The generic relationship of this fungus is rather uncertain, and
we have referred it for the present to Ceuthospora, though it does
not well agree with the description of the genus.

Valsa delicatula C. & E. — This fungus has been collected at Whites-
ville, N. J., on old cranberry stems which had been piled at the edge
of a bog. It also occurs on other ericaceous plants in New Jersey,
but has not heretofore been reported upon the cranberry. Associated
with the ascogenous perithecia on the same stems was found a Cyto-
spora, which is perhaps the pycnidial condition of this species.

Cladosporium oxycocci Shear.24 — There are occasionally found in
the spring on leaves of the previous year small, brownish, diseased
spots bearing a Cladosporium, to which the above name has been
given. The fertile hyphse are brown, septate, more or less flexuous,
and erect or spreading. They vary from 50 to 100 /x in length and
arise from a small, black, sclerotoid base (PL IV, fig. 24). The
conidia are acrogenous, varying from ovoid to cylindric-clavate, pale
yellowish brown, continuous or uniseptate, and 15 to 24 by 3 to 4 ^
(PL IV, fig. 24, a}. We have specimens from Arichat, Nova Scotia,
from Cape Cod, Massachusetts, and from Belleplain, N. J.

Another Cladosporium which has not been identified specifically
has also been found on dead tips of young shoots of the cranberry
from Massachusetts.

Plectrothrix globosa Shear. — This fungus was described by the
writer in 1902. 22 It occurred on cranberry leaves which were kept in a
sterile moist chamber in the laboratory and was quite regularly asso-
ciated with Pestalozzia guepini vaccinii, making its appearance soon
after the maturity of that fungus. It probably has no genetic rela-
tion to Pestalozzia, however. The plant has not been collected in
the field and is perhaps a simple saprophyte.

Chondrioderma simplex Schroet. — This myxomycetous fungus was
found at Hampton, N. J., covering living cranberry vines and other
plants. It apparently did no injury, however, except such as might
be caused by temporarily covering the surface of the leaves and
vines. The sporangia and spore masses soon rupture and disappear
after maturity and are not likely to do any permanent damage to the
plants,
no

PREVENTIVE AND REMEDIAL MEASURES. 49

Epicoccum. — An undetermined species of this genus was obtained
in three different cultures made from diseased cranberry vines from
Olympia, Wash. Whether this was the cause of the diseased condi-
tion of the vine is not known.

Diplodia. — Dead cranberry vines collected at Wareham, Mass.,
and near Belleplain, N. J., bear a Diplodia not yet satisfactorily
identified. The spores are brown, ujdseptate. and measure 14 to 18
by 8 fi.

Chaetomiiim. — One or two species of this genus have occurred on
leaves kept in a moist chamber and also in cultures made from cran-
berry stems and berries. In some cases they may have been due to
contamination and in any event are probably not of pathological
importance.

Oospora. — A fungus apparently belonging to this genus has
occurred on leaves kept in a moist chamber.

M acrosporium. — An undetermined species of this genus has also
been found in cultures and on leaves kept in a moist chamber.

PREVENTIVE AND REMEDIAL MEASURES.
REGULATION OF THE WATER SUPPLY.

Careful field studies have indicated beyond doubt that the physio-
logical condition of the plants, as well as their environment, has much
to do with their susceptibility to disease; therefore, anything which
promotes the production of vigorous and hardy plants serves as a
means of preventing the diseases to a certain extent. It is difficult, or
impossible, on account of the very complex factors involved in the
conditions of soil, moisture, and the plants themselves, to tell which
are of most importance in their relation to the occurrence of dis-
eases. Certain cranberry bogs, or portions of bogs, frequently show
much more loss from diseases than others. From the experience of
various growers, as well as from our own observations, it appears
that the control of the water supply is a very important factor.
The quantity of water necessary to keep the plants in the most
vigorous condition depends largely upon the nature of the soil and
subsoil, as well as the contour and natural drainage conditions of
the land. The supply of water should be constant and capable of
complete control, so as to avoid any great fluctuations during the
growing season. In order to accomplish this, the water supply
should be obtained from a reservoir rather than directly from a
running stream. Some very successful growers find that keeping
the water at such a level in the ditches that the surface of the bog

no

50 CRANBERRY DISEASES.

will be continually moist, but not wet, keeps the plants in the most
healthy condition.

DESTRUCTION OF DISEASED VINES.

It is also important that steps should be taken so far as practicable to
prevent the distribution and reproduction of the diseases by destroy1
ing all dead vines and leaves before the fungi have had opportunity
to mature and set free their spores. Small areas of vines frequently
die from the attacks of fungi and from other causes. All such vines
should be pulled or cut and collected early in the season, at least
within a week after the water has been drawn from the vines, and
burned. Vines which have been cut in raking bogs to prepare them
for scooping should also be destroyed in the same manner ; otherwise
the spores of the cranberry fungi develop in great numbers upon them
and are a fertile source of infection for the young leaves and fruit.
Little is to be feared from full-grown rotten berries, as the fungi
very rarely produce any spores upon them.

SELECTION AND BREEDING OF RESISTANT PLANTS.

The selection of individual plants showing ability to resist the
diseases is also an important means of avoiding them. It is a matter
of common observation that some of the varieties are much more
subject to disease than others. It may also be noticed that in any
badly diseased area of vines there is occasionally one Avhich bears
sound fruit. By selecting and propagating these apparently resist-
ant plants a variety much less subject to injury could probably soon
be produced.

APPLICATION OF FUNGICIDES.

After determining the life histories of the most serious parasites
causing the diseases it seemed very probable, judging from their
relationships and the manner in which closely related species attack
other fruits, that they could be successfully combated by the applica-
tion of fungicides, the same as their relatives were. Experiments
and tests of fungicides have been conducted for the past four years.
Several kinds were used the first season, as already mentioned. Bor-
deaux mixture applied in the form of a spray proved much more
satisfactory than any of the others. Besides these a dust Bordeaux
mixture has been used quite thoroughly by one of the cranberry
growers, but without any decided benefit,
no

PREVENTIVE AND REMEDIAL MEASURES. 51

HORDKAfX MIX'li III.

In the spraying experiments plats were selected where from 75 to
100 per cent of the crop had been lost by disease in former years.
In the- experiments of 1904 four applications of Bordeaux mixture
were made during the season. In order to determine accurately the
results, alternate plats were left unsprayed, as a check. According
to actual counts of the sound and diseased berries made at picking
time, from September 8 to 13, on 35-yard-square plats, representing
the average condition of the sprayed and unsprayed areas, it was
found that the greatest percentage of diseased fruit on any of the
sprayed plats was 27.5, as against 100 per cent on the unsprayed plats.
The minimum amount of disease on any of the sprayed plats was 13
per cent, as against 89 per cent on the check plats. The average num-
ber of diseased berries on all the sprayed plats was 21.7 per cent
and on the unsprayed plats 76.8 per cent, and in addition to the pro-
tection of the fruit from diseases the general vigor and appearance
of the sprayed plants was noticeably improved.

These experiments, owing to circumstances beyond our control, were
not entirely satisfactory, as the applications of the fungicide were
not made with sufficient frequency and at the most desirable time.
In 1905 a more thorough and satisfactory series of experiments was
conducted upon the same plats. The wrater was removed from the
bog May 10 to 12. It is the usual practice of cranberry growers to
flood the bogs from twenty-four to thirty-six hours during the first
week in June, in order to destroy insects. It had been planned to
spray part -of the experimental plats before this second flooding.
The water supply of the bog was, however, insufficient for a second
flooding, and the relation of spraying to this operation was therefore
not determined. Two of the plats were sprayed five times — May 19,
June 22, July 14, July 31, and August 15. At picking time, Sep-
tember 8, accurate counts were made of all the diseased and sound
berries on small areas which showed the average condition of the
fruit on the sprayed plats. Counts were also made on equal areas
showing the average condition of the fruit on the check plats. As a
result of these counts it wTas found that there was an average of only
0 per cent of rotten fruit on the sprayed plats, while there was a little
more than 91 per cent rotten on the unsprayed plats. TWTO other plats
sprayed five times, but beginning June 2 instead of May 19, showed
as a result of the counts made as in the experiment just mentioned
an average of 2.30 per cent of diseased berries on the sprayed plats
and 92.06 per cent of diseased fruit on the unsprayed plats. This
appears to indicate that the application made on June 2 was more
beneficial than that made at the earlier date, May 19.
no

52 CRANBERRY DISEASES.

Another plat was sprayed but four times, as follows : July 14, July
31, August 1, and August 15. Estimates of the amount of diseased
fruit on the sprayed and unsprayed plats, made as in the previous
cases, showed 18.3 per cent of rotten berries on the sprayed plat and
91.53 per cent on the unsprayed plat. This indicated what had
already been anticipated, from our knowledge of the time of ma-
turity of the parasites causing the diseases, that the earlier applications
are exceedingly important, most of the infection apparently occurring
before the fruit is half grown.

A portion consisting of 1,048 square feet of one of the plats which
was sprayed five times was carefully hand picked and produced 3
bushels of sound fruit, this being at the rate of about 125 bushels
per acre. The same area from the adjoining check plat gave a
scanty peck of sound fruit, or 10.42 bushels per acre. In other words,
'there was twelve times as much sound fruit on the sprayed plat as on
the unsprayed plat, or a saving of over 100 bushels per acre.

Preparation and application. — The method of preparation, as well
as the dates and manner of application, is of exceeding importance
in securing satisfactory results. The Bordeaux mixture should be
freshly made. Good stone lime should be used, and from 3 to 5
pounds of commercial resin-fishoil soap should be added to it. In
our first experiments, in which the plain Bordeaux mixture was used,
it was found that the spray either collected in drops upon the surface
of the leaves and fruit or ran off entirely, the surface of the cran-
berry leaves and fruit being so glossy that the mixture did not spread
and adhere properly. It was found that by adding the- resin-fishoil
soap the mixture not only formed a film and spread over the surface
of the leaves and fruit, but also adhered for a much longer time than
the plain Bordeaux mixture.

The comparison of sprayed and unsprayed fruit at the time of
picking does not show the full amount of profit to be derived from
the treatment, as there is usually a considerable loss from the develop-
ment of the diseases during the period between the time of picking
and the time of marketing the berries. In order to compare the
keeping qualities of the sprayed and unsprayed fruit, 2,400 perfectly
sound berries, so far as could be determined by external appearance,
were selected. Twelve hundred berries were from a sprayed plat and
1,200 from a check plat. They were all kept in the laboratory under
similar conditions in order to determine the amount of disease which
would develop in each case before the time for marketing the fruit.
On October 18, the date upon which most of the fruit from the bog
was marketed, and exactly one month from the date of picking, a
careful examination of the 2,400 berries showed only 9.8 per cent of
no

SUMMAKY. 53

the sprayed fruit diseased, while 138.1 per cent of the unsprayed fruit
was diseased. In other words, four times as much of the unsprayed
fruit as of the sprayed fruit decayed between the time of picking and
marketing. The decay which developed was apparently caused by
the dormant infection.

Cost of spraying. — The cost of spraying as it was done in these
experiments averaged -from $15 to $20 per acre, the Bordeaux mixture
being applied at the rate of 4 barrels, or 200 gallons, per acre at each
application, making for five applications a total of 1,000 gallons per
acre. The cost would probably vary somewhat under different condi-
tions and different methods, but in no instance should it exceed $20
per acre.

SUMMARY.

There are four serious fungous diseases of the cranberry — scald,
caused by Guignardi'a caccinii; rot, caused by Acanthorhynchus vac-
cinii; anthracnose, caused by Glomerella rufomaculans vaccinii, and
hypertrophy, due to Exobasidium oxycocci. The first three diseases
mentioned have heretofore been confused and considered as one.

Life history studies have shown that Guignardia vaccinii produces
two forms of fructification — pycnidial and ascogenous — and is
closely related to Guignardia bidwellii, which causes the black-rot of
the grape.

Similar studies of Acanthorhynchus vaccinii reveal only ascogenous
fructifications, but very striking and characteristic appressoria, which
perhaps fill in part the place of a pycnidial form, are produced.

Glomerella rufomaculans vaccinii is also found to produce both
conidial and ascogenous forms.

The production of ascogenous fructifications appears to depend in
both Guignardia raccinii and Glomerella rufomaculans vaccinii
chiefly upon some inherent potentiality of the race, strain, or genera-
tion from which the hyphse or spore used in the culture are derived.
The composition of the culture medium and the conditions of temper-
ature, moisture, and light are relatively unimportant factors.

The fungi producing scald, rot, and anthracnose, as well as Pesta-
lozzia guepini vaccinii, are able to live in the tissues of cranberry
leaves and fruit in a more or less dormant or noninjurious condition
for a considerable period and may apparently at any time develop
rapidly and destroy the tissues when conditions are favorable.

Thirteen other fungi have been found affecting cranberry fruit,
most of which have, however, not showrn indication of particular
pathological importance. Sixteen different species have been found
on either stems or leaves. Most of these do not seem to cause serious
injury to the plant,
no

54 CRANBERRY DISEASES.

Preventive measures should include renovation of the cranberry
bog, careful control of the water supply, and the cultivation of hardy
and disease-resistant varieties.

Thorough treatment with Bordeaux mixture has proved successful
in controlling the diseases. The addition of resin-fishoil soap is
essential in order to make the mixture properly cover and adhere to
the plants. As a result of five applications in 1905, only 2.30 per cent
of the sprayed fruit was found to be destroyed at picking time,
whereas 92 per cent of the unsprayed fruit on the plat a'd joining was
destroyed.

The cost of five applications, each of 200 gallons per acre, varies,
according to the conditions and methods employed, from $15 to $20
per acre,
no

BIBLIOGBAPHY OF CRANBERRY DISEASES.

1 FERNALD, M. L. Variations of American cranberries. Khodora, 4: 231-237,

Dec., 1902.

2 Report of convention of New Jersey Cranberry Growers' Association. New

Jersey Courier, Toms River, N. J., Sept. 4, 1873.

3 TAYLOR, THOMAS. Cranberry rot and scald. Monthly Rept. U. S. Dept. Agr.,

Oct., 1874, 439.

4 Op. cit, Jan., 18755> 42-44.

5 op. cit, Oct., 1875, 446.

6 Op. cit., Aug. and Sept., 1876, 350.

7 - — Ann. Rept. Dept. Agr., 1875, 193.

8 SCHROETER, J. Weisse Heidelbeeren. Hedwigia, 18 : 183, Dec., 1879.
•WORONIN, M. Ueber die Sclerotienkrankheit der Vaccinien-beeren. Mem.

Acad. Imp. St. Petersburg, ser. 7, 36: 28-30, 1888. v
IOHALSTED, BYRON D. Some fungous diseases of the cranberry. N. J. Agr.

Expt. Sta., 64; 1889.

— Experiments for the year upon cranberry diseases. Ann. Rept. N. J.

Agr. Expt. Sta. for 1890, 332-339. This paper was also published in Proc.

21st Ann. Meet. Amer. Cranberry Growers' Assn., Jan., 1891.
12 —Treatment of cranberry scald and cranberry gall fungus. Jour. Myc.,

<•> : 18, 1891.
— Diseases of the cranberry. Proc. 26th Ann. Meet. Amer. Cranberry

Growers' Assn., 10-12, Jan., 1896.
14 Laboratory study of fruit decays. Rept. N. J. Agr. Expt. Sta., 326-

330, 1892.

"WHITSON, A. R., HASKINS, L. P., and MALDE, O. G. Ann. Rept. Wis. Agr.
Expt. Sta., 22 : 294-295, 1905.

16 SANDSTEN, E. P., HASKINS, L. P., and RAMSEY, H. Preliminary report on cran-
berry investigations. Ann. Rept. Wis. Agr. Expt. Sta., 21 : 237, 1904.

— A report on cranberry investigations. Wis. Agr. Expt. Sta., 119;
42-44, Feb., 1905. This, with the exception of a few sentences, is a reprint
from the preceding work.

18 VIALA, P. Les maladies de la vigne. ed. 3, 179 et seq., 1893.
"KLEBS, GEORG. Die Bedingungen der Fortpflanzung bei einigen Algen und
Pilzen, pp. 543, tabs. 3, text figs. 15, Jena, 1890.

20 BLAKESLEE, A. F. Sexual reproduction of the Mucorinea3. Proc. Amer. Acad.

Sci., 40 : 205-319, 1904.

21 BREFELD, OSCAR. Untersuchungen aus dem Gesammtgebiete der Mykologie, 10 :

349,, 1891.

22 SHEAR, C. L. Mycological notes and new species. Bui. Torr. Bot. Club, 29 :

449-457, 1902.

— Arachniotus trachyspermus. A new species of the Gymnoascaceae.
Science, n. s., 16 : 138, July, 1902.

no

55

56 CRANBEEEY DISEASES.

24 SHEAR, C. L. New species of fungi. Bui. Torr. But. Club. 34: 305-317, 1907.
— Fungous diseases of the cranberry. U. S. Dept. Agr., Farm. Bui. No.
221, 1905.
26 — Cranberry spraying experiments in 1905. U. S. Dept. Agr., Bur. Plant

Industry, Bui. 100, pt. ], 1906.

— 32d Ann. Meet. Amer. Cranberry Growers' Assn., 8-11, 1902.
Investigations of cranberry diseases. Proc. 33d Ann. Meet. Amer. Cran-

berry Growers' Ass.n., 7-8, 1903.

A remedy for cranberry scald. Amer. Agriculturist, 72 : 309, 1903.

Report on cranberry spraying experiments. Proc. 34th Ann. Meet.

Amer. Cranberry Growers' Assn., 8-10, Jan., 1904.

— 'Progress of cranberry spraying experiments. Proc. 35th Ann. Conv.
Amer. Cranberry Growers' Assn., 6-7, Aug., 1904.

— Report of experiments on cranberry diseases. Proc. 35th Ann. Meet.

Amer. Cranberry Growers' Assn., 4-5, Jan., 1905.
— • — Fungous diseases of the cranberry. 37th Ann. Conv. Amer. Cranberry

Growers' Assn., 8-9, Aug., 1906.
Cranberry spraying apparatus. Proc. 37th Ann. Meet. Amer. Cran-

berry Growers' Assn., 6-8, Jan., 1907.

— and WOOD, A. K. Ascogenous forms of Gloeosporium and Colleto-
trichurn. Bot. Gaz., 43: 259-266, 1907.

30 DUBELL, E. H. Spraying with Bordeaux mixture for cranberry scald finan-
cially considered. Proc. 37th Ann. Meet. Amer. Cranberry Growers' Assn.,
3-6, Jan., 1907.

37 FISCH, C. Beitrage zur Entwickelungsgeschichte einiger Ascomyceten. Bot.

Zeit, 40 : 851-870, pis. 2, 1882.

38 FRANK, B. Ueber einige neue und wenigbekanute Pflanzenkrankheiten.

Ber. Deutsch. Bot. Gesells., 1: 29-34, 58-63, 1883; also Landw. Jahrb.. 12:

511-539, pis. 3, 1883.
* MEYER, B. Untersuchungen iiber die Entwickelu'ng einiger parasitischer

Pilze bei saprophytischer Ernahrung. Landw. Jahrb., 17: 912-945, pis. 4,

1888.
*°DEBAKY, A. Ueber einige Sclerotinieu und Sclerotinienkrankheiten. Bot.

Zeit, 44: 377, 1886.

41 BUSGEN, M. Ueber einige Eigenschafter der Keimlinge parasitischer Pilze.

Bot. Zeit., 51 : 53, 1893.

^ HASSELBRING, HEINRICH. Appressoria of the anthracnoses. Bot. Gaz., 42 :
135, 1906.

42 ZOPF, W. Mechanik der Sporenentleerung bei Sordarieen. Zeitschr. fiir

Naturwis., Halle, 56: 561, 1883.

44 GRIFFITHS, DAVID. The North American Sordariacese. Mem. Torr. Bot. Club,

11 : 32, May, 1901.

45 STONEMAN, BERTHA. A comparative study of the development of some anthrac-

•noses. Bot. Gaz., 26 : 69-120, 1898.

46 CLINTON, G. P. Bitter-rot. Bui. 111. Agr. Expt. Sta., 69 ; 1902.

4T VON SCHRENK, H., and SPAULDING, P. The bitter-rot of apples. U. S. Dept.

Agr., Bur. Plant Industry, Bui. 44 : 29, 1903.
48 SHELDON, J. L. Gloeosporium of sweet pea and apple. Science, n. s., 22 :

51, 1905.
48 SCOTT, W. M. The control of apple bitter-rot. U. S. Dept. Agr., Bur. Plant

Industry, Bui. 93, 1906.

110

BIBLIOGRAPHY. 57

so SCOTT, W. M., and QUAINTANCE, A. L. Spraying for apple diseases and the
codling moth in the Ozarks. U. S. Dept. Agr., Farm. Bui. 283, 1907.

51 ROSTBUP, E. Oin nogle af snyltesvampe foraarsagede misdannelser lios
blomsterplanter. Bot. Tidsskr., 14: 2:50, 1883.

62 — — Biologiske arter og racer. Bot. Tiddskr., 20 : 116-125, 1895-6.

63 PECK, CHARLES H. Report of the botanist. Kept N. Y. State Mus., 26: 73,

Apr., 1874.

M Report of the botanist. Rept. N. Y. State Mus., 25 : 106, 1873.

THOMAS, FB. Cranberry leafgall. Insect Life, 1 : 279, Mar., 1889.
SI>MONTAGNE, C. Notice sur les plantes cryptogames. Ann. Sci. Nat. Bot,

ser. 2, 1 : 347, 1834.
67 SCHWEINITZ, L. D. Synopsis of North American fungi. Trans. Amer. Phil.

Soc., n. s., 4 : 211, 1834.

•* FRIES, E. Systema Mycologicum, 2 : 451, 1822.
" RICHARDS, H. M. Notes on Exobasidium andromedae Pk. and Exobasidium

vaccinii (Fold.) Wor. Bot. Gaz., 21: 104, 1896.
80 FARLOW, W. G., and SEYMOUR, A. B. A provisional host index of the fungi of

the United States, 74, 1890.

110

DESCRIPTION OF PLATES.

PLATE 1. — Frontispiece. Cranberry scald, showing different stages in the prog-
ress of the disease. A. — Early stage. B. — Later stage, showing dark zones.
C. — Berry completely destroyed.

PLATE II. — Fig. 1. — A cranberry leaf, showing pycnidia of Guignardia vaccinii
thickly scattered over the under surface ; a, a cranberry blossom blasted by
Guignardia vaccinii, showing pycnidia on calyx, corolla, and pedicel; 7>, a
blasted fruit, showing pycnidia. Fig. 2. — A vertical section of a single pyc-
nidium of Guignardia vaccinii from a cranberry leaf, showing pycnospores
in various stages of development. Fig. 3. — An immature pycnospore of
the same fungus, showing the partially foruied appendage ; a, the same,
showing a little later stage of development ; It and c, fully developed pyc-
nospores and appendages. Figs. 4, 5, 6, 7, 8, and 9. — Various stages in the
germination and growth of pycnospores of Guignardia vaccinii grown in
weak sugar solution ; 4, 5, 6, and 7, seventy-two hours after sowing; 8 and 0,
eighty-six hours after sowing. Fig. 10. — A vertical section of a perithecium
of Guignardia vaccinii, showing asci, from a cranberry leaf collected in New
Jersey. Fig. 11. — Three asci, with ascospores showing variations in length
of the stipe and the arrangement of the spores ; a and &, from perithecia on
a leaf ; c, from a pure culture. Fig. 12. — A fresh, mature ascospore, show-
ing the usual condition, in which the protoplasm is very coarsely granular.
Fig. 13. — An old ascospore from a dried specimen, having its contents homo-
geneous. Fig. 14. — a, A portion of the coarse brown mycelium from the
interior of a scalded berry, from which a culture was made December 23,
producing pycnidia and ascogenous perithecia of Gmgnardia vaccinii ; 1), a
portion of younger, lighter colored hypha? from the same berry. Fig. 15. —
Pestalozzia gncpini vaccinii ; a, a conidium having an apical appendage with
three branches ; fr, a conidium having an apical appendage with four
branches ; o, a germinating conidium ; d, a germinating conidium sending
out two germ tubes.

PLATE III. — Fig. 1. — Vertical section through an acervulus of Glomcrella rufo-
maciilans vaccinii from the under surface of a cranberry leaf. Fig. 2. —
Four conidia from the same, showing some of the variations in form and size.
Fig. 3. — A portion of an acervulus of Glomerella rufomaeulans vaccinii from
a pure culture on corn meal, showing the dark-colored seta? which are occa-
sionally found; a and &, conidiophores and conidia from another pure cul-
ture on corn meal. The conidiophores arise from a dark stromatic layer
consisting of cells resembling appressoria, as shown in 3, a. No large acer-
vuli, forming dense masses, occurred in this culture. Fig. 4. — Appressoria
or chlamydospores from pulp of a cranberry from Massachusetts destroyed
by Glomcrella rufomaeulans vaccinii. Fig. 5. — Portion of mycelium from
corn-meal culture No. 736, forty-two days old. Conidia and appressoria
found, fifteenth day ; matured asci appeared the twenty-third day — no light
spots seen in these. Where they appear they are probably due to the presence
of vaeuoles or oil globules. Fig. 6.— An ascogenous perithecium of the same

no
58

DESCRIPTION OF PLATES. 59

fungus grown in a pure culture. Fig 7.— Asci from the same; a, cylindrical
form, with overlapping uniseriate spores; b, shorter subclavate form; c,
ascus from older culture, showing shorter stipe. Fig. 8. — Fresh, mature
ascospores from the same. Fig. 0. — Asci and fugaceous paraphyses from
culture of Glonierella rufotnaculans vaccimi. Fig. 10. — Portion of an
acervulus of Gloeosporium mi mix, from a pure culture from a diseased New
Jersey berry. Fig. 11. — Cornelia from the same. Fig. 12. — A portion of a
cranberry leaf, showing the slightly elevated epidermis and the protruding
neck of Acantliorhynclius vaccinii. Fig. 13. — A single perithecium of the
same fungus, taken from a pure culture on corn meal, showing portions of
the hyphse which form the thin, loose mycelial layer writh which the perithecia
are overgrown in artificial cultures. Fig. 14. — Asci and paraphyses from
the same pure culture ; a, a young ascus, in which the mature ascospores
are surrounded by granular gelatinous matter ; ft, a slightly older stage ; c,
a nearly mature ascus, in which the granular protoplasm is shrunken about
the spores and attached to the apex of the ascus. A portion of it remains
as a thin gelatinous envelope about the spores after they are expelled from
the ascus. Fig. 15. — Two aseospores of the same. Fig. 16. — A germinating
ascospore, bearing the peculiar appressorium. Fig. 17. — An appressorium
viewed from above. Fig. 18. — A group of appressoria attached to the sur-
face of a cranberry leaf. Fig. 19. — A germinating appressorium grown in a
poured plate. Fig. 20. — A germinating appressorium from the midrib of a
leaf, showing superficial branching hypha?. Fig. 21. — A section of a germi-
nating appressorium on a leaf ; a, a germ tube wrhich has entered the leaf
through a stoma. Fig. 22. — Another germinating appressorium ; a, the germ
tube entering the leaf through a stoma.

PLATE IV. — Fig. 1. — Ycnturia compacta. Massachusetts specimens on the under
surface of a leaf showing various aggregations of perithecia. (Natural
size.) Fig. 2. — Group of perithecia magnified 24 diameters. Fig. 3. — Single
perithecium, showing spines distributed over the upper half. Fig. 4. — Two
asci, showing variability in shape and length. Fig. 5. — A perithecium of
the same fungus from a Wisconsin specimen, showing fewer spines ar-
ranged about the apex. Fig. 6. — Three asci from the same, showing varia-
tions in shape and arrangement of the spores. Fig. 7. — A single ascospore
from the same. Fig. 8.— A perithecium of Anthostomella destruens from a
pure culture of the fungus. Fig. 9. — An ascus from the same. Fig. 10. —
Two ascospores of the same. Fig. 11. — A germinating ascospore of Antho-
stomella destruens. Fig. 12. — Pycnidia of Scptoria longispora on under sur-
face of a cranberry leaf. Fig. 13. — Section of a pycnidiuni of Septoria
longispora on a cranberry leaf. Fig. 14. — Three spores of Septoria longi-
spora from a cranberry leaf. Fig. 15. — Synchytrium vaccinii on pedicel,
bracts, and flower of a cranberry. (Natural size.) Fig. 1C. — Synchytrium
vaccinii. A single gall enlarged. Fig. 17. — Synchytrium vaccinii. A sec-
tion through a gall showing the hypertrophied tissue .and the sporocarp.
Fig. 18. — Arachniotus trachyspermus on a decayed and shriveled cranberry.
Fig. 19. — Arachniotus trachyspermus on the side of a culture flask. Fig.
20. — Ascogenous hypha? and asci of the same from a pure culture. Fig. 21. —
A single ascus of the same from a pure culture. Fig. 22. — A single asco-
spore of the same. Fig. 23. — Rclerotinia oxycocci Wor? Branching chain
of conidia, inverted ; a, a single conidium. Fig. 24. — Cladosporium oxy-
cocci. Conidiophores bearing conidia from a cranberry leaf; a, a single
septate conidium from the same.

110

60 CRANBERRY DISEASES.

PLATE V. — Fig. 1. — 8phaeronema ponioruin. A single pycnidium from a pure
culture ; a, three spores, showing variations in size and shape. Fig. 2. —
Plagiorhabdus oxy cocci. Vertical section of a pycnidium on a cranberry
leaf. Fig. 3. — Plagiorhabdus oxycocci, sporophores and spores; a, three
spores with basal appendages consisting of the greater part of the abstricted
sporophore. Fig. 4. — Helminthosporium inaequalis, showing fertile hypliu*
and the varied arrangement of the conidia. Figs. 5, 6, and 1. — Hclmintho-
sporium inaequalis. Conidia showing variation in size, shape, and septa-
tion. Fig. 8. — Helminthosporium inaequalis. A strand of the mycelium.
Fig. 9. — Helminthosporium inaequalis. Erect, branched, black, subcarbona-
ceous bodies produced in old cultures. Fig. 10. — Phyllosticta putrefaciens,
from a culture. Pycnidia ; a, four spores from the pycnidia, showing varia-
tions in size and shape. Fig. 11. — Ceuthospora (?) lunata on a cranberry
leaf, showing a vertical median section of a pycnidium. Fig. 12. — Ceutho-
spora (?) lunata. Sporogenous hyphse and sporophores as seen when
crushed out ; a, three spores showing variations in size and shape. Fig.
13. — Leptothyrium pomi (?). An early stage in the formation of the
" speck." The remains of a spore from which it seemed to have arisen are
still present. Fig. 14. — Leptothyrium pomi (?). An older condition. Fig.
15. — Leptothyrium pomi (?). A vertical section from a cranberry, showing
the structure of the interior. No signs of spore production. Fig. 16, n, I),
c.. — Leptothyrium pomi (?). Spores found associated with Leptothyrium
pomi on the surface of the fruit ; a, a germinating spore of an unknown
fungus from which some specks at least appeared to arise. Fig. 17. — Sporo-
nema oxycocci. Four pycnidia on a cranberry leaf. Fig. 18. — Sporonema
oxycocci. Vertical section from a cranberry leaf. Fig. 19. — Sporonema
oxycocci. Two sporophores with nearly mature spores. Fig. 20. — Sporo-
nema oxycocci. A single spore. Fig. 21. — Rhabdospora oxycocci. Section
of a pycnidium on a cranberry leaf. Fig. 22. — Rhabdospora oxycocci. Sec-
tion of a pycnidium from a leaf, showing the inner wall separated from the
outer and collapsed. Fig. 23. — Rhabdospora oxycocci. Branched sporo-
phores with young spores. Fig. 24. — Rhabdospora oxycocci. Another viewT
of branched sporophores and young spores ; a, two spores, showing pseudo-
septa. Fig. 25. — Sporonema pulvinatum. Two pycnidia on a cranberry leaf.
Fig. 26. — Sporonema pulvinatum. A vertical section of a pycnidium. Fig.
27. — Sporonemq pulvinatum. Sporophores and young spores. Fig. 28. —
Sporonema pulvinatum. Three spores showing variations in size and shape.
Fig. 29. — Leptothyrium oxycocci. Four pycnidia on cranberry leaf, showing
irregular shapes. The one in the foreground has broken away about its
base. Fig. 30. — Leptothyrium oxycocci. Section of a pycnidium, showing its
dimidiate character. Fig. 31. — Leptothyrium oxycocci. Portion of the wall
of the pycnidium, showing the parallel arrangement of the cells. Fig. 32. —
Leptothyrium oxycocci. Sporophores and spores. Fig. 33. — Leptothyrium
oxycocci. Four spores, showing the variations in size and shape.

PLATE VI. — Cranberries destroyed by blast and scald. From a photograph.
(Natural size.)

PLATE VII. — Cranberry Exobasidii. A and B. — Exobasidium vaccinii. C and
D. — Exobasidium oxycocci.

110

Bui. 110, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE II.

FUNGOUS PARASITES OF THE CRANBERRY.

Bui. 110, Bureau of Plant Industry, U. S. Dept. of Agriculture.

PLATE III.

FUNGOUS PARASITES OF THE CRANBERRY.

Bui. 110, Bureau of Plant Industry, u. S. Dept. of Agriculture.

PLATE IV

FUNGOUS PARASITES OF THE CRANBERRY.

PLATE V.

Bui. 110, Bureau of Plant Industry, U. S. Dept. of Agriculture.

LESS IMPORTANT CRANBERRY FUNQI.

.V

Bui. 1 10, Bureau of Plant Industry, U. S. Dept. of Agriculture

PLATE VI.

CRANBERRIES DESTROYED BY BLAST AND SCALD.

(Natural size.)

Bui. 1iO Bureau of Plant Industry, U. S. Dept. of Agricultur

PLATE VII

A. HOEN A CO., LITH.

CRANBERRY EXOBASIDII.

INDEX.

Page.

Acanthorhynchus vaccinii, appressoria 27-28

ascogenous form 27

characteristics of the fungus 27-30

conidia and pycnidia not found 27

cultures of the fungus 29-30

description - 12,27-30

fruiting specimens collected .__ 27

relationship of the fungus — 28-29

treatment 30

Anthostomella destruens, description - 14,43

Anthracnose, description, etc - 12,30-35

See also Glomerella rufomaculans vaccinii.

Arachniotus trachyspermus, description and cultures 41-12

Bibliography of cranberry diseases - 55-57

Blakeslee, work on Mucor, etc 20

Blast and scald, fungus causing, description, etc ____ _ 14-26

or blight, description and history___ 12-13

See also Guignardia vaccinii.

Blight, or blast, blossom, in Wisconsin . 12r-13

treatment with Bordeaux mixture 13

effect of fertilizers 13

in Wisconsin _ 12-13

Bordeaux mixture, application and preparation 13,50-53

formula used 26

results of spraying 25-26

Brefeld, views as to ascus formation 20

Ceuthospora (?) lunata, description - 47-48

Chaetomium, occurrence 49

Chondrioderma simplex, occurrence 48

Cladosporium oxy cocci, description __. 48

Copper sulphate applied to soil 24

Copperas applied to soil - 11,24

Cranberry, American 9

cultivation, effect 9

period 9

diseases, where most serious__ '•>

distribution 9

fungi heretofore found 9

scald. See Scald.

susceptibility to diseases 9

value of annual crop

Description of plates - 58-60

61

62 CRANBERRY DISEASES.

Page.
Dlplodia, occurrence 49

Discosia artocreas, occurrence 46

Diseases, confusion in designation by growers 10

description , 12-49

distribution A 9

history 9_12

less important 37—19

loss, annual 9

more important 12—37

treatment, preventive and remedial 49-54

Epicoccum. occurrence ; 49

Exobasidium oxycocci, description, etc 12,36-37

relation to other Exobasidii 36

treatment 37

vaccinii, description 36

Tungi attacking the fruit, descriptions 37-44

occurring on the leaves or stems, descriptions 11 19

Fungicides, application . 50-53

Bordeaux mixture, preparation, application, and cost 50-53

Gloeosporium lindemuthianum, appressoria, or chlamydospores 28

minus, description 40

Glomerella rufomaculans vaccinii, ascogenous form 31-32,33

fructification, .production. 33

appressoria, or chlamydospores 32

conidial form 31

cultures 32-33

description 12,31-35

dormant condition of the fungus 34-35

relationship -of the fungus 33-34

treatment 35

Guignardia bidwellii, pycnidial stage 15

vaccinii, acervuli, development 30

ascogenous form, description 15-16

factors determining production 19-21

conidial form not found 19

cultures 16-19

producing ascogenous form 17-18

pycnidial form 16

description, etc 14-26

dormant condition of the fungus 21-22

fungus causing blast and scald, description, cultures,

etc 13-26

occurrence __r 12-13

pycnidial form, description 14-15

time and manner of infection 22-24

treatment 24-26

application of fungicides 25-26

to soil of lime, plaster, salt,
sulphur, copper sulphate,

and iron sulphate 11,24

improvement of condition of plants 24-25

selection of resistant varieties 25

110

INDEX. .

63

Page.

Halsted, Byron D., experiments 11,13

Haskins, experiments 12,13,14

Helmintb&porttttQ inaequalis, description 39-40

Hypertrophy, description, etc 12,35-37

See a/.vo Exobasidium oxycocci.

Introduction to bulletin 9-10

Investigations of diseases, earlier 10-12

Iron sulphate applied to soil 24

Klebs, experiments 19

Leptothyrium oxycocci, description 47

pomi. description 44

Less important diseases, descriptions-, 37-49

Lime applied to soil 11,24

Macrosporium, occurrence: 49

Malde, experiments 12

Most serious diseases 12-37

New Jersey Experiment Station, cooperation 12

Oospora, occurrence 49

Penicillium glaucum, description 43-44

Pestalozzia guepini, description 39

vaccinii, description 38-39

Hiyllosticta putrefaciens, description 43

Plngiorhabdus oxycocci, description 46

Plaster applied to soil 24

Plectroihr'ix globosa, description 48

Prevention of diseases. Sec Treatment, preventive and remedial.

Ramsey, experiments 13, 14

Remedies. See Treatment, preventive and remedial.

Resistant plants, selection and breeding 50

Rhabdospora oxycocci, description. _ 47

Roseliinia, resemblance to cranberry fungus. _ 14

Rot, description 10, 26-30

See also Acanthorhynchus vaccinii.

Salt applied to soil ___ 11,24

Sandsten, experiments 13, 14

Scald, acidity in soil attributed as cause of disease 10

burning mummied fruit recommended 10

description, history, treatment, etc 10-26

discussion by cranberry-growers' associations 10

diseases covered by name 12

distribution 15-16

fungus causing, description, etc _ 14-26

Taylor, Thomas, investigations and remedy proposed 10, 11

See also Guignardia vaccinii.

Schroeter, suggestions to prevent diseases 11

Sclerotinia, believed by Schroeter to be cause of scald 11

oxycocci, believed by Woronin to be cause of scald__ 11

occurrence ^ 45-46

Septoria longispora, description 42

(toil, application of copper sulphate and plaster 24

copperas, lime, salt, and sulphur.- _ 11,24

SpliM-roneiiia pomorum, description , 42-43

110

64 ' ^HA^TBEEKY DISEASES.

Page.

Sporonerna oxycocci, description _______________________________________ 41

pulvinaturn, description ___________________________________ 46-47

Spraying, cost --------------------------------------------------- *___ 53

methods and results _________________________________________ 50-53

Sulphur applied to soil ________________________________________________ 11, 24

Summary of bulletin _________________________________________________ 53-54

Synchytrium vaccinii, description ________________________ • ______________ 37-38

Taylor, Thomas, investigation of cranberry scald _____ 10

treatment of soil suggested for cranberry scald __________ 24

Thomas, description of Synchytrium vaccinii ________ 37

Treatment, Acanthorhynchus vaccinii __________________________ _______ 30

Exobasidium oxycocci ___________________ 37

Glomerella rufomaculans vaccinii ___________________________ 35

Guignardia vaccinii _________________ ________________ 24-25

by fungicides ___________________________ 25-26

preventi ve and remedial _. _________________________ 49-53

application of fungicides ______ . _______ 50-53

Bordeaux mixture, cost of spraying, 53
preparation and

application ___ 52-53
results of experi-

ments ________ 51-52

destruction of diseased vines _________ 50

selection and breeding of resistant

plants _________ 50

water supply, regulation _____________ 49-50

scald, Taylor's remedy _______ s ______________________________ 10

Vaccinium macrocarpum, American cranberry, history ___________________ 9-10

myrtillus, disease mentioned by Schroeter ____________________ 11

oxycoccus, native cranberry _________________________________ 9

Valsa delicatula, occurrence ___________________________________________ '48

Venturia compacta, description ____________ _ ___________________________ 45

Vines, diseased, destruction ___________________________________________ 50

Water supply, regulation __________ ___________________________________ 49-50

White, J. J., paper regarding scald ___________ 10

Whitson, experiments ____ _________________ 12,13,14

Woronin, suggestion as to treatment of cranberry disease ________________ 11

110

O