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“FARMERS BULLETIN 1081 | MINTIED STATES DEPARTMENT OF AGRICULTURE

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‘CRANBERRY DISEASES

AND THEIR CONTROL

RANBERRY DISEASES cause large losses cach year. They are due to fungi and ahnormial con- ditions of growth and treatment.

The principal fungous diseases can be prevented largely by spraying with Bordeaux mixture.

The large losses due to smothering can be avoided hy proper methods and conditions of picking, stor- ing, and handling the fruit.

Berries should be pieked dry or dried quickly, handled carefully, kept in a cool well-ventilated place, and packed preferably in bushel or half-harre] boxes.

Contribution from the Bureau of Plant Industry WM. A. TAYLOR, Chief \ Washington, D.C. December, 1920 |

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CRANBERRY DISEASES AND THEIR CONTROL.

C, li. SHAR, Pathologist, Frait-Disease Investigations, Burcaw of Plant Industry.

CONTENTS. Vage. Page. Development of cranberry discases—_ 3 } Diseases discussed-—-Continued. Sanitary conditions. -__--_--- 4 Rose-bloom (Massachusetts false- Resistant varieties____ = + blossom, hypertrophy) ———~~- 12. Diseases discussed __ S32 eek a] Rad leaf-spot-____-_--- peated 13 Marly-rotes- 25-2 222 sc" a False-blossom (Wisconsin. false- Bitter-rot (anthracnose) - 8 blossom, phylody)—-------. -. 14 End-rot (blossom end-rot and Blachk-rotz-255-<5-45-s Be Sete 15 Stein @nd-rot) oo e 2k 9 Rugtie2 sn W= one ese e ea sae 7 Blotch-rot<(rot)s-2242002 22 --— 9 | Rot and spollage during storage, llard-rot and ae -blight—_. 10 shipping, and marketing ---_---- 17 Red-gallz_ 28. Slee as 11 | Smothering .---------- ae 18 | Spraying 22225 esa. SK aaa 19

DEVELOPMENT OF CRANBERRY DISEASES.

HE AMERICAN CRANBERRY ® has been in cultivation in

this country for nearly a centnry. Some of the present cran- berry meadows have been bearing frnit for 50 years or more, This long-continued growth of the same crop on the same land under the same conditions has favored the development and spread of certain diseases, some of which at present are unknown oi rarely found on wild cranberries, These diseases are gradually spreading and be- coming more serious.

Wild cranberry plants under natural conditions do not appear to be: seriously affected by disease. As is generally the case, however, when a plant is subjected to cultivation and changed conditions and planted over extensive areas, the opportunities for the development and distribution of parasites increase and its diseases become more serious, At the same time the plants under cnltivation appear in some eases to become weakened and more susceptible to disease.

The American wild cranberry occnrs from Newfoundland south- ward along the coast and through the Alleghenies to North Carolina and westward along the Great Lakes to Wisconsin and Minnesota. The commercial production of this frit is at present restricted to a few States, the bulk of the crop being grown in Massachusetts, New Jersey, Wisconsin, Oregon, and Washington. |

4 Vauchaun macrocarpum,

4 Farmers’ Bulletin 1081.

The cranberry plant differs greatly from most cultivated plants in its food and water requirements and also in its method of obtain- ing certain portions of its food. In common with most of the plants of the heath family, it requires an acid soil and obtains part of its nutriment through the aid of a beneficial fungus, known as myco- rhiza, which lives in the rootlets. There is much yet to be learned in regard to the best. conditions and methods necessary for the prodne- tion of the most vigorous and healthy cranberry plants. A plant, like an animal, when lacking proper and sufficient food or water hecomes weakened and more suseeptible to disease than one that is properly nurtured and hardy.

Every cranberry bog differs from every other, and in many cases different parts of the same bog differ in the origin and composition of the soil and in the character and distribution of the soil water and plant food. Experience, careful observation, and stndy must determine the most satisfactory methods of handling a particular bog in order to obtain the most vigorous, healthy, and productive vines.

SANITARY CONDITIONS.

Much can be done to prevent the development and spread of frngons diseases and inerease the vigor and resistanee of the vines by carefully regulating the water supply of the bog dnring the grow- ing season.

Many growers keep the bogs too wet, especially on rich peat bot- toms. This tends to produce an cxeessive growth of vines and favors the fungous diseases. Regular and judicions pruning shonld be practiced wherever the growth of vines is heavy. The prunings. unless used for planting, shonld be destroyed by fire in order to pre- vent the spread of the fungi which soon develop on them and furnish a source of infection for the bog. Rotten fruit discarded in sorting and screening should be buried or otherwise disposed of, so as to prevent the spread of disease.

RESISTANT VARIETIES.

Certain varieties of berries are more susceptible to disease than others. Therefore, in making a new planting varieties which have been found to be most healthy in the locality should be selected where practicable.

Little attention has yet been given to the selection and breeding of resistant varieties. In general, the smaller, firmer frnited varieties are less subject to rot than those bearing larger berries.

The average annual cranberry crop of the United States is about 500,000 barrels, valued at $3,000,000. The total loss from disease

Cranberry Diseases and Their Control. 5

is estimated to average at least 25 per cent, or $750,000 a year. Of this loss about 10 per cent occurs before the fruit is picked and 15 per cent after picking. The losses seem to be greater in the southern localities. The longer summers and higher average temperatures in the South are apparently less favorable to the production of hardy cranberry plants, while they seem more favorable to the development of certain serious fungous parasites.

DISEASES DISCUSSED.

The following diseases will be discussed here. They are arranged in the order of their destructiveness, the worst being presented first. Several others are known, but they are regarded as of no great eco- nomic importance at present.

Harly-rot . (seald, blast, Red-gall.

dead-spot, leaf-spot). Rose-bloom (Massaehusetts Ritter-rot (anthracnose). false-blossom, hypertrophy). End-rot (blossom — end- Red leaf-spot.

rot, stem end-ret). False-blossom (Wisconsin Bloteh-ret (rot). false-blossom, phyllody). Hard-rot. : Biack-rot, Tip-biight. | Rust.

EARLY-ROT.

‘

The name early-rot is applied to the disease caused by a fungus? closely related to that producing black-rot of the grape. The differ- ent stages and forms of reproduction of this parasite are shown in figure 1. The fungus attacks all of the aerial portions of the plant.

The most serious injury is usually caused by the destruction of the fruit, which may be attacked at any time during its development. Under favorable conditions for the growth and distribution of the fungus it attacks the flowers and very young fruits, causing the latter to shrivel and become blackened and finally covered with the spore-bearing pustules of the parasite. This form of the disease has sometimes been called blast and sometimes blight. Blossoms and young fruit frequently fail to develop from other causes, such as imperfect fertilization of the flowers, or from unfavorable weather conditions, such as excessive heat or cold or excessive moisture or drought, or from insects or fungous diseases. Wherever the injury is due to early-rot it is followed by the development of the minute black fruiting bodies of the fungus on the blackened and more or less shriveled young fruit of the cranberry.

The fruit attacked by this discase when half grown or more shows at first a minute light-colored soft spot on the surface. This spot

1Guignardia vaccinii Shear.

6 Farmers’ Bulletin 1081,

spreads in a conceutric manner until finally the whole berry becomes soft and sometimes marked by more or less distinet dark-colored rings. Ifthe rot develops rapidly, however, the berry may show little discoloration. Occasionally the rot is restricted to a small area on the fruit and the tissues become sunken, and sometimes the minute black spore-bearing bodies of the parasite develop. Ordinarily, how- ever, there is no indication on the surfaee of the fruit of the presence of the parasite exeept the oeeasional dark spots or brownish zones. Berries attacked before they are three-fourths grown fre- quently shrivel or become mummied and blackened and eovered with the fruiting bodies of the fungns. This condition is more frequent in New Jersey than in more northern localities, where the disease does not usually make its appearance until the fruit is nearly half grown,

The disease as it affeets the neatly grown fruit was for- merly called scald, espeeially in New Jersey. This name had its origin in the belicf previously held by many growers that the softening of the frnit caused by the fungus was due to the action of the hot sunshine upon the berries when wet with dew or rain. Occasionally a real scalding oceni's on berries which have

been overflowed and eovered Fie. 1.—The early-rot fungus: a, b, and ec,

| ‘half a day or Fruiting bodies on leaf, stem, and fruit (nat- ith water fou hal a di J u ural size); d and e, pycnidium and spores; More during ‘hot weather.

pe a ee ota and ascospores (much Tnjury of this kind, however, is infrequent and ean be dis- tinguished from that caused by fungi by the difference in effeet upon the tissues of the fruit. In the case of fungons injury the tissues beneath the skin are mostly destroyed. but the berries remain turgid and elastic nnder slight pressure. In the ease of sua seald, the tissues beneath the Hght-colored spot are more or less collapsed, or shrinken, or withered, and the spot does not increase in size, as in the ease of early-rot.

Cranberry Diseases and Their Control. q

Occasionally this fungus also attacks the foliage of the plant, causilg an irregular reddish brown spot, which may show spore- bearing pustules (pyenidia or perithecia) of the fungns. Usually, however, where the fungus invades the whole leaf it produces no spot, but causes the leaf to drop prematurely. The fruiting pus- tules of the fungus develop chiefly on the leaves after they have fallen. If cuttings from bogs affected with this disense are planted, the young g growth is frequently defoliated by this fungus and some- times is so seriously injured that the plants die. In old plantings the disease, when very severe, sometimes causes the death of the plants in spots. These are sometimes called dead spots and also, in- correctly, ringworm. The latter name should not be used in con- nection with fungous diseases, as there is an insect which produces similar dead spots. Where the vines are killed there is no evidence to be found of any injury to the root system by insects or other agencies and the dead foliage of the plants is covered with the fruiting pustules of the early-rot fungus. Sometimes other fungi are also associated with this, tending to increase the injury.

Early-rot is found in all the cranberry-growing sections of the country and is widely distributed on the native wild cranberry plants. It is most prevalent and produces most injury in the southern areas of cranberry cultivation. Tn the northern areas it appears later in the season and sometimes does not develop until after the fruit has been harvested. Much loss from this disease is caused as a result of dormant infections, which develop and destroy the berries during the period of sorting, packing, shipping. and marketing.

CONTROL.

Experiments conducted by the United States Department of Agri- culture and also the experience of varions growers during the last 10 years have demonstrated that this disease can be satisfactorily prevented by thorough spraying with 3-38-50 soap-Bordeaux mix- ture, This mixture should be prepared as follows:

Copper sulphate (blue vitrol or bluestone) ————— _pounds._ ° 3 Wreshi: “stone ulitne=s* 22-4 es Se eee EOS 228 Water _ ae nee eee -gnllons.. 50 Gonrnavelal ‘resiii- Aighotl soape_..- pee es Acne = pounds: =

The soap should be dissolved in about 10 gallons of water and added after the lime and bluestone have been mixed. The two requisites for the production of good Bordeaux mixture are fresh stone lime and the thorough mixing of the lime and_ bluestone solutions. The soap has been found necessary in order to cause the mixture to spread and adhere to the glossy stiface of the cranberry fruit and foliage. Where early-rot is serious, at least four applica-

8 Farmers’ Bulletin 1081.

tions of Bordeaux mixture should be made during the season, using 150 to 200 gallons to the acre. The first application should be made just before the flowers begin to open, the second when the blossoms begin to fall, the third two weeks later, and in severe cases a fourth not later than August 15, as later applications are likely to produce a staining of the frnit which may not be washed off before picking.

BITTER-ROT* (ANTHRACNOSE).

This disease is very similar to the bitter- rot of apples and other fruits. The different spore forms and the fructifi- cations of the fungus are shown in figure 2. This fungus attacks both the foliage and the fruit, causing most injury, how- ever, to the frnit. The appcarance of bitter-rot on the fruit is not easy to distinguish from several other rots which attack cranberries, and unless the fungus happens to be fruiting on the berries it is usually impossible to deter- mine positively the cause of the rot with- out making cnitures from the tissues of the affected berries or making a careful niicroscopic examination of the fungus in the mterior of the fruit. Affected berries become softened and show more or less of a brownish yellow discoloration.

Bitter-rot is widely distributed and has been found in New Jersey, New York, Massachusetts, Wisconsin, Wash- ington, and Oregon. Its seriousness in any particular locality appears to be

e é

Fig, 2.—The bitter-rot fungus: closely associated with the weather con- ty Be Sid Oy Conialal: tructi’ — sditions. Hot weather duting. July and cations; d, e, and f, perithe- E .

clum and ascospores. (All August appcars to be most favornble for pian Aen a) its development. The disease usually develops rather late in the season, and frequently not until after the fruit has been harvested.

‘Caused by Glomerella cingulate vaccinii Shear.

Cranberry Diseases and Their Control. 9 CONTROL.

Bitter-rot is somewhat more diffienlt to control than early-rot. The treatment should be the same as for early-rot, using Bordeaux mixture as recommended and making four applications. Special effort shonld be made to get the mixture on the vines before a rain. If this ean not be done, it should be applied immediately afterwards.

END-ROT* (BLOSSOM END-ROT AND STEM END-ROT).

End-rot is a fungous rot of eranberries which has been distin- guished from the other rots only within the last few years. It has been found, however, in all the cranberty-growing districts of the United States and has been the cause of considerable loss recently in Massachusetts and Wisconsin. It is called end-rot because, so far as known at present, it always starts at either the blossom or stem end of the berry. Most of the other rots usnally start at some other point on the fruit. Aside from the fact that this rot usually begins at the end of the berry, it has no characteristic which makes it distinguish- able from some of the other cranberry rots. The fruit when attacked becomes softened and the skin light colored or yellowish. The trouble develops late in the season, especially after picking and packing, and is most eommon in the northern sections.

CONTROL.

Experiments conducted during the last few years in cooperation with the Massachusetts Cranberry Experiment Station at East Ware- ham, Mass., have shown that end-rot is redueed by spraying with Bordeaux mixture, as reeommended in the regular treatment for early-rot.

BLOTCH-ROT?® (ROT).

As in the case of some of the other fungous rots of the cranberry, the appearance of the fruit attacked by blotch-rot is not sufficiently distinct for the grower to distinguish it from some of the other rots. The disease is due to the fungus which is shown in the accompany- ing illustration (fig. 3). This rot first appears as a small, light- colored, soft spot on the berry, finally spreading and destroying the whole frnit. In the later stages of its development it very fre- quently, though not always, prodnees small dark-colored blotches in the skin of the fruit. This appearance has snggested the proposed eommon name, blotch-rot. The only way in which this disease can be positively determined, however, is by making artificia} cultures of

1Caused by Fusicoccum putrefaciens Shear. 2Caused by Acanthorynchus vaccinit Shear.

141432°—-20——2

.

10 Farmers’ Bulletin 1081.

the fungus from the diseased berri ies, a method only available to the plant pathologist. This fungns also attacks the leaves, but it is

yes “YT Ts

lig. 8.——-Tbe blotch-rot fungus: a and B, Fruiting bodies; ¢ and d, organs of attachment; e€ and f, ascl and spores. (All much magnified.)

very rarely found fruiting on them until after they have fallen to the ground.

Blotch-rot has been found throughout the cranberry - growing sections of the United States and also Nova Scotia. Just how much of the annual loss from rot is due to this disease it is impossible to say, on account of the diffienlty of distin-

‘gnishing it from other diseases.

The fungus ocenrs so frequently, however, in. cultures from diseased berries that it is probably one of the common causes of rot,

CONTROL.

Spraying with Bordeaux mixture, as recommended fov early-rot, is a satisfactory preventive of this disease,

HARD-ROT AND TIP-BLIGHT.

Hard-rot and tip-blight are forms of a fungous disease caused by an organism closely related to the brown-rot fungus which attacks peaches and other fruits. The first appearance of this disease is to be fonnd on the young growing tips of the plants just before blossoming. The affected tips wilt and dry up, and the gray or white conidia of the fungus develop on them. Thisisthe tip-blight form of the disease.

Later in the season the fungus at- tacks the fruit, apparently gaining entrance through the blossoms and producing what is termed “hard- rot.” The appearance and character of the fruit affected with this dis-

ease are well marked and easily recognized when once seen. The

1 Caused by Sclerotinia orycocct Wor.

‘

Cranberry Diseases and Their Control. 11

affected berries instead of colormg up naturally as they approach maturity become a more or less sordid, pale, yellowish white color,. and instead of becoming softened, as in the case of most other fungous diseases, the tissues remain rather firm and leathery. Upon cutting an affected berry through the center the seed cavities will be found to contain a white fungous growth having a cottony appearance. Later in the season such berries shrivel, become darker and harder, and finally become mummied. These mummies contain the sclerotia or resting form of the fungus, which lives over winter. The mature or ascns-bearing form of the fnngus has not yet been found on the cranberry, but should be produced from these mummies during the following spring or early summer.

Hard-rot and tip-blight thus far have been found only in nWiseonsin and on the Pacific coast. Fortinately, the disease has not yet been very serious. If it should become general it has possibilities of cats- ing much loss, as the affected tips die and bear no fruit and the affected berries are worthless.

CONTROL.

The uncertainty of the occurrence of hard-rot and its scattered appearance have prevented the careful testing of fungicides. From our knowledge of diseases caused by closely related fungi, such as the brown-rot:of peaches, plums, etc., there is reason to believe that this disease can be prevented by spraying with Bordeaux mixture. The first application, however, should be made as soon as the new growth starts, in order to prevent the infection of the tips. Further apphecations should be made as for early-rot.

L Fia. 4.—The red-gall fungus,

RED-GALL. showing (a) leaves and

® k i flower bud affected wlth

The red-gall of cranberries is a disease — galls (natural size), (b) en-

which once seen is very easily recognized. (re\ teen Single gall The galls are caused by the fungus shown — (much magnified), showing in figure 4. The disease nsually appears — [he fines I 9 elveniar mass just before the blossoms open. The buds, ;

young leaves, and shoots become more or less covered with small, red, somewhat irregular globular galls about the size of bird shot. The affected shoots produce no fruit.

Red-gall is very erratic in its occurrence. The cases thus far observed have appeared on a large number of plants on certain bogs during a particular season and have frequently disappeared the next season. The distribution and development of the pea seen to

Z Cauaed. by Riiehajerwin ere Thenae.

12 Farmers’ Bulletin 1081.

'

depend primarily upon the water conditions of the bog and the amount and distribution of the rainfall. The spores of the fungns are adapted to distribution by water. The affected bogs are usually those which have an excessive water supply ov which are uneven and not properly drained. This disease has been found thus far only in eastern cranberry bogs and most frequently in New Jevsey.

CONTROL.

The proper grading of the bog and the control of the water sup- ply seem to be the best methods of preventing red-gall. Its uneer-

| ae

Pig, 5.—Cranberry rose-bloom, showing the abnormal, flowerllke, enlarged Jateral shoots.

tain occurrence and the impossibility of ascertaining its presence * until the young galls appear render it impracticable to employ spray- ing as 2 means of prevention. Bogs which are properly drained and from which the flood waters ave removed early ave rarely, if ever, seriously affected with this disease.

ROSE-BLOOM‘ (MASSACHUSETTS FALSE-BLOSSOM, HYPERTROPHY).

Rose-bloom was first observed in Massachusetts and has since been foimd in the States of Washington and Oregon. Tt does not appear

1Caused by Hrobasidium oaycocct Rost.

Cranberry Diseases and Their Control, 18

to be widely distributed at present and has proved a serious cause of loss on only a few bogs. Like the red-gall it is rather erratic in its appearance, occurring in abundahce one season and perhaps being of little importance on the sane bog the next season. It has been found most serions on the Matthews variety in Massachusetts. The disease first makes its appearance on winter-flowed bogs soon after the water has.been removed in the spring. The bunds in the axils of the Icaves of the frniting shoots, which usnally remain dormant, are attacked by the fungus, which stimulates growth, re- sulting in abnormal lateral shoots bearing enlarged, swollen pink or light rose-colored distorted leaves. The appearance of these shoots is shown in the accompanying illustration (fig. 5). These colored hypertrophied leaves being somewhat crowded together bear a slight superficial resemblance to a flower. This has led to the use of the common names, -rose-bloom and false-blossom. The term “false-blossom,” however, should be restricted to another disease, to be described later, to which it is more applicable. As this disease usually develops before the blossoms appear, the vitality of the shoot is exhausted and no fruit is produced. Vegetative shoots, or rnuners, are sometimes attacked also. In such cases, of course, the injury 1s of less inrportance. The occurrence of rosc-bloom is usually associated with an excessive water supply, which seems to favor its development. Tlolding the winter flowage nntil late and reflowing tend to increase the disease when present.

CONTROL.

Early spraying with Bordeanx mixture appears to be helpful in controlling rose-bloom. When the disease is known to occur on a bog the water shonld be removed earlicr in the spring than -usual and reflowing avoided if practicable.

RED LEAF-SPOT,’

Red leaf-spot is caused by a funens very elosely related to the one producing rose-bloom; in fact, some investigators regard them as merely forms of the same species. The effect upon the plant, how- ever, is quite different. The red leaf-spot, as shown in the accom- panying illustration (fig. 6), produces a more or less cirenlar spot upon the leaf and is usually bright red, especially on the upper side. On the lower side the spot is paler and covered with fine spore-bear- ing filaments of the fungus, giving the appearance of a dense bloom or powder.

This disease has been fornnd in all cranberry-growing sections, but it does not usually canse serions injury to the plants except in

Caused by Farohasidinm veaccinii (Mekl.) Wor.

14 Farmers’ Bulletin 1081.

Washington and Oregon, where the climatic conditions, especially damp weather, and the luxuriance of growth of the vines appear to furnish nnusually favorable conditions for the development and spread of the fungus. That an excess of moisture in the form of fog, rain, or flood is the principal factor in making this a serions disease is indicated by the behavior of this frneus in Massachusetts in 1916. The greater part of that season was unnsually wet,and red Jeaf-spot was much more common than usual, Thongh the fungi producing rose-bloom and red leaf-spot are so very closely related, the two diseases have been rarely found to oceur together. Ocea- sionally they may be found on the same bog, but rarely or never on the same plant.

CONTROL.

Spraying with Bordeaux mixture, as for carly-rot, ap- pears to be effective in eon- trolling red leaf-spot, accord- ing to the experience of some Pacifie-coast growers,

FALSE-BLOSSOM (WISCONSIN FALSE-BLOSSOM, PHYL- LODY).

The real cause of the dis- ease known as false-blossom is at present unknown. Studies thus far have failed to show that it is due either to insects or to fungi. It is also uncertam whether it is of an infectious nature. Some observations seem to indicate that the trouble may be caused, in part at least, by nnbalanced nutri- tive conditions. TFalse-blossom has been found chiefly in Wisconsin. The cases which have been found in Massachusetts, New Jersey, Washington, and Oregon appear to have originated, in most instances at least, from plants obtained from Wisconsin.

The chief features of this disease ave shown in the accompanying illustrations (figs. 7 and 8). In its siniplest form the flower pedicels become more or less erect instead of drooping, the calyx lobes become enlarged and somewhat leaflike, and the petals are short and broad and slightly reddish or greenish in color. The stamens and pistils are more or less aborted and malformed, and affected plants pro-

Fre, 6.--Red leaf-spot of the cranberry.

Cranberry Diseases and Their Control. 15

duce little or no fruit. All intermediate forms and gradations can be found among diseased plants, from the simplest stage, in which there is only a shortening and thickening of the parts of the flower, to cases in which the entire flower is replaced by: a short branch with small leaves, as shown in figure 8, d@ and e, Affected plants also show a marked tendency toward the development of abnormal terminal buds and of lateral branches arising from the usually latent axillary buds. Such branches are slender and weak and fail to produce normal flowers or frnit. They give the plant a kind of witches’-broom appearance, as shown in figure 7. .

This trouble is usually associated Q), with extreme wet or dry conditions of } the bog, but most frequently with an excessive water supply. In most of the localities in which it has been observed the affected plants were growing in a deep, coarse peat soil having an exces- sive water supply during the greater part of the growing season.

CONTROL.

In the absence of more definite know!- edge of the exact cause of false-blossom it is impossible to recommend satisfac- tory methods of prevention and control. The best conditions possible for normal growth should be provided, especially good drainage, clean culture, and prun- ing. Where a large number of the plants in a bog are affected with false- blossom it would probably be best to

e Fic, 7.—False-blossom of the eran- remove and burn the diseased plants perry, shoiving the witches'-broom

wid to Teplant “with healthy vines, To “foun due te:fhe abnormal develop

. ‘ , ment of axillary buds. prevent the further introduction and

spread of the disease only vines known to be absolutely free from false-blossom or coming from localities free from the disease should be used in planting.

BLACK-ROT.'

Black-rot develops chiefly in fruit after picking. The affected berries become very dark colored and softened. The fungus causing

21Caused by Ceuthespora lunata Shear.

ie Farmers’ Bulletin 1081.

GY Vy YY ye NW ip SB ir Qa ys : 1 ff

aay { | a) ‘ t Q\

Fie. 8.—False-blossom of the cranberry, showing various abnormal developments of the flowers: @ and 6, Floral parts changed to greenish leaflike bodies; c, d, and ¥, floral parts ehanged to leafy shoots,

Cranberry Diseases and Their Control. 17

this disease has also been found on dead and dying leaves, bnt has not caused much injury. It has becn found most frequently on fruit from Massachusetts and New Jersey.

CONTROL.

Bogs which have been thoroughly sprayed usnally show little of this trouble, and its development can be largely prevented by proper conditions of storage and handling of fruit, as mentioned on page 18.

RUST

This disease has thus far been observed only in the cranberry bogs on the Pacific coast and has caused no serious injury; but if it should develop in an epidemic form, as is possible, it might do consider- able harm to cranberries. It-is caused by one of the rust fungi, which forms minute yellowish powdery pustules on the under side of the leaves.

The early spore stage of this fungus develops on hemlocks, and on the Pacific coast will probably be found npon the western hem- lock. The disease is likely to occur, therefore, in the East or the West, wherever hemlock is found near cranberry bogs.

CONTROL.

Tf the rust shonld prove sufficiently serious to justify the expense, it could prebably be controlled by the removal of the hemlocks: m the vieinity of the cranberry bogs, if this should seem practicable.

ROT AND SPOILAGE DURING STORAGE, SHIPPING, AND MARKETING.

Tntil recently the losses from fungous diseases which occur after the erop is harvested have been more or less overlooked and neglected. In the ease of the cranberry, the losses after picking are frequently much more scrious than those occurring before harvest. These losses are due chiefly to two causes: Fungons parasites which have infected the fruit before picking but have remained in a dormant condition and the smothering or killing of the fruit by lack of ventilation.

By observation and investigation it has been found that abont one-half of the loss of berries after picking is due to fyngi. The most frequent and important of these fungous rots in recent years have been the early-rot and the end-rot. The development of these rots after picking depends largely upon the conditions under which the -fruit is kept and the methods of handling. Where experience

1Caused by Pucciniastrum myrtillt (Schum.) Arth.

18 Farmers’ Bulletin 1081.

has shown that serious losses occur after picking, spraying should be practiced, as recommended for the control of these rots, as this will prevent largely the infection of the fruit which oceurs before picking and thus greatly reduce the losses which develop after picking.

The fruit should be picked dry or dried very quickly after pickmg, as cranberries which are stored when wet rot more quickly than dry frnit. Great care should be used in handling the fruit. Even slight bruises greatly increase the amount of rot. The berries should be run through the separator only onee. In sorting or sereening. squeezing the berries should be avoided, and iu running berries into barrels or boxes some sort of easer should be used to break the fall and prevent brinsing.

The temperature under which the fruit is kept is a very important factor in determining its keeping quality. High temperatures greatly favor the development of fungous rots. As the fruit is usually warm when picked it should be placed in the shade and cooled as rapidly as possible. The storehouse should be well ventilated at night and closed as far as possible during the day, when the outside temperature is usnally higher thau that inside. In sorting or sereen- ing the fruit in cold weather the berries should be kept in a warm room as short a time as possible and packed in a cool room.

SMOTHERING.

Besides the fungous rots, a large amount of spoilage of stored frnit is due to the premature death of the berries and the physical and chemical changes which follow. Such fruit becomes somewhat softened throughout, discolored, and practically worthless. Upou eutting open such herries it will be found that the interior is red and juicy and its natural flavor gone. The cranberry, when picked, is a living organisin, carrying on active life processes which are continued under ordinary conditions for a considerable time after the frnit has been removed from the vines. In order to keep the fruit it is necessary to prolong as far as possible these life processes and prevent death. The cranberry may be said to breathe in its own peculiar way, and when it is prevented from so doing it suffo- cates and dies. The more rapid this breathing the more quickly is the fruit spoiled.

In general, it has been fonnd that high temperatines hasten the death of the fruit by smothering. High temperatures and lack of ven- tilation are the ehief causes of smothering. In order to reduce such loss to a minimum the frit shonld be cooled as quickly as possible after picking, being sct in a shady well-ventilated place either under trees or under a simple roof of boards or canvas. The berries should

Cranberry Diseases and Their Control. 19

never be covered tightly by spreading canvas or oilcloth over piles of boxes unless the weather is cold.

As much as possible of the hauling to the storehouse should be done early in the day, and the house should be so arranged as to cool] the fruit quickly and keep it cool. Ventilating should be done at night and the storehouse kept closed as much as possible during the day. In packing eranberries for market ventilated containers are preferable, especially during wavm weather. Half-barvel or bushel ventilated boxes have been found move satisfactory than barrels in reducing the losses from rot and smothering during shipping and marketing.

Fig, 9.—A gasoline-engine spraying outfit on two trucks.

SPRAYING.

The conditions under which cranberries are grown and the char- acter of the plants are so different from those which obtain with other fruits that special methods have been found neeessary for the most eeonomie and effective application of fungicides aud insecticides.

On the small areas sometimes found in Massachusetts knapsick sprayers may be sufficient, and on small bogs with a sufficiently firm bottom a barrel and cart outfit can be used. Tt is not often practicable to use a team on a bog, not only on account of the very soft bottom It especially because of the injury to vines and fruit. As it is not

20 Farmers’ Bulletin 1081,

¢, some other

feasible to haul avheavy power sprayer over the bog,

arrangement must be made.

The most gencrally satisfactory ontfit yet devised for the rapid, effective, and economical spraying of extensive areas of bog is a large gasoline engine sprayer with stock-supply tanks mounted on a sepa- rate truek, which may be moved to convenient points on the margins of the bog or dams, where water nay be pumped directly from the stream or ditch into the mixing tanks. Where the bog is not too large it may be sprayed by hose direct from the pump, moving the outfit about the margin of the bog or dams when necessary. The

¥ia, 10.——-Device for naking Bordeaux mixture. Pulverized bluestone is being dissolved in one compartment and lime in the other, the two solutions running together in the trough below.

spray mixture may then be distributed to various parts of the bog through galvanized-iron pipes arranged abont the margin of the bog and across it in sneh manner that by means of long leads of hose con- nected at different points all parts of the bog may be reached.

The capacity of the engine, pumps, and tanks will depend upon the area to be sprayed and the number of spray nozzles which can be most effectively used. The following description and illustrations of an outfit used on a large bog in New Jersey will indicate the essen- tial features. Those planning to install a spraying system for cran- berries should inspect and study some satisfactory outfit already in

Cranberry Diseases and Their Control. 91

operation in order to Jearn all the essential details and decide just what is necessary to adapt the system to their particular conditions.

The outfit referred to, with two trucks, engine, pumps, and tanks, is shown in figure 9. A 9-horsepower gasoline engine and a 3-cylin- der high-pressure puinp are used; also a centrifugal pump to fill the tanks. On the rear truck are two 200-gallon tanks and a mixing outfit. The arrangement for dissolving and mixing the bluestone and lime is shown in figure 10. A quantity of pulverized bluestone sufficient for a tank of spray mixture is placed in one of the vessels, and the necessary quantity of slaked or hydrated lime in the other. These materials are dissolved by pumping water through the hose inserted in the top of cach container. The dissolved materials come out of the lateral spouts at the bottom of the vessels and are mixed as they fall into a trough, in the sides of which blocks are inserted

Fic. 11.—A gang of five cranberry sprayers cach with a 4-nogzle spray rod.

to cause the more thorough mixing of the two solutions as they run into the spray tank. To provide a continuous supply of spray mix- ture one tank is being filled while the othcr is being used. The pumps are connected with hose with galvanized-iron piping, 1 inch or 1} inches in diameter, depending upon the length required to reach around the bog. This pipe is placed on posts about a foot high, to prevent rusting, and extends about the margin of the bog and the dams also if necessary. . In the illustration on the title-page the connection of the spray hose to the pipe line is shown; also a hose cart for moving the long leads of hose from one connection to another on the pipe line and for lengthening or shortening the hose according to the needs of the sprayers.

The spray mixture is distributed by a galvanized-iron spray rod with four or five nozzles attached at intervals near one end, as shown

99, Farmers’ Bulletin 1081.

in figure 11. The spray hose is carried from the reel across the bog on a series of short posts with rollers at the top, as shown in the right-hand margin of the illustration.

Two hose reels and two gangs of nine men are nsed with this ont- fit. The two gangs under favorable conditions can cover 8 acres an honr, using about 200 gallons of spray material to the acre. The

Fig, 12.—A galvanizediron spray rod with nozzles attached at cqual distances on the under side, id

usual maxininm area sprayed is 60 acres a day, as some unavoidable interruptions of the work are likely to occur. This general plan can be adapted to any large bog.

Another style of spray rod, shown in figure 12, is used by some growers. This consists of a galvanized-iron pipe with a number of nozzles attached at regular intervals on the under side and carried by two inen. This is very satisfactory for medium-sized bogs and fewer men.

WASHINGTON ; GOVERNMENT PRINTING OFFICE : 1820