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UNITED STATES DEPARTMENT OF AGRICULTURE

Y BULLETIN No. 714 Ya

Contribution from the Bureau of Plant Industry > aI
WM. A. TAYLOR, Chief

Washington, D. C. PROFESSIONAL PAPER August 9, 1918

SPOILAGE OF CRANBERRIES AFTER HARVEST.

By C. L. SHEAR and NE E. STEVENS, Pathologists; R. B. Witcox and B. A.
Rupo.ipeH, Scientific Assistants, Fruit-Disease Investigations.

(The work done in Massachusetts was in cooperation with the Massachusetts
Agricultural Experiment Station. )

CONTENTS.
Page Page.
Tim troduebl ONE ess ssa a ee ise ee ces = Dy al Cho ho Yea Ieee ee a IR a ee pene nic 6
Causes of the cranberry spoilage...........-. 2 miportancernssias 2 sccsse cacao CR eee 6
DS RUISIN eee eee SERS ARs oes (tars Py tae a as 2 Principal cranberry fungi which cause
Din ytee @Wbpes a oon ce SoS See eee EIS aa ie 3 TRU G LOLS ore eee oe a A are 6
Natural ripening processes.................-. 4 Control of fungous diseases.............-- 7
SIMOLMERIMI Rees eee ee SE eLE SEES SSE AC Summary 2 bh sake ee eee eres ce eee 18
Conditions which cause smothering. ..... Ap bracticalisugees ti OMS yas see ee 19
AWW UCTAS LOR AS Cee ee ere fe ae ene eee te OF | aiteClLatune:clted seepeeeee eee eee rem eree 20
Prevention ofsmothering................ 5
INTRODUCTION.

IMPORTANCE OF SPOILAGE AFTER HARVEST.

Three million dollars’ worth of cranberries are, on the average,
produced annually in the United States. Although effective control
measures are practiced by many growers, a considerable portion of
the crop, certainly not less than 10 per cent, is lost through fungous
diseases before the fruit is picked. Large losses also frequently ap-
pear after picking. In some respects this spoilage is more trouble-
some than that which occurs earlier. Fruit which spoils after it is
packed and shipped has cost the grower for handling and packing,
and further expense is frequently involved in claims for allowances,
shipments refused, inspection, and sometimes reseparating at the
market. On the average, at least 15 per cent of the crop is estimated
to be lost between the field and the consumer.

A less obvious but even more serious effect upon the demand for
and sale of cranberries is that produced by marketing spoiled fruit.
“Time and again,” says Mr. A. U. Chaney (3, p. 30), “have I no-

1 The serial numbers in parentheses refer te ‘‘ Literature cited’ (p. 20).

2 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE.

ticed that a retailer who has unsound and unattractive fruit in his
store has blocked his sale of cranberries.” As the trade becomes more
and more critical, not only of cranberries but of other fruits, the
time is rapidly approaching when (2, p. 80) “ growers must recognize
the absolute necessity of producing fruit that will be sound when it
goes before the consumer.”

PLAN OF THE PR®SENT WORK.

The senior writer has carried on investigations of the diseases of
cranberries since 1901. During the past two years (1916 and 1917),
however, the problem has been taken up with special reference to the
iosses which occur after picking. Field work and storage experi-
ments have been carried on in Massachusetts and New Jersey; labora-
tory studies of material shipped from these areas and from Wiscon-
sin, Michigan, Oregon, Maine, and West Virginia have been made at
Washington, D. C.; fruit has been inspected and studied in most of
the important markets east of the Mississippi River; and experimen-
tal shipments have been made from cranberry-growing centers to
Washington. New York, and Chicago. So far as practicable, the
field work in New Jersey and in Massachusetts has been conducted
along similar lines, in order to avoid errors due to peculiar local con-
ditions.

The investigations in Massachusetts have been carried on in co-
operation with the Massachusetts Agricultural Experiment Station,
the work at the State bog at East Wareham being in charge of Dr.
H. J. Franklin (4, 5). Prof. F. W. Morse, of the experiment sta-
tion, has also taken up certain important phases of cranberry respi-
ration in relation to spoilage. While the investigations are not yet
complete, the present paper aims to present the more important re-
sults and the conclusions thus far obtained in order that they may
be immediately available to cranberry growers.

CAUSES OF CRANBERRY SPOILAGE.

The spoilage of cranberries is due in general to one or more of the
following causes: Freezing, insect work, briusing, drying out, natural
ripening processes, fungous rots, and smothering. The writers pro-
pose to employ the term smothering to designate the pathological
conditions produced in fruits by sufficient interference with respira-
tion, whatever the cause of this interference.

As the cause of freezing and the means of its prevention are well
understood and the work of insects is outside the province of this
paper, these two causes of spoilage will not be discussed.

BRUISING.

Loss due to bruising is by no means confined to actual crushing of
berries by careless handling or spilling in sorting or packing houses,

__ a

SPOILAGE OF CRANBERRIES AFTER HARVEST. 3

though this is in itself a cause of considerable loss and should be
carefully guarded against. 3

Very important and more difficult to eliminate are the numerous
unnoticed injuries occurring in the processes of harvesting, separat-
ing (milling), sorting (hand screening), and packing the fruit. It
has been shown that these injuries, while too slight to affect the im-
mediate sale of the fruit, indirectly bring about serious losses by
starting decay. This relation of bruising to the starting of fungous
rot will be considered later. |

Slightly injured berries also dry out and shrivel much more quickly
than sound fruit. Shrinkage in storage will be reduced, therefore,
by care in harvesting and handling the fruit.

DRYING OUT.

Cranberries held in storage will gradually shrink even though no
decay occurs. An experienced observer (6, 1913, p. 20) estimates
this shrinkage as high as 10 per cent in the case of Karly Black cran-
berries held in common storage at the bog for late trade. A part
of this loss is due to the natural ripening processes mentioned below
and part in some cases to the actual loss of water by evaporation.
Bruising the fruit increases its rate of drying out and shriveling.

The rate at which water is lost by evaporation depends in part di-
rectly on the moistness of the air. In tests made by keeping weighed
quantities of cranberries in containers with air of known humidity
it was found that for any given temperature the loss in weight in-
creased with the decrease in the humidity of the air. (Table I.)

TasiLeE I.—Decrease in the weight of cranberries of the Howe variety held for
386 days in air of different humidities at certain temperatures.

Relative humidity (per cent).

Air conditions.

Temperature 5° to 10° C. (41° to 50° F.):

IGOSSHBSWCION Leesan aa cise mii ai per cent... 0 4 5 6 9
Temperature 2° to 5° C. (36° to 41° F.):

Wossimewel eh Geet oe cls os \sinacicisioes «esis = doses 5 1 & 3 4.5 6

a Over concentrated sulphuric acid.

Tt is evident from these results that considerable humidity in the
air of the storehouse is desirable to prevent the drying out of the
fruit. Under the conditions ordinarily obtaining in cranberry store-
houses the humidity is sufficient to prevent any serious loss from dry-
ing. In New Jersey the higher temperatures after picking are favor-
able for drying, and under some conditions of storage fruit kept for
a long time may actually shrivel.

It should be mentioned in this connection that in a series of tests
extending through both 1916 and 1917, in which cranberries of both

4 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE.

the Early Black and the Howe varieties were kept in containers of
known humidity, using a method already described by one of the
writers (13), no direct relation was found between the humidity. of
the air and the amount of rot of the fruit. Berries kept as well in
very moist air as in drier air unless they were actually wet.

NATURAL RIPENING PROCESSES.

Like other fruits, the cranberry when picked is a living organism,
carrying on its vital activities, which may be referred to in general
as ripening processes. Of these processes one of the most important
is respiration. Under normal conditions the respiration of a fruit
is marked by taking in oxygen and giving off carbon dioxid. In this
process the living matter of the fruit is broken down and the berry
gradually loses weight. If continued long enough this process would
end in the destruction of the berry. It has been demonstrated that _
respiration goes on more rapidly at high than at low temperatures;
consequently, the cooler the berries can be kept without freezing the
longer they will live and the better will be their condition.

SMOTHERING.

CONDITIONS WHICH CAUSE SMOTHERING.

In a paper published with the report of the Massachusetts
Cranberry Station for 1916 (11) the writers called attention to
the spoilage of cranberries caused by insufficient ventilation. As
pointed out at that time, cranberries kept in tight cans or in an
atmosphere of carbon dioxid lose their crispness and bright color,
become dull red and flaccid, and taste bitter. Since this kind of
spoilage is apparently caused by conditions which check normal
respiration, the writers designate it as smothering. Experience has
shown that whenever cranberries of good keeping quality are cov-
ered with some inert gas, such as carbon dioxid, buried for some
time in a big pile of berries, shut up in a tight container, kept under
water, or subjected to other conditions which prevent normal res-
piration, smothering occurs. The exact causes of this spoilage, as
well as the nature of the changes brought about in the fruit, are now
the subject of investigation by Prof. F. W. Morse, of the Massa-
chusetts Agricultural Experiment Station.

When berries are under water or under carbon dioxid, death due
to smothering occurs in a short time, often in one to two weeks,
whereas in tight containers or in large piles it results so slowly that
if the berries are of inferior keeping quality fungous rot may de-
stroy them before the effect of smothering appears. In case rot-
producing fungi are present, they develop rapidly on the weakened
berries, and a mass of rotten fruit results.

SPOILAGE OF CRANBERRIES AFTER HARVEST. 5
WATER STORAGE.

Storing cranberries under water is frequently recommended as a
means of keeping them for long periods. Berries stored in this way
soon die as a result of smothering. They can not, however, wither,
nor do they decay, since the growth of rot-producing fungi is pre-
vented. Water-stored berries do not have the bitter taste character-
istic of most smothered fruit and are therefore suitable for cook-
ing if used as soon as removed from the water. Such berries are,
of course, unsalable.

The effect of storing cranberries in tight packages and under
water as compared with storage in ventilated packages was shown
by a series of tests made at the State experimental cranberry bog,
Kast Wareham, Mass. In one experiment, uniform lots of appar-
ently sound berries, of both the Early Black and the Howe varie-
ities, were stored dry in closed bottles, under water in bottles, and in
ventilated boxes. The results of this test are given in Table II.

TABLE II.—Results of storing cranberries under different conditions for 386

days.

Number of berries. Total

Conditions of storage. ee Bees

Total. | Rotten.) Smothered. cent).

Temperature 38° to 8° C. (37° to 46° F.):

Wnderwaterninshottles cs secmoncceee soe ce ciwecece sss cnlecmicisecs 0 All, a 100
iniclosedjhottleidty.2t5.2ssa-5- eee es qian seee 1,054 777 | None apparent. 74
mavemttlaveds b Oar ecist eles cise sinner eis ee eeioe ,----| 1,364 382 0 28

a As explained in the text, these berries were still fit for cooking.

The results shown in Table IT are typical of those obtained in other
tests, some of which were carried out at much higher temperatures
and with other varieties of cranberries, and have been further sub-
stantiated on a commercial scale by shipments in various types of
packages and by storage tests. These will be considered later.

PREVENTION OF SMOTHERING.

Smothering may be prevented by ventilation. Berries should be
stored in ventilated boxes, never in barrels, and the boxes should be
so piled as to allow circulation of air through the berries. Cran-
berry storehouses should be provided with ventilators, which should
be opened whenever cold air can be admitted without danger of
freezing. Ventilated packages should be used where practicable.
These points are also of importance in the control of fungous dis-
eases and are discussed further in that connection.

6 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE.

FUNGI.
IMPORTANCE.

The writers’ observations (10) indicate that rot-producing fungi
cause at least one-half of all the loss in cranberries after picking.
These fungi are, however, by no means of uniform importance in
different regions or in different seasons. A study of a number of
neighboring bogs during a single year or of a single bog through a
series of years can not fail to impress the investigator with the ex-
treme variation in the loss due to decay.

An illustration of the variation in the amount of rot over a con-
siderable area in different seasons is found in the annual reports of
the board of inspectors of the New England Cranberry Sales Co. for
the last five years, as given by the chairman, Mr. H. S. Griffith (6).
The crop of 1918 was described as “remarkably free from fungous
disease”; in 1914 and in 1915 there was a large percentage of un-
sound fruit: the crop for 1916 was unusually sound up to November
1, after which a noticeable, though not very serious, amount of end-
rot developed; the crop for 1917 was in general of good keeping
quality, with a small amount of fungous disease. As these inspectors
determine the brand of the crops from representative bogs over much
of the Massachusetts cranberry area, their reports, no doubt, repre-
sent fairly well the condition for the entire region.

The prevalence of rot in some seasons seems to be associated with
weather conditions which would favor the growth and spread of
fungi. Our knowledge of these relations is too shght, however, to
permit of very definite conclusions. Differences in the amount of
rot on different bogs or on various portions of one bog are often
related either to lack of vigor or to excessive growth of the vines,
due to various causes. These relations will be considered later.

PRINCIPAL CRANBERRY FUNGI WHICH CAUSE FRUIT ROTS.

The fungi which cause the decay of cranberries after they are
picked are in a large part those which attack the fruit on the vines.
The molds which cause decay of such perishable fruits as strawberries
and raspberries are rarely found on cranberries and are, therefore,
of slight importance.

Among the diseases which are the principal causes of losses of
cranberries in storage are early-rot (8), caused by Guignardia vac-
cinti Shear, which is also the cause of scald and blast, and which is
especially destructive to fruit on the vines and early in the season
in New Jersey; end-rot (9),caused by /usicoccum putrefaciens Shear,
common on fruit in storage, especially late in the season and in the
northern cranberry regions; bitter-rot, caused by Glomerella cingu-
lata vaccinii Shear; ripe-rot,caused by Sporonema oxycocci Shear:
and blotch-rot, caused by Acanthorhynchus vaccinii Shear. Soft-rot,

SPOILAGE OF CRANBERRIES AFTER HARVEST. 7

caused by Penzcillium spp., is rather common on fruit held late in
storage, but is usually associated with other rots, and is not of great
importance. Ripe-rdt develops at a lower temperature than any
of the other rots, except end-rot, and is most frequent in Massa-

chusetts.
CONTROL OF FUNGOUS DISEASES.

Bog Management.

Since all the fungi which cause important storage rots of cran-
berries are found on the bogs and in large part gain entrance to the
berries before they are picked, control measures should begin with
the bog. Not all of the factors which determine the abundance of
fungi are understood at present; in fact, it sometimes seems as if
a bog is free from rot-producing fungi in spite of the treatment it
receives rather than because of its management. Certain phases of
bog management seem, however, to have a direct relation to the
keeping quality of the fruit produced. An excessive growth of vines,
whether produced by too much nitrogenous plant food or some other
cause, generally results in diseased fruit.

Many cranberry growers believe that frequent flooding to prevent
injury from early frosts in the fall seriously affects the keeping qual-
ity of the fruit, although this is not uniformly the case. The writers
had under observation one bog which during the fall of 1917 was
completely submerged on 12 nights, and the fruit still showed excep-
tional keeping quality. |

If the water is held for a considerable period Pon envieeie how-
ever, the result is very likely to be disastrous. Cranberries of the
Early Black variety on the Massachusetts State bog, which had been
submerged for two weeks after the bulk of the crop was harvested,
showed a great increase in the rot of the flooded fruit as compared
with the a harvested before the flooding. In this case, indeed,
a serious infection of Sporonema oxycocci (ripe-rot) occurred on the
berries which had been submerged. Only a few of the berries picked
before this flooding were found to be infected with this fungus. In
northern cranberry regions during cold periods bogs are sometimes
floodec and the water held so long that the fruit may be actually
smothered. This practice is certain to injure the fruit.

The holding of winter flowage until mid-July, thus sacrificing one
season’s crop, is occasionally practiced in both Massachusetts and
New Jersey as a means of reducing pests; this is one of the treat-
ments recommended by Franklin (4) and by Scammell (7) for the
reduction of several destructive insects. During the year following
this treatment a large crop of berries of excellent keeping quality is
said to be obtained, and the benefits, both in the reduction of field
rot and in the improvement of keeping quality, are frequently said
to persist for several years.

8 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE,
Spraying.

Thorough spraying has been found in all localities to reduce rot
_and improve the keeping quality of the fruit. In New Jersey and
on Long Island, where there is always considerable loss from fun-
gous disease before picking and where spraying has been practiced
in some cases for 10 years, thorough spraying has been found
profitable and no injury to the vines has been observed.

Experiments were conducted with the Early Black variety at
Whitesbog, N. J., during 1917 to determine the times at which
Bordeaux mixture should be applied in order to.control fungous dis-
eases most effectively and economically. Blast, early-rot, and a
storage rot, all due to Guignardia vaccinii Shear, were the principal
causes of loss on this bog during the year. Bordeaux mixture of
the formula 44-50, with about 1 pound of resin-fishoil soap, was
used throughout the experiments.

A single thorough application of Bordeaux mixture after the blos-
som buds had begun to open increased the total yield by more than
10 per cent (from 1738 to 192 bushels per acre) by controlling blossom
blast. Two applications before blossoming were no more éffective
than one. An application immediately before the spring reflow
showed no effect in the control of fungi. No trace of the spray was
observed on the vines when the water was removed. The applica-
tions before blossoming had no effect in reducing the rotting of the
fruit after picking.

Protection of the berries from infection during the first month
of their growth resulted in very satisfactory control of both field
and storage rots. This was accomplished by two thorough applica-
tions, one near the close of the blossoming period (before all the
petals had fallen) and another two weeks later. By these applica-
tions alone the total yield was increased, the rot at picking time was
reduced from more than 20 per cent to less than 2 per cent, and stor-
age rot from 6.7 per cent to 1.9 per cent. These two sprays applied
at the proper time effected a saving of 44 bushels of marketable
cranberries per acre, or one-fourth of the crop. Any delay in mak-
ing the first application after blossoming resulted in a marked in-
crease in both field rot and storage rot.

A third application after blossoming was of no increased benefit
in these experiments. It must be repeated, however, that early-rot
was the only fungous trouble of importance on this bog; furthermore,
the berries were picked before the middle of September. It is doubt-
ful whether two applications after blossoming will give satisfactory
control with all varieties or where other diseases, such as bitter-rot,
are concerned. <A similar series of experiments with cranberries of
the Centennial variety in New Jersey during 1917 gave unsatisfactory

SPOILAGE OF CRANBERRIES AFTER HARVEST. | 9

and unreliable results because of severe frost injury. Further ex-
periments along this line are necessary and are in prospect.

The use of Bordeaux mixture with resin-fishoil soap, which has
been found to be the most effective fungicide for cranberries, is
recommended. One application should be made just after the blos-
soms begin to open and should be repeated every two weeks until
August 15.

In Massachusetts small plats of berries on the State bog which
were sprayed with Bordeaux mixture for several years in succession
have shown some injury to the vines. More experiments are neces-
sary in order to determine the cause of this injury. As no injury
of this kind has been observed in New Jersey or on Long Island,
the writers feel that where losses from rot either before or after pick-
ing are heavy the benefit from spraying will more than offset any
probable injury.

Dry Picking.

Experiments conducted on a number of bogs in New England
have indicated that cranberries should be picked dry. The results
shown in Table III are summarized from tests made in 1917. In
each case from 4 to 10 bushels of berries were picked early in the
morning while still wet with dew and an equal quantity taken from
an adjacent portion of the bog as soon as the berries were thor-
oughly dry.

TABLE I11.—Comparative results of storing cranberries that were picked wet
and dry in 1917.

Percentage oi rotten

Dace cranberries.
Variety. Locality. SiG eo ee
Picked dry.|Picked wet,

Hotly SLAC kee oes oes caidas East Wareham, Mass............ 56 32 51
LOW OR ana a oe sae cciaoe se oeaocm oaleases GORA Seek Sak es SE eee see 44 13 40
Barly STAC Repan ee cree ee ae South Wareham, Mass.......... 24 a17 220
Wie hitye see: er ee See los Madrid< Me. asics ausen sth eae 60 2.4 5.0

a Contained about 10 per cent of rotten berries when picked.

That the inferior keeping quality is due to the fact that the berries
were wet and not to any injury received in picking is indicated by
the fact that similar deterioration in keeping quality followed: where
boxes of berries which had been picked dry were wet with clean
water.

During the latter part of the shipping season cranberries are some-
times removed from a cool storage house to a warm room for sort-
ing and packing. If the humidity of the air is high, moisture fre-
quently condenses on the berries to such an extent that they become
wet and sticky. This is injurious to their keeping quality and should
be carefully avoided. Cranberries should never be barreled or
shipped in this condition. The Bae aes of packing and, if pos-

61728° —18—Bull. 7142

10 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE.

sible, sorting in cool rooms, which will prevent wetting the fruit by
condensation from the air, is further considered under the next
topic.

Low Temperature.

A study of the temperature relations of many of the fungi which
eause fruit rots of cranberries (14, pp. 524 and 525) has shown that
most of them grow very slowly, if at all, below 10° C. (50° F.).
The only conspicuous exception is the end-rot fungus, which grows
somewhat even at 0° C. (32° F.). The rate of growth of all these
fungi, and consequently of the rot which they cause, increases rapidly
with rise of temperature above 10° C. (50° F.). As already men-
tioned, the ripening processes which result in the death of the cran-
berry itself also go on more rapidly as temperature rises.

As an illustration of the effect of temperature on the keeping
quality of cranberries, the results of temperature tests conducted at
Washington, D. C., during 1916 and 1917 may be cited (Table IV).
Equal quantities of apparently sound cranberries from uniform lots
were kept at different temperatures in the refrigeration apparatus
described by Brooks and Cooley (1). |

Table 1V.—liffect of temperature on the keeping quality of cranberries as shown
by tests made at Washington, D. C., in 1916 and 1917.

Percentage of cranberries spoiled in storage at temperatures—!

* Days in
Variety. 2
storage. 0° ©. 5° ©. 10° © 15°C. 20° ¢,
(G22eR5): (412K): (GD) (GLE IDE (68° F.).

Marly aplacksee cee ese c eee cee 28 2 4 5 12 19
TD X02 reenter caren at ae 28 1 ig hy 3.5 @) 13
IT OWer eee ere te Ono k ics 25 25 5 8 115505) 19
WarlyeBlacke: Saye eae eee 60 16 OH EIEN etieeh INR a eaa ae 48 72
COYNE ae EIR LAC Gee De Ages 0 60 29 DA ri tent Nel aee SE eg er D1 66
LD eee ee Snes Se ee 56 39 CRY Td eis ee 92 99

TOW ES ee cts ae eee 67 8 OH fae st\| 29 geen. ae 48 7

1 This includes smothering and all forms of fungous rot.

In the course of the first three tests, the results of which are given in Tabie IV,it was observed that cran-
berries color more rapidly at relatively low temperatures (5°C., 41° F.). It is, then, desirable from every
point of view for cranberries to be kept as cool as practicable.

When cranberries are picked they are usually at a temperature
considerably warmer than that of the air, and the sooner they are
cooled the better. To this end it is desirable that cranberries should
be removed from the bog as soon as practicable and placed in the
shade. They should be stored in ventilated boxes, never in barrels,
and the boxes should be so piled as to permit free circulation of air
among the boxes. ,

- The storehouse in which cranberries are held should be kept as
cool as is possible without danger of freezing the fruit. This can
be done most economically by having the house provided with ade-
quate ventilators to admit air at the bottom of the building. These

SPOILAGE OF CRANBERRIES AFTER HARVEST. nel

ventilators should be open during cool weather and closed when the
temperature of the outside air rises above that of the storehouse.
As already stated, cranberries which are held in the chaff and
shipped during cold weather are frequently brought from a cold to
a warm room for sorting. In order that sorters may work com-
fortably and efficiently the room in which the work is done must
be at a temperature of at least 15° C. (60° F.), while the fruit in
storage is often at a much lower temperature. If cool cranberries
are held in a warmer room long enough for proper screening, their
temperature is considerably raised, and if they are barreled in this
room the higher temperature may be maintained long enough to
affect their keeping quality seriously. As an instance of the injury
to keeping quality which may result from such treatment, a test
made in the fall of 1916 may be cited. Equal quantities of Early
Black cranberries were taken from! a barrel which had been kept
for some time at a temperature of 7° to 10° C. (45° to 50° F.). One
portion was taken to a warm room, about 24° C. (75° F.), and care-
fully hand sorted, the process taking in all about 40 minutes, after
which the sound berries were returned to the original temperature.
An equal portion was sorted in the cool room. At the end of 10
days the two lots were again sorted, with the results shown in

Table V.

TABLE V.—Comparative results of sorting cranberries in warm and in cool
rooms, in the autumn of 1916.

Berries rotten 10 days
after sorting.
s

Treatment. Huaee
Number. Per cent.
SontedsinyanwavmMenoom rene sencmcens cee see eee ocean coen cee 973 153 17

Sonbedsinvarc ooo sys ee eee oe ee noe cae eee eee 968 88

To avoid loss from this source and from wetting the fruit by con-
densation from the air, berries should not be sorted in a heated room
unless necessary. When weather conditions make this imperative
they should be removed from the warm room as soon as possible
and should not be packed in the sorting room. Packing in a warm
room means including in the barrel a quantity of warm air, which
in a tight package retains its heat for a considerable time.

Perhaps the most efficient means of overcoming this difficulty is
one that can be readily arranged where sorting belts are used. This
method is used by at least two growers, one in Massachusetts and the
other in New Jersey. The separators and packers are in a large room
which is kept at the temperature of the fruit, while the belts carry-
ing the fruit to be sorted pass through a smaller inside room which

12 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE.

is kept at a higher temperature and in which the sorters work.
With such a system, using belts 30 feet long, no berry is exposed to
warm air for more than 1 minute and the air in which the berries
are packed is as cool as that in which they were stored. Careful
temperature tests made in such a sorting house in Massachusetts
showed that with the temperature of the berries at 7° C. (45° F.) and
that of the sorting room at 18° C. (65° F.), the temperature of the
berries was raised not more than 1 degree centigrade in sorting.

Ventilation.

Adequate ventilation of the cranberry storehouse jis necessary first
of all as a means of lowering the temperature of the fruit as soon
as possible after it is picked. Its importance is not by, any means
confined to the effect on temperature, however, for, as pointed out
earlier, improper ventilation results in smothering and sometimes in
increased decay. In order to obtain the best results, cranberries
should be stored in ventilated boxes which are so piled as to permit
a free circulation of air among the berries.

The same principle may well be extended to the packages in which
cranberries are shipped, particularly for the early shipments, which
are frequently made during very warm weather. In this connection,
the writers carried on experiments during both 1916 and 1917, in
which berries were shipped in containers of different types. The
results of these experiments are summarized in Table VI. In general
it may be stated that the fruit in the smaller, well-ventilated con-
tainers kept better than that in the barrels. Of these containers the
ventilated shalf-barrel box is perhaps the most satisfactory.

Ventilated barrels in which there are from 28 to 32 small openings
(every other stave having two notches in each side) offer a convenient
substitute for the tight barrel and one which may be introduced at
slight expense and without the delay and effort incident to intro-
ducing a new package to the trade. Such barrels are now in use for
early shipments by at least one large grower. While the writers
have as yet been unable to carry out satisfactory comparative tests
of ventilated and tight barrels, in a simple shipment of Early Black
cranberries from Massachusetts the berries in the ventilated barrels
appeared drier than those in the tight barrels. It is hoped that next
season it will be possible to make shipping tests of a size sufficient
to settle the question as to the amount of advantage derived from
using ventilated barrels.

SPOILAGE OF CRANBERRIES AFTER HARVEST. 13

TABLE VI.—Shipping tests of cranberries in different types of containers during
" 1916 and 1917.

Percentage of spoilage.
; ; . Point of receipt and
Variety. Year. Point of shipment. Solar

eommation. In tight | In venti-

barrel. | lated crate.
Harlye Blackseeeessesc 1916 | East Wareham, Mass..| Washington, D.C..... 38 29
LD Xo eee ee ee 1916 | South Wareham, Mass.| Livermore Falls, Me.. 23 16
OW Ca asco encase 1916 | East Wareham, Mass..| Washington, D.C..... ai 11
iD ORS nea ee es UNOUY ‘Neosoe Otc ae Chi Ca rome seas See. 22 a18
ID) Oa Sere auels 917 | Wareham, Mass....... ING WwaVOn ks see ee nema 13 9

a Ventilated half-barrel box.

In this connection it may be noted that cranberries color better in
well-ventilated containers.

Careful Handling.

DECAY INCREASED BY BRUISING.

Bruises caused in harvesting, separating, or sorting cranberries
form, as already stated,an important cause of increased decay. This
was strikingly shown by a test made at Whitesbog, N. J., in 1916,
using Centennial cranberries immediately after harvesting, before
they had been separated or sorted. Each berry in a 10-pound sample
was examined critically for the presence of scratches, bruises, or
other blemishes which were so slight as not to be noticed in a casual
inspection or picked out by the most careful sorter. Nearly one-
fourth of the berries were found to be so injured; all of them were
marketable and, to the inspector, apparently sound; they showed no
signs of fungous decay. The injured and uninjured berries were
placed in separate ventilated corrugated paper boxes and left in the
storage house for two months. At the end of that time they were
reexamined and the results noted, as shown in Table VII.

TaBLeE VII.—Relation of slight injuries to the keeping quality of cranberries,
as shown by a test made at Whitesbog, N. J., in 1916.

Rotten after being

Number of stored two months.

berries. ~
Number. Per cent.

Condition before storage.

SOUT Mee ereera eee ren Nae Ee URS Oe Bae OMe Reh pa Nee 2,171 97 4.5
Slightlyinjured) but marketable... 9.5.0 5...2---2-- 22-2 sce- ass sees 697 316 45.3

Table VII shows that after two months in storage there was ten
times as much rot among the previously bruised berries as in the
sound ones. Many of these unnoticed injuries occur in each process
of handling the fruit. This emphasizes the need of care and of

14 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE.

improvement when possible in methods of harvesting, separating,
sorting, and packing cranberries.

HARVESTING.

Careful experiments in which the keeping quality of hand-picked
cranberries was compared with that of scooped berries have not
shown any very decided advantage in favor of either method, pro-
vided the scoopers were not allowed to pick up dropped berries from
the ground.

A series of tests in New Jersey in the fall of 1916 showed that the
keeping quality of these dropped berries was much inferior to that
of berries picked or scooped from the vines. The results of these
tests are summarized in Table VIII. The experiment with Early
Black cranberries was conducted by Mr. Franklin S. Chambers.
Adjacent similar plats of each variety were marked on the bog; then.
the berries from half the plats were picked by hand by experienced
pickers and the remainder harvested by experienced scoopers. All
berries were stored for two months in ventilated 1-bushel boxes in
adjacent piles in a ventilated storage house. =

TasBlLe VIII.—£ffect of different methods of harvesting upon the keeping quality
of cranberries, as shown by tests made in New Jersey in 1916.

Condition noted (per cent).

Total Immediately after
Variety. Method of harvesting. weight harvesting. Rotten
(pounds). after Rot
| pee ; developed
: store im Storage.
Sunny Rotten. | months.
|
Early Black. ..---- Picked Se te eae ee 1,148 | (4) (4) 12'- Fee
DOs SCOOPed hae Bases eee oe 1,054 1) (1) 145g!) See ee
Centennial. .-.....- Picked ees. eee eee eee 171 12 6 17 11
Dose ee Seooped seh kes eee ae 164 18 5 12 7
DOS ae eee a Picked up after scoopers. - 38 34 6 25 19
Howe ts wenee ah Picked). ee 5 Cece ADF | Seek ae ee = 4.5 3.5
DO ee ee i ere PSCOODEC saree we eee ae Bet fl ates ae Rntin —1 4.2 Bo.
DOS es 1 Me | Picked up after scoopers . . AIG eee ee —1 18.1 tiet

1 Not determined.

Berries picked up from the ground after scooping, as Table VIII
shows, bore a much higher percentage of the slight injuries men-
tioned above than did any of the other fruit, and, as was to be
expected, this was the cause of their poor keeping quality. It seems
from this evidence that if dropped fruit is picked up from the
ground it should be kept separate, in order not to lower the grade or
keeping quality of all the berries.

It is probable that neither method of harvesting can be said to be
best under all conditions, but that factors other than keeping quality.
such as length and uniformity of pine growth, will influence or de-
termine the method to be preferred in any particular locality.

SPOILAGE OF CRANBERRIES AFTER HARVEST. ASS

SEPARATING AND SORTING.

Very important and difficult to eliminate are the numerous un-
noticed injuries caused in the processes of separating, sorting, and
packing the fruit. Franklin (4, p. 21) has published data which
show that the bruising caused by running berries through the sepa-
rator and by dropping them into a barrel markedly increases the
amount of rot. The results of the investigation of the writers fully
substantiate these conclusions. Great injury is also caused by squeez-
ing the berries in sorting. In this process the decayed berries are
often detected by touch even more than by sight, and much sound
fruit is thus squeezed or pressed unnecessarily. The resulting bruises,
while imperceptible, frequently serve to start decay.

An illustration of the relation of bruises received in separating
and sorting to the development of decay in storage is found in the
results of a test made at Whitesbog, N. J., in the fall of 1917, in
which 75 bushels of Early Black cranberries were picked on Septem-
ber 14 from plats which had been thoroughly sprayed during the sum-
mer. On September 21 the berries from each plat were divided into
three representative parts. One part was then set aside in the storage
house without further handling. The second part was sorted by
hand on stationary sorting tables by commercial sorters, the percent-
age of unsound fruit noted, and the sound berries placed in the storage
house. The berries remaining were then separated by machine and
finally by hand in the usual commercial manner, the percentage
of unsound fruit noted, and the apparently sound berries placed in
storage. In this last method practically all unsound berries were re-
moved by the machines, and the berries therefore suffered very little
by handling during the final process of hand sorting.

All the berries were stored for nearly six weeks in ventilated stor-
age boxes of 1-bushel capacity in a house in which the temperature
varied from 15° C. to 7° C. during the season. For purposes of
further comparison, 32 bushels of the Karly Black variety that were
picked on the same day (Sept. 14) from unsprayed plats on the
same bog were divided, handled, and stored at the same time and in
the same manner as those from the sprayed plats. Berries of good
keeping quality (sprayed) were thus compared with those of poor
keeping quality (unsprayed) as to the effect upon them of separating
or sorting before storage.

On October 31 all the berries were removed from storage, sorted
by commercial sorters, and the percentage of unsound fruit noted.
The results are summarized in Table LX.

16 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE.

TABLE IX.—Jncrease in amount of rot due to separating or sorting cronberries,
as. shown by tests made at Whitesbog, N. J., in 1917.

Results noted (per cent).

: Total
Conditions of test. neo rotten on Rot area
(1 week Boe | developed | rot due to
_after aie A in storage. | previous
picking). storage). handling.
Berries of good keeping quality (sprayed):
Hand sortedsbetorestorag@a sense oe see eee eee 1.6 5.9 4,2 1.9
Separated and sorted before storage. --...........-.|....-----2-- 527 4.1 1.8
Nothandled'before:storageters os. an ah a See ee oe 73-9 PAR el oe ae
Berries of poor keeping quality (unsprayed):
Hand sorted before storage.....:...2.......2:.--.-- 21.6 30.4 8.8 7.8
Separated and sorted before storage. -...........--.-|..----.-.--- 28.3 6.7 5.7
Not handledsbefore storageba. sos. hee eee ee | ak BI: 2256 120) ake eee

Table IX shows that even with berries of excellent keeping quality
the amount of decay developed in storage was nearly doubled by a
previous sorting either by hand or by machine and that the effect of
hand sorting was at least as severe as that of machine separating.
On berries of potentially poor keeping quality the effect was similar
but very much more marked. It appears that these berries did not
decay in storage any faster than the sprayed berries unless they had
been bruised previously by sorting, but that when so bruised the rot
developed rapidly and in large amount. Here, again, hand sorting
alone proved slightly more injurious than separating by machine.

This experiment indicates that the berries should be handled as
little as possible and as late as possible before disposal, especially in
the case of fruit of bad or doubtful keeping quality. |

As another example of the increase in the amount of decay which
is caused by hand sorting, the results of a test made at Wareham,
Mass., in the fall of 1917 may be cited. Ten bushel boxes of Early
Black cranberries were scooped on September 12 in such a way that
two boxes came from each of five different regions of the bog, the
two boxes from each region being as nearly alike as possible. All
the berries were stored with abundant ventilation at a temperature
which varied from 15° to 5° C. (59° to 41° F.) as the season ad-
vanced. Five boxes, one of each pair, were carefully hand sorted on
October 3 and the good berries replaced in the boxes and held until
November 6, when all the berries were sorted. The results, sum-
marized in Table X, indicate that the sorting on October 3 more than
doubled the amount of rot during the following month.

SPOILAGE OF CRANBERRIES AFTER HARVEST. ily

Taste X.—Increase in rot due to the sorting of cranberries, as shown by a
test made at Wareham, Mass., in 1917.

Condition noted (per cent).

Treatment. ss is
otten on otten on
Oct.3. | Noy. 6, | 1oval tot.
SortedionceiduringistOragese-n ssacaenee seen eoese ene c ewes enossse 4.3 15.8 20.1
ING; SOreuaNG | Ghenrbaker Gyo else a ee Be eae eers Ace eee | Sees ee 11.0 11.0

To avoid such losses as have been cited, all berries, especially those
of doubtful keeping quality, should be handled as little as possible,
they should be cleaned as near the time of shipping as possible, and
in sorting care should be exercised not to touch or bruise the berries
unnecessarily. It is possible that separating machines may be de-
vised which will injure the fruit less than those at present in use.
Improvement can certainly be made in the methods of hand sorting.
The most thorough sorting is not necessarily the best if it is accom-
panied by too much handling of the berries. Sorting belts in which
the berries pass from the separator over a slowly moving belt which
carries them in front of the sorters and deposits those not removed
in a box or barrel at the end have the advantage of making it un-
necessary for sorters to handle the fruit roughly, provided there is
some device for turning the berries on the belt. An easer+ of some
kind should be used to prevent bruising when berries drop into a
barrel or other container.

SHIPPING IN THE CHAFF.

When berries come from the bog they have more or less leaves,
broken vines, or other foreign matter mixed with them. Fruit in
this condition is said to be “in the chaff.” |

As a result of the knowledge of the fact that the processes of
cleaning cranberries increase their tendency to decay and that it is
advantageous to place them before the consumer as soon as possible
after cleaning, some growers have attempted shipping berries in the
chaff and having them cleaned at destination. For berries particu-
larly subject to decay after sorting this plan is apparently to be
recommended. ~~

The writers have had the opportunity to test this method in only
one instance, a shipment of berries from a bog in Wareham, Mass.,
to Chicago, Ill. Two varieties were used in the experiment, and
equal quantities of berries as uniform as could be secured were
chosen. Half of each lot was carefully separated and sorted before
shipment and the shrinkage noted; the other half was shipped in
the chaff. At destination all lots were run through a separator and
the shrinkage again noted. The berries were packed in Wareham on

1Haser is a term the writers apply to any device for breaking the fall to prevent
bruising. :

18 BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE.

October 26 and examined in Chicago on November 15, 1917. The
results are given in Table XI.

TasBLe XI.—Comparative results of shipping cranberries before and after clean-
ing, as shown by tests made in 1917.

Shrinkage noted (per cent).

Variety. Condition when shipped.

motes | APS | no
: rating at otal.
cleaning. Chicago.
Mic Wahine sei eminn sieeve a). aC) ai ee aC aa ees ee A Ce I a a ee 28.7 28.7
ADO tee Re as ee Abc lle) a Separated and sorted........- ee 20 10.2 30.2
Mid dle boro eae eee Co) a2} i CSC Nae ie en iano alt Ne Pee Bene 27.0 27.0
CARP RT Ret ee MER Un eae Reg Separated and sorted............ 20 15.5 35.5

1 Contained more than 10 per cent of frozen berries.

It will be noted that with both varieties the total loss of berries
was greater with those cleaned before than with those cleaned after
shipment. This is particularly marked in the case of the Middleboro ©
variety, which contained no frosted berries and therefore gave a
more accurate test.

Shipping in the chaff naturally involves the extra expense of
freight charges and containers for the chaff and decayed berries
which would be taken out in cleaning. On the other hand, if fruit
is shipped in the chaff it may be held in storage and run through a
separator as sold. Under these conditions hand sorting will not
be necessary and the cost of preparing for sale is materially reduced.
In deciding whether to attempt shipping in the chaff each grower
will have to take into consideration his own expense of separating
and sorting, the probable keeping quality of his berries, and whether
the consignee has adequate facilities for separating the fruit. Ship-
ping in the chaff will then be confined to consignments to large
dealers and will be most profitable in the case of fancy fruit of rela-
tively poor keeping quality.

SUMMARY.

Recent observations and investigations have shown that about 15
per cent of the cranberry crop is lost between the field and the con-
sumer. The losses are due in part to fungous rots and in part to
smothering. |

Bruising of the fruit occurs in the operations of picking, separat-
ing, sorting, and packing. Such injury is not only a direct cause of
spoilage, but renders the fruit much more liable to decay. Much
more rot has been found in roughly handled or bruised fruit than
in carefully handled fruit. f ,

No direct relation has been found between the humidity of the air
in which the fruit is kept and the amount of rot which develops.
Death and spoilage of cranberries will finally result from natural
ripening of the fruit. This process is hastened by high temperatures
and reduced by low temperatures.

SPOILAGE OF CRANBERRIES AFTER HARVEST. 19

Cranberries kept in tight packages which do not permit ventila-
tion soon die from smothering and are of little value for food. Such
fruit is soft and the tissues are discolored. Spoilage by smothering
may be caused by keeping the berries in large piles, by having them
too closely crowded in unventilated storerooms, or by flooding for
too long a period, especially in warm weather.

Extended investigations indicate that at least one-half of the spoil-
age of cranberries after picking is due to fungous rots. These vary
much in prevalence and destructiveness in different seasons and _lo-
calities, depending upon a variety of factors.

The chief rots which develop after picking are early-rot, caused by
Guignardia vaccini,; end-rot, caused by Fusicoccum putrefaciens ;
bitter-rot, caused by Glomerella cingulata vaccinii; ripe-rot, caused
by Sporonema oxycocci, blotch-rot, caused by Acanthorhynchus vac-
cuit, and soft-rot caused by species of Penicillium. The fungous
rots which develop after picking, as well as before, may be largely
prevented by spraying with Bordeaux mixture to reduce infection.
Improved bog management also increases the vigor of the vines and
tends to reduce rot.

Cranberries picked and stored or packed wet show more rot than
those picked and packed dry; when cooled as soon as practicable
after picking and kept at low temperatures they show a great reduc-
tion in the amount of rot. The most favorable temperature for keep-
ing berries is 382° F. Temperatures above 50° F. produced rapid
increase in the development of rots. Berries warmed by being kept
in a heated room while being sorted showed an increase in the amount
of rot.

Ventilated barrels or other ventilated packages used in distribu-
tion gave less rot and other spoilage than tight packages.

A comparison of different methods of harvesting the fruit showed
but slight differences in its keeping quality.

A study of the effect of separating fruit by machines and by hand
sorting showed but little difference in the result. All lots developed
much more rot than the check. The results indicate that separating
and sorting should be delayed until the fruit is to be shipped.

Cranberries shipped in the chaff, that is, without cleaning or sort-
ing, and separated and sorted at destination, showed less loss from
rot than those separated and sorted before shipment.

PRACTICAL SUGGESTIONS.

Spray thoroughly to prevent fungous infection.

Pick and handle the fruit with great care to avoid bruising.

Cool the berries as quickly as possible after pists and keep them
cool until they are shipped.

Store and handle the fruit in a cool, well-ventilated building, and
use ventilated packages, especially for early shipments.

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(14)

LITERATURE CITED.

Brooks, CHARLES, and Coo.ey, J. S.
1917. Temperature relations of apple-rot fungi. Jn Jour. Agr. Research,
: v. 8, no. 4, p. 189-164, 25 fig., 3 pl.
CHANEY, A. U.
1915. Address to the members of the New England Cranberry Saies
Company. Jn Ann. Rpt. New Eng. Cranberry Sales Co., 1915,
p. 26-37.
1916. Address to the members of the New England Cranberry Sales
Company. In Ann. Rpt. New Eng. Cranberry Sales Co., 1916,
p. 23-33.
FRANKLIN, H. J.
1916. Report of cranberry substation for 1915. In Mass. Agr. Expt.
Sta. Bul. 168, 48 p.
1917. Report of cranberry substation for 1916. Jn Mass. Agr. Expt.
Sta. Bul. 180, p. 183-234. 1917.
GRIFFITH, H. S.
1913-1917. Report [as] chairman of inspectors. Jn Ann. Rept. New
Eng. Cranberry Sales Co., 1913, p. 17-24; 1914, p. 19-28;
1915, p. 48-52; 1916, p. 19-22; 1917, p. 17-24.
SCAMMELL, H. B.
1917. Cranberry insect problems and suggestions for solving them.
U. S. Dept. Agr., Farmers’ Bul. 860, 42 p., 38 fig.
SHEAR, C. L.
1907. Cranberry diseases. U.S. Dept. Agr., Bur. Plant Indus. Bul. 110,
64 p., 7 pl. (2 colored). Bibliography, p. 55-57.
191. Hind rot of cranberries: in (Jour. Agr: skeseareh:) yo imo
p. 35-42, 3 fig., pl. A. Literature cited, p. 41.
1917. Spoilage of cranberries after picking. Jn Proc. 48th Ann. Conv.
Amer. Cranberry Grow. Assoc., 1917, p. 6-9.

STEVENS, NEIL E., and RupOLPH, B. A.

1917. Observations on the spoilage of cranberries due to lack of proper
ventilation. Jn Mass. Agr. Expt. Sta. Bul. 180, p. 235-239.

and Witcox, R. B.

1918. The reduction of cranberry losses between field and consumer. J¢

Proc. Amer. Cranberry Grow. Assoc., v. 48, p. 7—L0.

STEVENS, NEIL E. ;
1916. A method for studying the humidity relations of fungi in culture.
In Phytopathology, v. 6, no. 6, p. 428-482. Literature cited,
p. 482.
1917. Temperatures of the cranberry regions of the United States in
~ relation to the growth of certain fungi. Jn Jour. Agr. Research,
Voidd; no. dO, p52 152955 fis,
20

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