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been injured. Quality was fairly good. A duplicate can was opened two weeks
later and here, also, the apples were in good condition though the quality was
mediocre. A rather high acidity was a contributing factor.

The can which was operated on the English s\'stem was examined on May 13.
The oxygen level had varied between 8 and 15 percent. With this system, the
sum of the oxygen and CO2 always equals about 21 percent. There was no scald,
core breakdown, or rot, but quality was rather poor.

Where flushing with nitrogen was utilized and a very limited amount of ventila-
tion provided, apples were still in good eating condition on May 13. The oxygen
in the can had varied between approximately 2 and 5 percent and the CO2 between
2 and 12 percent. Just why this treatment gave the best results is not clear
unless it was due to the frequent change of atmosphere in the can. The apples
(at 40° F.) were better than checks kept at 32°-33° F.

These tests indicate that more uniform control of the atmosphere in a modi-
fied-atmosphere storage room is a requisite to the successful operation of such a
room. Undoubtedly, the wide fluctuation in the composition of the atmospheres
in the cans was a determining factor in lowering eating quality.

The storage room which was "gas-proofed" in 1940 was not sufificiently tight to
allow respiration to reduce the oxygen to the desired 2 percent level. A contrib-
uting cause of this failure was the fact that brine coils and the shape of the room
allowed for only partial filling. This room was opened for inspection at 10 a. m.
on February 24 and closed again at 5 p. m., resulting in a total loss of the arti-
ficial atmosphere. The oxygen was again lowered to around 10 percent which
proved to be the minimum obtainable. The room was opened on March 24 and
the fruit placed in another room at 32° F. The Wealthy and Gravenstein apples
were past good eating condition; Cortland were fair to good; Delicious were very
firm and in excellent condition. Golden Delicious were also in excellent condition
and, where individually wrapped, these fruits showed no shriveling. Mcintosh
comprised the bulk of the apples. These were fairly ripe but not too much so for
immediate use. Quality was good and somewhat better than that of similar
apples stored as checks at 32° F. (Checks stored at 40° F. in normal air showed
internal breakdown.) There were considerable differences between different
lots of fruit. In general, the late picked Mcintosh had the best quality. High
color was associated with high quality. Some rot was in evidence on individual
fruits. Many apples did not hold up well at room temperatures, largely because



92 MASS. EXPERIMENT STATION BULLETIN 388

of overmaturity. Those kept at around 34° F. retained fair eating quality for at
least a month. A few fruits subsequently split open.

During the summer certain leaks in this room were corrected, the coils were
removed, and a small automatic blower system was installed. This arrangement
allowed for the storage of 100 additional boxes. With the 300 bushels, mostly
Mcintosh, this room is now considered sufficiently full and gas-tight for effective
operation as a modified-atmosphere storage room. It was filled and temporarily
sealed up in October but later the apples were removed in order that som^e altera-
tions might be made. It was again filled and sealed on November 27. Previous
leakage tests indicated less than 5 percent leakage per 24 hours. At the time of
this writing (December 20), this storage is performing satisfactorih-. The ox>'gen
level is now down to 2 percent.

It is entirely possible that modified-atmosphere storage, especially for Mcin-
tosh, ma\' shortly displace in some degree conventional cold storage methods.
It seems to offer advantages that are very desirable and perhaps necessary for the
continued prosperity of the industry.

Study of "Bud Sports" of the Mcintosh Apple. (J. K. Shaw and L. Southwick.)
Trees of 21 so-called "bud sports" were planted in the spring of 1941. Three
of these have been propagated for several years, while the others are selections
from orchard trees. Half of these are on dwarfing and half on vigorous stocks.
The purpose of this planting is to maintain the selections and to see what color
type of apples they bear. Most of them are supposed or known to be non-striped
strains.

Trees of six forms are ready for orchard planting next spring for the purpose
of measuring accurately not only the color type of the fruit but also the vigor,
productiveness, and other characteristics of both tree and fruit.

Nutrition of the High bush Blueberry, Especially in Relation to Soil Reaction.

(J. S. Bailey.) Mixing lime with the soil reduced the growth of blueberry plants.
Mixing 5 percent peat with the soil reduced slightly the bad effects of the lime.
This work was reported in the Proceedings of the American Society of Horticultural
Science 38, 1941.

An experiment was started in the spring of 1941 to compare the value of cow,
horse, and hen manure as fertilizer for blueberries. Manures have been thought
to be harmful to blueberries, especially when applied on soils with a pH above 5.
To date the plants look fully as good as those fertilized with mineral fertilizer.

Blueberry Culture. (J. S. Bailey.) During the summer a diversion ditch was
constructed around the experiment station blueberry planting so that trouble
from erosion should be reduced to a minimum.

The plantings yielded a little over 3000 quarts as compared with 2000 quarts
in 1940.

Experiments to control the cranberry fruit worm on blueberries by dusting
were continued. Because so few worms were present, even in the checks, the re-
sults were not conclusive.

The budding work of 1940 was a complete failure. The bud shields stuck to
the stocks but the buds died. This work was repeated in 1941. The buds were
set low and protected for the winter by piles of sawdust.

Since the war has cut off the supply of imported peat which has been quite
generally used for propagating blueberries, a substitute must be found. A com-
parative test of several domestic peats was started in the spring of 1940. Nothing
which is superior to the imported peat has been found. A leaf mold irom Massa-
chusetts and a sphagnum peat from Maine compare favorably with the im-
ported peat.



ANNUAL REPORT, 1941 93

A light supplementary application of ammonium sulfate about June 7 was
given all the blueberries except those in the manure test. The improved appear-
ance of the plants and the increased yield over previous years indicate that this
was a good practice.

Bulletin 358, Blueberry- Culture in Massachusetts, was revised.

Premature Dropping of Mcintosh Apples. (L. Southwick.) Work on this
project largely concerned investigations with "hormone sprays." Some chem-
icals such as naphthalene acetic acid and certain of its salts, naphthalene aceta-
mide and some others, have been shown to delay natural drop of apples at harvest
when applied in dilute spray solutions. These chemicals and several commercial
proprietary compounds employing these active ingredients were used in field
tests in 1940 and 1941. Bulletin 381, published in February, 1941, summarized
the results of experimental work conducted in 1940 and in it the authors at-
tempted to evaluate the method of "hormone spraying" especially in relation
to Mcintosh. Further tests in 1941 revealed no very different results. There
was some evidence that under certain conditions, drop-control sprays on Mcin-
tosh were not so effective as in 1940. Many check trees dropped comparatively
little this }'ear. In most cases, however, the prehar\est drop from sprayed trees
was less than that from check trees in the same block. Some typical percentage
drop comparisons, sprayed and unsprayed, follow: 3.7 and 14.5 percent; 12.9
and 20.2 percent; 2.3 and 7.5 percent; 10.2 and 13.4 percent; 11.6 and 21.4 per-
cent; 7.3 and 18.5 percent; 13.9 and 13.4 percent. It is apparent from these
figures that degree of control was not consistent.

There is some indication that the temperature at the time of application may
be important. Possibly fruit growers should wait for temperatures above 60° F.
before applying a drop-control spra}-. A more definite statement on this point
must await further experiments.

A limited test with Milton indicated little benefit from spraying. The sprayed
trees dropped 31 percent of the total crop compared with 34.6 percent from the
check trees.

Results again demonstrated the desirability of using standard strength sprays
with Mcintosh. Weaker sprays were usually less effective. Doubling the
standard strength increased the effectiveness of applications. How much im-
provement in drop control would be required to offset the increased cost of
stronger sprays is problematical and depends on several factors. It can be stated
with some assurance, however, that the so-called standard strength of "hormone
sprays" should not be reduced with Mcintosh in this State.

The use of special stickers or summer oil seems to merit some consideration.
Theoretically, these materials should tend to improve coverage. Actually, the
benefits from their inclusion in hormone sprays have been variable. Usually,
drop control has been somewhat better although in some cases improvement has
been negligible. It is at least certain that spreaders and stickers are not effective
substitutes for good coverage.

Dusts were tried this year for the first time. These were made up by two com-
mercial concerns and were compared with spra}' applications. In about half the
tests, dust was only slightly inferior to spray in lessening pre-harvest drop. In
the others, dusting was not effective. It is true also that spraying was prac-
tically ineffective in some cases. The heavier applications of dusts (4 pounds
per tree) seemed more effective than lighter dosages. Until further evidence
is at hand, the use of hormone dusts by growers is recommended for trial only.



94 MASS. EXPERIMENT STATION BULLETIN 388

Miscellaneous Work

Soil Acidity in the Orchard. Lime was applied to a Sudbury orchard in which
aluminum toxicity was suspected, as mentioned in the report of last year. It
appears that both grass and trees were improved by the treatment. With the
increasing use of wettable sulfur the danger of injuriously high acidity becomes
greater. Not only is there danger of aluminum toxicity, but nitrification in
the soil decreases as the soil acidit>' increases.

Lime and Phosphorus in Planting Trees. We have as yet no evidence that
phosphorus is directly beneficial to apple trees on our soils; we know that it is
readily fixed in the soil and it follows that orchard applications may not pass
into the relatively deep-rooted apple trees. An orchard of 36 Mcintosh trees of a
single strain on three clonal stocks was planted in the spring of 194 L One third
of the trees were treated with 10 pounds dolomitic limestone, one third with
5 pounds triple superphosphate, and one third were untreated. The materials
were placed in the bottom of the planting holes and well mixed with the soil.
As measured by trunk diameter increase, the trees treated with lime grew most,
those treated with phosphorus least, while the untreated trees were intermediate.

Weed Killing. The attempt to get rid of wild cherries, particularly choke
cherries, around the peach orchards was continued. A new weed killer, am-
monium sulfam.ate, was tried. It looks very promising. Used at the rate of
^ pound per gallon water, one application was enough to kill small choke
cherries and kill or badly damage black cherries. Chlorate weed killers used at
the same strength were not so effective on choke cherries and were ineffective
on black cherries.

Ethylene Dichloride Emulsion for Control of Peach Tree Borers. Because
of reports of damage from the use of this material in other sections, it is being
thoroughly tested in the station orchards. It has been used in 1939, 1940, and
1941 in one orchard and in 1940 and 1941 in several others. Applications have
been made at 15-day intervals during the fall. The emulsion has been used (1)
according to directions, (2) at slightly higher concentrations, and (3) in slightly
larger quantities, than recommended. Only one case of injury has occurred;
some very vigorous late-growing suckers from the base of some trees were in-
jured when applications of the emulsion at the concentration for three-3'ear old
trees was applied. This was an overdose for the year-old suckers. Unseasonably
hot weather following the application may have had an effect. Injury has never
occurred when applications were made according to standard directions.

Sawdust Mulch. In the summer of 1938, a sawdust mulching program was
begun in a small block of bearing apple trees An average of about 4 inches of
sawdust was placed under alternate trees to determine the effect of sawdust on
subjugation of sod, on soil nutrients and acidity, and finally on tree growth and
production The sawdust had little efifect in subduing the grass, which pro-
ceeded to grow apace throughout the summer and fall. Unlike hay or straw,
which tends to mat down, sawdust does not tend to smother grass. No addi-
tional applications were made during the next three years. Neither deleterious
nor particularly favorable effects on soil or tree have been observed to date.

In November and early December of this year, a considerably greater amount
of sawdust was applied to the same trees. This time, however, the sod on half
of the area under the branch spread was taken up and the soil shaken out. The
other half was left in sod. Sawdust to an average depth of 6 inches was applied
over the whole area. It is intended to determine the comparative feasibility of
using a sawdust mulch on cultivated soil and on sod in a bearing orchard.



ANNUAL REPORT, 1941 95

DEPARTMENT OF POULTRY HUSBANDRY
R. T. Parkhursl in Charge

Broodiness in Poultry. (F. A. Hays.) A number of specific facts have been
established in this study of the inheritance of the broody instinct in Rhode Island
Reds. Some of the most significant findings are the following. The length of
the non-productive period associated with broody behavior remains rather con-
stant at about fifteen days. Degree of broodiness as measured by the number
of broody periods is governed by inheritance. The time of appearance of the
broody instinct in the life of a female is highly variable. In flocks bred to eliminate
the broody instinct, the onset of broody behavior in individual females has been
about 57 percent in the first laying year, 34 percent not until the second laying
year, and about 8 percent not until the third laying year. These three classes
of females when used as breeders gave about the same percentages of broody
daughters. The selection of female breeders that did not exhibit the broody trait
during their first two laying years was effective in reducing the incidence of brood-
iness in the flock. There is no evidence of sex-linked inheritance.

At present efforts are directed toward the establishment of an entirely non-
broody line by applying all of the information now in hand.

Statistical Study of Heredity in Rhode Island Reds. (F. A. Hays and Ruby
Sanborn.) This project is devoted entirely to the preparation and analysis of
experimental data used for publication. During the year the following papers
have been prepared: The Importance of Length of Incubation Period in Rhode
Island Reds, Bulletin 384; Breeding for High Viability, a study covering seven
years, has not yet been published; A Preliminary Study of Molting Behavior,
covering three years, has not yet been published; and A Study of Variation in
Egg Weight, covering five years, is now in preparation.

A Genetic Study of Rhode Island Red Cobr. (F. A. Hays.) This study has to
do with the genetic complex concerned in the inheritance of Rhode Island Red
plumage and possible relationships between characters affecting fecundity and
plumage color. Two lines of birds are being carried, one breeding true for late
sexual maturity and the other selectively bred for early sexual maturity. There
is some evidence that one or both of the dominant genes for early sexual maturity
afi"ects plumage color. The relation between the red of the Rhode Island Red
plumage and the buff of the Orpington is also being studied.

Rate of Feathering in Rhode Island Reds. (F. A. Hays.) This experiment is
concerned primarily with the genetic aspects of rapid and slow chick feathering.
To study this problem three lines have been developed with respect to rate of
chick feathering; namely, a rapid-feathering line produced exclusively by the
use of breeding males that showed complete back feathering at eight weeks of
age; a slow-feathering line bred entirely from sires showing the absence of back
feathering at eight weeks of age; and a check line bred primarily for high fecundity,
with some of the sires rapid feathering and some slow feathering.

In the spring of 1941 the seventh generation was produced in the three lines,
and gave the following percentages of rapid-feathering sons at eight weeks:
line 1, 100; line 2, 10; and the check line, 84. The chicks were also classified
for the sex-linked gene for rapid feathering at twelve days of age. The males in
the three lines gave the following percentages with the sex-linked rapid-feathering
gene: line 1, 49; line 2, 0; and the check line, 6. An attempt was also made to
separate the rapid- and slow-feathered females by grading the feather growth in
the back region at four weeks of age.

All data available indicate that in Rhode Island Reds the sex-linked gene for



96 MASS. EXPERIMENT STATION BULLETIN 388

rapid feathering may or may not be present in rapid-feathered stock. There is,
however, a definite sex difference in the rate of feathering in the dorsal region.

The Effectiveness of Selective Breeding in Reducing Mortality in Rhode
Island Reds. (F. A. Hays.) This is a cooperative project with the Regional
Poultry Research Laboratory, East Lansing, Michigan. In the spring of 1934 a
project was begun to test in a small way the effectiveness of selective breeding in
reducing mortality in Rhode Island Reds.

The foundation stock consisted of pedigreed birds that had been bred for
characters associated with high fecundity since 1916. During the first five years
females alone were kept to the age of 18 months. Beginning with the sixth gen-
eration, hatched in 1939, both males and females were retained to the age of 18
months. An attempt has been made to establish two lines, one for low mortality
and the other for high mortality. Breeding males and females 24 months of age
were used as breeders and the sole basis of their selection was the mortality rate of
their sisters during their first laying \ear. A check line consisted of birds bred
for high fecundity. Inbreeding in both lines was avoided by the constant use of
males drawn from the check group but selected on the mortality basis. Limited
facilities available permitted the production of about 100 birds in each of the
mortality lines, and since 1939 about equal numbers of males and females have
been carried to 18 months of age. Complete mortality records have been kept
and post-mortem examinations have been performed by the Department of
Veterinary Science.

The limited data now available indicate in general that selective breeding was
effective in small groups in reducing the mortality rate from the miscellaneous
diseases and disorders appearing under our conditions.

Genetic Laws Governing the Inheritance of High Fecundity in Domestic FowL

(F. A. Hays and Ruby Sanborn.) Many phases of this problem have been studied
and reported upon. At the present time special attention is being given to the
genetics of intensity and winter pause. These two characters have a rather
complex inheritance and their interactions with other characters are very sig-
nificant. Possible interactions between genes affecting intensity and genes
affecting egg size are being given close study. The mortality problem as affected
by selective breeding is also being given constant attention.

Recent findings indicate that chicks emerging early from the shell are likely
to be superior from the standpoint of fecundity; that heavy body weight in both
males and females at six months of age is a significant criterion of future low
mortality; and that selective breeding for characters affecting egg production
has not reduced the viability of the stock. Reducing the variability in egg pro-
duction is a slow process because of the complex nature of inherited factors and
environmental interactions.

A Study of Fertility Cycles in Males. (F. A. Hays.) Histological studies of
testes from males in a wide age range, taken throughout a two-year period, in-
dicate that both age and season affect the rate of spermatogenesis. There is
definitely a cyclical behavior in males with respect to their fertility. Preliminary
breeding tests have not indicated that fertility is governed by inherited factors.
This problem of possible inherited factors is being studied further along with
environmental factors that may be in operation.

Physiological Relationships Between Molting Behavior and Fecundity Char-
acters. (F. A. Hays.) Bi-weekly individual molt records are being continued
on a fourth series of males and females from parents with known molt records.
The first breeding stage of this project began in the spring of 1941. Two lines



ANNUAL REPORT, 1Q41 97

were started, the first from females la\'ing but few eggs during molt and the
second from females laying for a relatively long period during the molt. Pre-
liminary studies over three years indicate that the ability to lay eggs and molt
simultaneously is a highly desirable trait. The change in body weight of males
and females during the annual molt is not very significant. Males already used
required an average of about 94 days to shed their wing primaries while females
averaged about 1 19 days. Some females lay very few eggs during this period while
others lay up to 40 or 50 eggs. Good females should shed at least three primary
wing feathers before laying stops. Completion of wing molt in December appears
to be desirable from the standpoint of first-year egg production.

Miscellaneous Genetic Studies. (F. A. Hays.) Linkage studies include genes
for shank feathering, comb form, and mottled ear lobes in Rhode Island Reds.
An effort is also being made to isolate the sex-linked gene for early sexual maturity.
A new method for separating sexes in Rhode Island Red chicks is being studied
and offers some possibilities. For auto-sexing, a gold-barred bird is being de-
veloped on a limited scale.

The Use of Crab Meal in Poultry Rations. (Raymond T. Parkhurst and
Marie S. Gutowska with C. R. Fellers of the Departnient of Horticultural Man-
ufactures cooperating.) In broiler production studies, Red-Rock cross chicks
were used and comparisons involved the 1940-41 New England College Con-
ference starter as the basal ration, the basal ration with 5.5. percent crab meal
replacing 2.5 percent fish meal, the basal ration with 5.5 percent crab meal re-
placing 5 percent milk and 2.5 percent fish meal, and the basal ration with 3
percent fish meal replacing 5 percent of dried skimmilk. The mineral contents
of the rations were adjusted. There were no significant differences in growth,
mortality, feed efficiency, feathering, or pigmentation.

When crab meal replaced fish meal on an equal-protein basis (4 pounds for
2.5 pounds) in the Massachusetts complete all-mash laying ration, there were no
significant differences in egg production, weight of eggs, feed efificiency, yolk
color, albumen quality, fertility, and hatchability. The egg production av-
eraged higher in the fish meal group, based on the birds that lived, but fewer
birds died in the crab meal group; with the result that total production, total
income, and the feed cost per dozen eggs were practically the same for the birds
on the two rations. The results to date show that crab meal is a satisfactory
ingredient in poultry rations and can replace fish meal on an equal-protein basis.
Further comparisons of these feeds are in progress.

The Manganese Requirements of Laying Hens. (M. S. Gutowska and R. T.
Parkhurst.) The effect of the addition of manganese to complete all-mash laying
rations was investigated from a practical standpoint. Forty-eight Rhode Island
Red pullets were kept on a basal all-mash ration for 12 lunar months (2 periods
each lasting 6 lunar months). The two high-manganese groups received in their



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