Picking maturity of apples

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Czrcular No. 711
October 1944 +¢ Washington, D.C.

UNITED STATES DEPARTMENT OF AGRICULTURE

Picking Maturity of Apples —_

By MArkK H. HAtteER, associate pomologist, and J. R. MAGNESS, heédyhorticulturist
in charge, Division of Fruit and Vegetable Crops and Diseases, Bureaw. of
Plant Industry, Soils, and Agricultural Engineering, Agricultural Research

Administration h Ay is _ Mf
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Contents Ea, 944
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Page toe aye Page
Need for and reliability of indexes of maturity_ 1 | Picking time in relation to-yarietal character-
Definitions of maturity terms_________________ 3 istics—Continued. oye CY /p ;
Orchard and storage disorders related to ma- Cortland Sees Meena et Panel alli £ Thy 3. 4
RC UnI tyne ee ee Re 3 Delicious a ee ls fn “OB £
Changes in apples approaching picking ma- Ganoand’ Black Benes .. 342.0 42007 i 14 ¢
(BOUVECGSY S SI S eg g 5 Golden; Delicious \. nays ewe rey oe Le
EMCREASESINYSIZA ME Ase ee 5 GrimesiGoldems cane By tais aU Sail ee °)
Change in seed color________________ anv 5 Jonathanssnan ya Ns elitr ale MG UT oc aa 16
Changes in chemical composition_________ 5 TAY BSD Bat eCOYS) oes ately Re Ea ay a 17
Corking over of lenticels__________- aa 6 INOKEHEENMES yi Nee Uae RTA RAE SpA 7;
Change in fruit color__________- see 6 Rhode Island Greening___________________ 17
Softer os eee shee ea Pes ie 7 OMe Beauty sais 2 be) ana aay screen ee 18
Loosening of fruit from spurs____________- 8 StaymanZzWanesapy owes a Mie ena en 18
Development of water core______________- 8 WIA SOM EN Ee MRO Ua a APD ou A UNA ar etna 19
Elapsed time from full bloom to picking ma- NYAVAT UU Ute orn Oia co esl rane Uae el ON oan ee eA 19
GUE Vee ire BIN oS ETE ac. 9 VATA CS oie ita faieh i eu Sioa tah Je ee La) av DN 19
Picking time in relation to varietal character- SViellowANiewibo wane Boe wee ay a ane la 20
TO GLC Serer ere N Tiere an ane ON OSE Se SN Sut St 10 Yellow @ransparent:. 222s.) l a ees 21
INGE FEO O ae hk eh asl er eee a tn 11 YORK MEI DOTA ane tek aaa Ne UD et 21
IAkansaseblac@kermmenan i bor otinn Aaa Rs 11 | Picking time in relation to handling_________-_ 22
Bal div ine aancr sn MEN Oa DSN VD PGIGELAGUTE CIEE Gye Oe eR aI paid 23
HS Cnp ID avy 1S eee sale Cay Ee 12

PPP PPP PEPPERELL GLA LLLALLLLAGLL LLL LLLILIIEAIGIG,

NEED FOR AND RELIABILITY OF INDEXES OF
MATURITY

The dessert quality, storage capacity, and commercial value of ap-
ples are influenced greatly by the maturity at which the fruit is picked.
If picked prematurely, apples are likely to be small, tough, poorly
colored, sour, off flavor, and subject to scald in storage. If picked
when overmature, they are likely to have developed water core while
still on the tree; with some varieties the red color may become too dark
and dull and the skin may become greasy or oily. Overmature apples
are likely to become mealy or to break down after storage and to be
flat in flavor. Generally there is a period of 5 to 20 days, depending
on variety and cultural and climatic conditions, during which the fruit
can be picked with the assurance that it will remain reasonably free
of the storage disorders associated with immaturity or overmaturity
and will ripen with reasonably good dessert quality. It is obviously

1This circular supersedes Department Bulletin 1448, Picking Maturity of Apples in
Relation to Storage (13).

602694°—44 1

important that means be devised for determining the beginning and
duration of this period, so that apples may be picked during this
period as far as practicable.

Many factors determine the best time to harvest an apple crop.
Each variety presents an individual problem. The importance of the
factors involved in establishing indexes of maturity will depend on the
variety but may vary within a variety, with different cultural and
climatic conditions. In the case of all varieties, however, the fruit
increases in size as long as it remains attached to the tree.

From this standpoint it is desirable to leave the fruit on the tree
as long as dropping does not equal or exceed the volume increase.
However, picking should be completed by the time the loss due to
dropping equals the gain due to volume increase. Since the time when
dropping is likely to become excessive cannot be predicted, picking

should start while the fruit is still adhering well.

It has been suggested that the time at which apples should be picked
may be determined by the ease with which fruit can be separated from
the spurs and the extent to which sound fruit is dropping. However,
under certain conditions the apples may start to drop before satis-
factory maturity from the standpoint of dessert and storage qualities
has been reached. As indicated, the tendency to drop is not a satis-
factory index of when to start picking; for once dropping has started
it is likely to become excessive before picking can be completed and
the change in ease of separation of the fruit from the spurs previous
to dropping is not sufficiently marked or distinct to be taken as a pick-
ing guide.

The amount of red color on red varieties, which increases during the
harvest period, is an important factor in the commercial value of the
erap, It “1s desirable to leave the apples on the tree until sufficient
red has developed. However, with some varieties and conditions the
fruit may become overmature before it becomes well colored. On the
other hand, apples of some of the red bud sports may become well
colored while still immature.

The change in the ground color from green to yellow is desirable,
particularly: with yellow varieties such as Golden Delicious and Grimes
Golden. This change has also been suggested as an index of picking
maturity. With many varieties there is no appreciable change in the
green color at the approach of maturity, and with others the changes
are not sufficiently marked or consistent to be of much value.

There is a gradual softening of the fruit on the tree previous to and
during the harvest period. This change is useful as an indication that
the fruit is becoming too soft for ood : storage quality.

Changes in horticultural practice and recent investigations * have
shown the need for some changes in the recommendations made in

2In a cooperative iny estigation between the Bureau of Plant Industry, Soils, and Agri-
cultural Engineering and various State agricultural experiment stations, data relative to
the elapsed time from bloom to maturity have been obtained in different apple-producing
districts as follows: For Virginia, Maryland, and West Virginia by Mark H. Haller, Bureau
of Plant Industry, Soils, and Agricultural Engineer ing: for W ashington by Edwin Smith,
Bureau of Plant Industry, Soils, and Agricultural Engineering ; for Illinois by Richard
V. Lott, Ilinois Agricultural Experiment Station ; EGE Ohio by C. W. Ellenwood, Ohio
Agricultural Experiment Station; for Michigan by Roy I 2. Marshall, Michigan Agricultural
Experiment Station ; for New York by Henry O. Bennett, Bureau of Plant Industry, Soils.
and Agricultural Engineering ; and for Oregon by Gordon Brown, Oregon Agr icultural
Experiment Station. A preliminary report (8) has been made of some of the data for
Virginia, West Virginia, and Maryland. The more recent data have not been published but
have been used as a basis for making recommendations relative to the number of days from
bloom to maturity in this circular. Such recommendations are based on the results of
these cooperative studies except when other references are cited.

2

1926 (73) * relative to methods of determining picking maturity.
The elapsed time from full bloom to maturity has been found to be
rather constant for a number of varieties and constitutes the most re-
lable index of the earhest maturity date.

DEFINITIONS OF MATURITY TERMS

As an apple develops on the tree it passes through several stages of
maturity from immature to overmature. The stage of maturity at
which an apple is picked is reflected in its subsequent storage and des-
sert qualities. Reference is made in this circular to several stages of
maturity as follows:

IMMATURITY.—Apples picked when immature will soften somewhat and may
turn yellow when ripened; but the flesh is likely to be tough, the taste sour, the
flavor lacking or undesirable, or the storage quality poor because of susceptibility
to storage scald, bitter pit, or other disorders associated with immaturity.

Harty MaArurity.—Apples picked at this stage ripen with only fair dessert
quality for the variety but will be reasonably free of disorders associated with
immaturity during storage. Earliest maturity is the beginning of this period.

OPTIMUM Matruriry.—Apples picked at optimum maturity can be stored with
a minimum of storage disorders and ripened with maximum dessert quality
for the variety and conditions of growth.

Late Maturiry.—Apples picked at this stage are still satisfactory for picking,
but they will be somewhat flat in flavor and may show a slight tendency to become
mealy and to develop disorders associated with overmaturity.

OVERMATURITY.—When allowed to remain on the tree until overmature, the
fruit may ripen quickly to a mealy condition, may be flat in taste, or may be
subject to internal break-down or decay during storage.

An apple is mature and satisfactory for picking during the period
from earhest maturity until overmaturity is reached.

The changes in the fruit on the tree that result in differences in its
storage and dessert qualities are gradual, so that it is possible only to
approximate the time at which a given stage of maturity 1s reached.
This is particularly true of varieties in which maturity is based pri-
marily on the dessert quality of the ripened fruit. Although good
storage and dessert qualities are usually rather closely associated, ‘they
do not always coincide and apples may attain satisfactory maturity
from the standpoint of storage quality earlier or later than they attain

satisfactory maturity from ‘the standpoint of dessert quality. This
also complicates the exact establishment of a given stage of maturity.

ORCHARD AND STORAGE DISORDERS RELATED
TO MATURITY

There is a direct association between various physiological disorders
of apples (6) and their degree of maturity when picked. Of these,
bitter pit and storage scald are associated with immatur ity, whereas
Jonathan spot, sogey break-down, water core, and internal break-
down are associated with overmaturity.

The most serious of these disorders is storage scald (6), a surface
browning or blackening that develops in 60 to 90 days after harvest
in such early ripening varieties as Grimes Golden and in 100 to 150
days with later kinds. It is more serious in cold storage than in com-
mon storage. The unblushed parts of the fruits are most affected, and

3 Italic numbers in parentheses refer to Literature Cited, p. 23.

3

immature apples are more susceptible than those picked later. Pick-
ing the fruit at proper maturity helps to prevent scald. Shredded
oiled paper or oiled-paper wraps are used to control scald, but neither
of these will prevent it in immature fruit of susceptible varieties.

Bitter pit (6), also called stippen, Baldwin spot, and York spot,
occurs as brown spongy or corky spots in the flesh usually just under
the skin and frequently causes depressions in the surface of the fruit.
It seems to develop most in storage on apples picked before they reach
proper maturity. It is particularly prevalent on Baldwin, Graven-
stein, Arkansas (Mammoth Black Twig), Delicious, Yellow New-
town, Rhode Island Greening, and Northern Spy. Bitter pit also
develops in fruit still attached to the tree, but probably to a less extent
than in fruit harvested early and placed in storage. Also much of
the fruit affected with bitter pit can be sorted out when mature fruit
is packed.

Water core (2,6), a functional disease that gives the flesh a water-
soaked appearance, develops under favorable conditions as apples
reach maturity; when it 1s present it may cause growers to pick the
fruit of some varieties earlier than otherwise desirable. A small
amount of water core at picking time, particularly in the slower sof-
tening, longer keeping varieties such as Winesap and Yellow Newtown.
will often disappear in storage, and the quality will not be lowered.
This disorder seriously affects the quality of rapidly ripening vari-
eties such as Jonathan and Delicious, in which it is hkely to lead to
internal break-down.

Internal break-down is a senility disease that is characterized by
brownish discoloration of the flesh, development of mealiness, and
loss of flavor (6). It is associated with apples that were overmature
or water-cored when picked or that have been held in storage too long.

Soggy break-down (6, 77, 78) is a low-temperature disorder that
occasionally occurs in Grimes Golden, Wealthy, Golden Delicious,
and a few other varieties. Soggy break-down is distinguished from
internal break-down in that in the former there is a sharp demarcation
between the sound and affected tissues and the affected tissue is wet or
soggy rather than dry and mealy. It is generally more severe in late-
picked apples, particularly if they are kept for a period at room tem-
perature before cold storage.

Soft scald (6, 18) is also a low-temperature disorder to which
Jonathan is particularly susceptible; occasionally it also occurs on
Northwestern Greening, Rome Beauty, Wealthy, Golden Delicious,
Winesap, and McIntosh. ‘It is distinguished from storage scald in
that the affected parts are more sunken and soft and occur in definite
patterns with a sharp demarcation between the affected and sound
tissues. Oiled paper, used to control storage scald, is ineffective for
soft scald. Although the severity of soft scald varies with different
maturities, its exact relation to maturity is not clear. Under some
conditions it may be more severe in early-picked apples and under
others in intermediate- or late-picked (78).

Jonathan spot is a superficial skin disease characterized by small,
black or brown spots, resembling freckles, that occurs on Jonathan,
King David, and Rome Beauty apples when they are left on the tree
until they approach overmaturity.

CHANGES IN APPLES APPROACHING PICKING
MATURITY

INCREASE IN SIZE

Previous studies (12, 14) have shown that as long as apples hold on
the tree growth in size continues. The rate of increase depends on
the availability to the fruit of elaborated foods and moisture. Spray
or other injury to the leaves, low temperatures, water shortage, senil-
ity of the leaves, and any other factors that decrease the photosyn-
thetic activity of the leaves reduce the growth rate of the fruit.
Fruits of summer varieties such as Yellow Transparent and Williams
are growing rapidly as they approach maturity and may increase as
much as 2 percent per day in volume during the harvest period.
Fruits of early-fall varieties such as Jonathan and Grimes Golden
normally average about 1-percent increase per day during the harvest
period whereas those of late varieties such as Winesap that mature
during the cool weather may not increase more than 0.5 percent per
day. Under conditions favorable to growth, delaying the picking
of the crop will result in larger fruit and an appreciable increase in
crop volume. From 0.5 to 1 percent of the fruit must drop daily
before the total tonnage will be materially reduced below that from
an earlier picking.

CHANGE IN SEED COLOR

The browning of the seeds in apples as they approach picking ma-
turity has often been suggested as an index of the best time for picking
the fruit. The seeds of winter apples, however, usually become brown
a considerable period prior to the optimum picking date. The time of
the coloring of the seeds varies so greatly with variety and season that
this change is of little value in determining when to pick the fruit.
It may be stated, however, that winter apples are practically never
ready to pick before the seeds have reached a full brown color.

CHANGES IN CHEMICAL COMPOSITION

There are a number of changes in the chemical composition of apples
as they approach picking maturity, but the extent of these changes is
not great and the rate of change is not rapid. In general, as the fruit
matures on the tree the astringent substances, including tannin, tend
to decrease, the acidity decreases, and the sugar content increases.
Many studies have been made to develop chemical tests for picking
maturity, similar to the sugar and acid tests used on citrus fruits and
grapes. Because of the wide variations in the chemical composition
of apples caused by factors other than ripening, however, a chemical
test for time of picking appears to be of little practical value. The
percentage of sugar varies with the quantity of fruit on the tree, the
moisture supply, and the climatic conditions, as well as with the degree »
of maturity. The sugar content of fruit from heavily loaded trees
is below that of fruit from lightly loaded ones under similar growing
conditions and in a similar stage of maturity (70). The work of
Caldwell (3) indicates that the sugar content of apples is higher in
seasons of high sunlight than in those of low sunlight. The changes

5

in chemical composition due to variations in growing conditions are so
great that any picking test based on chemical composition has proved
unsatisfactory.

Many tests have been made to determine whether the disappearance
of starch (determined by the iodine test) is an indication of maturity.
There is a gradual conversion of starch to sugar as the fruit matures,
but some varieties become mature before any appreciable change oc-
curs in the starch test. Some starch always remains when the fruit
is in the best condition for picking, but the extent of the conversion at
maturity may vary with different climatic and cultural conditions.
Thus, as with other chemical tests, those based on starch disappearance
have but limited value in determining stage of maturity of apples.

CorKING OveER OF LENTICELS

The lenticels, or pores in the skin, which in the immature fruit open
more or less directly to the flesh tissue below, become filled with cork
cells and sealed partially or wholly as the fruit approaches maturity
on thetree. The waxy coating also develops on the surface of the fruit
during the latter part of the growing season. The development of the
heavy wax coating and the sealing of the lenticels make the fruit that
is well matured at picking time somewhat more resistant to wilting
in storage than that picked in an immature condition. These changes,
however, are not sufficiently discernible to make them of much value
in determining when the fruit should be picked.

CHANGE IN Fruir CoLor

The change in color of apples as they mature on the tree is twofold.
One is the development of red in blushed or colored varieties, while
the other is the change in the unblushed portions. The green ground
color of the immature fruit changes first to greenish yellow and
finally to an almost full yellow as the fruit matures.

The development of the red color is a very important factor in
determining when to pick apples for commercial purposes, since high
color is essential to the advantageous marketing of many varieties.
The development of red depends very largely. however, upon the
exposure of individual fruits to sunlight and upon the prevalence
of bright, sunny days during the maturing season. The sugar con-
tent of the fruit also appears to be an important factor in color
development. Except in the early coloring sport strains, the develop-
ment of a good red color is usually indicative of maturity. However,
because of the variability in color development associated with
weather conditions, fertilizer practices, and other factors, red de-
velopment is not a fully dependable criterion of maturity. Some
fruit may be mature before it is well colored, whereas other fruit,
particularly that of colored strains, may be colored before it is
mature.

Light exposure has little to do with the disappearance of the green
ground color in the unblushed parts of apples, and in some varieties
this disappearance is a supplemental index of maturity. In the red
bud sports of some varieties the red frequently covers the surface
so completely and so early that the ground color cannot be observed.

6

In other varieties the ground color does not change appreciably as
the fruit becomes mature. With such varieties the ground color
cannot be used to indicate maturity; neither can it be used for this
purpose with fruit on trees highly fertilized with nitrogen, as such
fruit tends to retain the green color even when mature.

A color chart has been devised for use in determining the change
in the ground color of apples from green to yellow. This consists of
four colors from green (No. 1) to ‘yellow (No. 4), closely approxi-
mating the color stages Gee which apples pass as they mature
and ripen. A copy of this color chart may be obtained by writing
the Plant Industry Station, Beltsville, Md. The ground color of
the fruit is determined by matching the fruit color with one of the
colors on the chart. This is done by placing the fruit back of the
chart and fitting the unblushed portion into holes cut in the different
colors. This should be done in diffused daylight (not in direct sun-
light). When the color falls between two standard colors it may
be described by a number; for example a color between No. 3 and
No. 4 may be designated 3.5

SOFTENING

Under certain growing conditions and with some varieties, soften-
ing of the flesh “of the apple has been used as an indication of
maturity. Usually the fruit gradually softens as it approaches
maturity on the tree. The firmness at maturity varies considerably
from season to season and with growing conditions so that a precise
degree of firmness at which an apple becomes mature cannot be given.
However, if the fruit becomes too soft on the tree it may not hold
up well in storage. The principal value of firmness measurements
is to indicate when the fruit is becoming too soft or overmature,
particularly with varieties that soften rapidly i in storage and tend to
develop mealiness or a mealy break-down.

The firmness of the flesh of the fruit can be most accurately
measured by the use of a pressure-test apparatus. Such an appa-
ratus with methods for its use has been described in previous publi-
eations (7, 15) and is now available on the market. It measures
in pounds the pressure required to force a plunger seven-sixteenths
of an inch in diameter into the apple to a depth of five-sixteenths of
an inch, the skin being removed prior to making the test. Figure 1

FigurE 1.—Fruit pressure tester for apples, pears, and peaches, showing method
of use. (Photograph through courtesy of R. Schneider. )

illustrates the method of making the test. The fruit to be tested may
be placed against any convenient solid surface, such as a wall or the
trunk of a tree, if the test is being made in an orchard. The plunger
tip is placed in contact with the cut surface and pressure is applied.
When the plunger tip has penetrated to a depth of five-sixteenths
of an inch, as shown by a line on the plunger tip, the pressure in
pounds required to force the plunger into the fruit to this depth is
read directly on the scale. In order to obtain a satisfactory indica-
tion of the condition of any variety, at least 10 to 20 apples selected
from different trees and different parts of the trees should be used.
Two or more tests may be madé on each apple and the results
averaged. Tests should be made within a few hours after picking.
Values reported herein as firmness ranges for different varieties are
based on tests made as described with the peel removed prior to test-
ing. The application of pressure-test determinations to maturity
and ripeness of fruits has been discussed in a recent publication (7).

LOOSENING OF FRUIT FROM SPURS

As apples approach proper picking condition they generally tend to
loosen from the spur so that when the fruit is hfted the stem readily
separates. However, under certain growing conditions the fruits of
some varieties such as McIntosh and Delicious may loosen and release
easily before they reach satisfactory maturity. Early frosts also may
cause fruit to loosen and drop before it is mature. On the other hand,
fruits of certain varieties such as Jonathan and Stayman Winesap may
adhere tightly until the fruit becomes overmature. Ease of separation
of fruit from spurs, therefore, is not necessarily an indication of proper
maturity, but 1t may indicate when picking is necessary to save the
crop. In recent years harvest sprays of certain growth-modifying
chemicals such as «-naphthaleneacetic acid (7) have been used exten-
sively for the prevention of fruit dropping, making unnecessary the
premature picking of fruit that shows a tendency to drop early.

The ease with which fruit may be loosened from the spurs has
become even less reliable as an index of picking maturity since the
adoption of sprays for the control of harvest drop. The use of these
sprays has made the maturity problem more complex because after
their use fruit may be permitted to remain unharvested until it becomes
overmature.

The tenacity with which the fruit adheres to the tree can be esti-
mated only in a general way. If the stem of a sound fruit separates
from the spur when the fruit is lifted or is given a slight twist, it would
be considered that the fruit is loosening on the tree and separates eas-
ily. Under this condition it is probable that a small amount of sound
fruit may be dropping. If no fruit is dropping and if the fruit can
be picked only with considerable effort, it is considered that the fruit
is still firmly attached to the tree. The dropping of wormy or other-
wise injured fruit is not an indication of picking maturity.

DEVELOPMENT OF WATER CORE
The development of water core in the fruit is a very important con-
sideration in determining when to pick certain varieties. Investiga-
tions by Brooks and Fisher (2) have shown that water core usually

8

develops first in fruit exposed to the direct sunshine on the south and
west sides of the trees. Consequently, apples from the exposed south
er west and top parts of the tree should be examined for water core. If
water core is not found or if it is present in only a shght degree in fruit
from these positions on the tree, 1t is improbable that it will be present
to an injurious extent in fruit from more protected parts of the tree.

ELAPSED TIME FROM FULL BLOOM TO PICKING
MATURITY

Magness et al. (74) and Palmer (16) observed that the number of
days from full bloom to maturity was rather constant for a given va-
riety even when grown under widely different climatic and cultural con-
ditions. Further investigations of the reliability of this factor as a
means of predicting apple maturity have been conducted in recent
years (8).4. The results confirm the earlier observation that the num-
ber of days from full bloom to picking maturity is rather constant over
a wide range of climatic and cultural conditions and that this con-
stitutes a more reliable index of maturity than any other single factor
that has been suggested. Thus, the Delicious variety requires 145 to
150 days from bloom to reach acceptable picking maturity, and this
has been found under widely varying climatic, soil, and cultural condi-
tions of Washington, Oregon, Dhinois, Ohio, Michigan, New York,
and Maryland. It has not been possible to establish any influence of
temperatures prevailing during the growing season on the elapsed time
from bloom to maturity of apples although it may be a factor with
other fruits. However, there have been some variations in elapsed
time and certain factors undoubtedly influence this variation. Heavy
nitrogen fertilization, for example, results in delayed color development
of fruit and may result in greater scald development unless picking
is postponed. On the other hand, dropping may be more pronounced
from heavily fertilized trees than from trees not heavily fertilized.
Because fruit from nitrogen-fertilized trees is likely to show poorer
color and to be more susceptible to scald, it is usually desirable to post-
pone the time of picking such fertilized trees if the fruit is holding well
enough to permit it, and thus to increase the time interval from full
bloom to maturity. Similarly, a very light crop of fruit is likely to
mature earlier than a heavy one. The extent to which these or other
factors may retard or advance maturity has not been fully established.

The date of full bloom has been taken as the date when the first
petals fall. Theoretically the date of full bloom should be the time of
pollination or fertilization in the blossoms that set the fruit. During
some seasons warm weather brings out all the blossoms in a very few
days so that the time of full bloom can be readily established and 1s
nearly the same for all blossoms. During other seasons, however, a
_period of warm weather may bring the center or king blossoms into
full bloom and may be followed by cool weather that will retard the
opening and pollination of the other blossoms for a week or more.
Under such circumstances there is likely to be considerable error in
establishing the date of full bloom applicable to most of the fruit that
sets.

4 See footnote 2, p. 2.

2 9

602694°—44

The number of days from bloom to maturity for the varieties on
which considerable information is available is shown in figure 2. The
period of early maturity shown is either the period in which the
fruit would be mature under conditions that would tend to hasten
maturity, such as a light crop, or the early maturity for a more
normal crop. The period of optimum maturity shown is the one when
optimum maturity is most likely to occur; the period of late maturity
shown is the period in which overmaturity or dropping may become
imminent.

snubs afar’ waTuRtt,
MCINTOSH. he 8 ee a te WD HEE LATE MATURITY
SONA TBA Seth 5 BI fa aa ie Go, (ss

GRIMES: GOUDEN 9. ate acnae gan nee pie oe Gia

DELNCIOUS i> Si Soa es Figen: tay eae Se oT Zz

GOEDENDENICIOUS@ = it aoe Yio. _-_—

ENE OWE NIE WSTIOW, Night Yt WSS
ROME\BEAU IN. {Gwin s aera ts eae er eo Sie

STAYMAN WINESAP ------ £----------------- E
WINESAP ------- ---- -- eer e e err--
YORK IMPERIAL ------ £-------------- Hr: Z

70 80 120 130 140 150 160 170 180
ELAPSED TIME FROM BLOOM (DAYS)

FiguRE 2.—Days elapsing from bloom to maturity for 11 varieties of apples. The
period of early maturity shown is the period during which barely satisfactory
maturity normally occurs, but optimum maturity may occur in this period under
conditions that would tend to hasten maturity. Similarly, the period of late
maturity Shown is the period in which overmaturity or dropping may become
imminent, but optimum maturity may extend into this period under conditions
that retard maturity.

PICKING TIME IN RELATION TO VARIETAL
CHARACTERISTICS

Because of the wide variations even in the same variety of apple
when grown under the climatic conditions prevailing in different parts
of the United States and in the factors which determine optimum pick-
ing time for different varieties, it is difficult to discuss the relative
value of different picking-time tests for apple varieties in general.
The storage quality of certain varieties is greatly reduced by leaving
the fruit on the tree too long, whereas with other varieties the greatest
harm results from picking the fruit too early. It is believed best,
therefore, to discuss the merits of the different tests for time of pick-
ing and the best time for picking different varieties in detail in con-
nection with well-known commercial apples. The writers have set
down in this circular information on the picking time of a number of
varieties of apples which they have studied and on which they feel
justified in making recommendations.

10

ARKANSAS

The storage life of Arkansas (Mammoth Black Twig) apples is
limited largely by the development of storage scald, but under some
conditions this variety may be highly subject to decay and internal
break-down also. It is usually hard at time of picking and softens
rather slowly in storage, but it may become mealy and break down
while still relatively firm. It requires a long growing season, usually
over 160 days from bloom, to reach its best development on the tree.
Since well-matured fruit is less subject to scald in storage, it is es-
sential that this variety not be picked too early. However, since there
is some danger also of its becoming overmature and subject to decay
and break-down, picking should not be delayed too long after the
fruit is ready for picking. When it is to be held in cold storage, fruit
will be larger and of better color and will show less tendency to scald
if it is picked relatively late. If it is to be held in common or air-
cooled storage, fruit picked late will have greater firmness during the
storage season. Apples of this variety, in common with those of most
late-ripening apples, soften faster after being picked and while being
held at the temperature prevailing in air-cooled storage than while
attached to the tree. Thus, the later the fruit is picked the firmer it
will be.

Arkansas apples probably should be picked between 160 and 175 days
from bloom, but the exact interval from bloom to maturity has not been
well established. When a harvest spray is not used the tendency for
the apples to drop will help the grower to regulate the time of picking.
Ground color at maturity will range from No. 2 to No. 2.5 of the color
chart.

ARKANSAS BLACK

Arkansas Black is a very firm variety, softening very slowly in stor-
age. It is one of the hardest of the commercial varieties, usually
testing near 25 pounds when in picking condition.

Arkansas Black colors very highly and has only a slight tendency to
develop storage scald. There is little danger of its becoming so
ripe on the tree that the storage quality will be injured. The fruit
should be a full deep red when picked and should separate readily
from the spurs. Fruit of this variety that is to be held in common
storage should be picked as late as possible but before water core
becomes serious, since it will ripen less while attached to the tree
than while held in storage at the prevailing temperatures; the tend-
ency to drop and to develop water core, or the possible imminence of
severe freezing weather will determine when the fruit should be
picked. For cold-storage holding it may be picked when fully colored.

BALDWIN

In the southern apple-growing areas the picking period for Bald-
win usually falls in September, whereas in the north-central and
northeastern apple-growing regions where Baldwin is mainly grown it
blooms much later and the harvest normally falls in mid-October.
Since this variety ripens during hot weather in the South, it must be
handled in cold storage if an appreciable holding period is desired.

11

In the short-season regions with much later harvests and cooler falls,
to which Baldwin is best adapted, it can be held very successfully until
midwinter or later in common storage.

Baldwin tends to scald considerably in storage, particularly as
grown in the South, and to develop bitter pit when grown in the
North. Early picking would favor these disorders. It also has a
marked tendency to drop as soon as the fruit reaches the best picking
condition or in some cases before. This tendency to drop has largely
determined the time of picking.

The number of days from bloom to harvest for Baldwin, recorded
for a number of localities and seasons, varies greatly. The shortest
periods have been recorded. for New York with an average of 135
days for 4 seasons (19), but 145 days was recorded for 1 season.? The
longest periods have been recorded in Ohio, with an average of 161
days for 30 seasons (4) and a range of 147 to 166 days. Other records
(74) for only 1 or 2 seasons gave 136 and 146 days for Massachusetts,
142 and 160 days for Ohio, 138 days for Virginia, 145 days for New
York, 145 days for Washington, and 186 and 155 days ® for Michigan.
In nearly all instances these figures were derived from the records of
actual dates on which apples were harvested and did not include com-
parisons with earlier or later pickings to determine whether the har-
vest dates represented optimum maturity. Harvests made less than
140 days after bloom may have been necessitated by a tendency to
premature dropping that could have been retarded by harvest sprays.
On the other hand, in the more northern areas growers could not har-
vest their apples after an elapsed period after bloom of 160 days (re-
ported for Ohio), as their growing seasons from bloom to severe freez-
ing are generally not that long. On the basis of these results it seems
likely that at least 140 days should elapse from bloom before picking
of Baldwins starts and that a more nearly optimum time of picking
would be between 145 and 155 days from bloom. Any tendency for
apples to drop earlier than this should be controlled if possible with
harvest sprays.

Ben Davis

In the eastern half of the United States Ben Davis is grown com-
mercially over an extremely wide range of climatic conditions from
south to north. The condition of the fruit at picking time will vary
somewhat in these different areas, particularly as to firmness of flesh.

Probably this variety is handled more extensively than any other
in common storage. The fruit holds late on the tree and there is
little dropping ; consequently, it is usually well matured when picked
and relatively little scald develops during storage. If picked in an
immature condition, however, the variety often shows extremely
severe scald development.

Usually from 155 to 160 days elapses between the blooming season
and the time of picking Ben Davis. In the northeastern apple areas
it is frequently the last variety picked, and in the more southern apple
areas the normal picking season is in early October.

This variety should not be picked before the ground color reaches
the almost full yellow condition shown in Nos. 3 and 4 of the color
chart. The fruit should be highly colored, also. When this condi-

56 See footnote 2, p. 2.

12

tion is reached in the southern areas the pressure test will usually be
19 to 17 pounds, whereas in the more northern areas it will be 20 to
19 pounds. ;

In the southern areas fruit left on the tree until softer than a con-
dition represented by a pressure test of about 17 pounds is relatively
poor for storage. Fruit of this variety when picked in a more mature
condition than this will become soft relatively early in cold storage
and may show physiological break-down or a collapse of the flesh if
held in common storage. In the northern apple-growing areas there
is relatively little danger of Ben Davis being picked too late pro-
vided severe freezing weather is avoided.

CoRTLAND

The Cortland apple, developed from a cross of Ben Davis and
McIntosh, closely resembles the McIntosh parent; but it is described
as being somewhat later to mature and having a somewhat longer
storage life. Results for 3 seasons in New York (19) indicate
that Cortland was usually harvested at about the same number of
days from bloom (128) as McIntosh. One season’s results in New.
York, in which samples picked at different maturities were compared
after storage, indicated that both Cortland and McIntosh should be
picked somewhat later (about 185 days from bloom). Results for
10 seasons in Ohio (4) showed a still longer period from bloom to
harvest (average, 144 days; range, 133 to 155), which was also con-
siderably longer than the comparable average for McIntosh (129
days). From these results it seems likely that at least 180 days from
bloom should elapse before the picking of Cortland is started.
Optimum maturity probably occurs normally at about 135 days. Like
McIntosh the Cortland variety is fairly soft and ripens rapidly at high
temperatures. It is essential, therefore, that the fruit be picked before
it becomes too soft (pressure test of less than 15 to 14 pounds) and
that the fruit be placed under refrigeration promptly after harvest.

Cortland is exacting in its picking requirements, developing storage
scald if picked too early and break-down and mealiness if picked too
late. Because its fruit holds on the tree much better than that of
McIntosh, there has been a tendency to delay picking until harvest
of McIntosh is complete. This has resulted in some overmature and
poor-keeping Cortland fruit.

DELIcIousS

Delicious is grown over a wide range of climatic conditions. High
development of red is extremely desirable in this variety; in order to
obtain good color, therefore, it is sometimes left on the trees so long
that the storage quality is injured. On the other hand, if picked when
too immature Delicious is of extremely poor dessert quality.

Elapsed time from bloom is probably the most reliable means of
establishing the earliest time for picking this variety. Considerable
data relative to the number of days from bloom to earliest picking
have been accumulated. Earlier studies (74) from Massachusetts,
Michigan, Ohio, Virginia, and Washington indicated that from 134
to 153 (average, 140) days elapsed from bloom to optimum maturity.
Results for Ohio (4) for 30 seasons showed an average of 153 days

13

(range, 141 to 163) from bloom to harvest. Results for 4 seasons in
New York (79) showed an average of 1382 days from bloom to harvest.
Studies in Washington indicated that at least 145 days elapsed from
bloom to harvest. Recent cooperative studies in which samples were
picked at intervals and stored to establish proper picking maturity
more definitely, indicated that at least 145 days, and preferably 150
days, should elapse between bloom and picking in Washington,
Oregon, Illinois, Ohio, Michigan, New York, and Maryland. On the
basis of these results it would seem that this variety normally requires
at least 145 days to mature sufficiently to have fair quality and that
harvest should be completed by not more than 155 to 160 days for satis-
factory storage holding. Shorter periods indicated in some of the
reports may have been due to early harvest in which actual maturity
was not established by storage tests on several pickings.

Under long growing season conditions Delicious apples may become
overmature. Relative firmness may be used as an indication of the
approach of an overmature condition. The apples should be picked
before the pressure test drops below 15 pounds or preferably 16
pounds. Delicious grown in districts with long growing seasons has
a tendency to develop water core; such development is a further in-
dication that the fruit should be removed from the tree. Another
guide in determining the picking time is the fact that the flesh of
Delicious apples in proper picking condition is yellowish.

This variety holds for a long season in a firm, crisp condition if
moved at once after harvest into storage at 31° to 32° F. It softens and
becomes mealy with extreme rapidity, however, when handled at
higher temperatures; consequently, it is not well suited to handling
in common storage and any delay between date of picking and placing
fruit under refrigeration will greatly decrease the time the fruit will
remain in good condition in cold storage.

Delicious is subject to storage scald when harvested at a stage of
maturity suitable for fair, but not optimum, dessert quality. In Wash-
ington 150 to 155 days from bloom is considered necessary to reach a
scald-free stage of maturity. Where the size of the crop and the
physical facilities for packing and storage make it necessary to start
harvesting at the earliest possible date, it is important that such fruit
be not held for late storage. Even the use of oiled paper will not con-
trol storage scald on Delicious apples picked before they have passed
the susceptible stage.

Red bud sports of Delicious, particularly Starking and to a lesser
extent Richared, develop red color earlier than regular Delicious, and
the tendency in commercial practice is to pick them earlier. Maturity
investigations have shown (5), however, that these sports do not
mature any earlier than the regular Delicious; therefore they should
not be picked until at least 145 days from bloom.

GANO AND BLACK BEN

The picking-maturity characteristics of Gano and Black Ben are
similar. Both varieties are susceptible to storage scald if picked in
aun immature condition. As a consequence, it 1s necessary that the
fruit remain on the tree until it is practically full colored so that it
may have the best storage quality. Fruit of these varieties takes on a
very high color and generally can remain on the tree until it is almost

14

100 percent red. When apples of these varieties are in the best pick-
ing condition, the unblushed portions should be practically of the full
color corresponding to Nos. 3 to 4 of the color chart.

In districts with long growing seasons, a pressure test of about 18
pounds will indicate when the fruit is in best storage condition. The
fruit usually holds to the tree very well, but if it begins dropping
before it reaches the color condition and the pressure test suggested
it should be harvested or harvest sprays should be applied.

GOLDEN DELIcIOUS

Golden Delicious is not subject to scald in storage, but it has a
tendency to wilt, particularly when picked in an immature condition
or when extensively russeted. When picked while still fairly green
it does not develop in cold storage the attractive golden yellow that
adds greatly to the appearance of the fruit and it also lacks its fine
characteristic flavor. Generally Golden Delicious apples can be
picked over a fairly long period with satisfactory results. However,
it is a rather soft variety and there is a possibility of its becoming
too soft for good storage quality if picked late.

The quality of the fruit of Golden Delicious seems to be influenced
by the size of the crop to a greater extent than with some of the other
varieties. With a lght crop the ground color of the fruit turns yellow
sooner and satisfactory dessert quality may be obtained in fruit picked
7 to 10 days earlier than fruit of a heavy crop.

Golden Delicious varies with respect to the length of periods from
bloom to maturity, possibly due in part to crop size. With a light
crop it seems likely that satisfactory maturity may be obtained when
picking starts as early as 145 days from bloom; in general, 150 days
should elapse before picking starts. Optimum maturity probably
occurs between 150 and 160 days. At earliest maturity the ground
color should have changed to about No. 2.5 to No. 3 of the color chart
and should be between No. 3 and No. 4 at optimum maturity. For
best storage the firmness of the fruit should not drop below a pressure
of 14 pounds.

GrIMEs GOLDEN

If picked in an immature condition, Grimes Golden tends to scald
badly in storage even when packed with oiled paper. If picked while
still having a marked green color and moved promptly to cold storage,
this variety ripens in storage without attaining the golden-yellow
color so desirable on the retail market. It is a fairly firm variety and
could be left on the tree longer than ordinarily is done without becom-
ing too soft for good storage quality. However, it tends to drop badly
and for this reason generally should be picked before appreciable
yellowing occurs (8, 17).

Rather extensive records (4, 8, 74)" for this variety indicate that
Grimes Golden requires at least 140 days from bloom to reach satis-
factory maturity. When picked at this time the fruit still will be
green (corresponding to No. 1 to No. 1.5 on the color chart), but under
some circumstances considerable dropping may occur. Optimum
maturity is reached between 145 and 150 days from bloom. Even

7 See footnote 2, p. 2.

15

when picked this late Grimes Golden fruit will be rather green (proba-
bly about No. 1.5 to No. 2 of the color chart) and a harvest spray will
probably be necessary to prevent dropping.

Because of the likelihood of dropping and for other reasons, Grimes
Golden generally is picked somewhat earlier than is desirable for
obtaining the best storage and dessert qualities.

Storage of Grimes Golden at 36° F. rather than at 32° has been
recommended because of its greater susceptibility at 32° to scald (9)
and to soggy break-down (17). However, it has a relatively short
commercial storage period, deteriorating in dessert quality rather
rapidly during storage; this deterioration is more rapid at 36° than
at 32° (9). If the fruit is not picked until 145 days from bloom it
should be possible to control storage scald with oiled paper. Thus,
storage at 82° to retard loss in flavor would be preferable to storage
at 86° in districts where soggy break-down is not a factor.

JONATHAN

Jonathan usually requires about 135 to 140 days from full bloom to
early picking maturity (4, 8, 74, 19),§ but under some conditions
acceptable maturity may be reached in 130 days. Thus in the southern
section and the Pacific Northwest it becomes a fall variety; in the
short-season sections, such as Michigan and southern New England.
it is excellent for winter storage, being fairly well adapted to holding
even in air-cooled storage.

Jonathan, particularly as grown under long-season conditions, is a
variety which must be picked in just the right condition if good
marketability combined with good storage quality is to be obtained.
It is desirable to leave the fruit on the tree long enough for it to
develop a high degree of red and the characteristic spicy, aromatic
flavor. After this condition is attained there is frequently a relatively
short period before the fruit becomes overmature, and it may develop
Jonathan spot and water core while still on the tree. Even when
these conditions do not occur overmature fruit is hkely to become
overripe rather quickly in storage and to develop Jonathan spot,
break-down, or both during storage, particularly if moving into cold
storage is delayed. Under certain growing conditions Jonathan is also
subject to soft scald during storage. The severity of the soft scald
varies with the condition of the fruit at harvest, but its relation to
maturity has not been entirely consistent. In general, it appears to
be more severe on early to intermediate maturities.

Although the elapsed time from bloom to maturity has varied con-
siderably under different conditions, it is probably the most reliable
index of maturity. Jonathan generally requires at least 135 days
from bloom to earliest maturity and in some sections possibly 140 days.
Optimum maturity generally occurs between 140 and 145 days from
bloom. Under some conditions, however, the fruit may be overmature
before a period of 150 days has elapsed. The minimum period that
should elapse from bloom to picking is 1385 days. Picking may be
delayed for further development of the red color provided the fruit
is still firm and free from water core. The development of water core
or the softening of the fruit to 15 pounds’ pressure or less would indi-
cate that the fruit should be picked promptly.

5 See footnote 2, p. 2.

16

McIntTosH

McIntosh appears to be almost immune to storage scald; conse-
quently it is not essential to leave the fruit on the tree until late in order
to obtain good storage quality. As high color commands a premium,
the variety should be left on the tree long enough to attain this color.
McIntosh is not susceptible to water core. It has, however, a notice-
able tendency to loosen and drop from the tree frequently even before
prime picking maturity has been reached. This tendency can be over-
come partially by applying harvest sprays for the prevention of
dropping.

Data (4, 14, 19)® relative to the period elapsing from date of bloom
to maturity of McIntosh are rather consistent. They indicate that the
minimum period is about 130 days from bloom, with optimum maturity
generally between 135 and 140 days from bloom. Within these limits
picking may be determined by the development of red color and the
firmness of the fruit. If the fruit is poorly colored, picking may be
delayed provided the fruit is holding on the tree satisfactorily and the
firmness does not drop below 15 to 14 pounds’ pressure.

NorTHERN Spy

Northern Spy, like the McIntosh, is not susceptible to storage scald,
and in the northern districts where it is generally grown it does not
usually develop water core. It is, however, susceptible to bitter pit
and early picking should be avoided. Fruit of this variety usually
holds to the tree well and so may be allowed to remain rather late in
order to get the best color development.

In the districts where there are cool growing seasons, to which the
Northern Spy is best adapted, the fruit may be handled in common
storage with very good results. If fruit is to be held in common
storage ane should be delayed as late as possible, since the fruit
softens [ess and is less subject to bitter pit while on the tree than in
storage at prevailing temperatures. Color and the marketability of
the fruit are also improved by late picking. For cold storage the
variety may be picked whenever the color is satisfactory.

If Northern Spy is picked while very soft, it is essential that it be
handled carefully in order to avoid bruising. If the fruit is suff-
ciently mature to show a pressure test under 16 pounds, it is often
very severely bruised. Limited results indicate that this variety
requires 145 to 150 days from bloom to maturity.

RHopE IsLAND GREENING

Rhode Island Greening scalds badly in storage, and the commercial
cold-storage life of the variety is largely limited by this trouble.

As the variety is green and there is no incentive for leaving it on the
tree in order to obtain color, it is generally picked relatively early in
the districts where it is grown. Undoubtedly this variety is often
picked in a somewhat more immature condition than is most suitable
for storage, particularly considering its extreme susceptibility to
storage scald when picked at an immature stage. It is now generally

» See footnote 2, p. 2.

17

picked at a pressure test of 22 to 20 pounds. It appears likely that if
left on the tree until testing 20 to 18 pounds the fruit would show much
less tendency to scald in storage and it could still be held in cold storage
until well into the spring before it becomes overripe. The variety
softens rapidly at high temperatures and should be removed promptly
to cold storage if a long storage season is desired. Limited tests in-
dicate that Rhode Island Greening requires 135 to 145 days from bloom
to maturity.

Rome BEAUTY

Rome Beauty has a pronounced tendency to scald in storage, partic-
ularly if picked in a somewhat immature condition and when grown
under the conditions of a moderately long growing season, to which
this variety appears to be best adapted. The fruit tends to develop
water core if left on the tree too long. Generally it holds on the tree
fairly well, so that little dropping is probable until after the fruit has
passed prime condition. Large size is extremely desirable in this vari-
ety, since the fruit is used extensively for baking. Late picking re-
sults in larger fruit that is less subject to scald than early picked fruit.

At least 150 to 155 days (4, 76)?° should elapse from bloom before
picking of this variety is started. Optimum maturity generally is
reached between 155 and 165 days from bloom. —

If best storage is desired the fruit should be picked when the ground
color agrees with No. 2 to No. 3 of the color chart and the pressure test
is not lower than 17 pounds. If the fruit is softer than this at the time
of picking, it will ripen and become mealy relatively early.

This variety should be watched for the development of water core
and should be picked before it becomes serious. A small amount of
water core will apparently disappear while the fruit is in storage, and
no serious results will follow; but if water core is severe it will result
in an early break-down of the fruit.

Rome Beauty has a marked tendency to become mealy in storage
and should be handled promptly and placed in cold storage quickly
after picking 1f long holding is desired.

STAYMAN WINESAP

Stayman Winesap scalds badly if picked in a somewhat immature
condition. High color is very desirable in this variety. From the
standpoint of both scald resistance and appearance of the fruit, there-
fore, relatively late picking is desirable. There is a tendency for water
core to develop, however, if the variety remains on the tree too long
and storage break-down is common in very mature fruit. In some
seasons dropping may also be serious.

Generally this variety requires at least 155 days from bloom to ear-
hest maturity and 160 to 170 days for optimum maturity (4).% For
the best storage results it should not be left on the tree until the pres-
sure test is below 15 pounds. Fruit testing between 18 and 15 pounds
has been found very satisfactory for storage. In general it may be said
that this variety can stay on the tree until the pressure test reaches 15

1911 See footnote 2, p. 2.

18

pounds or slightly less, without serious injury to the storage quality.
If appreciable water core begins to develop the fruit should be picked.

Delayed picking is desirable to obtain high color, good size, and
good dessert quality. The number of days from bloom is probably the
most reliable index of time to start picking. The development of
water core often indicates the approach of overmaturity.

Stayman Winesap ripens relatively rapidly after being removed
from the tree; if long keeping is desired, therefore, the variety should
be placed under refrigeration immediately, particularly if picking has
been delayed until the fruit has become rather soft. °

W AGENER

The Wagener variety is extremely susceptible to water core while on
the tree and to scald while in storage. In general, in order to insure
high color and the greatest resistance to storage scald, the fruit should
be left on the tree until it begins to drop or until water core begins to
develop.

This variety is well adapted to a short period in air-cooled storage
in the shorter season districts. If intended for common-storage hold-
ing, fruit should remain on the tree as long as possible or until water
core development becomes serious. If intended for cold-storage hold-
ing, the fruit should be picked late or oiled paper should be used in
storing it. If placed in cold storage after being packed in oiled paper,
fruit showing a pressure test of 18 pounds or slightly above will ap-
parently give very satisfactory results.

Palmer (76) pointed out that Wagener fruit requires a long grow-
ing season of 170 days from bloom to develop good dessert quality and
resistance to scald and that it should not be grown in regions having
short growing seasons. In the United States, however, the variety is
most extensively planted in Michigan, and in that State it cannot be
left on the trees as long as 170 days because freezing may occur about
160 days from bloom.

WILLIAMS

The Williams variety blooms rather unevenly and also matures its
fruit unevenly ; usually several pickings, based on color and size of the
fruit, are made. The apples generally mature in about 70 days from
bloom (8). This brings them to maturity in midsummer, and they
ripen very rapidly at summer temperatures. If stored at all, ordinar-
ily they are held for only short periods. The fruit must be cooled
promptly after harvest if it is to be held in storage. This variety
drops badly when mature unless harvest sprays are used. Such sprays
are extremely effective in preventing dropping of Williams. If these
sprays are used, care must be taken not to allow the fruit to become
overmature on the trees or it will break down badly while on the
market.

WINESAP

When picked early, Winesap has a rather pronounced tendency to
scald late in the storage season. Moreover, it is of great advantage to
leave the apples on the tree sufficiently long to acquire maximum size
and the characteristic high color of the variety. Winesap apples

19

generally tend to be smaller than is desired in the domestic markets;
it is important, therefore, that the season of growth be extended as
long as possible.

Winesap has a long growing season, usually requiring about 155 to
160 days from full bloom to reach early maturity, and picking (14)”
should be completed not later than 175 days after blooming. It is
one of the very best varieties for long holding, since it softens rela-
tively slowly in storage. If placed in cold storage at once after pick-
ing and held at a temperature of 31° to 32° F., Winesap will remain
in a crisp, firm condition until early summer. In general, the pressure
test will be 20 pounds or above when the fruit is in best picking
condition.

Prior to reaching a good maturity for picking, the fruit tends to
adhere tightly to the spurs, but under some conditions fruit of this
variety has a tenglency suddenly to loosen and drop badly just when
it has reached the most desirable harvesting maturity. Commercial
expediency, therefore, demands the use of a harvest spray; and con-
sequently ease of separation cannot be used as an index of the time to
pick the fruit. Although it is desirable to leave Winesap fruit on the
tree as long as possible so that it will improve in size, color, and re-
sistance to storage scald, it is well to keep in mind that the Winesap
is rather subject to water core as it advances in maturity, especially in
seasons of warm days. There is relatively little lkelihood of the
fruit becoming too ripe on the tree for good quality, provided it is
picked before severe water core develops.

For long holding, the fruit should be placed in cold storage at an
early date after picking. Winesap, in common with other late-keep-
ing varieties, ripens less while on the tree than in common storage at
prevailing fall temperatures. If common storage is to be used, there-
fore, the later picking is delayed, within limits of weather and water
core development, the better the storage response of the fruit.

The variety is subject to soft scald; this disease frequently has been
associated with the practice of transferring the fruit to cold storage
at 81° to 32° F. after several weeks in common storage at higher tem-
peratures. When cold storage has been delayed Winesap should be
held in a storage temperature of 36°.

YELLOw NEwTOwn

The Yellow Newtown (Albemarle Pippin, Newtown Pippin) variety
is grown principally in the Pacific Coast States and in Virginia. It
is a firm, slow-ripening variety suitable for long storage, similar in
these respects to Winesap. In the Pacific coast section it has a long
growing season of 160 to 175 days although picking frequently
starts 155 days from bloom. In Virginia it has become the custom
to start commercial picking relatively early, frequently less than 145
days from bloom. This variety does not scald badly when packed
with oil paper unless picked extremely early, and as it is not necessary
to leave the fruit on the tree for color development there is less
reason for late picking than with some other varieties. However,
late picking is very desirable from the standpoint of increased size
of fruit and better flavor. As grown on the Pacific coast, Yellow

12 See footnote 2, p. 2.

20

Newtown apples adhere well to the tree until relatively late, but under
Virginia conditions they may start dropping prematurely in some
seasons. There is a tendency also toward red spotting of the skin
with a consequent lowering of grade when the fruit is allowed to
remain on the tree until very late.

Ground color changes in the Yellow Newtown are not sufficiently
marked to serve as an index of picking maturity, as the fruit when
picked usually is still green, corresponding to No. 1 of the color
chart. With a light crop the ground color starts turning yellow
earlier than with a heavy crop. Fruit from hght-crop trees appar-
ently matures earlier and should be picked before the greener fruit
on heavy-crop trees. As previously noted, fruits of other varieties
react in a similar way to crop size.

Probably the most satisfactory index of the time to pick Yellow
Newtown is the elapsed time from full bloom. Picking should not -
start until at least 150 days from bloom (8). By this time the apples
will ripen with just passable dessert quality and will not be likely
to develop storage scald when packed with oiled paper. Much better
dessert quality and larger size will be obtained by delaying picking
until 160 to 170 days from bloom, as reported for the Pacific North-
west (J6).12 However, under Virginia conditions the dropping or
fruit spotting, and under Oregon conditions fall rains and perennial
canker infections, may make such late picking unfeasible.

Like the other long-keeping varieties, Yellow Newtown intended for
common storage should be picked late. The fruit softens less rapidly
on the tree than while being held at prevailing outdoor temperatures.
Consequently, delaying the picking of this variety as long as possible
within weather limitations will improve its keeping quality if the
fruit is handled in common storage.

YELLOW TRANSPARENT

The Yellow Transparent apple is a very acid fruit that is generally
picked in a rather immature condition and used primarily for sauce.
Generally it is picked ahead of Williams; such picking would make
its harvest period about 65 to 70 days from bloom.

York IMPERIAL

York Imperial is similar to Arkansas in that its possible storage
life is determined almost entirely by the development of storage
scald; hence it should be picked at the latest possible date. The fruit
softens slowly in both cold and air-cooled storage. In cold storage
particularly, the fruit usually shows storage scald while still firm,
and even in air-cooled storage the possible holding period usually is
emu by scald development rather than by the ripeness of the

rult.

Picking of this variety should not begin earlier than approximately
155 days from bloom. Fruit picked after this time and packed with
oiled paper should not scald excessively during the normal storage
season.

#3 See footnote 2, p. 2.

21

In general, it may be stated that the later York Imperial fruit is
picked the better its storage quality will be. Unfortunately, this
variety tends to drop very badly during certain seasons, so that pick-
ing is often necessary before the fruit reaches the best storage condi-
tion. Harvest sprays are helpful in preventing dropping but gen-
erally have been less successful with York Imperial than with earlier
ripening, longer stemmed varieties, in which the apples do not crowd
each other off from the spurs by pressure of their own growth. If
the fruit is holding on the tree, it should be left until the ground color
attains a shade corresponding to No. 2 to No. 3 of the color chart.
When the fruit reaches this condition the pressure test usually will
be about 20 to 18 pounds. The fruit often begins to drop so badly,
however, that picking is necessary before it reaches this condition.
Fruit to be placed in common storage should be held on the tree as
long as possible before picking. York Imperial is a very satisfactory
variety for holding in air-cooled storage, since it will remain firm for
a considerable period even if held at moderately high temperatures.

PICKING TIME IN RELATION TO HANDLING

It should be noted that when the different varieties remain on the
trees until late or until the flesh is soft they become very sensitive to
mechanical injury. Stayman Winesap, Delicious, and Jonathan test-
ing 16 pounds or less are not only easily bruised but are also extremely
susceptible to stem puncture and other mechanical injuries. This 1s
true also of Northern Spy and McIntosh when in condition for pick-
ing. When harvesting is delayed for any reason, particularly with
these tender-fleshed varieties, unusual care in handling is essential.
The details of handling apples are discussed by Fisher (6).

When picked at an early stage of maturity apples of many varieties
are rather susceptible to injuries from washing, especially where
the washing solutions are heated. With advancing maturity, changes
in the wax of the skin give the fruit added protection and permit the
use of washing solutions of higher temperatures or stronger concen-
trations. Where heavy spray residues necessitate severe washing
treatments, it is advantageous to permit apples to reach optimum ma-
turity on the tree to avoid the hazards of washing injuries. On the
other hand, if they are left on the trees until they have a heavy cover-
ing of wax, residue removal will be difficult and some type of wax
solvent may have to be incorporated in the washing process to remove
the residue effectively.

bo
bo

LITERATURE CITED

(1) Barser, L. P.

1943. HARVEST SPRAYS FOR THE CONTROL OF FRUIT DROP. U. S. Dept. Agr.

Cir. 685, 16 pp., illus.

(2) Brooks, C., and FIsHER, D. F.

1926. WATER CORE OF APPLES. Jour. Agr. Res. 32: 223-260, illus.

(3) CALDWELL, J. S.

1928. CHEMICAL COMPOSITION OF APPLE JUICES AS AFFECTED BY CLIMATIC

CONDITIONS. Jour. Agr. Res. 36: 289-865, illus.

(4) ELLENWwoop, C. W.

(5)

1941. BLOOM PERIOD AND YIELD OF APPLES. Ohio Agr. Expt. Sta. Bul. 618,

21 pp., illus.

1941. FRUIT CHARACTERISTICS OF RED STRAINS OF APPLES. Ohio Agr. Expt.

Sta. Bimo. Bul. 26: 120-127.

(6) FISHER, D. F.

1942. HANDLING APPLES FROM TREE TO TABLE. U.S. Dept. Agr. Cir. 659,

39 pp., illus.

(7) HAtter, M. H.

(8)

(9)

(10)

1941. FRUIT PRESSURE TESTERS AND THEIR PRACTICAL APPLICATIONS. U. S.

Dept. Agr. Cir. 627, 22 pp., illus.

1942. DAYS FROM BLOOM AS AN INDEX OF MATURITY FOR APPLES. Amer. Soc.

Hort. Sci. Proc. 40: 141-145.

——— and Lutz, J. M.
1941. A COMPARATIVE STUDY OF STORAGE AT 32° AND 36° F. OF APPLES GROWN

IN THE POTOMAC RIVER VALLEY. U. S. Dept. Agr. Tech. Bul. 776,
42 pp., illus.
and Maengsss, J. R.

19383. RELATION OF LEAF AREA AND POSITION TO QUALITY OF FRUIT AND TO

BUD DIFFERENTIATION IN APPLES. U. 8. Dept. Agr. Tech. Bul. 338,
36 pp., illus.

(11) HeEsskg, C. O., and Hirz, C. W.

1939. MATURITY STUDIES WITH JONATHAN AND GRIMES GOLDEN APPLES.

Amer. Soc. Hort. Sei. Proc. 36 (1938) : 351-857, illus.

(12) MaAensss, J. R., and DIrnt, H. C.

(13)

(14)

(15)

1924. PHYSIOLOGICAL STUDIES ON APPLES IN STORAGE. Jour. Agr. Res.

27: 1-88, illus.

—— DIEHL, H.C., and HAtrer, M. H.
1926. PICKING MATURITY OF APPLES IN RELATION TO STORAGE. U. S. Dept.

Agr. Dept. Bul. 1448, 20 pp., illus.
DIEHL, H. C., HALLER, M. H., and others.

1926. THE RIPENING, STORAGE, AND HANDLING OF APPLES. U.S. Dept. Agr.

Dept. Bul. 1406, 64 pp., illus.
and TAYLOR, G. F.

1925. AN IMPROVED TYPE OF PRESSURE TESTER FOR THE DETERMINATION OF

FRUIT MATURITY. U.S. Dept. Agr. Dept. Cir. 350, 8 pp., illus.

(16) Parmer, R. C.

1928. APPLE HARVESTING INVESTIGATIONS. Canada Expt. Farms, Summer-

land (B. C.) Sta. Rpt. Supt. (1927 Western) : 4-30, illus.

(17) Puacer, H. H., and Maney, T. J.

(18)

1928. SOGGY BREAKDOWN OF APPLES AND ITS CONTROL BY STORAGE TEMPERA-

TURE. Iowa Agr. Expt. Sta. Res. Bul. 115, pp. [61]-118, illus.
and Maney, T. J.

1937. FACTORS INFLUENCING THE DEVELOPMENT OF SOGGY BREAKDOWN IN

APPLES. Jour. Agr. Res. 55: (39-768, illus.

(9) Rukaye EB:

1942. TIME INTERVAL BETWEEN FULL BLOOM AND FRUIT MATURITY FOR SEVERAL

VARIETIES OF APPLES, PEARS, PEACHES, AND CHERRIES. Amer. Soc.
Hort. Sei. Proc. 40: 133-140.

U. S. GOVERNMENT PRINTING OFFICE: 1944

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