Apple Growing

M >> M. C. Burritt >> Apple Growing

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Pruning a tree is a way of thinning the fruit and a good one. It may
sometimes be used to influence the bearing year of trees like the
Baldwin, which have an alternate bearing habit, but this is a more
theoretical than practical method. Fruit bearing is determined more by
the habitual performance of the tree than by any method of pruning,
and this is especially true of old trees. It is easier to influence
young trees. Conditions which tend to produce heavy wood growth are
unfavorable for the formation and development of fruit buds. A
quiescent state is a better condition for this.

REASONS FOR PRUNING.--With these fundamental principles in mind we may
safely outline a method of pruning an apple tree. As the desired end
is different so will the method of pruning a young tree differ from
that of an old one. There are five important things for which to prune
a young tree, namely:

1. To preserve a proper balance between the top and root at the time
of setting out. This usually means cutting off the broken and the very
long roots to a reasonable length and cutting back from one-half to
two-thirds of the growth of the previous season.

2. To make the top open in order to admit the sunlight freely. In the
humid climate of the Northeastern States, it is usually advisable to
prune a tree so as to have a rather open top. This is necessary in
order properly to color and mature the fruit.

3. To regulate the number of limbs composing the top. Probably three
branches well distributed on the trunk would make most nearly the
ideal head, but as these cannot always be obtained the best practice
is to leave from three to five branches from which to form the top.

4. To fix the branches at the proper height from the ground. This is
more or less a matter of opinion, some growers preferring a low and
others a high head. The character of the tree growth, the method of
culture, and the purpose of the tree whether temporary or permanent
greatly influence the height of the head. An upright growing variety
should be headed lower than a spreading one. Trees kept in sod or
under extensive methods can well be headed lower than those under more
intensive culture where it is desirable to carry on cultural
operations close around them. Permanent trees should be headed higher
than temporary trees. Apple trees should seldom be headed lower than a
foot from the ground, nor more than four feet above it. For upright
growing varieties intended as permanents, the writer prefers three to
three and one-half feet and for more spreading varieties four feet;
while for temporary trees eighteen inches should be a good height.

5. To do away with weak crotches and to remove crossing or interfering
branches. A crotch formed by two branches of equal size, especially
when the split is deep, is a weak crotch and should be avoided. Strong
crotches are formed by forcing the development of lateral buds and
making almost a right angle branch from the parent one. All branches
which rub each other, which tend to occupy the same space with
another, or which generally seem out of place, are better removed as
soon as any of these tendencies are found to exist.

IDEALS IN PRUNING.--The general method of pruning the old trees and
the ideal in mind for it will also influence the pruning of the young
tree, especially the shaping of it. Once determined upon, the ideal
should be consistently followed out in the pruning of the tree as it
becomes older. As the tree comes to bearing age it will be necessary
to prune somewhat differently and for other purposes. These we can
conveniently consider under six heads:

1. Every tree should be pruned with a definite ideal as to size,
shape, and degree of openness in mind. To have such an ideal is very
important. It is only by industriously and consistently carrying it
out that the ideal tree in these respects can be ever obtained.
Haphazard cutting and sawing without a definite purpose in mind are
really worse than no pruning at all.

2. It almost goes without saying that to remove all dead, diseased, or
injured wood is a prime purpose of pruning. Dead and injured branches
open the way for rot and decay of contiguous branches, and disease
spreads through the tree. The removal of all such branches is as
essential to the health of the tree as it is to its good appearance.
In removing them the cut should be made well behind the diseased or
injured part to insure the checking of rot and disease.

3. All mature apple trees should be so pruned as to keep them in the
most easily manageable shape and to facilitate in every possible way
the operations of tillage, spraying, and harvesting. It is most
important to have the tree low enough down so that spraying and
picking can be easily done. It is difficult to spray properly a tree
which is more than twenty-five feet in height. Even this height
necessitates a tower on the spray rig and the use of an extension
pole. An apple tree should be so pruned that all the fruit can be
readily picked from ladders not longer than eighteen to twenty-two
feet.

Of course, if the tree has been allowed to get higher than this under
previous management, sometimes we have to make the best of a bad
situation. If the trees are too high head them back by cutting off the
leaders, but it is not always wise to lower all trees to twenty-two
feet. Heading back of old trees will be more fully discussed in the
chapter on "Renovating Old Orchards." Ladders longer than twenty-two
feet are heavy and clumsy to handle.

If cultivation is to be carried on close up under the tree the lower
limbs must be pruned so as to allow this. It is not necessary,
however, to drive a team closer than twelve or fifteen feet from a
mature tree, contrary to the common belief and practice. Cultivation
is least important in the first few feet of space around a mature
tree. By the use of set-over tools, all that is necessary can be well
cultivated without crowding the team under or against the branches.

4. As has been pointed out in the discussion of the pruning of young
trees, in humid regions where the sunlight is none too abundant
through the growing season, the open head is most desirable. Sunlight
on the leaves as well as on the fruit is essential to good color of
the fruit, and good color is a very important factor in the flavor and
attractive appearance of the fruit. An open center with upright
growing leaders removed gives the greatest opportunity for sunlight to
penetrate through the tree.

5. As we have seen, pruning in the dormant season tends to increase
the vigor of the tree. Thus winter pruning serves to secure a normal
and vigorous wood growth, which is most essential to a healthy
fruit-bearing tree. On the other hand, such pruning may be excessive
and produce wood growth at the expense of fruit buds, throwing the
tree out of bearing.

6. The sixth and last reason for pruning is to regulate the number and
distribution of the wood and the fruit bearing buds. The proper
balance between these is greatly affected by pruning and can be best
regulated by experience with the particular tree or variety. A perfect
balance is hard to get, but with study and skill it can be closely
approximated. Pruning, too, may thin the fruit, as removing branches
removes fruit buds. This is best done by removing small branches near
the ends of larger ones. It is a much cheaper method of thinning than
picking off individual fruits, but not as effective.

TIME OF PRUNING.--The particular time of the year for pruning is not
vital. As between summer and winter pruning, winter is to be preferred
because of the physical effect on the tree. Summer pruning is an
unnatural process and should only be practiced as a last resort to
check growth or induce fruitfulness, as it may result in injury to the
tree. It is essential that a tree mature its foliage, which it
frequently does not do after summer pruning. Diseased, dead, or
injured wood should be removed when first observed, summer or winter.

Spring is the logical and usually the most convenient time to prune on
the general farm. While dormant season pruning may be done at any
time between November 1st and June 1st, the cuts heal more rapidly in
the spring when the sap begins to flow. In regions subject to severe
and drying winds in the winter, pruning should be deferred at least to
late winter. Considered from every standpoint, March and April are
quite the best months in which to prune. After the removal of useless
branches, the normal amount of food material is delivered to fewer
buds under greater sap pressure and the remaining buds are made more
strong and vigorous.

In removing small branches with a knife or other cutting tool, the cut
should be made upward from below and opposite a bud. On upright
growing varieties the last bud left should be an outside one to induce
the tree to spread as much as possible, while on spreading trees
leaving as the last bud an inside one has a tendency to make the tree
grow more upright. Always cut close to the parent branch, never
leaving a stub no matter how young or old the tree.

Cuts of lateral branches should be made just at the shoulder of the
branch where it joins the parent. A cut behind the shoulder will not
heal, neither will one too far ahead of it. A stub left on a trunk or
large branch does not heal, but soon begins to rot at the end where
the heartwood is exposed. This gradually works back into the main
branch and the tree finally becomes "rotten at the heart." All that is
needed to complete the destruction is a heavy wind, an ice or a snow
storm, or a heavy load of fruit.

All wounds more than two inches in diameter should be painted either
with a heavy lead paint, which is preferable, or with some gas tar
preparation. These things do not in themselves heal a cut, but they
keep out the decaying elements, air and moisture, thus helping to
preserve the branch and by protecting it to promote healing in
nature's way. A little lamp black will serve to deaden the color of
the paint.

PRUNING TOOLS.--The best tool to use in pruning is one which brings
you nearest to your work and over which you have the greatest control
to make all kinds of cuts. In the writer's experience no tool does
this so smoothly and conveniently as a properly shaped saw. A good saw
should be quite rigid, rather heavy at the butt, where its depth
should be about six inches, tapering down to about two inches at the
point. It should have a full, firm grip, be not more than thirty
inches long, and should always be kept sharp. Two-edged saws should
not be used because of the injury done to the tree when sawing in
crotches.

Cutting shears are often very useful, especially the smaller,
one-handed type which is almost indispensable in pruning young trees.
The larger, two-handled shears are useful in thinning out the ends of
branches or in heading back new growth. They should not be too heavy,
as they are tiresome to use. The extension handled types are too
cumbersome, too slow to work with, and the operator is of necessity
too far away from his work for the best results.

FRUIT THINNING.--A matter which is quite nearly related to pruning is
thinning the fruit, and may properly be treated here. That this is not
as common a practice with most fruit-growers as it should be, the
great lack of uniformity in our ordinary market apples is ample
evidence. Many persons will at once raise the question as to whether
or not it is practicable to thin the fruit on large apple trees. The
answer is that many growers find it not only practicable, but most
profitable to do so. Wherever fruit of a uniform size and color is
desired, thinning is a practical necessity, especially when the crop
of fruit is heavy.

The proper time to thin the fruit is just after what is commonly known
as the "June drop," i.e., the falling off of those fruits not well
enough pollinated or set to hold on to maturity. In thinning the fruit
should be taken off until they are not closer than from four to six
inches apart on the same branch, although the distance apart on any
branch will depend somewhat on the amount of the crop on other parts
of the tree. Never leave clusters of fruit on any branches, as some of
them are sure to be small and out of shape. Furthermore two apples
lying together afford a fine place for worms to get from one apple to
another and they seldom fail to improve the opportunity. Step ladders
and ordinary rung ladders are used to get at the fruit for thinning.
The cost of the operation is not nearly as large as might appear at
first thought and in practically all cases is a paying investment.

CHAPTER V

CULTIVATION AND COVER CROPPING

In its broad sense cultivation is the treatment of the soil. Thus
understood orchard cultivation includes the sod mulch system as well
as the stirring of the soil with various implements. In its more
common and restricted meaning, however, cultivation is the stirring of
the soil about plants to encourage growth and productivity. To have
the apple tree in sod was once the commonly accepted method of orchard
treatment--a method of neglect and of "letting well enough alone."
With the advent of more scientific apple culture the stirring of the
soil has come to be the more popular method. But within the last few
years an improved modification of the old sod method, known as the sod
"mulch" system, has attracted much attention because of the success
with which a few men have practiced it. For a correct understanding of
these practices and of the relative desirability of these systems we
must again turn to underlying principles and purposes.

It may be said on first thought that tillage is a practice contrary to
nature. But it accomplishes what nature does in another way. Tillage
has been practiced on other crops than trees for so long that we think
of it almost as a custom. There are, however, scientific and practical
reasons for tillage.

THE EFFECTS OF TILLAGE on the soil are three fold, physical, chemical,
and increasing of water holding capacity. Tillage affects the soil
physically by fining and deepening it, thus increasing the feeding
area of roots, and by bringing about the more free admission of air
warms and dries the soil, thus reducing extremes of temperature and
moisture. Chemical activities are augmented by tillage in setting free
plant food, promoting nutrification, hastening the decomposition of
organic matter, and the extending of these agencies to greater depth.
Tillage conserves moisture by increasing the water holding capacity of
the soil and by checking evaporation.

Of all these things which tillage accomplishes in a soil, two should
be especially emphasized for the apple orchard, namely, soil moisture
and soil texture. That moisture is a very important consideration in
the apple orchard the effects of our frequent droughts are ample
evidence. The amount of rainfall in the Eastern States when it is
properly distributed is fully sufficient for the needs of an apple
tree. By enlarging the reservoir or water holding capacity of the soil
and by preventing the loss of water by evaporation, an excess of
rainfall in the spring may be held for later distribution and use.

As a rule, the improvement of a poor soil texture is as effective as
the supplying of plant food and much cheaper. The latter is of no
consequence unless the plant can use it. Scientists tell us that there
is an abundance of plant food in most soils. The problem is to make it
available. Plant food must be in solution and in the form of a film
moisture surrounding the smallest soil particles in order to be
available to the fine plant rootlets which seek it. Good tillage
supplies these conditions. Can they be obtained equally well in
another way?

It is claimed by the advocates of the sod mulch system of orchard
culture that it also supplies these conditions. Humus or decayed
vegetable matter holds moisture. Grass or other mulch decaying in the
soil increases its humus content and hence its water holding capacity.
By forming a mulch over the soil evaporation may be checked to some
extent, although probably not as effectively in a practical way, as by
cultivation. If there is a good grass sod in the orchard, moisture and
plant food made available by that moisture are utilized, and if the
grass is allowed to go back into the soil it continues to furnish
these elements to the tree. But there is a rapid evaporation of
moisture from the surface of the leaves of grass. In fact, grass may
well serve to remove an excess of moisture in wet seasons, or from wet
lands.

Laying aside theoretical considerations, let us see what practical
experience teaches on this subject. We have the accurate data on a
large number of western New York orchards showing the results of
cultivation and other methods of soil management. These data are
overwhelmingly in the favor of cultivation. In Wayne County the
average yield of orchards tilled for five years or more was 271
bushels per acre, as compared with 200 bushels per acre for those in
sod five years or more but otherwise well cared for,--an increase of
thirty-five per cent. in favor of good tillage. In Orleans County,
under the same conditions, the increase in yield due to cultivation
was forty-five per cent. and in Niagara County it was twenty-two per
cent. Records were made on hundreds of orchards and the results should
be given great weight in determining the system to be practiced, as
intelligent consideration of trustworthy records is to be encouraged.

These results were obtained in one region under its conditions and it
is quite possible, although not probable, that other conditions might
give different results. There are, however, special conditions as will
be pointed out later, under which the sod mulch method might be more
advisable than tillage. It is cheaper, makes a cleaner cover for the
drop fruit, avoids the damage from tillage implements to which tilled
trees are liable, and can be practiced on lands too steep to till. It
often happens, too, that it fits into the scheme of management on a
general farm better than the more intensive and specialized system of
cultivation. And it must be remembered that we are dealing with this
question from the point of view of the home farm rather than of the
commercial orchardist. So that where the sod mulch gives equally good
results it would be preferred under these conditions.

LATE FALL AND EARLY SPRING PLOWING.--The common tillage practice in
the sections where it is most followed is to plow either in late fall
or as early as possible in the spring. Whether fall or spring plowing
is best depends on two things: the character of the soil and
convenience. On heavy clay soils where drainage is poor it is not
advisable to plow in the fall as the soil is apt to puddle and then to
bake when it dries, making it hard to handle. On gravel loams, medium
loams, and all well drained soils which are fairly open in texture
either fall or spring plowing is practiced depending on which period
affords the most time.

On the general farm where there are several crops for which the land
must be prepared in spring, it would seem best to get as much of the
plowing as possible done in the fall. But a large crop of apples or a
large and late corn husking or potato digging may interfere with this
on some farms and make spring plowing more desirable. Always plan this
work in connection with the other farm work so as to give the best
distribution of labor.

After fall plowing either the spring-tooth harrow or the disk harrow
is best to use to work up the soil and no time should be lost in
getting at this as soon as the land is dry enough in the spring.
Sometimes the disk harrow can be used to work up the soil in the
orchard in the spring without any plowing at all, especially on loose
loams where there are few stones. But on newly plowed land a disk cuts
too deep and there is too great danger of injuring the roots. On
spring plowed land the spring-tooth harrow usually gives the best
results. After the soil is thoroughly fined and worked into a mellow
bed and as soon as the period of excessive moisture in spring is
passed, a lighter implement like the smoothing harrow or a light
shallow digging cultivator should be used to stir the surface of the
soil only.

The growing period for an apple tree begins as early as growth starts
in the spring and continues up to about midsummer. If cultivation is
to stimulate growth as much as possible, it should be done during this
period. The first object of cultivation in the early spring is to
loosen up, aerate, and dry out the soil, which is usually too wet at
that time. As cultivation is continued the soil will become fined and
firmed again by the time drier weather comes on. A fairly deep
digging and lump crushing tool is the best implement to use up to this
time, and a disk or spring-tooth harrow meets these requirements.

After this period is passed and during drier weather, cultivation is
carried on for a different purpose, namely, to conserve moisture by
making a thin dust mulch of soil over the surface. This is best
accomplished by shallow-going implements of which the spike-tooth
harrow, the acme harrow, or a light wheel cultivator are best. As the
season and the amount of rainfall vary, so must tillage operations be
varied. In an early dry season begin with the lighter implements
earlier. In a late wet season keep the digging tools at work later. As
soon as the soil is in good physical condition the principal object of
tillage is to modify moisture conditions.

As a matter of practice three to four harrowings at intervals of a
week to ten days are necessary. Sometimes more, sometimes less are
required, according to the character and condition of the soil and the
season. The later moisture-conserving tillage should also be carried
on every week or ten days, according to weather conditions. It is good
practice to stir the soil after every heavy or moderately heavy rain.
Use the smoothing tools after light to medium rains and the heavier
tools after packing or beating rains. In practice from five to eight
or ten of these cultivations are necessary. The drier the season the
more necessary does frequent cultivation become.

A COVER CROP is so closely associated with tillage that it is usually
considered a part of the system. It should be sown in midsummer as soon
as tillage ceases. This time will vary from July first to August
fifteenth, depending on the locality, the rainfall, the crop of fruit
on the trees, and on how favorable the conditions for securing a good
stand of the cover crop are. The farther south the locality, or the
earlier the fruit, the sooner the crop should be sown. Absence of
sufficient rainfall necessitates a continuation of the cultivation,
both because it is necessary to conserve all the moisture possible and
because it is difficult to get a good stand of a cover crop--especially
of one having small seeds--at a dry time in midsummer.

In a year when there is a full crop of fruit on the trees cultivation
should be continued as late as possible as all the stimulus that can
thus be secured will be necessary to help the fruit attain good size
and maturity, and at the same time enable the tree properly to mature
its fruit and leaf buds for the following year. On the other hand, in
a year when there is not a full crop of fruit cultivation should be
stopped early so as to avoid forcing a too rank growth of wood and
foliage and continuing the growth of the next season's buds so late
that they may not mature and therefore may be in danger of winter
killing.

The different kinds of cover crops which may be used in the apple
orchard will be considered in the next chapter as they are so closely
associated with fertilization. Strictly speaking, however, a cover
crop is used principally to secure its mulching and physical effects
on the soil in the intervals between the seasons of tillage. In
addition to its physical and feeding effects the cover crop serves to
check the growth of trees in the latter part of the season by taking
up the nitrates and a part of the moisture, thus helping to ripen the
wood.

SOD MULCH.--The ordinary sod culture which is practiced in so many
orchards should not be confused with the sod mulch system. The one is
a system of neglect, the other of intention. In the sod mulch system
the grass sod is stimulated and encouraged and when the grass dies or
is cut, it is left on the ground to decay, forming a soil mulch
meanwhile. The removal of grass from the orchard as hay is poor
practice and should be discouraged. The grass mulch may well be
supplemented by the addition of other grass, straw, leaves, coarse
manure, or other similar materials. Sometimes this mulch is put on to
the depth of six inches or even a foot around the tree. Thus practiced
it is very effective in conserving moisture and in adding the humus
which is so necessary to the soil.

Sod and tillage have somewhat different effects on the tree and on the
fruit. Let us see what these effects are. It is common knowledge that
fruit is more highly colored when grown in sod than when grown under a
tillage system. This is probably largely due to the fact that tillage
keeps the fruit growing so late that it does not mature so well or so
early. Fruit is usually two or three weeks later in tilled than in sod
orchards. It has been shown that fruit grown under tillage keeps from
two to four weeks longer than that grown in sod. It is claimed
also--but this is a disputed point--that tilled fruit has a better
quality and flavor. Certain it is that fruit grown in sod is drier
and less crisp and juicy.

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