Home Vegetable Gardening - F. F. Rockwell (nice books to read .txt) 📗

CHAPTER XVII

PRUNING, SPRAYING, HARVESTING

 

The day has gone, probably forever, when setting out fruit trees and

giving them occasional cultivation, “plowing up the orchard” once in

several years, would produce fruit. Apples and pears and peaches have

occupied no preferred position against the general invasion of the

realm of horticulture by insect and fungous enemies. The fruits have,

indeed, suffered more than most plants. Nevertheless there is this

encouraging fact: that, though the fruits may have been severely

attacked, the means we now have of fighting fruit-tree enemies, if

thoroughly used, as a rule are more certain of accomplishing their

purpose, and keeping the enemies completely at bay, than are similar

weapons in any other line of horticultural work.

 

With fruit trees, as with vegetables and flowers, the most important

precaution to be taken against insects and disease is to _have them

in a healthy, thriving, growing condition_. It is a part of Nature’s

law of the survival of the fittest that any backward or weakling plant

or tree seems to fall first prey to the ravages of destructive forces.

 

For these reasons the double necessity of maintaining at all times good

fertilization and thorough cultivation will be seen. In addition to

these two factors, careful attention in the matter of pruning is

essential in keeping the trees in a healthy, robust condition. As

explained in a previous chapter, the trees should be started right by

pruning the first season to the open-head or vase shape, which

furnishes the maximum of light and air to all parts of the tree. Three

or four main branches should form the basis of the head, care being

taken not to have them start from directly opposite points on the

trunk, thus forming a crotch and leaving the tree liable to splitting

from winds or excessive crops. If the tree is once started right,

further pruning will give little trouble. Cut out limbs which cross, or

are likely to rub against each other, or that are too close together;

and also any that are broken, decayed, or injured in any way. For trees

thus given proper attention from the start, a short jackknife will be

the only pruning instrument required.

 

The case of the old orchard is more difficult. Cutting out too many of

the old, large limbs at one time is sure to give a severe shock to the

vitality of the tree. A better plan is, first, to cut off close

all suckers and all small new-growth limbs, except a few of the most

promising, which may be left to be developed into large limbs; and then

as these new limbs grow on, gradually to cut out, using a fine-tooth

saw and painting the exposed surfaces, the surplus old wood. Apples

will need more pruning than the other fruits. Pears and cherries need

the least; cutting back the ends of limbs enough to keep the trees in

good form, with the removal of an occasional branch for the purpose of

letting in light and air, is all the pruning they will require. Of

course trees growing on rich ground, and well cultivated, will require

more cutting back than those growing under poorer conditions. A further

purpose of pruning is to effect indirectly a thinning of the fruit, so

that what is grown will be larger and more valuable, and also that the

trees may not become exhausted by a few exceptionally heavy crops. On

trees that have been neglected and growing slowly the bark sometimes

becomes hard and set. In such cases it will prove beneficial to scrape

the bark and give a wash applied with an old broom. Whitewash is good

for this purpose, but soda or lye answers the same purpose and is less

disagreeably conspicuous. Slitting the bark of trunks and the largest

limbs is sometimes resorted to, care being taken to cut through the

bark only; but such practice is objectionable because it leaves ready

access to some forms of fungous disease and to borers.

 

Where extra fine specimens of fruit are desired, thinning is practiced.

It helps also to prevent the tree from being overtaxed by excessive

crops. But where pruning is thoroughly done this trouble is usually

avoided. Peaches and Japan plums are especially benefited by thinning,

as they have a great tendency to overbear. The spread of fruit

diseases, especially rot in the fruit itself, is also to some extent

checked.

 

Of fruit-tree enemies there are some large sorts which may do great

damage in short order—rabbits and field mice. They may be kept away by

mechanical protection, such as wire, or by heaping the earth up to a

height of twelve inches about the tree trunk. Or they may be caught

with poisoned baits, such as boiled grain in which a little Rough on

Rats or similar poison has been mixed. The former method for the small

home garden is little trouble, safer to Fido and Tabby, and the most

reliable in effect.

 

Insects and scale diseases are not so easily managed; and that brings

us to the question of spraying and of sprays.

 

For large orchards the spray must, of course, be applied with powerful

and expensive machinery. For the small fruit garden a much simpler and

very moderate priced apparatus may be acquired. The most practical of

these is the brass-tank compressed-air sprayer, with extension rod and

mist-spray nozzle. Or one of the knapsack sprayers may be used. Either

of these will be of great assistance not only with the fruit trees, but

everywhere in the garden. With care they will last a good many years.

Whatever type you get, be sure to get a brass machine; as cheaper ones,

made of other metal, quickly corrode from contact with the strong

poisons used.

 

APPLE ENEMIES

 

The insects most commonly attacking the apple are the codlin-moth,

tent-caterpillar, canker-worm and borer. The codlin-moth lays its eggs

on the fruit about the time of the falling of the blossoms, and the

larvae when hatched eat into the young fruit and cause the ordinary

wormy apples and pears. Owing to these facts, it is too late to reach

the trouble by spraying after the calyx closes on the growing fruit.

Keep close watch and spray immediately upon the fall of the blossoms,

and repeat the spraying a week or so (not more than two) later. For

spray use Paris green at the rate of 1 lb., or arsenate of lead (paste

or powder, less of the latter: see accompanying directions) at the rate

of 4 lbs. to 100 gallons of water, being careful to have a thorough

mixture. During July, tie strips of burlap or old bags around the

trunks, and every week or so destroy all caterpillars caught in these

traps. The tent-caterpillar may be destroyed while in the egg state, as

these are plainly visible around the smaller twigs in circular,

brownish masses. (See illustration.) Upon hatching, also, the nests are

obtrusively visible and may be wiped out with a swab of old bag, or

burned with a kerosene torch. Be sure to apply this treatment before

the caterpillar begins to leave the nest. The treatment recommended for

codlin-moths is also effective for the tent-caterpillar.

 

The canker-worm is another leaf-feeding enemy, and can be taken care of

by the Paris green or arsenate spray.

 

The railroad-worm, a small white maggot which eats a small path in all

directions through the ripening fruit, cannot be reached by spraying,

as he starts life inside the fruit; but where good clean tillage is

practiced and no fallen fruit is left to lie and decay under the trees,

he is not apt to give much trouble.

 

The borer’s presence is indicated by the dead, withered appearance of

the bark, beneath which he is at work, and also by small amounts of

sawdust where he entered. Dig him out with a sharp pocket-knife, or

kill him inside with a piece of wire.

 

The most troublesome disease of the apple, especially in wet seasons,

is the apple-scab, which disfigures the fruit, both in size and in

appearance, as it causes blotches and distortions. Spray with Bordeaux

mixture, 5-5-50, or 3-3-50 (see formulas below) three times: just

before the blossoms open, just as they fall, and ten days to two weeks

after they fall. The second spraying is considered the most important.

 

The San Jos� scale is of course really an insect, though in appearance

it seems a disease. It is much more injurious than the untrained fruit

grower would suppose, because indirectly so. It is very tiny, being

round in outline, with a raised center, and only the size of a small

pinhead. Where it has once obtained a good hold it multiplies very

rapidly, makes a scaly formation or crust on the branches, and causes

small red-edged spots on the fruit (see illustration). For trees once

infested, spray thoroughly both in fall, after the leaves drop, and

again in spring, before growth begins. Use lime-sulphur wash, or

miscible oil, one part to ten of water, thoroughly mixed.

 

CHERRY ENEMIES

 

Sour cherries are more easily grown than the sweet varieties, and are

less subject to the attacks of fruit enemies. Sweet cherries are

troubled by the curculio, or fruit-worm, which attacks also peaches and

plums. Cherries and plums may be sprayed, when most of the blossoms are

off, with a strong arsenate of lead solution, 5 to 8 lbs. to 100 gals.

water. In addition to this treatment, where the worms have once got a

start, the beetles may be destroyed by spreading a sheet around and

beneath the tree, and every day or so shaking or jarring them off into

it, as described below.

 

PEACH ENEMIES

 

Do not spray peaches. For the curculio, within a few days after the

flowers are off, take a large sheet of some cheap material to use as a

catcher. For large orchards there is a contrivance of this sort,

mounted on a wheelbarrow frame, but for the home orchard a couple of

sheets laid upon the ground, or one with a slit from one side to the

center, will answer. If four short, sharp-pointed stakes are fastened

to the corners, and three or four stout hooks and eyes are placed to

reunite the slit after the sheet is placed about the tree, the work can

be more thoroughly done, especially on uneven ground. After the sheet

is placed, with a stout club or mallet, padded with a heavy sack or

something similar to prevent injury to the bark, give a few sharp

blows, well up from the ground. This work should be done on a cloudy

day, or early in the morning—the colder the better—as the beetles are

then inactive. If a considerable number of beetles are caught the

operation should be repeated every two or three days. Continue until

the beetles disappear.

 

Peaches are troubled also by borers, in this case indicated by masses

of gum, usually about the crown. Dig out or kill with a wire, as in the

case of the apple-borer. Look over the trees for borers every spring,

or better, every spring and fall.

 

Another peach enemy is the “yellows,” indicated by premature ripening

of the fruit and the formation of stunted leaf tufts, of a light yellow

color. This disease is contagious and has frequently worked havoc in

whole sections. Owing to the work of the Agricultural Department and

the various State organizations it is now held in check. The only

remedy is to cut and