PRUNING.

_Winter Pruning, or Pruning Hard Wood._--The pruning of vines comprises

two different processes. The first one has for its object the shaping of

the vines, the second one similarly the shortening of the branches

properly so as to enable them to bear better fruit. These two points

must always be kept in view, much more so of course during the first few

years, before the vines have reached their bearing age. But even in

after years the pruning must be so conducted, that the shape of the vine

is not changed so as to interfere with the work in the field, or with

the perfect development of the grapes. As regards the shape of the vine,

it has been decided that in our raisin districts the Muscat requires to

be pruned low, in order to properly protect the grapes from sun and

wind. The head should be as low as possible, or even rest on the ground,

and in no instance be more than a few inches above the same. Many of the

bunches will then rest on the ground or hang a few inches above it, and

experience shows us that such low bunches are the best and those which

produce the finest raisins. Tall Muscat vines never produce as sweet and

as large bunches or grapes as those headed low, and their grapes are apt

to sunburn or be otherwise checked in their growth. During the first

year, the young vine should be cut back to a single stem, it being

enough to leave two or three eyes above the ground. The second season

these canes should all be cut away except three, which are to form the

future head of the vine. Each one of these may be cut to two eyes, thus

leaving six eyes on the vine. In the majority of vines, the head should

by this time have been formed, as the following year will be the first

year in which the vines will bear.

When Muscat vines have grown two seasons, they should be pruned for

fruit. The third season will always give some fruit, while, in many

localities where the vines have been well cared for, the yield may be

quite large and pay handsomely. No direction as to pruning, which will

apply to every locality or to every vine, is possible. In different

localities the climatic and other conditions are so variable that the

methods of pruning may be modified. Where the vines grow strong and

vigorous more wood should be left. In cool and sheltered places the

vines should be given a greater spread to allow more sun and air to

enter. In warm localities, with a broiling sun, the principal object in

pruning should be to properly shelter the grapes. There is danger, or at

least there are great disadvantages in pruning either too long or too

short, and in leaving too many or too few spurs. In pruning too long, or

leaving too many eyes, the shape of the vine is changed or even

seriously injured. In leaving too many spurs, the vines may bear too

many and too small grapes. To find the medium between these extremes is

always the great object and study to which the grower should devote his

attention. In rich and moist soils which produce strong vines, more eyes

should be left, and in sandy, poor soil a few eyes may suffice to cause

the vine to bear much more that it can properly mature and perfect. The

year before the vines bear their first good crop, the spurs left should

not exceed three or four, and each spur should not have more than two

eyes, including the eye nearest the old wood, which eye is often

overlooked and not counted in. The next year a few more spurs may be

left, but at no time should each spur be allowed to carry more than two

eyes. If more eyes are left, the lower eyes will not develop, and the

only thing attained by such pruning is to increase the size of the head,

and to place the leaves and the grapes farther away from the center of

the vine.

At the age of six years, or when the vine is in full bearing, no more

spurs should be added, as the vine has then attained a mature age, and

the yield will increase independently of an increased number of spurs.

How many spurs should be left it is not possible to say. The experience

with most growers is generally that too few spurs are left, and that

from ten to fifteen spurs are not too many on large and healthy vines.

The tendency of the growers is now to leave more spurs than formerly,

and to always restrict the spurs to two eyes each. This experience has

been acquired simultaneously in Fresno, San Bernardino and San Diego

counties. Many growers affirm the fact that the difficulty is to get

spurs enough, and my own experience is that, after the vine has once

attained its age of full bearing, all the strongest branches are

required to furnish spurs, and that only the weak and sickly shoots

should be cut away entirely. The strong flow of sap in the spring

requires many outlets, so as not to unnecessarily push the cell walls

and cause disorders, and in case the soil is not strong enough to

sustain and perfect so many grapes, it is better to manure it heavily

and make it rich enough for all purposes. I believe an average of from

eight to ten spurs are required by strong and bearing vines. Only strong

canes should be left at any time. Weak and immature canes should be cut

off close to the trunk or to the head.

[Illustration: Muscatel Vine Eight Years Old, after Winter Pruning.]

This method of pruning differs materially from that this season adopted

by A. B. Butler. He leaves now only from five to eight spurs on the

vines, generally the lesser number. He maintains that his object is to

produce large and superior grapes, and not to have his vines overbear.

The outcome of such close pruning has not yet been demonstrated, but it

may be possible that this is the proper way. Mr. Butler has certainly

one point in his favor, and that is that it has not yet been

demonstrated that very close pruning causes the disease known as

black-knot, as quite frequently the unpruned vines show this disease

much more than those which are pruned close. Another point in favor of

this pruning is that it has been practiced in Malaga for years without

any ill effects. But, before such very close pruning can be generally

recommended, our experience in this direction should be more extensive,

and several years more will be necessary to come to any satisfactory

conclusion in this respect. We know, however, that too many (say from

twenty to twenty-five) spurs will exhaust the low-headed Muscatel vines,

and in order to bring such vines back to proper bearing it has been

found necessary to reduce the number of spurs at once to one-third and

then gradually increase their number as the vines grow stronger. Every

grower should study his own vines and adapt the number of spurs to the

quality of the crop. If the crop is inferior, reduce the number; if

again the crop is superior, we may try to gradually give a few more

spurs in order to reach the greatest yield of first-class grapes. In

pruning the spurs, the cut should be made a little above the eye or bud,

and not so close to it that it will be injured and dry out.

Suckers from the roots should be removed to a limited extent, that is,

now and then a sucker may be left in order to give material for forming

a new head, if this should be found necessary. But as a rule the many

suckers which rise from the roots should be removed in early spring with

a sharp-pointed stick, and even those which rise from below the regular

head should be broken off while young, or be pruned off in winter time.

Another system of pruning called the Chaintre system has been

introduced, or at least spoken of during the last few years. As,

however, it is not generally used, or even to my knowledge used at all,

for raisin grapes, I need only here allude to it. It consists of pruning

the vine to one single long stem, which is carried along the ground and,

at a distance of six or eight feet from the root, fastened to a stake.

This branch is pruned to shorter branches and spurs, each of the latter

to one or two eyes each to furnish wood and fruit. The advantages of the

Chaintre pruning are claimed to be principally two,--a greater yield of

grapes and a larger outlet for the abundant sap in the spring. It is

supposed that, if the vine is pruned too short, the sudden flow of sap

in the spring has a great tendency to poison some of the cells and

vessels of the wood, and cause the disease known as black-knot. The

Chaintre system endeavors, by furnishing the vine with more cells and

vessels, and thus a larger outlet for the sap, to overcome this

difficulty. The Chaintre system has, however, some great inconveniences.

It interferes considerably with the tillage of the soil. It increases

the cost of the vineyard through the extra stakes necessary to support

the vines,--inconveniences so great that I doubt whether the system will

ever be seriously adopted anywhere on this coast, even if it should

prove of any advantage.

The time for the pruning depends upon the season. The only safe rule is

that vineyards may be pruned as soon as the vines are dormant. If pruned

too soon, a new growth will start, which will be killed by the first

frost. In many seasons the pruning may be done in November and December;

in large vineyards it must be begun early, so as to finish before the

plowing commences. Early pruning will cause the vines to start early in

the spring, while late pruning will considerably delay the starting of

the buds. When the spring frosts are to be feared, the pruning may be

deferred for some months, or until the end of January, as it delays the

budding out of the vine in the spring, sometimes as much as fourteen

days. But, on the other hand, the first warm spring weather is so

favorable to the development of the grapevines and the setting of the

fruit, that every advantage should be taken of the same. The very best

crops are generally had on early pruned vines.

_Bleeding of the Vines._--The bleeding of the vines after pruning in the

spring is by many considered injurious. So far as I know, no direct

experiments to prove this have been made in this country, but European

experiments with wine grapevines point to no ill effects from the

bleeding of the vines. The bleeding retards the budding out, and this

fact has led some growers to the practice of pruning twice. In the first

pruning an extra eye is left on every spur, and these eyes are again

clipped off shortly before the eyes begin to swell in the spring. The

bleeding of the vines thus causes the eyes to be retarded until the

frost is over. I believe such practice is both unnecessary and too

costly, and is not required in any of our raisin districts, and where

such practice must be employed the raisin grape cannot be perfectly at

home. Of late years spring frosts have become very rare in our principal

raisin districts, and the practice of double pruning is no longer

thought of.

_Summer Pruning, or Pruning Green Wood._--Summer pruning is a much

disputed vineyard operation, which, however, at least in some

localities, is of great importance. This summer, or rather spring,

pruning consists of cutting back the young growing shoots from one-third

to one-half just after the berries have set well. The proper time of the

year is in May, but the exact time must necessarily be different in

different localities and seasons. In Fresno the cutting back should not

be done later than May, and never except when the vines show a vigorous

growth. The principal object the summer pruner has in view is to force

the secondary branches of the vine as much towards the center of the

vine as possible, so as to form there a perfect canopy of shade to serve

as a protection to the young and tender berries. If let alone, the

branches of the vine will throw out these secondary shoots near the top

of the branches, thus leaving the head of the vine unprotected from the

sun. The shortening in of the branches necessarily throws the new shoots

to the center of the vine. A not less important object to be sought by

the summer pruning is the strengthening of the young branch. In May,

when the vines are covered by the young and vigorous shoots, they are

yet exceedingly brittle, and only a slight pushing is required to break

the branch off just at its junction with the old wood. A heavy wind at

this time sometimes does an immense damage, and the vineyard will look

as though every vine had been dragged over. Half of the branches may be

broken and hang partially attached to one side of the vine. A single

wind may ruin two-thirds of the crop. This can only be prevented by the

summer pruning of the vines. By a heavy shortening in of the branches,

the latter expose so much less surface for the wind to act on, that no

branches are broken, and we have failed to see the heaviest wind cause

any noticeable damage in vineyards which had their vines properly

shortened in. The summer pruning in no way injures the vines. The sap is

checked in its flow only for a few days, and within a week the new side

shoots make their appearance. But the vineyardist must be careful not to

summer prune after the hot summer weather has set in, as the hot weather

will burn or scald the young grapes and ruin them entirely. For the San

Joaquin valley raisin districts, I cannot advise summer pruning after

the first days of June; in Southern California, somewhat later.

Grapevines on sandy, dry and poor soil should not be summer pruned, or

only very lightly so. They have not strength to start a new growth and

will remain stunted all through the season.

Many growers of Riverside, El Cajon and Fresno consider summer pruning

beneficial, if not necessary, and practice it every year regularly. It

is necessary to summer prune heavily or not at all. Cut back one-half of

the growth, or cut back leaving one or two leaves above the bunch of

grapes on every cane. If the young canes are only topped, the secondary

branches will come out near the ends of the canes and bear them down, in

time exposing the bunches to the sun as well as causing the second crop

to grow too far from the main trunk, the summer pruning thus acting the

opposite of which it was intended. In Greece the wine grapevines are

summer pruned, but the currants are never so treated.

_Root-pruning._--The pruning of the roots of grapevines, in order to

cause them to bear, is entirely unnecessary, and is never done by

experienced growers. Some growers have practiced the cutting of the

surface roots of the vines so as to cause the tap roots or the main

roots to go farther down, and they claim that by this method greater

crops are harvested. I am satisfied this is only a theory not supported

by facts. Surface roots are as necessary to plants as deep-soil roots,

and serve the plants in their way, bringing atmospheric air to the

circulation in the roots. If too many surface roots are formed, it is a

sure indication of too much water in the top soil, as too frequent

irrigation with a small stream of water will cause such roots to form.

The proper remedy is to irrigate less frequently, but more at a time.

The above does not refer to the pruning of the roots of grafted vines.

In cases where Muscats have been grafted on resistant stocks, it is of

importance that the graft should not make roots of its own, as these

would soon overpower the stock and in their turn succumb to the enemies

which it was the intention to avoid. When rooted vines are planted in

the vineyard, their roots should be well pruned, and all dead and

decaying, as well as dried-up, parts should be removed. If they are

allowed to remain on the vines, they will draw moisture from the sound

parts at a time when all the moisture is needed for the formation of new

roots.

_Suckering._--The object of this process is to relieve the raisin-vine

of superfluous wood before the latter has had time to draw on the

strength of the vine and deprive it of the elements necessary to support

the fruit-bearing branches. The proper time for suckering is early in

the spring, when the young wood is yet tender and easily broken. With a

hard and flat piece of wood, the lower suckers are dug out from below

the ground, while the upper suckers may be broken by hand. A sucker must

be understood to be any branch which does not produce fruit at a time

when the vine is old enough to bear. In strong and moist soil and on

strong vines even the lowest shoots produce grapes, and can therefore

hardly be called suckers. But as a rule even they should be removed,

unless we have a special object in view, such as renewing the trunk of

the vine, lowering its head, or in otherwise encouraging the lower

branches.

While few vineyardists take sufficient care and time to sucker their

vines, there can be no doubt that the operation is of the greatest

importance, in order that as large and good a crop as possible may be

secured. It is not only best to remove all the non-fruit-bearing

branches which spring out from the root and the trunk, but also a little

later on, after the shoots have reached a foot or more, to cut any

branch from the head of the vine which does not produce fruit. In many

instances, however, it is necessary to renew the head of the vine, and

for that purpose lower suckers may be allowed to grow. For a year or two

these are pruned regularly and made to bear, and the old sickly head is

then removed.