Vine Pruning In California





The systems of pruning in use in California may be divided into two

classes according to the arrangement of the arms on the trunk of the

vine. In the commonest systems, there is a definite head to the trunk,

from which all the arms arise symmetrically at nearly the same level.

The vines of these systems may be called "headed vines." In the other

systems, the trunk is elongated four to eight feet and the arms are

distributed regularly along the whole or the greater portion of its

length. The vines of these systems, owing to the rope-like form of the

trunks, are called "cordons."



The headed vines are divided according to the length of the vertical

trunk into high, 2-3 feet, medium, 1-1-1/2 feet, and low, 0-6 inches.

The cordons may be vertical or horizontal, according to the direction

of the trunk, which is from four to eight feet long. The horizontal

cordons may be single (unilateral) or composed of two branches

extending in opposite directions (bilateral). Double and even multiple

vertical cordons occur, but they are very inadvisable and have no

advantages.



The arrangement of the arms of a headed vine may be symmetrical in all

directions at an angle of about 45 degrees. Such a vine is said to be

"vase-formed," though the hollow center which this term implies is not

essential. This is the form used in the great majority of our

vineyards whether of wine, raisin, or shipping grapes. It is suitable

for the "square" system of planting and cross cultivation. Where vines

are planted in the avenue system, particularly when trellised and

where cross cultivation is impossible, the arms are given a

"fan-shaped" arrangement in a vertical plane. This arrangement is

considered to be essential for the economical and easy working of

trellised vines.



On the vertical or upright cordon, the arms are arranged at as regular

intervals as possible on all sides of the trunk from the top to within

twelve or fifteen inches of the bottom. On the horizontal cordon the

arms are arranged similarly, but as nearly as possible on the upper

side of the trunk only.



Each of these systems may again be divided into two subsystems,

according to the management of the annual growth or canes. In one,

spurs of one, two, or three eyes are left for fruit production. This

system is called short or spur pruning. In the other, long canes are

left for fruit production. This is called long or cane pruning. In

rare cases an intermediate form is adopted in which long spurs or

short canes of five or six eyes are left. In cane pruning, each fruit

cane is accompanied by one or two short renewal spurs. These must also

accompany half-long pruning. Systems of pruning, when only long canes

are left without renewal-spurs, are not in use in California. In all

systems, replacing-spurs are left wherever and whenever needed.



Other modifications are introduced by the manner of disposal of the

fruit canes. These may be tied up vertically to a stake driven at the

foot of each vine or bowed in a circle and tied to this same stake, or

they may be tied laterally to wires stretching along the rows in a

horizontal, ascending or descending direction.



The different systems differ therefore in: (1) the shape, length, and

direction of the trunk; (2) the arrangement of the arms; (3) the use

of fruit spurs or fruit canes with renewal spurs; (4) the disposal of

the fruit canes.



The principal possibilities of the pruning are shown in the following

table:





A. HEAD PRUNING: VASE-FORM



} { (a) Fruit spurs or

} {

1. High trunk: } { (b) Half-long canes and renewal

} { spurs or

2. Medium trunk: } with {

} { (c) Fruit canes and renewal

3. Low trunk: } { spurs; canes vertical

} { or bowed.





B. HEAD PRUNING: FAN-SHAPED; TRELLISED



1. High trunk: Fruit canes and renewal spurs; canes descending.



2. Medium trunk: Fruit canes and renewal spurs; canes horizontal or

ascending.





C. CORDON PRUNING



1. Vertical: Spur; half-long; cane.



2. Horizontal-unilateral: Spur; half-long; cane.



3. Horizontal-bilateral: Spur; half-long; cane.



All possible combinations indicated by this table represent 24

variations. Some of these combinations, however, are not used and some

are rare. The most common are shown in Figs. 23, 24, 25, 26 and 27.



Figure 23 B represents a headed, vase-formed vine, with a medium trunk

and short fruit spurs. This is the most common system used in all

parts of California and is suited for all small growing vines which

bear on the lower buds, for most wine grapes and for Muscats. The unit

of pruning in this case is a fruit spur of 1, 2, or 3 internodes,

according to the vigor of the variety and of the individual cane.



Figure 23 A differs from 23 B only in the higher trunk and longer

arms. It is commonly used for Tokay and other large growing

varieties, especially when growing in rich soil and when planted far

apart.




high trunk; B, spur pruning with medium trunk; C, half-long with

medium trunk.]



Figure 23 C has the same form of body as A and B, except that the arms

are somewhat less numerous. The unit of pruning is a short fruit cane

of four to five internodes, accompanied by a renewal spur of one

internode. It is suited for vigorous table grapes, which do not bear

well on short spurs. It is used especially for the Cornichon and

Malaga in rich soil. This is a difficult system to keep in good shape

owing to the tendency for all the vigor to go to the growth on the

ends of the fruit canes. It is difficult to obtain vigorous canes on

the renewal spurs. Occasional short pruning is usually necessary to

keep the vines in proper shape.



Figure 24 A is similar to 23 C in form, but the number of arms is

still further reduced to 2, 3, or at most 4. The unit of pruning is a

fruit cane of 2-1/2 to 3-1/2 feet with its renewal spur. Owing to the

length of the fruit canes they require support and are tied to a high

stake.



This method is used in a large number of vineyards with Sultanina,

Sultana and certain wine grapes, especially Semillon and Cabernet. It

is not to be recommended in any case, as it has several very serious

defects.



The difficulty of obtaining new wood from the renewal spurs is even

greater than in the system shown in Fig. 23 C. The length and vertical

position of the fruit canes cause the main growth and vigor of the

vine to be expended on the highest shoots. The renewal spurs are thus

so shaded that, even though their buds start, the shoots make but a

weak growth. The result is that at the following pruning all the good

new wood is at the top of the fruit canes of the previous year, where

it cannot be utilized. The pruner has to choose then between reverting

to spur pruning and getting no crop or using the weak growth from the

renewal spurs for fruit canes, in which case he may get blossoms but

little or no fruit of any value.




canes and renewal spurs; B, bowed fruit canes and renewal spurs.]



Other defects of this method are that the fruiting shoots are

excessively vigorous and therefore often tend to drop their blossoms

without setting and the fruit when produced is massed together so that

it ripens unevenly and is difficult to gather. It also requires a tall

and expensive stake.



Figure 24 B represents an improvement on the last system. It differs

only in the method of treating the fruit canes. These are bent over

in the form of a circle and tied by their middle part to a stake which

may be smaller and lower than that needed for the vertical canes.



This bowing of the canes has several useful effects. The change of

direction moderates the tendency of the vigor of the vine to expend

itself only on the terminal shoots. More shoots therefore are formed

on the fruit canes and as their vigor is somewhat decreased they tend

to be more fruitful. The slight mechanical injury caused by the

bending operates in the same direction.




tied to horizontal trellis.]



The excess of vigor thus being diverted from the fruit canes causes

the renewal spurs to form vigorous shoots, which soon grow above the

fruit shoots and obtain the light and air they need for their proper

development. This method is used successfully for certain wine grapes

such as Riesling, Cabernet, and Semillon. It is unsuited to large

vigorous varieties or for vines on rich soil planted wide apart. In

these cases two fruit canes are usually insufficient and, if more are

used, the grapes and leaves are so massed together that they are

subject to mildew and do not ripen evenly or well. The bowing and

tying of the canes requires considerable skill and care on the part of

the workmen.



The body, arms, and annual pruning of the system shown in Fig. 25 are

similar to those of Fig. 24, with the exception that the arms are

given a fan-shaped arrangement in one plane. It differs in the

disposal of the fruit canes, which are supported by a trellis

stretching along the row from vine to vine.



This method is largely used for the Sultanina (Thompson's Seedless),

and is the best system for vigorous vines which require long pruning,

wherever it is possible to dispense with cross cultivation. It is also

suitable for any long-pruned varieties when growing in very fertile

soil.



Figure 26 is a photograph of a four-year-old Emperor vine,

illustrating the vertical cordon system. It consists of an upright

trunk 4-1/2 feet high with short arms and fruit spurs scattered evenly

and symmetrically from the top to within fifteen inches of the bottom.

This system is used in many Emperor vineyards in the San Joaquin

Valley.






Its advantages are that it allows the large development of the vine

and the large number of spurs which the vigor of the Emperor demands,

without, on the one hand, crowding the fruit by the proximity of the

spurs or, on the other hand, spreading the vine so much that

cultivation is interfered with. It also permits cross cultivation.





One of its defects is that the fruit is subjected to various degrees

of temperature and shading in different parts of the vine and the

ripening and coloring are often uneven. A more vital defect is that it

cannot be maintained permanently. The arms and spurs at the top of

the trunk tend to absorb the energies of the vine and the lower arms

and spurs become weaker each year until finally no growth at all is

obtained below. After several years, most of the vines therefore lose

their character of cordons and become simply headed-vines with

abnormally long trunks.



The cordon can be reestablished in this case by allowing a vigorous

sucker to develop one year from which to form a new trunk the next.

The following year the old trunk is removed entirely. An objection to

this method is that it makes very large wounds in the most vital part

of the vine--the base of the trunk.



Figure 27 is a photograph of a four-year-old Colombar vine,

illustrating the unilateral, horizontal cordon system. It consists of

a trunk about seven feet long, supported horizontally by a wire two

feet from the ground. Arms and spurs are arranged along the whole

horizontal part of the trunk.




spurs.]



This system accomplishes the same objects as the vertical cordon. It

allows a large development of the vine and numerous fruit spurs

without crowding. It is superior to the vertical cordon in the

distribution of the fruit, which is all exposed to approximately the

same conditions owing to the uniform distance from the ground of the

fruit spurs. All parts of the trunk producing an annual growth of wood

and fruit are equally exposed to light and the tendency of the growth

to occur principally at the part of the trunk farthest removed from

the root is counteracted by the horizontal position. There is not the

same difficulty therefore in maintaining this form of vine permanently

that there is with the vertical cordon.



This system should not be used for small weak vines, whether the

weakness is a characteristic of the variety or due to the nature of

the soil. It is suited only to very vigorous varieties such as

Emperor, Almeria, and the Persian grapes when growing far apart in

rich, moist soil.



Periods of development.



The first year in the life of a vine is devoted to developing a

vigorous root system; the next two or three years to building up a

shapely trunk and head, and a like period to forming the full

complement of arms. At the end of from five to nine years the

framework of the vine is complete and should undergo no particular

change of shape except a gradual thickening of trunk and arms.



There are, therefore, several periods in the life of the vine with

varying objects, and the methods of pruning must vary accordingly.

These periods do not correspond exactly to periods of time, so it may

be misleading to speak of pruning a two-year-old or a three-year-old

vine. One vine under certain conditions will reach the same stage of

development in two years that another will reach only in three or four

years under other conditions. The range of time of these periods is

about as follows:



First period--Formation of a strong root system 1 to 2 years

Second period--Formation of stem or trunk 1 year

Third period--Formation of head 2 to 3 years

Fourth period--Complete development of the arms 2 to 3 years

Total time of formation of framework 6 to 9 years



Under exceptionally favorable conditions the first and second periods

may be included in the first year and a completely formed vine may be

obtained in five years.



Before planting.



For planting, cuttings, one-year-old rooted vines, or bench grafts are

used. In all cases, they need some attention from the pruner.



The usual way to prune a good rooted vine of average size having a

single cane at the top and several good roots at the bottom is to

shorten the cane to one or two buds and the roots to two or four

inches, according to their size. Shortening the cane makes the vine

less liable to dry out before rooting and forces the growth from the

lower buds which produce more vigorous shoots. The roots are shortened

so that there will be no danger of the ends being turned upwards when

planted. If they are to be planted in a large hole, they may be left

as long as five or six inches; if to be planted with a crowbar or

dibble, they must be cut back to half an inch.



If the rooted vine has several canes, all but one should be removed

entirely, and this one shortened to one or two eyes. The one left

should be that which is strongest, has the best buds, and is the best

placed. Where a horizontal cane is left, it should be cut back to the

base bud. Otherwise the main growth may occur at a higher bud and the

vine will have a crook which will result in a badly formed trunk.



If canes are growing from different joints, it is usually best to

leave the lower cane if they are equally vigorous. This brings the

buds from which growth will come nearer to the roots, and leaves less

of the original cutting, which are advantages. The upper joint between

the canes is, moreover, often more or less decayed or imperfect.



First growing season.



The treatment during the first spring and summer will depend on what

growth the vines are expected to make and on whether the vines are

staked the first year.



With cuttings and with both rooted vines and grafts where the growth

will be moderate, staking the first year is unnecessary, though it has

some slight advantages. In these cases, no pruning of any kind is

necessary until the winter following the planting, except in the case

of bench grafts. The pruning in the last case is confined to the

removal of the suckers from the stock and roots from the cion. If the

stocks have been well disbudded by the nurseryman, few suckers will

develop. In moist soil, the cion roots may develop vigorously and must

be removed before they grow too large, or they may prevent the proper

development of the resistant roots.



The removal of roots should usually be done some time in July. For

this purpose the hill of soil is scraped away from the union and after

the cion roots and suckers are removed it is replaced. In this second

hilling up, the union should be just barely covered so that the soil

round the union will be dry and unfavorable to a second growth of

roots. Later in the season, about September, the soil should be

removed entirely from around the union and any new roots that may have

formed removed. The union is then left exposed to harden and mature,

so that it will pass the winter without injury.



First winter pruning.



At the end of the first growing season, an average good vine will have

produced from three to five canes, the longest of which will be from

two to three feet long.



Soon after the leaves have fallen in December or early in January the

vines should be pruned. The method is precisely similar to that used

for rooted vines before planting except that the main roots are not

touched. All the canes are removed entirely except one. This one

should be well matured, at least at the base, and should have

well-formed eyes. It is shortened to two eyes. It is well also to cut

off all shallow roots within three or four inches of the surface. This

is necessary in the case of grafted vines if any have escaped the

summer root-cutting.



Some of the vines may have made an exceptionally large growth. Such

vines may sometimes possess a cane large enough from which to start

the trunk in the way described later for the second winter pruning.



Staking.



If the vines have not been staked before, the stakes should be driven

soon after pruning and before the starting of the buds.



In order to preserve the alignment of the vineyard, the stakes should

be driven on the same side of every vine at a uniform distance. The

best distance is about two inches. If driven closer they may injure

large roots or even the main underground stem if the vines have not

been carefully planted vertically or slanting towards the side on

which the stake is to be placed.



The side on which the stake should be placed depends on the direction

of the prevailing winds during the growing season. This side is the

leeward. That is, the stake should be so placed that the wind will

press the vine towards the stake instead of away from it. This will

much facilitate the work of keeping the vine upright and attached to

the stake. If the vine is on the other side the pressure of the wind

will stretch the string tight and the swaying of the vine will

gradually wear the string until it breaks, necessitating retying. By

carefully observing this rule, very few vines will require retying

even if weak material like binding twine is used.



Second summer pruning.



Before the starting of the buds, in the spring following the planting,

most of the vines appear about the same as when they were planted.

There is, however, a very notable difference, in that they have

well-developed root systems in the soil where they were formed. The

result is that they make a much more prompt and early start and will

produce a much larger growth than they did the first season. For this

reason they require very careful attention from the pruner during the

spring and summer of the second season. Vines neglected at this time,

in this respect, may make as large a growth, but a large part of it

will be wasted, the vines will be misformed and it will require from

one to two years longer to develop a suitable framework and to bring

them into bearing, even though they are properly handled during

subsequent years. The more vigorous the vines, the more necessary it

is to handle them properly during this period.



The main object during this second growing season is to develop a

single, strong, vigorous and well-ripened cane from which to form the

permanent trunk of the vine.



This is done by concentrating all the energies of the vine into the

growth of a single shoot. As soon as the buds start, or when the most

precocious has developed a shoot of a few inches in length, the vines

should be disbudded. This consists in rubbing off with the hand all

buds and shoots except the two largest and best placed. The lowest,

upright shoots are usually the best. Leave only those which will make

a straight vine. It is better to leave less developed buds than a

shoot which, when it grows, will make an awkward crook with the

underground stem.



After this disbudding, the two shoots left will grow rapidly, as they

receive all the energies of the root system. When the longest have

grown from ten to fifteen inches, they should be tied to the stake.

Unless this is done, they are liable to be broken off by any heavy

wind, owing to their soft, succulent texture. Only the best placed and

most vigorous of the two shoots should be tied up. If this shoot is

growing upright and near the stake, this can be done without any

danger of injuring it. In this case the second shoot should be

removed. If the shoot has to be bent over in tying it to the stake it

may be injured. In such a case the second shoot should be allowed to

grow until it is known whether the first has been injured. In case of

injury the second shoot can be tied up the next time the vines are

visited and the injured shoot removed.



At the tying up of the reserved shoots, all new shoots which have

developed since the first disbudding should be removed. The shoots

should be tied up loosely, as they are soft and easily injured, and

they should be brought around carefully to the windward side of the

stake.



The shoots will require tying once more when they have grown another

foot or eighteen inches. There will then be two ties, one at two or

three inches from the top of the stake and the other at about the

middle. If the vines have a tall stake and are to be headed very high,

another tying higher up may be needed later.



With vines making only a moderate growth, no other pruning will be

needed until the winter. Exceptionally vigorous vines, however, may

make a cane eight, ten or more feet long. Such a cane is heavy and is

very likely to break the ropes by which it is attached to the stake.

In this case it may break off at the bottom, or at least will form an

awkward crook near the ground when it matures. In either case it is

difficult to form a good trunk the following year. Even when the ties

do not break, the cane will not be well suited for the commencement of

a trunk, as the joints will be so long that it will be impossible to

leave enough well-placed buds at the winter pruning.



Both these difficulties are avoided by timely topping. When such

vigorously growing canes have grown twelve or eighteen inches above

the top of the stake they are cut back about level with the stake.

This is most conveniently done with a long-bladed knife or piece of

split bamboo. After topping, the cane ceases to grow in length and

laterals start at most of the joints. It is less exposed to the

action of the wind, and the laterals supply the buds needed for

forming the vine at the winter pruning.






The result of the second season's growth, then, has been to produce a

single vigorous cane with or without laterals. This is the cane which

is to develop into the final and permanent trunk of the vine. It must

not only be large and vigorous, but must be properly matured. If the

vine is allowed to grow too late in the season, an early frost may

destroy the unmatured cane, and much of the results of the year's

growth will be wasted. Such a frost may indeed kill the entire vine.

Grafted vines are particularly liable to injury from this cause, as if

they are killed down to the union they are completely ruined.

Ungrafted vines when killed to the ground may be renewed from a sucker

next year. This sucker, however, is likely to grow with such vigor

that it is even more liable to injury from an autumn frost than the

original shoot.



This late growth is much more likely to occur with young vines than

with old. The old vines stop growing earlier because their energies

are directed into the crop, and as they produce a larger amount of

foliage they draw more upon the moisture of the soil, which therefore

dries out earlier.



Late growth of the young vines must be prevented and the wood matured

before frost if possible. This is accomplished by means which promote

the drying of the soil in autumn. Late irrigations should be avoided.

Cultivation should usually stop by midsummer. In very moist, rich

soils, it is often an advantage to grow corn, sunflowers or similar

crops between the rows of vines to take off the surplus moisture. In

some cases it is good practice to let the summer weeds grow for the

same purpose.



Second winter pruning.



With vines which have been treated as described and to which no

accident has happened, the second winter pruning is very simple. It

consists simply in cutting back the single cane which has been allowed

to grow to the height at which it is desired to head the vine.



The vine so pruned consists of a single cane which with the older wood

at the base reaches nearly to the top of the stake, or fifteen inches.

This if properly treated will develop into a vine with a trunk of

about twelve inches, though this length can be modified slightly, as

will be explained later.



This cane consists of about seven or eight joints or internodes, with

an equal number of well-formed eyes and an indefinite number of

dormant buds, principally near the base of the cane or junction of the

one- and two-year-old wood. Only the buds on the upper half of this

cane will be allowed to grow. These buds--about four--should give six

to eight bunches of grapes and four, six, or eight shoots from which

to form the spurs at the following winter pruning.



With a vine which has been cut back to form a high head, the cane is

about twenty-four inches long and can be used to form a trunk eighteen

inches high, though this height can be modified as in the last case.

As with the shorter cane, only the buds on the upper half will be

allowed to produce shoots. These--about six--should give ten to twelve

bunches and the shoots necessary for the formation of spurs.



In all cases a full internode has been left above the top bud. This is

done by cutting through the first bud above the highest which it is

desired to have grow. This cut is made in such a way as to destroy the

bud but to leave the diaphragm intact and part of the swelling of the

node. This upper internode is left partly to protect the upper bud,

but principally to facilitate tying. By making a half-hitch around

this internode, the vine is held very firmly. If the swelling at the

node of the destroyed bud is not left, many vines will be pulled out

of the hitch when they become heavy with leaves and supple with the

flow of sap in the spring.



In tying the vines, no turns or hitches must be made around any part

except this upper internode. A hitch below the top bud will result in

a crook-necked vine, as the top will bend over in the summer under the

weight of the foliage. A hitch lower down is even more harmful, as it

will girdle and strangle the vine.



A second tie about half way from the upper to the ground is always

necessary to straighten the cane. Even if the cane is straight when

pruned, a second tie is needed to keep it from curving under the

pressure of leaves and wind in the spring. For high-headed vines three

ties are usually necessary.



For the top tie, wire is particularly suitable. It holds better than

twine and does not wear. Even though it is not removed, it does no

harm, as the part around which it is wound does not grow. The lower

ties should be of softer material, as wire has a tendency to cut into

the wood. They should be placed so that the cane is able to expand as

it grows. With thin and especially with round stakes this means that

the tie must be loose. With large, square stakes there is usually

sufficient room for expansion, even when the twine is tied tight.



Third summer pruning.



During the third season, average well-grown vines will produce their

first considerable crop and develop the canes from which will be

formed the first arms.



Such a vine, soon after the starting of the buds in spring, will have

one vigorous shoot about three inches long grown from the old wood and

five fruit buds started above on the cane. All the buds and shoots

below the middle of the cane should be removed.



This will leave the four or five fruit buds and will give the vine the

opportunity to produce eight or ten bunches of grapes. These buds will

produce also at least four or five shoots. If the vine is very

vigorous and the season favorable, they may produce eight, ten or

more.



When the five shoots grow, the height of the head will be determined

at the next winter pruning by which of the corresponding canes are

left as spurs. If the highest two canes are cut back to spurs and all

others removed, the vine will be headed as high as possible, as these

two spurs form the two first arms which determine the length of the

trunk. If the lowest two canes are chosen and all of the vine above

them removed, the trunk will be made as low as possible. Intermediate

heights can be obtained by using some other two adjacent canes and

removing the rest. It is often advisable to leave some extra spurs

lower than it is desired to head the vine and to remove these lower

spurs the following winter after they have borne a crop. For example,

the three or four upper canes might be left, if the vine is vigorous

enough, and the lowest one or two of these removed at the next

pruning. This, however, is not often necessary with properly handled

vines and is objectionable because it makes large wounds in the trunk.



Third winter pruning.



At the end of the third season's growth the vine should have a

straight, well-developed trunk with a number of vigorous canes near

the top from which to form the arms.



Figure 28 represents a well-grown vine at this period. No shoots have

been allowed to grow on the lower part of the trunk and the five buds

allowed to grow above have produced nine vigorous canes. The pruner

should leave enough spurs to supply all the fruit buds that the vine

can utilize. The number, size and thickness of the canes show that the

vine is very vigorous and can support a large crop. It will depend

somewhat on the variety how many buds should be left. For a variety

whose bunches average one pound, and which produces two bunches to the

shoot, twelve fruit buds should give about twenty-four pounds, or

about seven tons per acre, if the vines are planted 12 by 6 feet, as

these were. The number of spurs will depend on their length. Six spurs

of two buds each will give the required number, but as some of these

canes are exceptionally vigorous they should be left a little longer,

in which case a smaller number of spurs will suffice.






When the number and length of the spurs are decided on, the canes

should be chosen which will leave these spurs in the most suitable

position for forming arms. This position will depend on whether we

want a vase-form or fan-shaped vine. In the first case, we choose

those which will distribute the spurs most evenly and symmetrically on

all sides, avoiding any which cross or point downwards.



In the second case, we choose only those canes which run in the

direction of the trellis, avoiding canes which stick out between the

rows. Downward pointing canes may be used in this case.




head.]



Figure 29 shows the vine after pruning for a vase-formed head. The

pruner has used two of the strongest canes to form two three-bud

spurs and three of medium vigor to form three two-bud spurs. The head

is of good shape, though some of the spurs are a little too low. One,

two, or three of these can be removed at the following winter pruning,

and the permanent arms and head of the vine formed from canes which

develop on the two highest spurs. If the vine were too high, the head

could be developed the next year from the three lowest spurs and the

upper part removed.




vase-formed, and B, for a fan-shaped head.]



Figure 30 shows vines of the same age of practically perfect shape.

Less spurs have been left because the vines were less vigorous. It is

easier to properly shape vines which make only a moderate growth

during the first three seasons. On the other hand, very vigorous vines

can finally be brought into practically perfect shape and the somewhat

larger and more numerous wounds necessary are more easily healed by a

vigorous vine.



Pruning after the third winter.



For the pruner who understands the pruning of young vines and has

brought them to approximately the form represented in Figs. 29 and 30,

the subsequent winter pruning is very simple. It involves, however,

one new idea--the distinction between fruit and sterile wood.



Up to the third winter pruning, this distinction is not necessary;

first, because practically all the wood is fruit wood, and second,

because the necessity of forming the vine controls the choice of wood.

From this time on, however, this distinction must be carefully made.

At each winter pruning a number of spurs of fruit wood must be left to

produce the crop to be expected from the size and vigor of the vine.

Besides these fruit spurs, it may be necessary to leave spurs of

sterile wood to permit of increasing the number of fruit spurs the

following year.



This will be made clear by comparing Figs. 30 A and 31. Figure 30 A

shows a vine at the third winter pruning with two fruit spurs of two

buds each and one fruit spur of one bud--five fruit buds in all.



If these five fruit buds all produce vigorous shoots during the

following summer, they will supply five canes of fruit wood which can

be used to form five fruit spurs at the following winter pruning,

which will be about the normal increase necessary. Some of these fruit

buds, however, may produce weak shoots or shoots so badly placed that

they would spoil the shape of the head if used for spurs. Other

shoots, however, will be produced from base, secondary and

adventitious buds which, while less fruitful, can be used to form

spurs for the starting of new arms.




head.]



Figure 31 shows a vine after the fourth winter pruning which had

developed from a vine similar to that shown in Fig. 30 A. From the

three fruit spurs left the previous year four canes have been chosen

for the fruit spurs of this year. The old spur on the left has

furnished two new spurs and the two old spurs at the right each one

new spur. The pruner, judging that the vine is sufficiently vigorous

to stand more wood, has formed two spurs from water sprouts which,

while not likely to produce much fruit the first season, will supply

fruit wood for the following year. The result is a very well-shaped

vine with six almost perfectly balanced spurs. These spurs will

develop into permanent arms, some of them furnishing finally two or

three.



Figure 32 shows a high-headed vine of the same age. It has five spurs,

of which four are fruit spurs and one a spur of sterile wood left to

shape the vine. The two more or less horizontal spurs on the right

will bear fruit the following autumn and will be removed entirely at

the following winter pruning, as they are badly placed. The arms of

the vine will then be developed from the three upright spurs, which

are excellently placed.




head.]



Each year thereafter the same process must be followed. First, enough

fruit spurs, as well placed as possible, must be left to produce the

crop. Second, on most vines supplementary spurs of sterile wood must

be left to supply more arms where they are needed, and finally, when

the full complement of arms has developed, to supply new arms to

replace those which have become too long or are otherwise defective.



Fan-shaped vines.



With headed vines, the treatment up to the third winter is the same

except for the variations in the height of the head. At the third

winter pruning, however, the formation of the head commences, and the

pruner determines whether it shall be vase-formed or fan-shaped. The

production of a vase-formed head has already been described.



At the third winter pruning, the vine should be pruned to two spurs,

as shown in Fig. 30 B. More vigorous vines should not be given more

spurs, as in Figs. 29 and 30 A, but the spurs should be made longer,

with four, five, or even six eyes in some cases. This is in order to

obtain some fruit, which might not be obtained from long pruning

varieties by leaving many spurs. With extremely vigorous vines one

fruit cane may be left at this pruning. The wires of the trellis

should be put up this year, if this has not already been done.



Fig. 33 A and 33 B illustrates the second step in the production of a

fan-shaped head. This form of head is used only for trellised vines

and long-pruned varieties. The formation of the head and the

management of the fruit canes are therefore conveniently discussed

together.






By comparing the pruned vine, Fig. 33 B, with the unpruned, Fig. 33 A,

the method of pruning will be made clear. The unpruned vine shows two

arms, the spurs of the previous year, from one of which have grown

three vigorous canes and from the other two somewhat less vigorous.

The pruned vine shows a complete unit, that is, a fruit cane with its

accompanying renewal spur on the vigorous side and a spur for the

production of fruit wood for the following year on the other side. If

the vine had been more vigorous two complete units would have been

left and one or two extra spurs.



As the form of the vine is determined by the renewal spurs, special

attention should be paid to their position. In this case, the middle

cane on one arm and the lower cane on the other have been used for

renewal spurs. This brings them both to the same height above the

ground and determines the place of the permanent arms. The next year

each of these spurs will furnish a fruit cane and one or two renewal

spurs. The arms will thus in two or three years be increased to four,

or, with very large vines, to six. These spurs should be chosen as

nearly as possible in the plane of the trellis, that is, they should

not project out sideways. Figure 25 shows vines of this kind of full

size and in full bearing.



The fruit canes also should be as nearly as possible in the direction

of the trellis, though this is not so important, as they can be bent

over to the wire when tied up, and in any case they are removed the

next year.



Double-headed vines.



Some growers attempt to arrange the arms of their vines in two stages,

one above the other, forming double-headed or two-crowned vines. The

method is applied to both vase-formed and trellised vines. It is open

to the same criticisms as the vertical cordon, the chief of which is

that it cannot be maintained permanently. The lower head or ring of

arms finally becomes weak and fails to produce wood.



It is easier to maintain in trellised vineyards and has some

advantages, the chief of which is that it makes it easier to keep the

vine in the single plane and to prevent arms getting into the

inter-rows. The double trunk is not necessary and is, in fact, a

disadvantage, as one trunk has a tendency to grow at the expense of

the other.



Vertical and bowed canes.



Figure 24 A shows a long-pruned vine in which the fruit canes have

been tied vertically to a tall stake. This is a method used commonly

in many vineyards. The unit of pruning is the same as in the method

just described, consisting of a fruit cane and a renewal spur. The

framework of the vine consists of a trunk of medium height, with a

vase-formed head consisting of three or four arms. The defects of this

system have been pointed out on page 155.



It is used with fair success with seedless Sultanas and with some wine

grapes such as Colombar, Semillon, Cabernet, and Riesling, in the

hands of skillful pruners. The results with Sultanina are very

unsatisfactory.



By this method, on most of the vines, the fruit canes start from high

up near the middle of the stake, and are therefore too short for the

best results. The canes which start from low down are in most cases

suckers, and therefore of little value for fruit bearing.



Figure 24 B shows a vine with bowed canes. The method of pruning is

exactly the same as in the method just described. The bowing of the

canes, however, overcomes some of the defects of that method. It is

used regularly in many wine grape vineyards of the cooler regions. It

is unsuited for very vigorous vines in rich soil.



Vertical cordons.



In head pruning, the treatment of young vines up to the second or

third winter pruning is identical for all systems. In cordon pruning

the treatment for the first and second is also the same. That is, the

vine is cut back to two buds near the level of the ground until a cane

sufficiently long to serve for the formation of the trunk is obtained.



In the vertical cordon the trunk is three to four feet long instead of

one to two, as in head pruning. This makes it necessary to have a

longer and more vigorous cane to start with. It may require a year

longer to obtain this. That is to say, at the end of the second

season's growth many vines will not have a single cane sufficiently

developed to give the necessary three and one-half feet of

well-ripened wood and properly developed buds. At the second winter

pruning, therefore, it will often be necessary to cut the vine back to

two buds, as at the first winter pruning.






Finally, a cane of the required length will be obtained. The vine is

then formed as already described for the second winter pruning of

headed vines, except that the cane is left longer. When such a vine is

pruned, spurs are left at intervals along the trunk, as shown in Fig.

34. Each of these spurs is a fruit spur and is also the commencement

of an arm. The future treatment of these arms is the same as that of

the arms in head pruning.



Horizontal cordons.



During the first two or three years, vines which are to be given the

form of horizontal cordons are treated exactly as for vertical

cordons, that is, they are pruned back to two buds each winter and the

growth forced by disbudding into a single cane during the summer.



As soon as a well-ripened cane of the required length is obtained, it

is tied to a wire stretched horizontally along the row at from fifteen

to twenty-four inches from the ground.



For this system of pruning, the rows should be twelve to fourteen feet

apart and the vines six, seven, or eight feet apart in the rows. As

the cordon or trunk of each vine should reach the next vine, it will

have to be six to eight feet long. The best shape is obtained when the

trunk is all formed one year from a single cane. It is necessary,

however, sometimes to take two years for the formation of the trunk.

In any case, the cane first tied down should reach at least half way

to the next vine. The following year a new cane from the end of this

should be used to complete the full length of the trunk.



In attaching the cane to the wire, it must be bent over in a gentle

curve and care taken not to break or injure it. The proper form of the

bend is shown in Figs. 27 and 35. Sharp bends should be avoided.




pruning.]



The cane should be placed on top of the wire, but should not be

twisted around it. The end should be tied firmly and the rest of the

cane supported by strings tied loosely in order to avoid girdling when

the cane grows.



In the following spring, most of the buds on a good cane will start.

If the cane is short jointed, some of the shoots should be removed and

only those shoots allowed to develop which are conveniently situated

for permanent arms. If the vines are to be short pruned, the arms

should be developed every eight to twelve inches from a few inches

beyond the bend to the extreme end. For long pruning, the arms should

be farther apart, twelve to twenty inches. Shoots starting from the

top of the cane and growing vertically upwards are to be preferred.



As the shoots develop, the strongest should be pinched repeatedly, if

necessary. This will tend to force the growth of the weaker shoots and

to equalize the vigor of all. At the end of the season, there should

be from five to ten canes growing on each cordon of full length. These

canes are then pruned back to two or three buds, or a little longer

for long-pruned varieties.



During the following spring and summer, the vines should be carefully

suckered and unnecessary water sprouts removed. Any shoots coming from

the lower side of the cordon should be removed early to strengthen the

growth in the shoots on the upper side. Such vines are apt to become

dry or decayed on the upper side. At the end of this year, which

should be the fourth or fifth from planting at the latest, the cordon

will be fully formed and the final style of pruning can be applied. A

short-pruned cordon vine is shown in Fig. 27. The arms and spurs are a

little too numerous and too close together. If this vine required the

number of buds shown it would have been better to have left the fruit

spurs longer and to have left fewer and shorter wood spurs.



The upper vine of Fig. 35 shows a cordon pruned half long. This is an

excellent system for Malaga, Emperor, and Cornichon when growing in

very fertile soil. It gives the half-long fruit canes, which these

varieties need to produce good crops. The fruit canes may be attached

to a wire twelve or fifteen inches above the cordon or bent down and

tied to the cordon itself, as in the lower vine of the figure. The

first method is the more convenient, but the second is necessary where

there is difficulty in obtaining satisfactory growth from the renewal

spurs. When the fruit canes are tied down, as indicated in the lower

vine, renewal spurs may not be needed, as vigorous shoots will

usually be obtained from the lower buds of the fruit canes.



Choice of a system.



In choosing a system, we must consider carefully the characteristics

of the particular variety we are growing. A variety which bears only

on the upper buds must be pruned "long," that is, must be given fruit

canes. It should be noted that many varieties, such as Petite Sirah,

which will bear with short pruning when grafted on resistant roots

require fruit canes when growing on their own roots. In general,

grafted vines require shorter pruning than ungrafted. If pruned the

same, the grafted vines may overbear and quickly exhaust themselves.

This seems to be the principal reason for the frequent failure of

Muscat vines grafted on resistant stock. The cultural conditions also

affect the vine in this respect. Vines made vigorous by rich soil,

abundant moisture, and thorough cultivation require longer pruning

than weaker vines of the same variety.



The normal size of the bunch is also of importance. This size will

vary from one-quarter of a pound to 2 or 3 pounds. It is difficult to

obtain a full crop from a variety whose bunches are very small without

the use of fruit canes. Spurs will not furnish enough fruit buds

without crowding them inconveniently. On the other hand, some shipping

grapes may bear larger crops when pruned long, but the bunches and

berries may be too small for the best quality.



The possibilities of development vary much with different varieties. A

Mission or Flame Tokay may be made to cover a quarter of an acre and

develop a trunk four or five feet in circumference. A Zinfandel vine

under the same conditions would not reach a tenth of this size in the

same time. Vines in a rich valley soil will grow much larger than on a

poor hillside. The size and shape of the trunk must be modified

accordingly and adapted to the available room or number of vines to

the acre.



The shape of the vine must be such as to protect it as much as

possible from various unfavorable conditions. A variety susceptible to

oidium, like the Carignane, must be pruned so that the fruit and

foliage are not unduly massed together. Free exposure to light and air

are a great protection in this respect. The same is true for varieties

like the Muscat, which have a tendency to "coulure" if the blossoms

are too moist or shaded. In frosty locations, a high trunk will be a

protection, as the air is always colder close to the ground.



The qualities required in the crop also influence our choice of a

pruning system. With wine grapes, even, perfect ripening and full

flavor are desirable. These are obtained best by having the grapes at

a uniform height from the ground and as near to it as possible. The

same qualities are desirable in raisin grapes, with the addition of

large size of the berries. With shipping grapes, the size and

perfection of the berries and bunches are the most essential

characteristics. The vine, therefore, should be so formed that each

bunch hangs clear, free from injurious contact with canes or soil and

equally exposed to light and air.



The maximum returns in crop depend on the early bearing of young

vines, the regularity of bearing of mature vines and the longevity of

the vineyard. These are insured by careful attention to all the

details of pruning, but are possible only when the vines are given a

suitable form.



The running expenses of a vineyard depend in a great measure on the

style of pruning adopted. Vines of suitable form are cultivated,

pruned and the crop gathered easily and cheaply. This depends also

both on the form of vine adopted and on care in details.



It is impossible, therefore, to state for any particular variety or

any particular location the best style of pruning to be adopted. All

that can be done is to give the general characteristics of the variety

and to indicate how these may be modified by grafting, soil or

climatic or other conditions.



The most important characteristic of the variety in making a choice of

a pruning system is whether it normally or usually requires short,

half-long, or long pruning. With this idea, the principal grapes grown

in California, together with all those grown at the Experiment Station

on which data exist, have been divided into five groups in the

following list:



1. Varieties which require long pruning under all

conditions.--Clairette blanche, Corinth white and black, Seedless

Sultana, Sultanina white (Thompson's Seedless) and rose.



2. Varieties which usually require long pruning.--Bastardo, Boal de

Madeira, Chardonay, Chauche gris and noir, Colombar, Crabbe's Black

Burgundy, Durif, Gamais, Kleinberger, Luglienga, Marsanne, Marzemino,

Merlot, Meunier, Muscadelle de Bordelais, Nebbiolo, Pagadebito,

Peverella, Pinots, Rieslings, Robin noir, Rulaender, Sauvignon blanc,

Semillon, Serine, Petite Sirah, Slancamenca, Steinschiller, Tinta Cao,

Tinta Madeira, Trousseau, Verdelho, Petit Verdot, Waelcherisling.



3. Varieties which usually require short pruning.--Aleatico,

Aligote, Aspiran, Bakator, Bouschets, Blaue Elbe, Beba, Bonarda,

Barbarossa, Catarattu, Charbono, Chasselas, Freisa, Frontignan,

Furmint, Grand noir, Grosseblaue, Green Hungarian, Malmsey, Mantuo,

Monica, Mission, Moscatello fino, Mourisco branco, Mourisco preto,

Negro amaro, Palomino, Pedro Zumbon, Perruno, Pizzutello di Roma,

Black Prince, West's White Prolific, Quagliano, Rodites, Rozaki, Tinta

Amarella, Vernaccia bianca, Vernaccia Sarda.



4. Varieties which require short pruning under all

conditions.--Aramon, Burger, Chardonay, Chauche gris and noir,

Colombar, Crabbe's Black Burgundy, Durif, Black Morocco, Mourastel,

Muscat of Alexander, Napoleon, Picpoule blanc and noir, Flame Tokay,

Ugni blanc, Verdal, Zinfandel.



5. Varieties of table grapes which usually require half-long or

cordon pruning.--Almeria (Ohanez), Bellino, Bermestia bianca and

violacea, Cipro nero, Dattier de Beirut, Cornichon, Emperor, Black

Ferrara, Malaga, Olivette de Cadenet, Pis-de-Chevre blanc,

Schiradzouli, Zabalkanski.



These lists must not be taken as indicating absolutely for all cases

how these varieties are to be pruned. They simply indicate their

natural tendencies. Certain methods and conditions tend to make vines

more fruitful. Where these occur, shorter pruning than is indicated

may be advisable. On the other hand, other methods and conditions tend

to make the vines vigorous at the expense of fruitfulness. Where these

occur, longer pruning may be advisable.



The more usual factors which tend towards fruitfulness are:



Grafting on resistant vines, especially on certain varieties such as

those of Riparia and Berlandieri;



Old age of the vines;



Mechanical or other injuries to any part of the vine;



Large development of the trunk, as in the cordon systems.



The more usual factors which tend towards vigor at the expense of

fruitfulness are:



Rich soil, especially large amounts of humus and nitrogen;



Youth of the vines;



Excessive irrigation or rainfall (within limits).



In deciding what system of pruning to adopt, all these factors,

together with the nature of the vine and the uses to which the fruit

is to be put, must be considered. It is best when the vineyard is

started to err on the side of short pruning. While this may diminish

slightly the first one or two crops, the vines will gain in vigor and

the loss will be made up in subsequent crops. If the style of pruning

adopted results in excessive vigor of the vines, it should be

gradually changed in the direction of longer pruning with the object

of utilizing this vigor in the production of crop.



This change should be gradual, or the risk is run of injuring the

vitality of the vines by one or two excessively heavy crops.

Finally, each year the condition of the individual vine should

determine the kind of pruning to be adopted. If the vine appears weak,

from whatever cause, it should be pruned shorter or given less spurs

or fruit canes than the year before. On the contrary, if it appears

unnecessarily vigorous, more or longer spurs or fruit canes should be

left. Every vine should be judged by itself. It is not possible to

give more than general directions for the pruning of the whole

vineyard. It cannot be well pruned unless the men who do the actual

pruning are capable of using sufficient judgment to properly modify

their methods for each individual vine.





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