Part 16 (1/2)

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.

[Ill.u.s.tration: FIG. 34. Vertical cordon, young vine pruned.]

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.

[Ill.u.s.tration: FIG. 35. Unilateral horizontal cordon with half-long 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 Pet.i.te 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 princ.i.p.al 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 s.h.i.+pping 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 circ.u.mference. 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.