Chapter 9

Pruning and Training Grapevines

Grapevine Training Systems

Training determines the form and direction of the trunk and arms and the position of the shoots that develop from the buds retained at pruning. It consists principally in attaching the vine as it grows to various forms of support on the trellis. There are many different types of training systems used throughout the world, but most are classified as either “head-trained” or “cordon-trained.” In the “head-trained” system, a trunk is established and a few to several short main branches are developed that sustain renewal spurs (head-trained, spur-pruned system) and fruiting canes (head-trained, canepruned system). In the “cordon-trained” system, a trunk and two or more permanent horizontal arms, or cordons, are established and spur pruning is typically practiced.

Head-Trained, Spur-Pruned System

Head-trained, spur-pruned is one of the oldest training systems in use. Head-trained vines are free-standing that is, they grow without the support of a trellis (See Figure 9.1). The trunk is kept very short, 12 to 20 inches (30 to 55cm) with a number of permanent arms that are positioned around the main trunk of the vine that bear spurs.

Head-Trained, Cane-Pruned System

The vine has a trunk similar in form to that of the head-trained, spur-pruned system (See Figure 9.2) but the vine differs in being fan-shaped in the plane of the trellis. It provides a more favorable canopy microclimate by permitting more buds to be retained along the horizontal canes away from the head compared to head-trained, spur-pruned vines. Cane pruned systems require the use of a trellis and wires along each row to support the crop.

Cane Establishment

First select two to four new fruiting canes per vine during dormancy. The number of canes to retain depends on the capacity of the vines, which can be determined by observing the growth during the season. If the canes were of normal size than the same number of canes should be left on the vine as the year before with adjustments made accordingly based on the size of the canes. The canes should have good periderm formation and not excessively thick or thin. The length of the internodes is a useful indicator to the type of growth for the variety.

Replacement Spurs

Following selection and cutting back of the canes, choose an additional strong cane arising near the base of each cane and cut it off leaving a spur with usually one to two buds. These are the replacement spurs that are used to reestablish, and thus maintain, the shape and training system of the vine.

Cordon-Pruned, Spur-Pruned System

Cordon pruning is done on a vine trained to a permanent wood framework 2 years or older called cordons attached to a trellis wire (See Figure 9.3). Cordons are simply modified horizontal trunks with spurs that can be decades old and achieve diameters of several inches or more.

Spur Establishment

Once the cordons are established the next step during dormancy is select canes at intervals and cut back to become the first set of spurs. Spurs provide fruiting and shoot renewal functions. Select shoots that grew upward in a well-lighted environment for fruitful spurs. Shoots that grew in the shade the previous summer often do not contain as many fruitful buds.

Spur Establishment

Once the cordons are established the next step during dormancy is select canes at intervals and cut back to become the first set of spurs. Spurs provide fruiting and shoot renewal functions. Select shoots that grew upward in a well-lighted environment for fruitful spurs. Shoots that grew in the shade the previous summer often do not contain as many fruitful buds.

Spur Pruning

To spur prune the vine, completely remove the cane that is the farthest away from the permanent cordon. The cane that is the closest, however, is pruned to 2 to 4 buds, depending on the fruitfulness of basal buds and the desired cropping level, which will grow into next year’s spurs. From these spurs will grow the new fruiting canes.

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