Initial Response of Baco Noir Grapevines to Pruning Severity, Sucker Removal, and Weed Control

Abstract

Excessive vegetative vigor of Baco noir (Vitis spp.) grapevines results in late season growth and winter injury. Various levels of weed control, pruning severity, and suckering were applied to 6-year-old vines and their effects on vine size, vine growth and nutrition, cold resistance, grape maturity, wine quality, and productivity were measured. Decreased pruning severity and sucker removal both reduced vine size while increasing yield per vine. Weed cover reduced vine size and was related to a very large yield reduction. Otherwise, weed control and sucker removal acted similarly and generally opposite to decreased pruning severity in their effects of increasing vine nitrogen, fruitfulness (yield/node retained), the number of clusters/node retained, wine extract, pH, color, and panel preference, and causing later fall acclimation. These initial data suggest that Baco noir grapevines should be pruned less severely than is now commercially practiced, that weed control should be practiced, and all suckers should be removed except those retained for trunk renewal.