Effect of Level of Crop on Vine Behavior and Wine Composition in Carignane and Grenache grapes

Abstract

Carignane and Grenache vines were each adjusted by pruning and thinning to two crop levels referred to as normal-crop and high-crop vines. The effect of 3 years of overcropping on the vines, fruit, must, and wine made from the fruit was followed.

Both varieties proved to be quite resistant to overcropping in these experiments. The main symptoms of overcropping were a delay in maturation of fruit, and premature drying up of foliage in autumn in case of Carignane. The leval of total carbohydrates (sugars and starch) was moderately depressed in canes and roots of Carignane. Pruning brush weights were usually less in over-cropped vines, but 3 years of overcropping failed to markedly weaken the vines.

The final wine rating was just as high in over-cropped Carignane vines as in normal-crop fruit, and the difference was only slightly in favor of the normal crop in Grenache. Analyses of winery data indicated that fruit from low-crop vines would produce wines with better keeping quality and ones with a better potential for aging.