Irrigation-Depressing Effect on Floral Initiation of Cabernet Sauvignon Grapevines in Bordeaux Area

Abstract

An irrigation experiment is described in combination with a training-systems trial, conducted on Cabernet Sauvignon grapevines in the Bordeaux area from 1975 to 1977. The physiological development of vegetative parts was normal, but was increased along with two kinds of strong depressing effects on floral initiation: 1) a general depression, probably due to a decline in capture of solar energy at the renewal-area level: and 2) a specific depression, mostly on primary buds, which could be inhibited during the floral-initiation period by too great a water flow in the tissues. The influence of the level and rhythm of water provision is discussed. Some implications for field practices are indicated, particularly in regard to wine quality.