Effects of Timing and Severity of Summer Hedging on Growth, Yield, Fruit Composition, and Canopy Characteristics of de Chaunac. I. Canopy Characteristics and Growth Parameters

¹ Agriculture Canada Research Station, Summerland, British Columbia, Canada V0H 1Z0.

Vigorous de Chaunac vines were subjected to a combination of one of three hedging severities (5, 10, or 15 leaves retained per shoot), one of three timings of hedging (postbloom, lag phase, veraison) and a non-hedged control over a three-season period. Vine vigor decreased linearly as hedging severity was increased, while count shoots and percent budbreak were reduced proportionally by delays in hedging as well as by increases in hedging severity. Leaf area per shoot, per main shoot, and per vine tended to decrease in proportion to severity and lateness of hedging, but vines hedged severely at postbloom had relatively high leaf areas due to lateral shoot growth. Canopy density decreased and fruit exposure increased as hedging became more severe or was delayed. Length and depth of canopy were both reduced by increases in severity of and delays in timing of hedging. Nearly all hedging treatments reduced vine vigor and leaf area compared to the control but had minor impact on shoot production. Use of severe postbloom hedging may lead to improvements in canopy characteristics with minimal reductions in vine vigor and winter cold tolerance.

Key words: canopy management, hedging, de Chaunac

Submitted on September 6, 1988