EFFECT OF PRUNING AND PLASTIC COVER ON BUD BREAK, BLOOMING AND MATURITY OF GRAPE

Abstract

The objective of this study was to determine the possibilities to induce earlier ripening in ‘Cardinal’ table grape (Vitis vinifera L.) in
San Miguel de Allende, Gto. Vines were submitted to five pruning dates (January 12^th and 20^th; February 9^th, 17^th and 24^th; in 1995), covered with plastic and irrigated. The control was left uncovered and pruned on February 24^th. The data recorded included bud break and blooming percent, stem length, total soluble solids, acidity and berry color. Earlier pruning treatments increased bud break by late March, but by mid April, all of the treatments showed a similar bud break. The highest stem length for March 30^th and April 12^th was observed on vines pruned on January 20^th, while the highest percentage of blooming for April 12^th was recorded on vines pruned on January 12^th (with 75%). Treatments pruned in January 12^th and 20^th, and February 9^th, allowed an earlier maturity (June 6^th). We conclude that plastic cover promotes a significant anticipation of bud break and a superior stem development; when combined with early pruning, harvest dates were registered at least 20 days before the controls which facilitate marketing.