Effect of time of pruning and hydrogen cyanamide on growth and development of glasshouse-grown Cardinal grapes

Abstract

Weekly pruning treatments combined with hydrogen cyanamide applications from early May to late June in 1987 and 1988 were evaluated for their ability to advance budburst, flowering, colouring and maturity of Cardinal grapes grown in unvented, unheated vegetable glasshouses. The glasshouse provides protection from frost, hail, wind and birds, and permits production of unblemished fruit. Hydrogen cyanamide-treated vines reached maturity approximately 1 month earlier (P<0.05) than untreated vines pruned on the same day. Budburst occurred 28-61 days after pruning with application of hydrogen cyanamide. The interval between pruning and vine responses was variable over the 2 years, but manipulation of the time of pruning significantly (P<0.05) affected the time of ripening in the glasshouse environment. Ripe grapes were produced from 7 November to 19 December by using different pruning times.