Growth, reproductive development and dormancy characteristics of paclobutrazol-treated tart cherry trees

Abstract

SummaryA single spring application of paclobutrazol (0.5 g a.i. in 1986 or 0.75 g a.i. in 1987) round the bases of five (1986) or seven (1987) year-old ‘Montmorency’ tart cherry trees decreased shoot growth during both the first and second growing seasons following treatment. Paclobutrazol treatment increased the proportion of flower buds to vegetative buds as monitored during the first dormant period following treatment. The date of full bloom in the field, in the spring following treatment, was advanced two to four days by paclobutrazol. The number of growing degree (°C) hours required to reach full bloom was decreased by 700–900 in paclobutrazol-treated trees. Rest intensity curves, based upon the amount of GA3 needed to cause vegetative bud break under favourable environmental conditions, indicated that rest was completed at least by early December and that lateral buds completed rest about one week before terminal buds regardless of treatment. Paclobutrazol tended to decrease rest intensity in both t...