ISHS Acta Horticulturae 199: II International Workshop on Temperate Zone Fruits in the Tropics and Subtropics
BUD BREAK AND FRUITFULNESS OF THREE GRAPE CULTIVARS UNDER TROPICAL CONDITIONS |
| Author: | D.A. Bautista |
| Abstract:
The degree of bud break and fertility of buds on canes with one to 10 nodes was determined in three grape cultivars (Villaneuva, Alphonse Lavallee, and Italia) under field conditions during 4 growth cycles. Ninety percent or more of the distal buds grew in all cultivars and seasons studied. The average percentage of bud break was relatively similar and tended to decline in a quadratic curve from apex to base. Bud opening progressed from apical to basal buds, but was concentrated in the distal buds, indicating apical dominance. Inhibited buds represent unrealized vegetative and productive potential. Canes with 7 or more nodes show a second peak of bud break in basal buds, presumably because apical dominance is partial, affecting only the buds nearest the apical sprout. In all three cultivars percentage bud break of fruitful buds paralleled that of total bud break, but was lower. This difference was accentuated in the basal one to 4 nodes of the cane, especially in the cultivars Italia and Villaneuva. The coefficients of fertility observed are similar to those commonly reported in other grape producing regions. They tend to be lowest in the basal portion of the cane, increase slightly in the median section, and remain constant in the distal section. The number of racemes increases with the number of nodes per cane in response to the degree of budbreak and the coefficients of fertility corresponding to the buds breaking. | |
