The effect of leaf removal and canopy height on whole-vine gas exchange and fruit development of Vitis vinifera L. Sauvignon Blanc.

摘要: Canopy topping and leaf removal are management practices commonly used in New Zealand vineyards to increase light pesticide penetration the fruit zone, thus, reducing disease incidence. Previous research has suggested that an photosynthesis occurs when leaves removed, this may compensate for reduced area. However, it is difficult extrapolate single-leaf measurements a whole-plant scale. Therefore extent of compensation unknown. To evaluate impact canopy height on whole-vine photosynthesis, treatments were imposed during lag phase berry growth. Leaves removed from lower quarter canopy, or vines topped three quarters control plants, two-by-two-factorial design. Both caused decrease immediately after imposed. Leaf removal, but not height, per unit area basis. This suggests portion contributes more than upper photosynthesis. When made again approximately two months later, tall without had higher rate other treatments. Fruit yield, sugar content, vine carbohydrate reserves pruning weights followed trends similar those observed suggesting although some photosynthetic occurred, defoliation negative effect