COMPARISON OF FRUIT THINNING SPRAYS ON FOUR APPLE CULTIVARS
Single tree plots were sprayed by hand gun (2 700 L/ha) and assessed at harvest by comparing the distribution of fruits over eight size classes.
Terbacil at 200 ppm was effective as a fruit thinning spray but caused temporary leaf damage and some leaf drop. Treatments that included a carbaryl spray increased the proportion of larger size fruits. A single spray mixture of carbaryl (1 200 ppm) and NAA (10 ppm) increased the proportion of Golden Delicious apples in commercial sizes by 36%. Some thinning sprays reduced the weight of crop harvested in commercial sizes on Red Delicious and Granny Smith.