Effect of promalin on fruit shape, set, yield and quality of apple cv. starking delicious

Promalin was sprayed on 12 years old Starking Delicious apple at a concentration of 3.25, 7, 15, 30 and 60 ppm at 50 per cent full bloom of the king blossom from 1998 to 2000. Increasing the concentration of promalin increased the fruit length and fruit weight. Fruit set increased up to 7.5 ppm and the fruit yield increased up to 15 ppm after that they decreased. Promalin at 15–30 ppm were effective in improving the shape of Starking Delicious apples.