Use of growth regulator CPPU in harmonising the growth and quality of apple cv. Red Delicious

Two different stages, full bloom flowers and pea size fruits of ‘Delicious’ apple (Malus x domestica Borkh.) were sprayed single and repeatedly after 15 days during fruit sets with 0, 2.5, 5.0, 7.5 and 10 ppm CPPU {N-(2-chloro-4-pyridinyl)N-phenyl urea} in temperate conditions. Maximum fruit set increased 1.74 times with Sitofex application as compared to control. At both application times, the fruit length and diameter of treated fruit linearly increased with increasing concentration. Fruit length: diameter (L/D) ratios generally increased with higher doses. Fruit weight and volume significantly influenced with all CPPU concentrations. The maximum fruit volume increased by 79% with CPPU application as compared to control. Maximum yield 37.26 kg tree-1 with 10 ppm Sitofex was superior to 2.5, 5.0, 7.5 ppm Sitofex application. The yield was minimum in control, 28.09 kg tree-1. These effects either in an increase or decrease were associated with increasing Sitofex concentrations. Thus, proper PGR use could play an important role in providing higher quality products to their customers at lower cost.