Effect of exogenous application of growth regulators on fruit drop, cracking and quality of litchi (Litchi chinensis sonn.) cv. Dehradun

Dehradun litchi tends to suffer from massive fruit-let drop and cracking. Varying concentrations of NM (15, 30 ppm), 2, 4, 5-T (15, 30 ppm) and GA₃ (25, 50 ppm) were applied on Litchi panicles at different intervals in terms of two sprays (At fruit set + 2 weeks later), three sprays (At fruit set +2 weeks +4 weeks later), four sprays (At fruit set + 2 weeks + 4 weeks + 6 weeks later) in order to ascertain their effects against fruit drop, cracking and quality of litchi. It was noticed that intensity of fruit drop and cracking decreased with increase in number of sprays of all growth regulators. The best results were obtained with four sprays of NAA (15 or 30 ppm) application respectively and likewise fruit quality was also improved.