Effect of Growth Regulators on Shoot Maturity, Flower Induction and Yield of Litchi cv. Shahi

A field experiment was conducted to induce the flowering in litchi through growth regulators in 8-9 years old litchi orchard (junior bearing stage) consecutively for 2 years comprising of 12 treatments of four PGRs i.e. GA3 (25, 50, 75 ppm), Ethrel (100, 150 ppm), NAA (15, 25, 40 ppm), MH (15, 20, 25 ppm) and control (water spray) with three replications. Three spraying of NAA, Ethrel, MH along with control and two spraying of GA3 was applied at pre flowering stage from 1st week of October at 30 days interval, while 3rd spraying of GA3 was given after fruit set. Data revealed that PGRs treated plants showed comparatively lesser twig length, number of leaflet/twig, twig length and twig diameter ratio, leaflet and twig diameter ratio and more twig diameter, emergence of pure panicle and fruit yield than control (without treated plant). Plant treated with Ethrel @ 100 and 150 ppm expressed significantly higher number of pure panicle emergence (86.67 and 91.67%, respectively) and fruit yield (53.33 and 52.50 kg/plant, respectively) than other treatments. Relationship of pure panicle with fruit yield showed positive and moderately strong correlation (r = 0.71, R2= 0.51).