Effect of auxin and gibberellic acid application on fruit set of sapota cv. Kalipatti

The present investigation on fruit set of sapota cv. Kalipatti was carried out to increase the fruit set and yield. Eight year old uniformly grown plants planted at 9 × 9 m2 spacing were sprayed with NAA @ 50, 75, 100 and 125 ppm and GA3 @ 25, 50, 75 and 100 ppm except T9 (water spray) and T10 (control) in the month of May, August and September during flowering and at pea stage. Field data on number of flower buds per shoot, pollen viability, fruit set, fruit drop and fruit retention was recorded. Among all the spraying treatments, NAA @ 125 ppm in August resulted in maximum fruit set (24.34%), fruit retention (91.20%) and minimum fruit drop (8.80%). Significant increase in yield (37.13 kg/tree) was recorded in the plants sprayed with NAA @ 125 ppm. It was concluded that foliar application of NAA @ 125 ppm during flowering and pea stage resulted in higher fruit set, fruit retention and yield of sapota cv. Kalipatti.