Effect of Foliar Application of Gibberellic Acid (GA3) and Boron on Growth, Yield, and Quality of Phalsa (Grewia asiatica L.)

Abstract

The present investigation was conducted to evaluate the effect of boron and gibberellic acid (GA3) on the vegetative growth, fruiting, yield, and biochemical quality of phalsa (Grewia asiatica L.). Foliar application of boron (0.2% and 0.4% and GA3 (25 ppm and 50 ppm), alone and in combination, significantly influenced vegetative, reproductive, and quality parameters compared to the control. Vegetative attributes such as shoot length, shoot diameter, number of shoots per plant, and number of leaves per shoot were markedly enhanced by combined treatments. The maximum shoot length (142.69 cm), shoot diameter (0.98 cm), and number of leaves per shoot (45.86) were recorded with GA3 50 ppm + boron 0.4%. Fruit set, fruit number per shoot, fruit weight, and yield also improved significantly under combined treatments. GA3 50 ppm + boron 0.4% registered the highest fruit set (76.02%), fruit number (83.46/shoot), and yield (6.48 kg/plant and 99.73 q/ha). Similarly, physical attributes such as fruit diameter (1.08 cm) and volume (1.30 cc) were maximized under the same treatment. Biochemical constituents including TSS, sugars, and ascorbic acid content increased with GA3 and boron application, while titratable acidity decreased. The highest TSS (26.41%), total sugars (20.06%), and ascorbic acid (41.68 mg/100 g) were recorded with GA3 50 ppm + boron 0.4%. Overall, the combined application of GA3 50 ppm with boron 0.4% proved most effective in improving vegetative growth, yield, and fruit quality of phalsa.