Impact of Foliar Application of Plant Bio-Regulator and Micro-Nutrients on Fruit Retention, Yield and Quality Attributes of Aonla

An experiment was carried out in the Garden, Department of Fruit Science, C. S. Azad University of Agriculture and Technology, Kanpur (UP) in 2023 to investigate the impact of foliar application of plant bio-regulator and micronutrients on fruit drop, retention, yield, and quality attributes of Aonla, using nine treatments viz., NAA at 20 and 40 ppm; Borax at 0.2% and 0.4% and Zinc sulphate 0.3% and 0.6%, NAA @ 20 ppm + Borax @ 0.2% + ZnSO₄ @ 0.3%, NAA @ 40 ppm + Borax @ 0.4% + ZnSO₄ @ 0.6% including a control treatment (water spray) on twenty-three old trees of aonla cv. NA-7 replicated thrice in Randomized Block Design. From the experiment, it is recorded that the higher concentration of NAA @ 40ppm + Borax 0.4% + zinc sulphate 0.6% significantly reduces fruit drop (23.80%) with maximum fruit retention (76.20%), fruit yield (89.88kg/plant), fruit length (4.66cm), fruit breadth (5.04cm), fruit volume (27.56cc), fruit weight (29.95g), specific gravity (1.08g/cc), pulp weight (43.92g), pulp: stone ratio (42.84), TSS (13.120Brix), ascorbic acid (627.24mg/100g pulp), TSS: acid ratio (9.86), total sugars (11.19%) and with minimum stone weight (1.08g) and titratable acidity (1.33%) followed by NAA 20 ppm + Borax 0.2% + zinc sulphate 0.3% (T₇) as compared to control (T₀) treatments.