Evaluating the impact of plant growth regulators and micronutrients on fruit set, yield and chemical characteristics of mango leaves

Abstract

The research was conducted over two spring-summer seasons at the Horticultural Research Farm, Department of Horticulture, B.A. College of Agriculture, Anand Agricultural University, Anand, focusing on mango cultivar Mallika during 2013-14 and 2014-15. The objective was to evaluate the impact of foliar application of growth regulators (NAA and GA3 ) and micronutrients (ZnSO4 and borax) on mango fruit set, yield, and leaf properties. The study utilized mango trees of uniform size and age (15 years). Fifteen treatments were administered, including varying concentrations of PGRs (NAA at 20 mg/L of water and 40 mg/L, GA3 at 25 mg/L and 50 mg/L) and micronutrients (zinc sulfate at 0.5%, and borax at 0.2%), as well as combinations of these treatments. These combinations included NAA with zinc sulfate or borax, GA3 with zinc sulfate or borax, and a control treatment with water spray (T15). The foliar sprays were applied at key stages of mango fruit growth: full bloom, pea, and marble stages. Among the treatments, the combination of NAA at 20 mg/L with borax at 0.2% showed significant enhancements in fruit set percentages at pea, marble, and harvest stages, as well as an increase in fruit yield (79.97 kg/tree). Notably, treatments combining NAA at 20 mg/L with zinc sulfate at 0.5% (T7) and NAA at 20 mg/L with borax at 0.2% (T8) resulted in the highest zinc and boron content in mango leaves, respectively.