Effects of Foliar Feeding of Boric Acid and Zinc Sulphate on Yield and Yield Attributing Parameters of Mango cv. Zardalu

Abstract

Mango (Mangifera indica L.) belongs to the family Anacardiaceae with chromosome number 2n = 40. It thrives in tropical and subtropical climates with temperatures ranging from 24-27°C during fruit development. India is the world’s leading mango producer, accounting for nearly 50% of global mango supply. It is the leading fruit crop of Bihar with an approximate share of 50 per cent of the total area under fruit crops. Mango, particularly the Zardalu cultivaris a geographically indicated variety since 2018, holds a prominent position in both national and international markets due to its unique flavor and aroma. It is especially popular in Bihar, with Bhagalpur district being its primary growing region. However, the fruit size in Zardalu generally ranges between 100-200 g, whereas the demand in metropolitan cities of India and abroad is largely for fruits exceeding 200g. This size constraint reduces its competitiveness in premium markets despite its superior organoleptic qualities, necessitating improvement in both fruit size and quality for better economic returns. In a study conducted during 2023-24 at Bihar Agricultural University. Different concentrations of boric acid (0.3%, 0.4% and 0.6%) and zinc sulphate (0.3%, 0.6% and 0.9%) were applied along with one control. Among which foliar application of zinc sulphate (0.90%) was found most effective in improving fruit size and quality parameters, recording maximum fruit length (89.99 mm), diameter (55.59 mm), volume (156.10 cc), weight (213.43 g), pulp percentage (63.26%) and minimum stone percentage (21.46%). Meanwhile, boric acid (0.60%) significantly enhanced yield (79.70 kg per plant), number of fruits per plant (342.67) and fruit retention (7.33%) though specific gravity remained statistically unchanged. Collectively, these findings indicate that balanced micronutrient foliar feeding can substantially improve both marketable quality and overall productivity of Zardalu mango, making it more suitable for high-value markets.