Effect of naphthalene acetic acid (NAA) on the fruit drop, yield and quality of mango (Mangifera indica L.) cultivar Langra

The effect of growth regulator i.e. naphthalene acetic acid (NAA) on fruit drop, yield and quality in mango, cultivar 'Langra' was studied. Full grown mango plants were sprayed with 10, 20,30 and 40 ppm NAA at different stages of fruit development. Although, application of NAA in any concentration significantly reduced the fruit drop, but the dose of 20 ppm NAA highly minimized the fruit drop at all stages of its development and gave maximum fruit retention at maturity i.e. 22.20%, yield (11.332 kg/treatment), accelerated fruit ripening (109.33 days) and fruit weight (273.53 g). In case of untreated trees 13.24% fruit retention, yield of 7.99 kg/treatment, delayed fruit ripening (112.33 days) and heaviest fruit of 231.79 g were observed. ln general, the use of 20-30 ppm NAA as foliar spray resulted in increase of total soluble solids (21.73 - 22.22%) and sugar contents (16.81 - 16.86%) whereas acidity decreased significantly (0.31%) but minimum total soluble solids (20.09%), sugars (15.04%) and increased acidity (0.34%) were detected in the fruits obtained from the plants under control.