Effect of Diammonium Phosphate on Aonla (Emblica officinalis Gaertn.) Grown in Laterite Soil

Abstract

In West Bengal (India), aonla (.Emblica officinalis Gaertn.) is growing in red and laterite soil where severe fruit drop, has been experienced. To minimize the fruit drop, an experiment with different levels of diammonium phosphate (DAP) was taken up for three successive years on 10 year old aonla plants cv. NA-10. The treatment included as DAP at 200, 500, 1000,1500 and 2000 g/plant/year with constant does of 400 g single super phosphate, 500 g of muriate of potash and 40 kg Farm Yard Manure in two split doses Le. on 15th March and 15th June every year. The results of three consecutive years of study revealed that DAP at 500 g /plant/year resulted in maximum fruit retention (25.3%) which consequently gave highest fruit yield followed by DAP at 200 g. The minimum fruit retention was noted with DAP at 2000 g/plant. Fruit quality in respect of TSS and acidity was not significantly differed among the treatments but ascorbic acid content was maximum in the plant received DAP at 500 g and minimum in the plant with DAP at 200 g (lowest does). Foliar N and K status were rot significantly differed but phosphorus was significantly improved with higher levels of DAP.