Effect of nitrogen and phosphorus on fruit drop and endogenous level of GA_3 in Kinnow mandarin under high density planting

摘要

In high density orchard of Kinnow budded on Troyer citrange rootstock, the application of 400g nitrogen along with 256 g phosphorus in splits was most effective in reducing total fruit drop. Irrespective of treatments, the GA_3 content was maximum inFebruary - March flush than the July - August flush. Furthermore, the GA_3 contents were also higher in four-months old leaves of both the flushes with application of 400g of nitrogen and 256g of phosphorus during the same period. As regard to individualeffect of N and P, GA_3 was found significantly higher in N2 (400g N) in February - March flush, however in July - August flush, GA_3 content was maximum in N3 (500g N) during both the years. However, application of 256g of phosphorus resulted higher level of GA_3 in both the flushes.