Effect of nitrogen and phosphorus on fruit drop and endogenous level of GA₃ in kinnow mandarin under high density planting

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 GA₃ content was maximum in February-March flush than the July-August flush. Furthermore, the GA₃ 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 individual effect of N and P, GA₃ was found significantly higher in N2 (400g N) in February–March flush, however in July–August flush, GA₃ content was maximum in N3 (500g N) during both the years. However, application of 256g of phosphorus resulted higher level of GA₃ in both the flushes.