Optimizing fertilizer requirement for new castor hybrid YRCH 2 under irrigated ecosystem

Abstract

Field experiment was conducted at Gopalapuram village of Salem district, Tamil Nadu during Rabi, 2017 under irrigated condition with an objective of optimizing the fertilizer dose and split application of N and K for obtaining higher productivity in castor hybrid YRCH 2. The experiment was conducted in randomized block design with three replications. The treatments consisted of two graded dose of fertilizers viz., 100 and 125% with the combination of 3splits (basal, 30 and 60 DAS), 4 splits (basal, 30, 60 and 90 DAS) and 5 splits (basal, 30, 60, 90 and 120 DAS). The results drawn from partitioning efficiency revealed that the higher partitioning efficiency of root, stem, leaves and spikes were noticed with 125% of RDF along with five splits at basal, 30, 60, 90 and 120 DAS. In respect of physiological parameters viz., Chlorophyll ‘a’, ‘b’ and total chlorophyll, soluble protein and nitrate reductase were higher with 125% RDF with five split application at basal, 30, 60, 90 and 120 DAS (T7) at 130 DAS. However, the lower soluble protein and nitrate reductase activity was observed under control. With regard to floral phenology, maleness and interspersed flowers were lower with application of 125% RDF with five split application at basal, 30, 60, 90 and 120 DAS (T7) and control (T1). Majority of the yield attributing characters viz., the number of spikes plant-1, number of capsules primary spikes-1 and higher bean yield, the higher values were recorded in 125% RDF with five splits at basal, 30, 60, 90 and 120 DAS (T7). Similar to bean yield, density of castor bean and shelling percentage were also higher in T7 which resulted in higher gross return, net return and benefit cost ratio.