Influence of integrated nutrient management practices on yield attributes, seed yield, oil yield and nutrient uptake of castor under irrigated conditions

Field experiments were conducted during summer (Feb-June) and rabi (Aug-Dec) seasons of 2004 to study the effect of integrated nutrient management practices on yield characters, economic yield, economics and nutrient uptake of castor (Ricinus communis) under irrigated conditions. Application of FYM @ 12.5 t ha⁻¹+ Azospirillum + phosphobacteria recorded significantly maximum length of primary spike, more number of spikes plant⁻¹, capsules spike⁻¹, seed and oil yield and nutrient uptake as compared to pressmud @ 2 t ha⁻¹+ Azospirillum + phosphobacteria and sugarcane biocompost @ 1 t ha⁻¹. Similarly the maximum length of primary spike, more number of spikes plant⁻¹, capsules spike⁻¹, seed and oil yield and nutrient uptake of castor were recorded with application of 75% RDF NPK + ZnSO₄ @ 12.5 kg ha⁻¹ as basal + ZnSO₄ 0.25% foliar spray twice at 30 and 45 DAS as compared to other inorganic nutrients. The similar organic and inorganic nutrient treatment proved to be more economical in view of its higher net returns and benefit: cost ratio in both the seasons, summer and rabi.