Abstract

Field experiments were carried out at Agricultural College and Research institute, Madurai during summer (Feb-June) and rainy (Aug-Dec) seasons of 2004 to study the effect of integrated nutrient management practices on yield components and oil quality of castor. Among the organic nutrients, application of FYM @ 12.5 t ha-1 Azospirillum + Phosphobacteria recorded significantly more number of spikes per plant, capsules per spike and seed yield as compared to pressmud @ 2 t ha-1+ Azospirillum + Phosphobacteria and sugarcane biocompost @ 1 t ha-1. Similarly the highest number of spikes per plant, capsules per spike, and seed yield were recorded in application of 22.5:11.5:11.5 kg NPK ha-1 + Zn SO4 @ 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 treatments proved to be more economical in view of its higher net returns and benefit: cost ratio in both the seasons of summer and rainy, respectively.

Keywords: Castor, FYM, pressmud, sugarcane biocompost, NPK, ZnSO4.