Performance of Rabi Castor (Ricinus communis L.) under Zero-Tilled Conditions after Different Preceding Crops

A field experiment was conducted during kharif and rabi 2010–11 and 2011–12 at College Farm, College of Agriculture, Rajendranagar, ANGRAU. The experiment was laid out in split plot design, replicated thrice, with four preceding crops in main plots (green gram, groundnut, bajra and maize) and five nitrogen levels to rabi castor in sub plots (0, 40, 80, 120 & 160 kg N/ha). The results showed that among different preceding crops evaluated, green gram markedly increased growth parameters, yield attributes viz., length of primary spike, number of spikes/plant, number of capsules/primary spike and total number of capsules/plant of castor were also higher when castor followed green gram. The green gram-castor system recorded higher castor seed yield over bajra-castor, groundnut-castor and maize-castor systems. However, the seed yield of former two systems was found at a par during both the years. Stalk yield, harvest index followed the same trend. Among nitrogen levels, application of 160 kg N/ha and 120 kg N/ha, being at par, recorded better yield components like number of spikes/plant and more number of capsules/primary spike of castor over lower N levels. Similarly, the seed yield and stalk yield of castor at 160 kg N/ha was comparable to that of 120 kg N/ha and both were found superior to lower N levels during two years of study.