Effect of sowing date and plant spacing on growth, yield and quality of castor (Ricinus communis L.) in Transitional Luni Basin Plain Zone of Rajasthan

A field experiment was conducted during kharif 2011 and 2012 at farmer's fields and Krishi Vigyan Kendra, Jalore to study the time of sowing and plant spacing for castor. The experiment was laid out in a split-plot design with five replications. The treatments consisted of three main plots (Time of sowing-15 July, 30 July and 15 August) and three sub plots (Plant spacing 60x45 cm, 90x45 cm and 90x 60 cm). Sowing of castor hybrid ‘RHC-1’ was done as per the time of sowing treatment at different spacing. The oil content increased gradually, while the plant population, plant height, number of branches per plant, number of effective spikes per plant, number of capsules per spikes, 100 seed weight, seed yield, biomass production, harvest index, oil yield, net return and BC ratio was decreased gradually to delay sowing dates from 15 July to 30 July and 15 August. Further, wider sowing of castor in spacing 90x60 cm observed significantly higher plant height, number of branches per plant, number of effective spikes per plant, number of capsules per spikes, 100 seed weight, seed yield, harvest index, oil content, oil yield, net return and BC ratio over 90x 45 cm and 60x45 cm plant spacing.

Interaction effects of sowing dates and plant spacing revealed that 15 July sowing of castor produced significantly highest seed yield (4513 kg ha⁻¹), oil yield (2395 kg ha⁻¹) and net return (104200 Rs ha⁻¹) with wide plant spacing of 90x60 cm, further sowing at 30 July, produced maximum seed yield (3807 kg ha⁻¹), oil yield (1848 kg ha⁻¹) and net return (83599 Rs ha⁻¹) with plant spacing of 90x45 cm.