Effect of N, P and S on summer castor

Globally, India ranks second in production under castor after Brazil. The annual production of 10.03 lakh tonnes from an area of 7.52 lakh ha and productivity of 1334 kg ha-1 in India (Anonymous, 2010a). The major castor production states in India are Gujarat, Andhra Pradesh, Karnataka and Orissa. It is also grown in Tamilnadu, Bihar, Maharashtra and Rajasthan. Gujarat ranks first in India with respect to area, production and productivity, which as 4.22 lakh hectares, 4.31 lakh tonnes and 1972 kg ha-1 respectively (Anonymous, 2010b). Scattered cultivation of castor is found in almost all districts of Gujarat. Castor is an important non-edible oilseed crop with good export potential. It is used in the manufacture of high grade lubricant, soap, paints, varnishes, resins, plastic nylon, textile dying, refined oil, perfumed hair oil; Castor oil has also medicinal value being used as purgative. Recently, it is used as resins for surface coating, synthetic rubber and synthetic fibers. It is also used as bactericides and fungicides. Castor cake provides excellent organic manure with 4.5% N, 2.6% P, 1.0% K (Balasubramaniyan and Palaniappa 2000).