Sulphur (S) is an essential plant nutrient required by all crops for optimum production. Soils those are low in organic matter prone to S deficiency. Researches on crop physiological and agronomical practices have been shown that the dry matter accumulation, S-uptake and chlorophyll content can be increased considerably at different intervals and stages of plant growth with judicious application of sulphur. Field study was planned under this content at Zonal Agricultural and Horticultural Research Station, Hiriyur, Karnataka during three consecutive years (2010- 2011, 2011-2012 and 2012-2013) of Kharif seasons indicated application of 20 kg S/ha through gypsum recorded significantly the highest yield (1751 kg/ha), gross returns (Rs. 58234/ha), net returns (Rs. 43277/ha) and B:C ratio (3.9) over control under rainfed conditions. The large scale demonstration on three farmers' fields in Chitradurga district also revealed that application of 20 kg sulphur/ha through gypsum was effective in realizing higher castor seed yield (7%) with higher profitability (B:C ratio 4.2).