At the National Commodity and Derivative Exchange, castor seed for delivery in March dropped Rs 39, or 0.93 per cent, to Rs 4,142 per quintal, with an open interest of 17,380 lots.
The commodity for delivery in February contracts also fell Rs 31, or 0.75 per cent, to Rs 4,090 per quintal, clocking an open interest of 61,380 lots.
Marketmen said the fall in castor seed futures was mostly attributed to a weak trend at the spot market due to low demand from consuming industries amid increased supplies in spot market.