The May contract of mustard seed on the NCDEX was down because of a likely rise in output this year and a rise in stocks at NCDEX-accredited warehouses. Output of mustard seed in Rajasthan is expected to rise 14.5% on year to 3.7 million tonne in 2016-17 (Jul-Jun), according to the state farm ministry. The most active May contract of mustard seed traded down 0.7%. Stocks of mustard seed at NCDEX warehouses were at 32,074 tonne, compared with 27,946 tonne a week ago.