Mustard seed May contract was down for the fifth session on the NCDEX and hit a two year low because of a likely rise in output this year. Output is expected to rise 14.5% on year to 3.7 million tonne in 2016-17 (Jul-Jun) in Rajasthan. The most-active May mustard seed contract traded down 1%. A rise in stocks at NCDEX-accredited warehouses also weighed on sentiment. Stocks of mustard seed at exchange warehouses were at 28,887 tonne, compared with 22,885 tonne a week ago.