Prices of mustard seed fell in Jaipur due to expectation of a rise in arrivals in the coming days. In Jaipur, mustard seed sold down 10 rupees. Arrivals of the oilseed are likely to increase to 19,125 tn from current daily average of 15,300 tn as traders liquidate stocks, not sure about levies under GST. Arrivals across the country 16,150 tn vs 17,000 tn. Weak demand for mustard meal and oil in domestic markets is also seen weighing on prices. July contract on NCDEX slightly up 0.1%.