Prices of mustard seed hit an 18-month high in Jaipur owing to robust demand for mustard oil in the ongoing monsoon season. The seasonal demand for mustard oil rises by 20-25% during the monsoon season, which supports seed prices. In Jaipur, the benchmark market, the oilseed was sold at 4,250-4,270 rupees per 100 kg, up 10-20 rupees. Demand from stockists and crushers and a fall in arrivals also supported prices. Arrivals in Rajasthan were estimated at 55,000 bags (1 bag = 85 kg), down 5,000 bags. On NCDEX, the most-active July contract was at 4,105 rupees per 100 kg, up 13 rupees.