Mustard seeds are the small round seeds of various mustard plants. The seeds are usually about 1 to 2 millimetres (0.039 to 0.079 in) in diameter and may be colored from yellowish white to black. They are important herbs in many regional foods and may come from one of three different plants: black mustard brown Indian mustard, or white mustard.
Rajasthan and Uttar Pradesh are the major rapeseed producing States in the country. Together, they produce about 90% of the produce. Hapur, Alwar, Bikaner and Jaipur are the active spot markets of rapeseed in the country.