Mustard seed or Rapeseed, which is cultivated throughout the world, belongs to the family Cruciferae under the genus Brassica with large number of species and sub-species cultivated in India. Brassica juncea L. (rai) was originally introduced from China into northeastern India, from where it has extended into Afghanistan via Punjab. Eastern Afghanistan, together with the adjoining northwestern India is one of the independent centers of origin of brown sarson (Brassica campestris var. brown sarson).

Mustard crop is grown both in subtropical and tropical countries. In Asia, it is mainly grown in China, India and Pakistan. It is also grown in Europe, Canada and erstwhile USSR. Major producing countries of mustard seed are EU-27, followed by China, Canada and India. Among exporting countries, Canada is on the top with the share of 69% of total global exports. Other major exporting countries are Ukraine, followed by Australia, United States and Belarus. Major importing countries of mustard across the globe are Japan, followed by EU-27, Mexico, China and United States.

Rapeseed-mustard is the second most important edible oilseed crop in India after groundnut Mustard is one of the major sources of oil and meal to India. Mustard oil is traditionally the most important oil for the Northern, Central and Eastern parts of the country. Major mustard producing states in country are Rajasthan, accounting more than 50% of its production followed by Uttar Pradesh, Haryana, Madhya Pradesh and Gujarat.

Peak arrival period for mustard seed is between February & May. Thereafter, its arrivals start declining and least in the month of October. Delhi and Hapur are the major market for mustard in India and the prices of these markets serve as 'reference' for other subsidiary markets.