In India and other places where the seed is the main product, harvesting, threshing, and winnowing are carried out by the family. Extraction of oil from the seed is by rotary mill, expeller, and hydraulic processes. For Mustard greens, plants are cut off at ground level when they are young and tender. Mustard greens are uually shipped in bushel baskets or wire-banded crates. Yields and Economics As much as 12 MT leaf is reported per hectare.
Mustard greens are on market all year round.
Greens are also grown in Michigan, Ohio, Indiana, New Jersey, Arizona, and the states from Texas to Florida, north to Arkansas and Tennessee. Annual imports in the United States tons per year. In United States, Canada, and western Europe, most of the crops are grown for mustard greens, a large number of horticultural varieties or strains being grown, mostly of Japanese or Chinese stock. Montana is the largest mustard seed producing state, the oil being expressed as a preliminary step in making food products and has been used as a special lubricant in place of rapeseed oil. Alberta is the principal mustard growing region in Canada, up to 41,000 ha.