Brassica napus includes different cultivated forms with distinct uses. Two major forms are: (1) oilseed rape (B. napus subsp. napus), including spring and winter types, and (2) the swollen-rooted swede or rutabaga (B. napus subsp. rapifera, also referred to as B. napus var. napobrassica). Other forms may be cultivated for forage or as vegetables.
Oilseed B. napus includes both conventional rapeseed and “canola-quality” varieties. “Canola” is a quality designation rather than a taxonomic designation and generally refers to varieties selected for low levels of erucic acid in the oil and glucosinolates in the meal. In Canada, for example, canola-quality seed is defined as containing less than 2% erucic acid in the oil and less than 30 µmol/g of specified glucosinolates in the air-dried, oil-free meal. Canola-quality varieties have been developed in B. napus, B. rapa and B. juncea.
B. napus is cultivated extensively for edible vegetable oil and protein-rich animal feed, as well as for industrial oils, biofuel, forage and vegetable production. High-erucic-acid rapeseed varieties are also cultivated for specialized industrial applications.