rzepak

Rzepak, known scientifically as Brassica napus, is a flowering herbaceous plant in the Brassicaceae family. It is grown primarily for its seeds, which are pressed to yield a light-yellow to golden oil used for cooking, as well as for meal that serves as a protein-rich animal feed. In English, the crop is commonly referred to as rapeseed; varieties bred for edible oil with low erucic acid and glucosinolates are marketed as canola.

Rzepak thrives in temperate climates with cool springs and moderately long growing seasons. It can be sown in autumn in milder regions or in spring in colder areas. Plants reach 60-150 cm depending on variety. They produce yellow flowers in early summer; harvest typically occurs in late summer or autumn, once the seeds reach high oil content. Crop rotation helps manage pests and diseases. Common pests include flea beetles; diseases include sclerotinia stem rot and blackleg.

Oil is used for cooking and in food products; it also serves as a feedstock for biodiesel and various industrial applications. After oil extraction, the remaining meal is a high-protein feed for cattle, pigs, and poultry, though antinutritional compounds are managed through processing. In canola varieties, lower erucic acid and glucosinolates improve suitability for human and animal consumption.

Rzepak has a long history in Europe as an important oil crop. Breeding in the 20th century aimed to increase oil content and disease resistance. In the 1960s–70s, Canadian breeders developed canola-type rapeseed with low erucic acid and low glucosinolates, expanding edible uses and markets.

It is among the world's most important oilseed crops, with extensive production in Europe, Canada, China, and India. Poland is a notable producer in Central Europe, where rzepak is a staple of crop rotations and a key source of edible oil and feed.