Oilseed rape is a member of the Bracassia family and is grown for its oil content.

There are a number of types of oilseed rape, both winter and spring, which can be grown.

Oilseed rape can be further segregated into “Double low” varieties, HEAR varieties and HO, LL varieties. Oilseed rape naturally produces contain some unwanted compounds, erucic acid and glucosinolates. These compounds were found to be harmful (immunotoxic) to both humans and animals.

• ‘Double low’ varieties (low erucic acid, less than 2% of measured fatty acid, and low glucosinolates, less than 35mmol/kg in the meal) are the most commonly grown in Ireland and typically have an oil content of 43-44%.
• HEAR (high erucic acid rape) varieties are more specialised and are generally grown for specialist markets (including bio-fuels) and are regarded as non-food crops.
• HO, LL (high oleic, low linolenic fatty acid profile) varieties are healthier for human consumption and have highly stable oil for the food processing industry.

Oilseed rape acts as a break crop from the take-all fungus which adversely affects wheat. The yield of wheat sown after sowing rape can increase by 0.5-1.5 t/ha depending on the incidence of take-all during the growing season.

The returns from oilseed rape often compare less favourably with cereals, however, the rotational benefits from first cereals after oilseed rape can result in extra profitability from the cereal crop and so the return over two years is usually similar to two cereal crops.