Annual Rapeseed Varieties

Description

• Rapeseed is a small-leaved annual plant. There is a spring and a fall strain of the plant, which can grow from 3 to 5 feet tall. The four-petaled flowers are saffron yellow and a blooming field makes a golden spectacle. The rapeseed has industrial and canola grades, and the plants all look the same. Industrial rapeseed is used for birdseed and lubricant oils. Canola rapeseed has a low percentage of erucamide, which is used in plastics, while industrial rapeseed has a high percentage of the compound.

Canola Species

• Rapeseed grows in a variety of soil types but prefers a pH range between 5.5 and 8.3. The canola rapeseed must contain less than 2 percent erucic acid, which comes from the erucamide. The three main species that are grown for canola oil production are Brassica rapa, Brassica napus and Brassica juncea. There is ongoing research into crosses that produce superior canola crops. But it takes eight to 10 years before a cross variety is registered and two or three more years until seed production is sufficient to release for commercial use.

Seasonal Crops

• The selected species of Brassica for canola become different strains or varieties with manipulation of the crops and cross breeding. There are new releases almost annually. Some newer fall/winter varieties are Erika, Athena and Selkirk. According to University of Idaho researchers, these all have higher yields than previous varieties, as well as extreme hardiness. The Canola, Rapeseed and Mustard Breeding Group released Sterling, Garnet and Sunrise for spring production. These varieties are reported to produce the purest strains of canola oil.

Growing Rapeseed

• Freshly sown rapeseed may emerge in seven to 14 days. The seedling stage is the most precarious, when insects and energy gathering may be a problem. The plant soon becomes a rosette, and then stays in this form for several weeks until warm temperatures cause the plant to bolt and send up a flower stalk. Flowering lasts for up to three weeks and pods are mature and ready for harvest in 35 to 45 days. The spring varieties mature 74 to 120 day after seeding, and the winter varieties take 66 to 111 days. Fall plants need to be sown in mid August to early September. Spring planting can occur once the soil is dry and workable.