Canola Production and Management

Canola and/or rapeseed are cool season crops and yield highest when grown in moderate agricultural climates, where extreme heat and moisture are not usual. As well, growing other crops susceptible to sclerotinia (stem rot) too frequently in the rotation, can increase the risk of stem rot in canola and reduce yields.

 

Choose varieties to match the conditions in your area and on your field. Variety characteristics to consider are:

 

Disease tolerance (blackleg, sclerotinia, clubroot)

Maturity

 

Lodging tolerance 

 

Herbicide tolerance (Roundup Ready, Invigor, Clearfield) 

Yield Potential - actual yield is a function of all the above attributes and growing season conditions that contribute to the final yield potential.  Appropriate variety selection and crop management will increase the probability of obtaining the highest yields.

 

Oil Profile - beside the distinguishing oil profiles between 'canola' and 'rapeseed', within canola there are different oil profiles (Nexera and Cargill Specialty Oil) which are sold into different markets on contract basis.   

Treatments

 

Canola seed is usually treated with both a fungicide and insecticide. The fungicide minimizes seedling losses to damping off, root rot and seed-borne blackleg. The insecticide seed coating is for very early flea beetle control. When flea beetles are expected to be a serious problem, an additional foliar insecticide application may need to be considered to extend the duration of flea beetle control past three to four weeks after emergence.

 

 

Final plant stands of seven to eleven plants/ft2 or 70 to 110 plants/m2 are ideal. Seeding rates should be based on the seed size (thousand seed weight), desired plant stand and environmental conditions at the time of seeding.  Seeding rates on the high end of the recommended range should be used when seeding is late, soil is prone to crusting, conditions are cool or there is heavy weed pressure. When emergence problems occur, thin plant stands usually provide a better crop than would a reseeded crop.

 

 

0.5 to 1.5 inches. Seed should be placed only deep enough to reach moisture. If soil is dry down to two-inch depth, seed shallow and wait for rain.

 

 

After canola forms a canopy, it is very competitive vs. weeds. Optimal timing of weed control for is at the 2 - 4 leaf stage. Under heavy weed pressure or with hard to control weeds, two herbicide applications may be needed. 

 

Weed seeds that are difficult to remove or cannot be cleaned out of canola and cause downgrading are wild mustard, oriental mustard, brown mustard, ball mustard, cow cockle and cleavers. If canola is going into a field known to be very weedy, select the herbicide tolerance carefully for products that will be able to effectively control the weed spectrum.

 

 

Canola is highly susceptible to sclerotinia, and therefore crop rotations that include field beans, field peas, mustard, sunflowers and other sclerotinia-susceptible crops increase the risk of infection on the canola crop. In canola, several fungicide treatments are available for control of sclerotinia.

 

Other major diseases that affect canola are blackleg, alternaria black spot and clubroot. Varieties tolerant to blackleg are available and should be grown in all parts of Manitoba to minimize the impact of this disease.

 

 

Canola can be swathed when 40% to 60% of the seeds on the main stem have begun to change from green to brown (equals 30% seed moisture). Swathing at this stage minimizes the amount of green seed in the harvested crop. Swathing earlier increases the risk of high green seed content. Once the crop is in the swath, damage from frosts is reduced. 

 

 

Canola typically is not desiccated, since the pods shatter easily after desiccation. Desiccation accelerates plant dry-down, not plant maturity. For detailed information on desiccation, consult the Guide to Field Crop Protection.

 

 

 

Canola is considered ready to combine when moisture reaches 10% or less and minimal green seed can be found. Pickup speed should match ground speed to minimize shattering losses. Cylinder speed should be about 500-900 rpm. If the cylinder speed is too fast, seeds will crack. Wind speed should be kept low in order to minimize seed losses with the chaff.

 

 

 

Canola straw breaks down quite readily. In order to minimize seeding problems in the spring, the straw and chaff should be spread behind the combine rather than placed in a row.

 

 

 

Canola is marketed at 10%. For long-term storage, canola should be at 8% to 9% moisture and below 20°C.

 

 

 

Once in storage, canola should be cooled since the seed continues a high respiration rate for up to six weeks. This respiration rate creates moist areas (sweating) in the bin that become hot spots. Once binned, canola should be monitored carefully for heating problems.