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The longer a ripe canola crop stands in the field, the greater the risk of shattering by wind and severe weather. Severe weather can cause yield losses ranging from 5 to 75%, therefore canola should be harvested in a timely fashion.1
Most of the canola grown is the northern Great Plains and Canada is swathed prior to harvest due to the need for accelerated, uniform dry-down.2 However, with warm, windy conditions of the southern Great Plains, direct combining is the most common method for harvesting canola for that area.3 Swathing can still be an option for southern areas when risk of pre-harvest shattering is high.
Direct combining is most successful when the crop matures evenly and crop density is uniform. A thin stand may lead to more branching and pods on younger branches which mature later, resulting in less uniform ripening. Direct combining works well when the crop is relatively heavy, tall, partially lodged, or with pods “laced” together. These conditions reduce the risk of pod drop and pre-harvest shattering.
Figure 1. Swathing canola with a roller. Photo courtesy of M. Stamm, Kansas State University.
Canola should be cut just below the seed pods, which reduces the amount of green material entering the combine. The reel should be set as far back over the grain table as possible to reduce the effects of shattering by the header. The reel speed should match ground speed and placed just far enough into the seedpods to lightly pull the crop onto the grain table. Direct combining canola is at a slower speed compared to combining wheat.
Start with the settings for rapeseed or canola in the operator’s manual. Adjustments should be made based on what is coming out the back of the combine. Check for grain losses ahead of the combine (shattering), behind the header (header loss), and behind the combine (tailings). Always refer to the manufacturer’s operating manual before performing any adjustments.
Harvest should begin based on seed color and seed moisture content. Waiting until all seed pods are brown and dry may result in potential yield loss. Do not wait until the stems dry down to begin combining. Since canola seed is small, it may be useful to have a roll of duct tape or caulk available to plug holes in combines and trucks.
Figure 2. Combine with a pick-up header used for swathed canola. Photo courtesy of M. Stamm, Kansas State University.
Disadvantages of direct combining include:
Figure 3. Canola pods with various seed colors.
Swathing is generally implemented in cool areas where dry-down may be slow. A pull-type (Figure 1) or self-propelled draper swather should be used; do not use a swather with a crimper. The process involves cutting the crop just below the seed pod area so adequate residue remains to hold the windrow above the ground and increase airflow for ripening. Later the swaths can be harvested with a combine equipped with a pickup header (Figure 2). Depending on drying conditions, combining may occur about 7 to 14 days after swathing or until seed moisture content is 8 to 10%.1,3
Seed color change is used to determine when canola is ready to swath (Figure 3). The optimum time for swathing is when the crop is between 40 to 60% seed color change with 30 to 40% seed moisture content.1,3 Consider swathing during the cooler morning or evening hours, which allows the seed to dry down at a slower rate.
Advantages of swathing canola include:
Disadvantages of swathing include:
A canola pusher is a convex shield mounted on the front of a tractor. The goal is to lean or “push” the plant over (forced lodging), but not resulting in a kink or pinch in the canola stem, therefore allowing grain fill to continue. Canola plants that have been pushed lay about 1 to 2 feet from the soil surface and are held in place by other plants. The result allows for airflow around the plant and continued seed ripening. A standard combine header may be able to be used for combining but the header width should match the width of the pusher.
Advantages of pushing include:
Disadvantages of pushing include:
Herbicides can be used as a desiccant prior to harvest to even out maturity differences within a field, control weeds, and stop growth when excessive lodging exists. Desiccation should take place when 85% of the seeds on the main stem have turned color from dark green to reddish-brown, brown, or black. Always follow pesticide label directions.
Generally, any canola that is run over from ground herbicide application will be lost. However, desiccation can be a viable option when conditions are not favorable for swathing or pushing, and the standing crop needs to be harvested promptly.
Selecting the right seed product for an individual field is an important factor to maximize yield potential. Technologies are available to add both harvest and agronomic attributes to canola seed products, including shatter tolerance. Consult your agronomist or sales representative for more information about selecting the right product for your fields