Bees have been mentioned in the media recently due to their vital importance in the global food supply and concerns over their health. Outside of canola hybrid seed production, where seed is produced for growers and pollination is critical, canola is self-pollinating. Canola grown as a cash crop does not require bees to pollinate and produce yield. However, a visit to a flowering canola field quickly reveals that bees enjoy canola. Many producers wonder what indirect benefits bees provide to the 20 million plus acres of canola planted annually in North America.
After spring pollination of crops in the Western U.S., bee hives are relocated to the Midwest and Canada, where apiarists look to place bee hives near flowering crops like canola. Bees are drawn to canola flowers, because the nectar produced has a desirable sugar profile for honey production and the pollen provides additional nutrition needed. Additionally, the long flowering period of canola and abundant flowers provide an ample food supply within a small radius.
Even without beehives placed nearby, many native species of bees will appear to feed on canola flowers. Research on the topic of bees and canola yields suggest a couple of benefits.
Canola produces good yields without pollinators, but studies suggest a yield bump of 13 percent, to as high as 46 percent, is possible when honeybee hives are present. A study in Quebec showed a nearly 50 percent increase in yield with a high density of bees (about 1.2 hives per acre) compared to the absence of hives. While that type of yield increase from a high density of pollinators is likely not achievable across big acres, it does highlight the potential with good pollinators present. A 10-20 percent yield increase is more reachable.
The presence of pollinators in canola can also lead to an earlier and more uniform pod set, according to a Canadian study. The research compared a high density of honeybees (1.2 hives per acre) to the absence of honeybees and saw a 17 percent reduction in bloom time. They concluded that better pollination resulted in fewer flowers being produced, allowing the plant to reach its maximum yield potential. Fewer flowers and a compressed flowering window could come with the added benefit of better disease management. Sclerotinia (white mold) requires the right weather conditions and a food source (flower pedals) to infect plants. By reducing both, the risk can theoretically be reduced.
- Canola produces good yields without bees, but the additional yield potential available from their presence is economical and should not be ignored.
- Growers need to take this economic value into consideration when making insecticide management decisions that can negatively impact pollinators.