Lately, there has been concern about seeing “masses” of aphids in winter canola (Figure 1). The aphid in question is likely the Cabbage aphid; however, the Green Peach and Turnip aphid are also known to attack canola. Aphids are most problematic before and during the flowering period. Feeding at the flowering stage can cause deformation or complete loss of reproductive parts and can severely impact yield (Figure 2).
When it comes to aphid management, control may be required if there are 25 or more aphids per 10-centimeter on shoot tips or when 10-20 percent of the examined plants are infected when plants are at the late flowering stage. While seeing masses of aphids can be a cause of concern later in the growing season, oftentimes, the damage is rarely significant since the bulk of pod formation has already been completed and any damage to the top few young green pods contributes little to the overall yield.
For questions or comments, contact Dale Whaley via email at dwhaley@wsu.edu or phone at 509-745-8531.