IPM and Pollinator Protection in Canola Production in the USA

Abstract

Canola belongs to the genus Brassica, and the varieties employed currently yield oil containing less than 2% erucic acid. In the USA, concerted efforts to grow canola began in 1985. Major pests of canola in the USA are the cabbage seedpod weevil (Ceutorhynchus assimilis Paykull) and the flea beetles (Phyllotreta cruciferae Goeze and Phyllotreta striolata Fabricius). The best management of these insect pests still includes pesticides, especially neonicotinoids as seed treatments, while plant pathogens and weeds are managed with conventional fungicide and herbicides. Honey bees and wild solitary bees in various families are the major pollinators of canola, and along with other benefits they increase yield by causing the plant to set seeds earlier, allowing for easier harvesting. While insecticides (including seed treatments) cause greater damage to bees than fungicides and herbicides, all groups of pesticides can be harmful to pollinators, especially when mixed together and with adjuvants. Improving communication between canola growers and beekeepers, selecting low toxicity pesticides, and following label instructions before application all are steps that can reduce bee poisoning. Similarly, increasing plant biodiversity near canola fields to provide habitat and food resources can also improve bee population size and health. A greater focus on cultural and biological management generally would improve pollinator health, and pollinator management should play a major role in the integrated pest management of canola.