New Crop Rotation Recommendations for Swede Midge

Abstract

Swede midge (Contarinia nasturtii) is an invasive insect that can seriously damage plants in the family Brassicaceae, which includes broccoli, cauliflower, cabbage, kohlrabi, and kale. Larval feeding on brassica crops results in distorted plant growth, corky scarring, and/or blind heads, which can reduce marketable yield and quality (Fig. 1). Swede midge control is challenging on small-scale and organic farms, where season-long production of brassica crops in close proximity is common. This continuous supply of host plants allows swede midge populations to explode. Research shows that economic damage to crops can be avoided by “crashing” the swede midge population. New crop rotation recommendations provide a feasible population management strategy for some small farms.