by Becky Sideman, UNH Cooperative Extension
From 2013 to 2015, we performed experiments comparing different varieties of Brussels sprouts as well as different topping practices. In these experiments, we observed severe infestations of cabbage aphid. Although our research did not focus on the aphids, they were quite a nuisance and rendered most sprouts unmarketable. From conversations with growers in the region, we came to realize that many growers, especially organic growers, were struggling with cabbage aphid management.
As part of her senior thesis, undergraduate student Talia Levy conducted a study to compare two different methods of managing cabbage aphids: intercropping with beneficial flowers and using a rotation between two organic insecticides. The short story is that, while we observed lots of aphid predators and parasites on the flowering plants, they did not provide sufficient control of cabbage aphids. On the other hand, weekly scouting and application of organic pesticides when economic thresholds were reached DID provide good control of cabbage aphid.
Want to learn more, and get the full scoop? The entire report is available here.