Aphid resistant versus susceptible soybean varieties
Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a pest to soybeans in Iowa. In certain years, it can be economically devastating to a farming operation. Conventional farmers can use insecticides to control soybean aphid populations but those insecticides can also harm natural enemies that feed on soybean aphids. In addition, organic farmers do not have good pest deterrent alternatives to insecticides to control aphids. Data from four farmers in western Iowa who tested aphid-resistant (AR) and susceptible (SC) soybean varieties suggest that in 2011, at three of four locations the aphid-resistant varieties were equal to or outperformed the susceptible varieties. At one location the susceptible variety outperformed the aphid-resistant varieties. Based on the 2011 data considering the crop protection costs, yield and aphid-pressure differences, planting an AR variety might be a good insurance policy in both organic and conventional farming systems.