By Scout Nelson
Soybean aphid populations are increasing across South Dakota, creating a growing concern for soybean growers during the current growing season. High aphid numbers can reduce plant health and lead to yield losses if infestations are not identified and managed in time. Regular field scouting remains an important step in protecting soybean crops.
Adam Varenhorst, Associate Professor and SDSU Extension Field Crop Entomologist, along with Philip Rozeboom and Patrick Wagner, are providing information on current soybean aphid populations and management recommendations for South Dakota growers. Their guidance encourages producers to monitor fields closely as aphid numbers continue to rise.
Recent observations near Volga, South Dakota, showed soybean aphid populations ranging from about 280 to 700 aphids per plant. The Economic Injury Level for soybean aphids is 674 aphids per plant. When populations reach or exceed this level, growers should pay close attention to crop conditions and consider suitable management options.
The observed aphids appear healthy and are expected to continue increasing. This makes regular scouting especially important during the next several weeks. Growers should continue checking soybean fields until plants reach the R6 growth stage, when the crop has reached full seed development. Scouting should continue for about two more weeks based on the current crop stage.
Growers can use speed scouting methods to check soybean fields more efficiently and identify areas with rising aphid numbers. Early detection allows producers to make informed pest management decisions before populations become more damaging.
SDSU Extension does not recommend using pyrethroid insecticides to control soybean aphids in South Dakota. Previous research has identified soybean aphid populations resistant to pyrethroids across much of eastern South Dakota. Recent field reports also show that these products may not provide effective control.
Growers should review the current South Dakota Pest Management Guide: Soybean for a list of labeled insecticides and appropriate management options.
Photo Credit: South Dakota State University
Categories: South Dakota, Crops, Soybeans