By Scout Nelson
The annual Small Grains Update, a cornerstone event for growers in northwest Minnesota, recently focused on a persistent challenge in the region: managing soybean aphids. Angie Peltier, a crops educator with the University of Minnesota Extension, shared her expertise on the best practices for controlling this prevalent pest.
Soybean aphids are small, soft-bodied insects that overwinter on buckthorn and migrate to soybean fields in the summer. They feed on plant sap, significantly diminishing soybean yield and quality. The mild temperatures of summer 2024 created optimal conditions for aphid proliferation across Minnesota, emphasizing the necessity of vigilant field scouting.
Peltier explained the critical nature of monitoring aphid populations closely, as they can double in just three to four days under ideal conditions. She advocated for adherence to the economic threshold of 250 aphids per plant before considering pesticide applications. This threshold is strategically set to give producers enough time to act before aphids reach levels that could cause economic harm.
“Scouting is crucial, and relying on reports from neighboring fields isn't enough,” Peltier emphasized. She pointed out that premature spraying could lead to unnecessary or multiple applications, increasing costs and potentially exacerbating pest resistance issues.
To combat resistance, Peltier urged growers to rotate their use of pesticides, particularly due to the growing resistance to pyrethroids observed in aphid populations. “Rotating chemicals not only addresses the immediate problem but also slows the development of resistance strategies in pests,” she stated.
Peltier also recommended continued vigilance even after pesticide application. With newer active ingredients, aphids might remain on the plants but cease feeding, which can mislead growers about the success of their pest control efforts. She advised assessing the effectiveness of treatments and continuing to scout through the R6 growth stage to ensure comprehensive management.
These insights from the Small Grains Update underscore the complexity of pest management in modern agriculture and highlight the ongoing need for education and strategic action in crop protection.
Photo Credit:minnesota-soybean-council
Categories: Minnesota, Crops, Soybeans, General