| Soybean Aphids Moving North |
| Written by Kelvin Heppner | |
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Soybean aphids may not be a problem in Manitoba this year. "I'm just starting to see soybean aphids moving into South Dakota. South-central Minnesota has been spraying for about a week now and we're seeing a few in the southeastern part of North Dakota," says Matt Hubsch, South Dakota-based agronomist with Legend Seeds. "As I get into northern Minnesota and North Dakota I'm not seeing any sign of aphids." He says soybeans in Manitoba may be far enough advanced when the aphids arrive that insecticide application may not be economical. "I'm never going to say never but I'm picking soybeans [in Manitoba] that are in R2 and R3 stages. Generally, a rule of thumb, once they get into early R6, which is full pod fill, I cut off spraying for aphids." "By the time they get here and we reach thresholds for spraying, there's a good chance we won't need to spray in Manitoba." Meanwhile, Hubsch says growers should be checking the nodulation on their soybean plants. Fields with poor nodulation may require a top-dress application of nitrogen. |
