Soil-applied herbicide is the foundation of weed management for food grade non-GMO soybeans. But escapes do happen, and when weeds evade control, growers need to act.
On this episode of RealAgriculture Soybean School, Ontario Ministry of Agriculture, Food and Rural Affairs weed specialist, Mike Cowbrough, shares tips on how IP growers can tackle weedy escape artists.
Research shows that the ideal time to apply post-emerge herbicides to control these weeds is three to four weeks after planting. To best manage the culprits, Cowbrough recommends growers start scouting fields two weeks after planting, returning every three to four days and “get ready to pull the trigger at three to four weeks after planting.”
In this video, Cowbrough visits the Elgin Soil and Crop Improvement Association research site near St. Thomas, Ont. Here he’s finding grassy weed escapes at the ideal stage for herbicide control — the three to four-leaf stage. He’s also seeing grasses that are starting to put out tillers, the maximum or latest stage where herbicides will deliver effective control, as well as ragweed which has progressed to the four-leaf stage. “It really is the perfect time to come in here and take out those weeds.”
Cowbrough also provides tips on how to properly identify grassy weeds. In this field, he identifies witch grass by examining the shape of the stem and whether the leaf blades have hair.
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