Every year soybean growers invest in weed control to keep their fields clean. But quite often, new, uninvited weed pests enter fields.
Where do they come from? How do they break though weed control defences and gain a foothold in fields? On this episode of the RealAgriculture Soybean School, OMAFRA weed specialist Mike Cowbrough looks at what weeds can lurk in field boundaries and how to control them before they enter the field.
Field boundaries are a significant source of difficult-to-control weeds. A little effort after in-field weed control measures have concluded can stamp out theses invaders “and save a lot of grief down the road,” says Cowbrough.
In the video, Cowbrough looks at weeds that have taken root in the field boundary surrounding the Elgin Soil and Crop Improvement Association research site near St. Thomas, Ont. Perennial sow thistle is starting to creep into the field, and if it gets too big, the root system could move in. If left unattended, the plants can produce flowers and seed can be wind blown and establish in the field.
“The time is right to hit the plant with a selective or a non-selective herbicide,” says Cowbrough. “Once it gets to this size, or even up to early bud stage, it’s the perfect time to knock it back.”
Cowbrough also shares control tips for Canada thistle, Italian ryegrass and a bluegrass species — three other unwanted weed pests he discovers in the field boundary.
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