One of the most important steps in no-till weed control is to start with a clean field. This means you should use a burndown treatment to make sure the field is clean at or shortly after planting.
Small weeds draw a lot of moisture away from the crop and can reduce yields. Research at Midwestern universities show significant yield losses can occur due to small weeds.
These small weeds are harvesting too much soil nitrogen and other nutrients. This drop in available early season nitrogen can cause the crop to produce well short of its yield potential.
The bottom line is we need clean fields to maximize yields. Usually, a two-pass herbicide system is the best because it gives us two opportunities to apply herbicide mixtures that can provide full-season weed control.
With a two-pass system, lower rates usually can be used and weeds will be controlled much more effectively than using high rates with one pass. Consider saving some dollars on the herbicide products and putting those dollars toward application to help offset the cost of a second pass.
I’ve often seen producers not use a burndown treatment on soybeans. In these cases, the weeds begin to outgrow the small bean plants. These weeds take valuable sunlight and nutrients away from the beans and reduce yields by 10% to 20%.
When we first started no-tilling in the early ‘80s, weed control was really a challenge because we didn’t have the burndown herbicide options we have today. Glyphosate helped to…