A growing body of university research sheds light on just how much weeds can hurt yields for each day they go uncontrolled. University weed scientists and Extension specialists are also discovering that there might be more to weed competition and control than we typically think.
See the links to university information:
- University of Nebraska-Lincoln defined a "critical period of weed control"
- Iowa State University found 3- 4-inch weeds can reduce yields by 3 bu/A for every day they are uncontrolled.
- The Ohio State University reported planting happens earlier in the season now than it did 25 years ago. Researchers say this poses different challenges when it comes to achieving season-long weed control, and they identify four considerations to keep in mind when making weed control decisions.
Of course, weed control doesn’t stop with the early season. As Jody Wynia, corn marketing manager for Bayer CropScience says, early-season control is vital to keep fields weed free all season. A preemergence week control program might not hold weeds down, especially if growing conditions are exceptional good for weeds while less than ideal for corn.
“The best way to manage weeds for a full season is to get ahead of them,” Wynia said. “And that starts by getting out there when the weeds are young.
“Consider how quickly some of these weeds grow and how many seeds they produce. If you have to try to catch up with your weeds, you’ll play catch up all season.”
What this philosophy encourages is using a postemergence herbicide that also provides residual control of weeds all the way until the corn has canopied the row. Shading of the row greatly shuts down the weed growth, and a weed-free field until the point of shading conserves yield potential.
Bayer CropScience promotes its Capreno herbicide for postemergence weed control in corn because of its long residual benefits for growers.
For more information about season-long weed control, Bayer encourages farmers to check with their retailer, local Extension office or a Bayer CropScience representative.