Early-season weed control impacts yield and return on investment.

While glyphosate may have the ability to handle tall weeds, crop quality and yield may suffer while waiting until weeds are taller to control them. Research shows that it is the early-season weeds that pose the greatest threat to yield. Smaller weeds that emerge at or near the same time as the crop are competing for the same resources. Whereas weeds that emerge later are competing with crops that are already established and are less vulnerable. Early emerging weeds, such as lambsquarters, can be too large to be adequately controlled by label rates when application is delayed. Waiting to control weeds leaves crops susceptible to weather, which can even further delay applications, allowing weeds to compete for a longer period of time at the critical crop-development stage.  

Early season weed competition isn't just something to be concerned about in corn. A University of Southern Illinois study of weeds in soybean fields showed that early-season weed control led to increased yields and a strong return on investment.

Syngenta recommends applying a residual pre-emergence corn herbicide like Lumax^® to weeds when they are between 4 and 6 inches-about the size of a pop can. This offers post application flexibility for glyphosate, creating a program that offers season-long weed control.

Read more about how controlling weeds early can protect yields and check out more information and research on early-season weed control. Have you been able to quantify yield loss due to early season weed competition? What results have you found?

Lumax^® is a registered trademark of a Syngenta Group Company.