The Rewarding Residual
Source: University of Illinois, 2008.
The ease and efficiency of glyphosate-based programs encouraged growers to shy away form pre-emergence residual herbicides. With the growing number of glyphosate-resistant weeds and bottom lines suffering from early-season yield loss, it's time to revive the residual herbicide in soybeans and corn. Set a firm foundation for crops this spring by using a soil-applied residual herbicide, as recommended in this 2008 University of Illinois article.
In corn, early-season weed competition can dramatically take away yields. It is ideal to make herbicide applications before weeds reach 4 inches tall in corn. Illinois researchers have estimated a 4 bu/A corn yield loss for every inch the weed height reaches over 4 inches. Using a residual herbicide, like Lumax® or Lexar®, is an effective way to fend off early-season weeds. If you wait, factors outside your control, like the weather, might further delay your application and further potential yield loss.
In soybeans, yield may only decrease by 1 bu/A for every inch in weed height over 6 inches. When an application is delayed, early-emerging weeds such as common lambsquarters and waterhemp are often too large to be controlled by label rates resulting in inadequate control and more resilient weed populations.
There are other benefits of using a pre-emergence residual herbicide in addition to fending off early-season weed competition. What other benefits have you seen? Have you been able to calculate the economic value of a pre-emergence herbicide in your operation?
Important: Always read and follow label instructions before buying or using these products. Lexar and Lumax are Restricted Use Pesticides. Lexar® and Lumax® are registered trademarks of a Syngenta Group Company.