Start clean: Protect yields now in no-till soybean
Editor’s note: This article is from the archives of the MSU Crop Advisory Team
Alerts. Check the label of any pesticide referenced to ensure your use is
Timely burndown herbicide applications in no-till fields are extremely important in protecting soybean yield. As no-till drills start planting soybeans, remember the importance of a timely burndown application. The tendency for a number of growers, particularly those planting Roundup Ready soybean, will be to plant into a weedy mess and not worry about applying their burndown herbicide until later, or to wait until most of the summer annual weeds have emerged before making their first post-emergence glyphosate application.
These delayed burndown applications can reduce soybean yield, by inhibiting soybean emergence and growth. By delaying these applications, weeds become larger and can often be tougher to control. Many times dense weed populations (or mats) can even interfere with planting. Competition from these early-season weeds can reduce soybean yield by as much as 16 percent (8.3 bu) (Figure 1). This could lead to as much as a $56.44/A loss in revenue at the end of the season with current soybean prices ($6.80).
Additionally, these carpets of weeds can harbor soybean insects and diseases causing additional problems for the soybean crop. Remember early control of these weeds is important. If a burndown herbicide application cannot be made prior to planting, it should be made shortly thereafter. Any delays in these applications can reduce soybean yield. A complete listing of burndown herbicides and their effectiveness ratings can be found in Table 2C of the 2007 Weed Control Guide for Field Crops (E-434). Remember, treatments that contain 1 pt/A of 2,4-D ester need to be applied a minimum of seven days before soybean planting.