Delaying burndown herbicide applications in no-till soybean can reduce yield
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 included.
Timely burndown herbicide applications in no-till fields are extremely important in protecting soybean yield. Within the next two weeks soybean planting will be in full-force. As several no-till drills start planting fields, 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 postemergence glyphosate application. These delayed burndown applications can reduce soybean yield by inhibiting soybean emergence and growth. Also, by delaying these applications weeds become larger and can often times can be tougher to control and 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% (8.3 bu).
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 can not 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 2006 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.
Dr. Sprague's work is funded in part by MSU's AgBIoResearch.