Weeds in Mississippi
Do I need a residual herbicide with Roundup Ready?
Currently, Monsanto markets the Roundup Ready soybean system as a stand alone program. Roundup can be used at rates and frequently enough to control most annual broadleaf and grass weeds in soybean. In order to use this system as marketed, one must decide to use a postemergence weed management program in soybean. Fortunately Roundup Ultra is a herbicide with broad spectrum of activity on both grasses and broadleaf weeds. However, there are some annual weeds, like hemp sesbania, pitted morningglory, prickly sida, Pennsylvania smartweed, velvetleaf, entireleaf and ivyleaf morningglories that will require high rates or multiple applications for control.