Successful weed resistance management requires growers to thoughtfully choose the proper tools for weed management consistent with their farm operation. Uncontrolled grass weeds such as foxtails, different species of Panicum and various species of crabgrass are particularly powerful in preventing corn from attaining its maximum yield.
A diversified weed control program that includes rotating or combining multiple herbicide modes of action is a core principle for successful long-term weed-resistance management, according to Mark Jeschke, DuPont Pioneer agronomy research manager. Grass weed control in corn is achieved primarily with herbicides having one of three modes of action: the chloroacetamide herbicides, glyphosate and the sulfonylurea herbicides.
Corn shows tolerance to the sulfonylurea herbicides because it rapidly metabolizes the herbicide molecules. However sensitive weeds such as grass and broadleaf plants do not rapidly metabolize these molecules and are therefore controlled. DuPont Crop Protection has developed the “Q” herbicides – AccentQ, RealmQ, ResolveQ and Steadfast Q – which include a safener for improved corn crop safety. The safener reduces the risk of corn crop injury from herbicide damage without reducing efficacy on targeted weed species. Safeners included in DuPont postemergence corn herbicides help accelerate herbicide metabolism by the cornplant and reduce risk of injury.
Safeners work by reducing the ability of herbicide molecules to reach and interact with their target site in the corn plants, which can be accomplished by directing interaction between the safener and target site. It can also be completed by reducing translocation of the herbicide to the target site and accelerating breakdown of the herbicide into inactive metabolites.