Polymeric Herbicidal Ionic Liquids

Abstract

Nonselective herbicides (glyphosate) and selective systemic herbicides such as dicamba, MCPA, 2,4-D, clopyralid, metsulfuron methyl, and iodosulfuron methyl-sodium were paired with two polymeric ammonium cations, namely, p-(diallyldimethylammonium) p-[DADMAC] or p-[bis(2-chloroethyl) ether-alt-1,3-bis[3-(dimethylamino)propyl]urea] p-[PEA], to form novel polymeric herbicidal ionic liquids [p-(HILs)]. First, the synthesis, thermal properties, and solubility of these compounds were described; then, their postemergence herbicidal activity against several target plant species was examined via greenhouse and field experiments. Due to the presence of multiple active ingredients with different modes of action, p-(HILs) often have synergistic effects that increase their efficacy compared to those of known HILs. Polymer compounds in which selective herbicides were combined with glyphosate, despite the use of reduced doses, showed greater effectiveness at the level of a commercial herbicide based on glyphosate at the recommended dose. P-(HILs) that incorporate active ingredients with different modes of action from one molecule have demonstrated high weed control potential and can be considered an element of weed management strategy for preventing the occurrence of biotypes of weeds resistant to herbicides.