MSMA for Weed Control in Wheat (Triticum Aestivum)

Abstract

Postemergence applications of MSMA (monosodium methanearsonate) for weed control in spring wheat (Triticum aestivumL.) were evaluated in the field, greenhouse, and controlled environmental chamber. MSMA controlled weeds better when applied to wheat at the four- to five-leaf stage than when applied at the two- to three-leaf stage. MSMA, tank mixed with barban (4-chloro-2-butynyl-m-chlorocarbanilate) or diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid}, controlled wild oat (Avena fatuaL.), green foxtail, [Setaria viridis(L.) Beauv.] and broadleaf weeds better than did MSMA applied alone. Wild oat control with tank-mix applications of MSMA and difenzoquat (1,2-dimethyl-3,5-diphenyl-1H-pyrazolium) was variable. Weed control with MSMA was enhanced by 30 C air temperatures, 90% relative humidity, and adequate soil moisture. A simulated rainfall of 0.5 mm within 0.5 h or 4 mm with 4 hr after application reduced wild oat control with MSMA.