Effectiveness of Adjuvants with Nicosulfuron and Primisulfuron for Wirestem Muhly (Muhlenbergia frondosa) Control in No-Till Corn (Zea mays)

Abstract

Greenhouse and field experiments were conducted to evaluate the effectiveness of nicosulfuron and primisulfuron with different adjuvants on wirestem muhly control. The adjuvants evaluated with the two herbicides included a nonionic surfactant, crop-oil concentrate, crop-oil concentrate plus urea-ammonium nitrate, methylated vegetable-oil concentrate, and organosilicone methylated vegetable-oil concentrate. In the greenhouse, nicosulfuron and primisulfuron performance was similar, although small differences occurred between adjuvants and herbicides. In the field, changing adjuvant affected nicosulfuron performance more than primisulfuron and in general, greater control was achieved with nicosulfuron than with primisulfuron. Among adjuvants, methylated vegetable-oil concentrate provided greater wirestem muhly control with nicosulfuron and sometimes primisulfuron compared to the others, while the nonionic surfactant was the least effective with both herbicides. Regardless of adjuvant, none of the field-applied treatments controlled wirestem muhly much beyond the 12 wk-evaluation period.