Late Season Application for Efficacy Screening of Select Herbicides for Post-Emergence Control of Khakiweed

Abstract

Khakiweed (Alternanthera pungens) was treated late in the season with select herbicides for initial screening of herbicides for post emergence control. Treatments were applied on October 7, 2004 and evaluated five weeks after treatment on Nov 16, 2004. The F ratio for the treatment main affect was highly significant for percent weed control. All rate affect contrasts were not significant for those treatments applied at two or more active ingredient levels. The "S.U. herbicides" vs. "all others" contrast was significant at P=0.05, as the S.U.. chemicals as a whole provided better coverage than the 2-4, D type and Penoxsulam. Percent weed control ranged from 7% to 99% late season control of Khakiweed. There were noticeable differences between S.U. products, as Revolver provided minimal weed control (7%) while Manor and Monument provided very good to excellent control (94% to 99%). Both Manor rates resulted in 99% control, while the three rates of Monument produced 94%-98% mean percent weed control values. Penoxsulam was intermediate, providing 56% and 70% control for the SC and G formulations, respectively. Banvel, 2-4, D and Buctril produced 22%-24% Khakiweed control. Tranxit had minimal affect (12%), as did Revolver at 6%.