Evaluation of the efficacy of mesotrione plus nicosulfuron with additives as tank mixtures used for weed control in maize (Zea mays L.)

Abstract

The evaluation of the effects of grass and broadleaf weed control with different mixture rates of mesotrione plus nicosulfuron with methylated rapeseed oil and urea-ammonium nitrate liquid fertilizer (UAN) applied postemergence in maize was conducted in field experiments during the agricultural seasons of 2006, 2007 and 2008. Contact angle and surface tension were measured for all tank-mix solutions. There was no phytotoxicity observed on maize following the application of the herbicide-plus-additives treatment. Reduced rates of herbicide with additives provided similar control levels of Echinochloa crus-galli (L.) Beauv. as mesotrione used alone. The tank-mix of herbicides and adjuvants gave no antagonistic effect and it increased weed control. Plots treated with a reduced rate of tank-mix with additives, were always among the highest yielding as compared to untreated plots. Any reductions in cob and grain yield were associated with high weed fresh matter yields, indicating that it was the competition with weeds that led to a reduction in the maize grain yield and not the herbicide phytotoxicity.