The evaluation of effect of the grass and broadleaf weed control of different mixture rates of mesotrione plus pethoxamid and terbuthylazine applied postemergence in maize was conducted in the field experiments during the 2005 and 2006 growing seasons. There was no phytotoxicity observed on maize after herbicide treatments. Herbicide mixture provided higher levels of Echinochloa crus-galii (L.) Beauv. control than mesotrione used alone. In the postemergence trials, the broadleaf weeds, except Chenopodium album L., were not well controlled by the mesotrione-alone treatment. The addition of pethoxamid plus terbuthylazine to mesotrione significantly improved the control of broadleaf weeds. Mesotrione and mesotrione plus pethoxamid and terbuthylazine treated plots were always among the highest yielding as compared to untreated plots. Any reductions in cob and grain yield were always associated with high weed fresh matter yields indicating that it was the weed competition that led to reduced yield and not herbicide phytotoxicity.

Weeds in sugar beet ( Beta vulgaris L.) can contribute to a significant reduction in the root yield. The species composition of these plants is an important factor influencing the competition with crops. The aim of the 2-year field experiment with mixtures of: phenmedipham + ethofumesate + metamitron + quinmerac; ethofumesate + metamitron + metamitron + + quinmerac + triflusulfuron-methyl; phenmedipham + ethofumesate + metamitron + + quinmerac + triflusulfuron-methyl + clopyralid + lenacil, and phenmedipham + ethofumesate + metamitron + quinmerac + triflusulfuron-methyl + clopyralid applied in split doses, microdoses and Conviso Smart technology was to determine the weed species community composition and effectiveness of weed control strategies. The most common species occurring in both years were: Chenopodium album L., Fallopia convolvulus L., and Geranium pusillum L. The communities had the highest values of biodiversity indices in 2020 and lower values in 2021. There were no statistically significant differences in the herbicidal effectiveness of the tested herbicidal technologies over both years of research and for individual main weed species – 95–99%. The use of all herbicide variants contributed to achieving significantly higher yields than untreated treatments, and contributed to an increase in profitability of cultivation, but this result depended on the selected strategy. The presented herbicide solutions were characterized by direct income at a similar level.