Subsequent crops are often sensitive to acetolactate synthase (ALS)-inhibiting herbicide residues, particularly in alkaline soils. The main objective of this study was to compare the impact of different ALS-inhibiting residual herbicides on growth of oil-seed rape (Brassica napus L. subsp. napus) and sugar beet (Beta vulgaris L.) in alkaline soil. In this regard, three experiments were conducted in Prague, Czech Republic, during 2021-2023. In spring, six herbicides (amidosulfuron, chlorsulfuron, imazamox, propoxycarbazone, pyroxsulam, sulfosulfuron) were applied at three application rates (1N - full, 0.5N - half, and 0.05N - 5 % of full). One and four months after application, half of each plot was sown with oilseed rape, and the other half was sown with sugar beet. Herbicide phytotoxicity and aboveground biomass were assessed four weeks after crop emergence. Weather conditions during experimental years, herbicides used, herbicide application rates and the period between herbicide application and crop sowing affected herbicide phytotoxicity and aboveground biomass of both crops. The most damaging effects were recorded with the application of chlorsulfuron for oilseed rape (phytotoxicity was 96-98 % at one month after 1N application) and sulfosulfuron and chlorsulfuron for sugar beet (phytotoxicity was 97-100 % and 90-100 %, respectively). Pyroxsulam caused the least damage to both the crops (average phytotoxicity was 18 %). Herbicide phytotoxicity was 3-times higher, and crop biomass was almost half as much as at the first assessment compared to the second assessment. Sugar beet was more sensitive than oilseed rape to chlorsulfuron and sulfosulfuron, especially in dry conditions, where 0.05 N rates caused biomass reduction of 20-60 % in sugar beet. Most of the tested herbicides could have residual effect that likely damages crops in rotation, particularly if a dry period occurs after the application of herbicides and/or sowing of crops.

来源平台：CROP PROTECTION