Carryover of [imazapic + imazapyr] on differents crops systems in lowland areas with ALS tolerant rice

Abstract

This study aimed to assess the impact of the herbicide associated to the Clearfield^® technology of rice cultivation on ryegrass planted in succession, as well as on both non?Clearfield^® rice and soybean planted in rotation. Was installed in the Lowlands Experimental Field, Embrapa Clima Temperado, Capão do Leão, Brazil, from 2016 to 2018. The experiment comprised the application of Kifix^® (imazapic + imazapyr) to Clearfield^® rice grown at the first experimental year, evaluating its impact on the Clearfield^® rice (1^st summer), on ryegrass grown on the succeeding winter, as well as on soybean and non?Clearfield^® rice grown on the following summer cropping season (2^nd summer). The randomized blocks design was used with four replications, with plots measuring 72 m² at the first cropping season and winter cropping, being later split (32 m²) for the second summer cropping season, to allow planting both non?Clearfield^® rice and soybean. Our experiments reported mild damages from Kifix^® residues on ryegrass planted in succession to Clearfield^® rice, as well as on non?tolerant rice and soybean in rotation to Clearfield^® rice, under lowland areas of Southern Brazil. Furthermore, the possibility of accumulation of Kifix^® residues in soil, after repeated applications should be verified in further studies.