CONTROL SPECTRUM OF THE NEW HERBICIDE PYROXASULFONE

Resumo

There is not sufficient information about the efficiency of pyroxasulfone to the control of the main weeds that infest Brazilian agricultural areas. Thus, the objective of this study was to evaluate the efficiency of the pyroxasulfone treatments to control some of the main weeds present in Brazil, comparing it to S-metolachlor and trifluralin. The treatments consisted of five increasing doses of pyroxasulfone (50, 100, 150, 200 and 250 g ha^-1), two doses of S-metolachlor (960 and 1920 g ha^-1), two doses of trifluralin (562.5 and 1125 g ha^-1) and a untreated check. The control (scale from 0 to 100%) was evaluated at 14, 28 and 42 days after application and the shoots were collected at 42 DAT for biomass quantification. Each weed species constituted an independent experiment, namely: Amaranthus viridis, Chloris elata, Conyza spp., Echinochloa crus-galli, Urochloa decumbens, Digitaria horizontalis, Digitaria insularis, Eleusine indica, Lolium perenne ssp. multiflorum, Panicum maximum, Raphanus raphanistrum, Spermacoce latifolia, Spermacoce verticillata. The results observed in this study suggest that the application of 100 g ha^-1 of pyroxasulfone in pre-emergence was an effective treatment to control all weeds evaluated. The application of 100 g ha^-1 of pyroxasulfone was like or higher than the highest doses of S-metolachlor and trifluralin. These results confirm that pyroxasulfone, a new herbicide registered in Brazil, could become an important tool for weed management in many crops as well as it might help to mitigate herbicide resistance, especially for grasses.

CONTROL SPECTRUM OF THE NEW HERBICIDE PYROXASULFONE