Levantamento de plantas daninhas em lavoura de arroz irrigado com pivô em Cachoeira Do Sul - RS

The survey of weed species in crops allows the identification, quantification of weed flora, its evolution in the area and helps in decision making for control of species. In this sense, the objective of this work was to survey weeds in pivot-irrigated rice fields in Cachoeira do Sul, Capané district, in the experimental area of the Rio Grandense do Arroz Institute (IRGA). Evaluations were performed by applying the 0.25 m2 square method, randomly launched sixty-eight times. Weeds in the sampled areas were removed from the soil, species identified and quantified. The evaluations were performed after the application of Gamit (preemerging), Ricer and Clincher and Imazethapyr (postemerging). Even after herbicide applications, 13 species were identified, representing the families Asteraceae, Poaceae, Malvaceae and Rubiaceae. Knowledge of the weeds present in the crop allows planning to improve control, avoiding unnecessary expense with herbicides or even using other methods to control these species.