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

Abstract

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.

Crop management and its effects on weed occurrences

“…Identifying species as well as understanding their cycles, propagation methods, and growth habits within conventional or direct sowing systems enables the adoption of management strategies, thus minimizing losses (Adegas et al 2010;Santos et al 2015), which can range from 23%-70% of grain productivity (Vidal and Merotto Júnior 2001). In cultivated areas with different cultures, monocot and dicot weed species have been observed to be predominantly from the families Poaceae and Asteraceae, respectively (Silva et al 2019;Ávila et al 2020;Machado et al, 2020;Santos et al 2015;Schmidt et al 2020).…”