Controle de arroz-vermelho e seletividade ao arroz irrigado pela aplicação de herbicidas do grupo das imizadolinonas

Abstract

The weedy rice (red rice and black) and cultivated rice belong to the same genus and species (Poaceae - Oryza sativa L.) with morphophysiological similarities that hinder the adoption of chemical control with herbicides. Herbicides inhibitingacetolactate synthase (ALS) have selectivity to rice due to the mutation process iscarried out on the line 93AS3510 for that express tolerance to these products. Laterhe moved to tolerance via classical breeding for cultivar IRGA 417, IRGA 422 CL generating the, the latter being tolerant to herbicides belonging to the imidazolinone group. Given the context, with the objective was to evaluate thecontrol of red rice and rice selectivity by applying herbicides of the imidazolinonechemical group. The variables investigated were control of red rice made at 14, 28 days after application of treatments (DAT) and pre-harvest rice, and phytotoxicity to cultivated rice determined at 07, 14 and 21 DAT. The commercially formulated mixtures composed of imazapic + imazapyr from the recommended dose (140 g ha-¹) + imazapic and imazethapyr at twice the recommended dose (2 L ha-¹) were effective for controlling red rice. These same mixtures were also selective to cultivate Puita Inta-CL, regardless of the applied doses of the products. Herbicidesnot registered for the control of red rice imazethapyr and imazapic did not havesatisfactory control of red rice.