Seletividade de trigo Clearfield® a imidazolinonas e eficácia no controle de plantas daninhas

Abstract

Wheat cultivation is gaining prominence in the Western Border of RS, becoming an option for winter cultivation. But it suffers from phytosanitary limitations, such as the incidence of weeds. The objective of the work was to analyze the selectivity of CL® wheat and the control of weeds with the application of herbicides from the chemical group of Imidazolinones in post-emergence. The work was conducted at UNIPAMPA, Campus Itaqui, harvest 2023. With 9 treatments and 4 replications (DBC). To ensure the presence of weeds, turnips, oats and ryegrass were sown. Followed by sowing the wheat crop (TBIO Ello CL®). After 40 days, the treatments were applied, with three controls: no application of products; weeded; and, chemical control with the product registered for wheat cultivation. Plus the herbicides Imazapir + Imazapique and Imazetapir at doses of 100, 66 and 33% of the recommended dose for CL® irrigated rice. The evaluations were the visual measurement of the selectivity of the herbicides, based on the phytointoxication of the CL® wheat crop, and the effectiveness in controlling weeds. At 8, 16, 25, 35 and 44 DAA, according to a grading scale from 0 to 100%. And also, plant height, thousand grain mass, productivity, hectoliter weight, number of ears per m², and number of grains per ear. The herbicides did not present considerable phytotoxicity to CL® wheat. Configuring possible selectivity of the TBIO Ello CL® cultivar to the herbicides used. The Imazapir + Imazapique 33% treatment showed the lowest percentages of injuries in CL® wheat. The effectiveness in weed control expressed only half of the minimum recommended control. Imazapir + Imazapique 100% and 66%, and Imazetapir 100%, demonstrated the best control results. Contrasting selectivity with the productivity and quality components of wheat, the Imazapir + Imazapique 66% treatment stood out, presenting greater grain productivity.