Seletividade de herbicidas aplicados em pré emergência na cultura do sorgo

Abstract

One of the main problems in sorghum cultivation has been weed management, due to the reduced number of products that control these species when applied in pre-emergence and are selective for the crop. Therefore, the objective of this study was to evaluate the selectivity of grain sorghum subjected to chemical control using molecules not recommended for the crop. The experiment was carried out in an experimental area of the Technology and Production Laboratory of the Campus of Engineering and Agricultural Sciences of the Federal University of Alagoas, Rio Largo - AL. The experimental design adopted was randomized blocks, in a factorial scheme 3 x 7, with four replications. The sorghum genotypes used were 1G-100 and 1G-233, with 7 doses of the pre-emergent herbicides atrazine, tebutiuron, and amicarbazone, with the following treatments: T1 - control; T2 - 25% of the commercial dose (625, 300, and 350 g.a.i.ha-1 ); T3 - 50% of the commercial dose (1250, 600, 700 g.a.i.ha-1 ); T4 - 75% of the commercial dose (1875, 900, 1050 g.a.i.ha-1 ); T5 - 100% of the commercial dose (2500, 1200, 1400 g.a.i.ha-1 ); T6 - 125% of the commercial dose (3125, 1500, 1750 g.a.i.ha-1 ); and T7 - 150% of the commercial dose (3750, 1800, 2100 g.a.i.ha-1 ). Evaluations were made of green and dry biomass (leaves, panicle, and stem), plant biometric characters (plant height, stem diameter, number of leaves), and weight of one thousand grains and grain mass. The data obtained were subjected to analysis of variance and mean comparison test. The atrazine herbicide at the commercial dose was selective for sorghum crop. Tebutiuron and amicarbazone herbicides were not selective for sorghum crop at the commercial dose.

Keywords: Grains, Weed Control, Hybrids