Weed interference is a major problem in Saccharum officinarum (sugarcane) production, and pre-emergence herbicides are widely used due to their broad spectrum and residual effect.However, sugarcane agro -industrial residues can interfere with their effectiveness across weed emergence flows.Thus, the objective of this study was to evaluate the effectiveness of pre-emergence herbicides applied over sugar and alcohol industry residues in controlling Panicum maximum seeding flows.The experiments were conducted in a greenhouse using a completely randomized design with four replicates, in a 4 × 6 factorial scheme.Four treatments with industrial residues were evaluated: bare soil, soil covered with sugarcane straw (10 t ha⁻ ¹), vinasse (50 t ha⁻ ¹), or filter cake (30 t ha⁻ ¹), and six sowing periods of P. maximum (0, 7, 15, 30, 45 and 60 days after herbicide application -DAA).Additionally, a control without chemical control was evaluated in each period.The herbicides pyroxasulfone + flumioxazin, sulfentrazone, s -metolachlor, and pendimethalin were evaluated separately in trials.Phytotoxicity was evaluated at 7, 14, 21 and 28 days after emergence (DAE), with the dry mass of the aerial part determined at 30 DAE.Pendimethalin showed higher and more consistent control of the species throughout the sowings, and at 28 DAE maintained around 75% control in bare soil and up to 95% in vinasse-treated soil.Pyroxasulfone + flumioxazin showed effective control until sowing at 15 DAA, with little interference from residues.Sulfentrazone showed improved control in the presence of straw, especially at 0 DAA (>80%), but its effectiveness declined in later sowings, indicating limited residual control.S -metolachlor had increased control by vinasse and reduced control by filter cake.In general, in sowings carried out from 30 DAA onwards, the herbicides were not effective in controlling the species.It is concluded that residues from the sugarcane agro-industry can interfere with the effectiveness of pre-emergent herbicides in a positive or negative way, and that the late emergence of the species makes chemical management less effective.
Brumatti et al. (Tue,) studied this question.