Two experiments were carried out to evaluate the susceptibility of Panicum repens and Paspalum repens Bergius to different herbicides applied in postemergence. The plants were cultivated in reservoirs and the treatments tested were: glyphosate (Rodeo) at 2,400, 3,360 and 4,320 g a.e. ha-1 plus Aterbane 0.5% v/v; glyphosate at 2,400, 3,360 and 4,320 g a.e. ha-1 plus Silwet 0,1% v/v; imazapyr (Arsenal) at 750 and 1,500 g a.e. ha-1, diquat (Reward) at 400 and 800 g a.i. ha-1 (in sequential applications of 200+200 g a.i. ha-1 and 400 + 400 g a.i. ha-1, respectively) and an untreated control. A CO2 backpack sprayer with 2 bars and consumption of 200 L ha-1 of spray solution was used.The experimental design was completely randomized with four repetitions. The control was evaluated visually and plant dry matter determined at the end of the study. The herbicide glyphosate at 4,320 g a.e. ha-1, regardless of the adjuvant used, and at 3,360 g a.e. ha¹ with Aterbane, provided a good control of Panicum repens, and an excellent control of Paspalum repens at all the doses tested; the herbicide imazapyr, regardless of the dose tested, presented unsatisfactory results in controlling Panicum repens plants, but provided an excellent control of Paspalum repens; the herbicide diquat was inefficient in controlling both species, despite the two applications and regardless of the dose applied.
aquatic plant; adjuvant; glyphosate; imazapyr; diquat
