The objective of this research was to evaluate the efficiency of the herbicide MSMA in controlling the weed Cyperus rotundus. Different spray volumes, associated or not to organosilicone surfactants were used. The treatments were arranged in a randomized complete blocks design with four replications: MSMA (2.4 kg ha-1), MSMA (2.4 kg ha-1 + organosilicone surfactante [commercial product = Silwet L-77] 0.05% v/v) and MSMA (2.4 kg ha-1 + [commercial product = Break Thru] 0.05% v/v), applied at four spray volumes (100, 200, 300 and 400 L ha-1), and two check treatments (weeded and weed free). The boom sprayer pressure (3.0 kgf cm-2) was maintained constant for all treatments. At the application timing, C. rotundus plants were at the stage of eight leaves average. The surfactant commercial product Silwet L-77 showed a tendency of accelerating MSMA toxicity on the shoot of C. rotundus. Spray volume associeated or not to addition of the organosilicone surfactants did not increase C. rotundus control. MSMA presented only a fair control of C. rotundus (60-70%).
weed; spraying technology; organosilicones
