Chemical control of Pistia stratiotes, Eichhornia crassipes and Salvinia molesta in reservoirs

摘要

Three trials were carried out in Brazil in 1999 to study the effect of herbicides on aquatic weed control in reservoirs. The herbicides and doses used were: diquat at 460, 960 and 1,400 g ha-1; 2.4 D at 1,340 g ha-1; glyphosate at 3,360 g ha-1, imazapyr at 250 g ha-1 and a control. The experiment was arranged in a randomized complete block design with four replications. The plots were constituted by reservoirs with 60 x 60 x 60 cm dimension. The diquat herbicide at all doses showed excellent control of Salvinia molesta, Pistia stratiotes and Eichhornia crassipes. The herbicides 2.4 D and imazapyr did not promote a good control for P. stratiotes while glyphosate showed a very good control. For E. crassipes, 2.4 D and glyphosate showed an efficient control. The herbicides imazapyr, 2.4 D and glyphosate did not show a good control over S. molesta.