A greenhouse experiment was carried out at Federal University of Rio Grande do Sul in order to verify the activity of flumetsulam and trifluralin herbicides on soils with different values of pH (5.1 and 6.4) and density (1.3 e 1.6g cm-3). The herbicide activity was avaluated using Avena sativa L. as indicator plant. Flumetsulam and trifluralin were sprayed at rates of 24g ha-1 and 180g ha-1, respectively. Flumetsulam was more active than trifluralin. There was not interaction among herbicide, pH, and soil density indicating that the herbicide activity is not influenced by pH or soil density. Flumetsulam activity was not affected by soil density, but the elevation of soil pH from 5.1 to 6.4 increased activity of this herbicide. Trifluralin activity was not affected by either soil density or soil pH.
Avena sativa L.; residual herbicides; persistence; crop rotation
