Persistence of Tebuthiuron in Surface Runoff Water, Soil, and Vegetation in the Texas Blacklands Prairie1
- R. W. Bovey2,
- E. Burnett2,
- R. E. Meyer2,
- C. Richardson2 and
- A. Loh3
The concentration of tebuthiuron (N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl)-N,N′-dimethylurea) applied in the spray or pellet form was measured in surface runoff water from watersheds which received natural or simulated rainfall. The persistence of tebuthluron in soil and vegetation was also investigated.
Pelleted tebuthiuron was applied at 2.24 kg/ha (active ingredient) to a 1.3-ha rangeland watershed. A 2.8-cm rain, 2 days after application, produced 0.94 cm runoff which contained an average of 2.2 ppm of tebuthiuron. Tebuthiuron concentration decreased rapidly with each subsequent runoff event and after 3 mo was <0.05 ppm; none was detected in runoff water 1 year after treatment. The concentration of tebuthiuron, applied as a spray at 1.12 kg/ha, decreased to <0.01 ppm within 4 mo in runoff from a small plot which received simulated rainfall. On 0.6-ha plots, mean tebuthiuron (sprays and granules) concentration was 0.50 ppm or less in water when the first runoff event occurred 2 mo after application. Concentrations of tebuthiuron in soil and grass from pellet applications were low (<1 ppm) and decreased with time.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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