Formulation effects on isoxaben and trifluralin in runoff water from container plant nurseries

Abstract

Abstract Sprayable and granular formulations of isoxaben and trifluralin were applied to container plant nursery beds to determine formulation effects on herbicide runoff and weed control. In 1998 herbicide application was followed by 0.8 cm of irrigation delivered in 60 min, and runoff water samples were collected on the day of application (DOA). The highest concentrations of isoxaben and trifluralin detected in runoff water were 0.50 and 0.15 μg ml−1, respectively. Total isoxaben in runoff water was greater from the granular than from the sprayable formulation, but no differences attributable to formulation were detected for trifluralin. In 1999 herbicide application was followed by irrigation applied in three pulse cycles of 30 min each (0.8 cm per cycle). Runoff water samples were collected daily through 2 d after herbicide application (DAA). The highest herbicide concentrations were found in the first runoff sample on the DOA. Isoxaben was detected at 1.6 μg ml−1 from both formulations, and triflural...