Cyclic irrigation and grass waterways combine to reduce isoxaben losses from container plant nurseries
Briggs, J.; Whitwell, T.; Riley, M.B.; Lee, T.
Journal of Environmental Horticulture 16(4): 235-238
This study evaluated the remediating effects of the combination of cyclic irrigation and grass waterways on pesticide loads in runoff water. Cleary's 3336 (thiophanate-methyl), Dursban (chlorpyrifos), and Snapshot TG (trifluralin plus isoxaben) were applied to container nursery beds. The two treatments were continuous irrigation (90 min duration) with runoff emptying through a clay/gravel waterway and cyclic irrigation (three 30 min cycles with 90 min between cycles) with runoff emptying into a grass waterway. Samples of runoff water were collected at the end of the waterways on the day of application and 1, 2, 4, and 8 days after application. Cyclic irrigation reduced runoff water volume 15% compared to continuous irrigation. All pesticides were detected in runoff water on the day of application from both treatments. Isoxaben was detected in runoff water through 8 days after application from both treatments. Isoxaben concentrations and amounts were reduced by the cyclic irrigation/grass waterway treatment on the day of application and as a total for the duration of the study.