Streamwater Contamination After Aerial Application of a Pelletized Herbicide

James Miller; A.C. Bace

doi:10.2737/SO-RN-255

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Streamwater Contamination After Aerial Application of a Pelletized Herbicide

Informally Refereed

Authors:

James Miller, A.C. Bace

Year:

1980

Type:

Research Note

Station:

Southern Research Station

DOI:

https://doi.org/10.2737/SO-RN-255

Source:

Res. Note SO-255. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 4 p.

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Abstract

Concentrations of hexazinone and its metabolites were monitored in a Piedmont stream for 8 months after aerial application of a pelletized formulation (Velpar® Gridball™). Downstream water-users and fish are probably safe from toxic exposure if treatment areas have only small streams (less than 50 cm average channel width) and if labeled rates are not exceeded. Hexazinone concentrations were highest 30 minutes after application at 2.4 ppm, declining to less than half at 1 hour, 1.1 ppm, and half again at 2 hours, .49 ppm. No contamination was evident after the Sthday sampling. Stream contamination from pellets was as much as 100 times the concentrations reported for foliar sprays, aerially applied over brush-covered streams at similar rates.

Keywords

hexazinone, Velpar®, Gridball™, chemical silviculture

Citation

Miller, James H.; Bace, A.C., Jr. 1980. Streamwater Contamination After Aerial Application of a Pelletized Herbicide. Res. Note SO-255. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 4 p.