Title: Quantifying vapor drift of dicamba herbicides applied to soybean

Abstract: Recent advances in biotechnology have produced cultivars of corn, soybean, and cotton resistant to the synthetic-auxin herbicide dicamba. This technology will allow dicamba herbicides to be applied in new crops, at new periods in the growing season, and over greatly expanded areas, including postemergence applications in soybean. From past and current use in corn and small grains, dicamba vapor drift and subsequent crop injury to sensitive broadleaf crops has been a frequent problem. In the present study, the authors measured dicamba vapor drift in the field from postemergence applications to soybean using greenhouse-grown soybean as a bioassay system. They found that when the volatile dimethylamine formulation is applied, vapor drift could be detected at mean concentrations of 0.56 g acid equivalent dicamba/ha (0.1% of the applied rate) at 21 m away from a treated 18.3 × 18.3 m plot. Applying the diglycolamine formulation of dicamba reduced vapor drift by 94.0%. With the dimethylamine formulation, the extent and severity of vapor drift was significantly correlated with air temperature, indicating elevated risks if dimethylamine dicamba is applied early to midsummer in many growing regions. Additional research is needed to more fully understand the effects of vapor drift exposures to nontarget crops and wild plants. [J. Franklin Egan & David A. Mortensen (2012). Quantifying vapor drift of dicamba herbicides applied to soybean. Environ. Toxicol. Chem., 31: 1023–1031.] Comment

Keywords: Herbicide; Dose–response modeling; Plant toxicology; Environmental transport; Genetically modified organisms


Original source




Article: WeedsNews4137 (permalink)
Categories: :WeedsNews:research alert, :WeedsNews:herbicides, :WeedsNews:pollution, :WeedsNews:vapour drift
Date: 20 December 2012; 1:20:39 pm Australian Eastern Daylight Time

Author Name: David Low
Author ID: adminDavid