Initial deposits and persistence of forest herbicide residues in sugar maple (Acersaccharum) foliage
作者:
Dean G. Thompson,
D. G. Pitt,
T. Buscarini,
B. Staznik,
D. R. Thomas,
E. G. Kettela,
期刊:
Canadian Journal of Forest Research
(NRC Available online 1994)
卷期:
Volume 24,
issue 11
页码: 2251-2262
ISSN:0045-5067
年代: 1994
DOI:10.1139/x94-289
出版商: NRC Research Press
数据来源: NRC
摘要:
Initial deposition and subsequent fate of herbicide residues in sugar maple (AcersaccharumMarsh.) foliage were quantified following applications of three different formulations of glyphosate (VISION®, TOUCHDOWN®, MON14420) and one formulation of triclopyr ester (RELEASE®) in a comparative field study. Maximum initial residues were 529, 773, 777, and 1630 mg of acid equivalent per kilogram dry mass, respectively. Initial foliar residues were dependent upon application rate (r2 = 0.63 to 0.87) and increased by a similar factor (233 to 313 mg•kg−1) for each kilogram per hectare applied, irrespective of formulation type. Foliar residues dissipated following a negative exponential pattern with time, rates of which varied with initial concentration. Mean times to 50% dissipation were 2 days for all glyphosate formulations, 1.5 days for triclopyr ester, and 4 days for triclopyr acid. Mean times to 90% dissipation were <16 days for glyphosate formulations, 9 days for triclopyr ester, and 33 days for triclopyr acid. Multivariate analyses of intercept and rate parameter estimates indicated significant (p = 0.02) differences in dissipation patterns among treatments. Orthogonal contrasts confirmed a priori hypotheses that glyphosate residue dissipation was independent of the salt formulation applied, and that triclopyr ester dissipated faster than either glyphosate (p = 0.004) or triclopyr acid residues (p = 0.07). Results are considered in terms of the exposure and resultant potential toxicity to forest songbirds inhabiting or foraging in treated hardwood canopies.
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