ISSN:
1365-3180
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Terbutryn (2-ethylamino-4-(tert-butylamino)-6-methylthio-s-triazine) was applied in June 1978, to two farm ponds (A and C) near Winnipeg. Canada, to give 100 μg/l water concentrations. The persistence of the herbicide and its degradation products was monitored over a 61-week period following application. The half-life of terbutryn m the water column ranged from 3 weeks in Pond C, which contained heavy growths of cattails (Typha sp.) and duckweed (Lemna sp.), to 30 days in Pond A. which was free from aquatic macrophytes, Terbutryn residues m sediment reached a maximum of 1.4 μg/g (dry wt) in Pond A and 0.5 μg/g in C. Maximum concentrations of N-deethylated terbutryn (2amino-4-(tert-butylamino)-6-methylthio-s-tria-zine)(DET) were 14.4 μg/l in Pond A water after 61 weeks and 0.14 μg/g in Pond C sediment after 30 weeks. The maximum concentration of hydroxy-terbutryn (2-hydroxy-4-ethyl-amino-6-(tert-butylamino)-s-triazine) (HT) observed in pond water was 6.4 μg/l in Pond C after 7 weeks. HT was not detected in sediment (〈0.05 μg/g) during the study. After 61 weeks, about 50% of the terbutryn that was added could still be accounted for in Pond A and 35% in Pond C. Terbutryn. DET and HT represented an estimated 71, 28 and 1%, respectively, of total terbutryn remaining in Pond A and 65, 29 and 6%, respectively, of that remaining in Pond C, 61 weeks after application, Terbutryn residues in Typha ranged from 0.3 μg/g (dry wt) in the shoot to 3.3 μg/g in the roots. After 12 weeks, terbutryn residues in plants (Pond C) were estimated to account for 1 to 4% of the herbicide in the pond.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3180.1981.tb00097.x
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