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Persistence studies with the herbicide sethoxydim in prairie soils
Author(s) -
SMITH ALLAN E.,
HSIAO ANDREW I.
Publication year - 1983
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1111/j.1365-3180.1983.tb00547.x
Subject(s) - loam , persistence (discontinuity) , soil water , chemistry , environmental chemistry , agronomy , environmental science , biology , soil science , geology , geotechnical engineering
Summary The persistence of [ 14 C]sethoxydim (2‐[1‐(ethoxyimino)butyl]‐5‐[2‐(ethylthio)propyl]‐3‐hydroxy‐2‐cyclohexene‐1‐one) at the 2 μg g −1 level was studied under laboratory conditions in three soils at 20°C and 85% of their field capacity moistures. Following extraction of the soils with methanol, the herbicide remaining was determined using radiochemical techniques. Loss of radioactivity was more rapid on moist clay loam and sandy loam, where the half‐lives were 12 days, than on heavy clay in which the half‐life was 26 days. Loss of radioactivity from air‐dried soils (15% of field capacity) was negligible with over 94% of the applied activity being recovered after 28 days. The persistence of sethoxydim at a rate of 1 kg ha −1 was investigated under field conditions using small plots at three prairie locations for 3 successive years. Using an oat‐root bioassay procedure, no residues were detected in the 0–10 cm depths of any soils, any year, in September following May treatments.