Mobility and degradation of the herbicide imazosulfuron in lysimeters under field conditions.
The mobility and degradation of imazosulfuron, labeled with carbon-14 at the imidazole ([imi-(14)C]imazo) or pyrimidine ring ([pyr-(14)C]imazo), in lysimeters with 1 m(2) surface and 110 cm depth were investigated for three years. One lysimeter was treated with [imi-(14)C]imazo in two successive years at the rate of 50 g of active ingredient (ai)/ha each. The other two lysimeters were treated once with [pyr-(14)C]imazo and a mixture (1:1, w/w) of the two labeled imazosulfurons, respectively (50 g of ai/ha). In the first and second years of monitoring, the yearly mean concentration of (14)C in the leachate water was <0.10 microg/L in each lysimeter. Although in the third year the concentration of (14)C in the leachate water was 0.17 microg/L for the lysimeter treated twice with [imi-(14)C]imazo, the concentration of imazosulfuron and its degradation products in the leachate water ranged from 0.01 to 0.06 microg/L. At the study termination, the main portion of (14)C recovered was found in the upper 30 cm soil layer in each lysimeter, and no (14)C was detected below a depth of 50 cm. These findings indicated that imazosulfuron and its degradation products in soils translocated into groundwater only slightly.
Mikata
Kazuki
K
Agricultural Research Laboratories, Agro Company, Takeda Chemical Industries, Ltd., 10 Wadai, Tsukuba, Ibaraki 300-4247, Japan. Mikata_Kazuki@sumi-take.co.jp
Schnöder
Frank
F
Braunwarth
Carola
C
Ohta
Kazunari
K
Tashiro
Shigeki
S
D002250:Carbon Radioisotopes; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006540:Herbicides / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis; D011725:Pyridines / Q000737:chemistry*; D011743:Pyrimidines / Q000737:chemistry*; D012987:Soil / Q000032:analysis*; D014867:Water / Q000032:analysis*
D002250:Carbon Radioisotopes; D006540:Herbicides; D010573:Pesticide Residues; D011725:Pyridines; D011743:Pyrimidines; D012987:Soil; D014867:Water; C433346:1-(2-chloroimidazo(1,2-a)pyridin-3-ylsulfonyl)-3-(4,6-dimethoxypyrimidin-2-yl)urea