Behavior of sprayed tricyclazole in rice paddy lysimeters

• Published in: Chemosphere (Oxford) Vol. 74; no. 8; pp. 1085 - 1089
• Main Authors: Phong, Thai Khanh, Nhung, Dang Thi Tuyet, Yamazaki, Kenichi, Takagi, Kazuhiro, Watanabe, Hirozumi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.02.2009; Elsevier
• Subjects: Applied sciences; environmental fate; Exact sciences and technology; fields; fungicide residues; Fungicides, Industrial - chemistry; Half-life; Hydrolysis; leaves; Lysimeter; lysimeters; Oryza - chemistry; Oryza sativa; paddy water; pesticide application; Photolysis; phylloplane; Plant Leaves - chemistry; Pollution; spraying; Thiazoles - chemistry; tricyclazole; Volatilization; Wash-off; water; Water - chemistry; Hydrolysis; Half-life; Photolysis; Lysimeter; Wash-off; Pollutant behavior; Liquid chromatography; Plant leaf; Rain; Ultraviolet radiation; Agriculture; Paddy field; Kinetics; Mass spectrometry; Half life; Photochemical degradation
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2008.10.050

The behavior of sprayed tricyclazole in rice paddy lysimeters was studied. Tricyclazole residues were measured from rice leaves and paddy water after tricyclazole spraying in paddy lysimeters. The rate of photolysis and hydrolysis of tricyclazole on the surface of rice leaves was also determined in a laboratory experiment. Tricyclazole was extracted from leaf and water samples and determined by liquid chromatography with UV or mass spectrometry. The hydrolysis half-lives of tricyclazole on rice leaves were 11.9 and 5.1 d for the formulated product and standard, respectively. The photolysis half-lives were longer, 16.4 d for the formulated product and 20.9 d for the standard. In the paddy lysimeter, tricyclazole dissipation on leaves involved either biphasic first-order kinetics or single-phase first-order kinetics, depending on the rainfall pattern. Half-lives of tricyclazole on lysimeter rice leaves were from 3.0 to 5.7 d. The dissipation of tricyclazole in paddy water followed single-phase first-order kinetics with half-lives ranging from 2.1 to 5.0 d.