Phototransformation of chlorimuron-ethyl on leaf surface |
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Authors: | Dr Partha P Choudhury Amitava Bhattacharya Prem Dureja |
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Institution: | 1. Department of Biochemistry , Uttar Banga Krishi Viswavidyalaya , Pundibari, Coohbehar-736 165, India parthatinku@yahoo.com;3. Department of Biochemistry , Bidhan Chandra Krishi Viswavidyalaya , Mohanpur, Nadia, West Bengal, India;4. Division of Agricultural Chemicals , Indian Agricultural Research Institute , New Delhi-110 012, India |
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Abstract: | Chlorimuron-ethyl, a post-emergent herbicide selectively used in soybean and maize, degrades mainly through chemical hydrolysis. Photolysis has also an important role in the degradation of this compound. Phototransformation of chlorimuron-ethyl takes place through the cleavage of the sulfonylurea bridge, dechlorination, de-esterification and cyclization. Enzymatic de-esterification usually takes place in plant system to liberate the free acid, chlorimuron, which, in fact, inhibits the acetolactate synthase enzyme. In the non-enzymatic environment, de-esterification generally does not occur at normal pH and in moisture-free medium. But on the leaf surface of maize crop de-esterification of chlorimuron-ethyl takes place. The moisture deposited on leaf surfaces by virtue of evapo-transpirational loss of water may cause the de-esterification of chlorimuron-ethyl to the free acid, chlorimuron. |
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Keywords: | Sulfonylurea herbicide chlorimuron-ethyl chlorimuron photolysis leaf surface glass surface sunlight |
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