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|Section2= |Section3= }} Propanil is a widely used contact herbicide. With an estimated use of about 8 million pounds in 2001, it is one of the more widely used herbicides in the United States.〔(2000-2001 Pesticide Market Estimates ), U.S. Environmental Protection Agency〕 Propanil is said to be in use in approximately 400,000 acres of rice production each year.〔(''Management of Propanil Resistant Sedges'' ), (June 19, 2014).〕 ==Mode of action== The principal mode of propanil's herbicidal action against weeds is inhibition of their photosynthesis and CO2 fixation. Plants photosynthesize in two stage. In stage I photosynthetic reactions capture sunlight energy and yield molecules with high energy content. In stage II these molecules react to capture CO2, yielding carbohydrate precursors. In the stage I reaction a chlorophyll molecule absorbs one photon (light) and loses one electron, starting an electron transport chain reaction leading to the stage II reactions. Propanil inhibits the electron transport chain reaction and its conversion of CO2 to carbohydrate precursors. That inhibits further development of the weed.〔Irina V. Ustyugova, (''Propanil (3,4-DCPA)-induced alterations of macrophage function'' ) 2-3 (Ph.D. thesis 2007). See also (''Inhibition of Photosynthesis: Inhibition at Photosystem II'' ) §§ 1–4.〕 Rice is relatively immune to propanil but most weeds are susceptible to it. The reason for the selectivity is that rice contains a high level of the enzyme aryl acylamidase (AAA), which rapidly metabolizes propanil to relativity nontoxic 3,4-dichloroaniline. Susceptible weeds lack the gene(s) coding for the AAA enzyme and thus succumb to propanil. However, intensive use of propanil and natural selection have caused some weeds to become resistant to propanil.〔() 215-16 (Stephen B. Powles & Dale L Shaner eds. 2001).〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「propanil」の詳細全文を読む スポンサード リンク
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