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|Section2= |Section3= |Section7= |Section8= }} 2,4-Dichlorophenoxyacetic acid (usually referred to by its abbreviation, 2,4-D) is a common systemic herbicide used in the control of broadleaf weeds. It is a synthetic auxin (plant hormone) and one of the most widely used herbicides in the world. 2,4-D is a possible carcinogen per WHO, and some ester forms are highly toxic to fish and other aquatic life.〔(【引用サイトリンク】url=http://npic.orst.edu/factsheets/24Dgen.html )〕 Since 2014 Enlist Duo, which contains 2,4-D choline and glyphosate, has been approved in Canada and the U.S., and is used on genetically modified soybeans and genetically modified maize resistant to 2,4-D and glyphosate. 2,4-D was one of the ingredients in Agent Orange, a herbicide widely used during the Vietnam War,〔 but it was not 2,4-D but the other ingredient in Agent Orange, 2,4,5-T (since banned in the United States), and its contaminant dioxin, which created the controversy regarding health effects of Agent Orange.〔〔 (【引用サイトリンク】url=http://www2.epa.gov/ingredients-used-pesticide-products/24-d )〕 == Applications == 2,4-D is primarily used as a selective herbicide which kills many terrestrial and aquatic broadleaf weeds, but not grasses. It acts by mimicking the action of the plant growth hormone auxin, which results in uncontrolled growth and eventually death in susceptible plants. Because it was discovered in the 1940s, there is no longer a patent governing the manufacture and sale of 2,4-D, and any company is free to produce it. Thus, it is sold in various formulations under a wide variety of brand names.〔 2,4-D can be found in commercial lawn herbicide mixtures, which often contain other active ingredients including mecoprop and dicamba. Over 1,500 herbicide products contain 2,4-D as an active ingredient.〔EPA Last revised March 30, 2007 (EPA Chemical Summary: 2,4-Dichlorophenoxyacetic Acid (2,4-D) ) 〕 A wide variety of different sectors use products containing 2,4-D to kill weeds and unwanted vegetation. In agriculture, it was the first herbicide found to be capable of selectively killing weeds but not crops. It has been used since 1945 to control broad-leafed weeds in pastures, orchards, and cereal crops such as corn, oats, rice and wheat. Cereals, in particular, have excellent tolerance to 2,4-D when it is applied before planting. 2,4-D is the cheapest way for farmers to control winter annual weeds by spraying in the fall, often at the lowest recommended rate. This is particularly effective before planting beans, peas, lentils and chickpeas. In domestic lawn and garden maintenance, 2,4-D is commonly used for weed control in lawns and other turf. It is used to kill unwanted weeds such as dandelions, plantain, clover and chickweed. In forestry, it is used for stump treatment, trunk injection, and selective control of brush in conifer forests. Along roadways, railways, and power lines it is used to control weeds and brush which might interfere with safe operation and damage equipment. Along waterways it is used to control aquatic weeds that might interfere with boating, fishing and swimming or clog irrigation and hydroelectric equipment. It is often used by government agencies to control the spread of invasive, noxious and non-native weed species and prevent them from crowding out native species, and also to control many poisonous weeds such as poison ivy and poison oak.〔 2,4-D continues to be used, where legal, for its low cost. Where municipal lawn pesticide bylaws exist, such as in Canada, alternatives must be used. A 2010 monitoring study conducted in the US and Canada found that "current exposures to 2,4-D are below applicable exposure guidance values."〔Aylward LL et al. (Biomonitoring data for 2,4-dichlorophenoxyacetic acid in the United States and Canada: interpretation in a public health risk assessment context using Biomonitoring Equivalents. )''Environ Health Perspect''. 2010 Feb;118(2):177-81. doi: 10.1289/ehp.0900970. PMCID PMC2831914 PMID 20123603 〕 2,4 D has been used in laboratories for plant research as a supplement in plant cell culture media such as MS medium since at least 1962.〔Murashige, T. and F. Skoog. A revised medium for rapid growth and bioassays with tobaccotissue cultures. Physiol. Plantarum 1962. 15:473-97. in: Sharp WR1, Gunckel JE. (Comparisons of Pith Callus With Crown-Gall and Genetic Tumors of Nicotiana glauca, N. langsdorffii, and N. glauca-langsdorffii Grown in Vitro. II. Nutritional Physiology. ) Plant Physiol. 1969 Jul;44(7):1073-9.PMC396217.open access 〕 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「2,4-Dichlorophenoxyacetic acid」の詳細全文を読む スポンサード リンク
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