jeffquitney
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2,4-D Herbicide: "Death to Weeds" 1947 Dow Chemical
🕑 Added 2019-07-09 20:49:04 +0000 UTCmore at http://quickfound.net/
NEW PESTICIDES, INCORPORATING 2-4-D, ARE SHOWN. GOOD CROP-DUSTING. BEFORE-AND-AFTER SCENES OF CROPS & FIELDS. "DEATH SENTENCE" TO WEEDS AT START. TIME-LAPSE SHOT OF WEED WITHERING IN POT.
Originally a public domain film from the Library of Congress Prelinger Archives, , slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).
https://en.wikipedia.org/wiki/2,4-Dichlorophenoxyacetic_acid
Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/
2,4-Dichlorophenoxyacetic acid (usually called 2,4-D) is an organic compound with the chemical formula C8H6Cl2O3. It is a systemic herbicide which selectively kills most broadleaf weeds by causing uncontrolled growth in them, but leaves most grasses such as cereals, lawn turf, and grassland relatively unaffected.
2,4-D is one of the oldest and most widely available herbicides and defoliants in the world, having been commercially available since 1945, and is now produced by many chemical companies since the patent on it has long since expired. It can be found in numerous commercial lawn herbicide mixtures, and is widely used as a weedkiller on cereal crops, pastures, and orchards. Over 1,500 herbicide products contain 2,4-D as an active ingredient...
The discovery of 2,4-D as well as the similar hormone herbicides 2,4,5-T, and MCPA occurred during World War II and was a case of multiple discovery by four groups working independently under wartime secrecy in the United Kingdom and the United States: William G. Templeman and associates at Imperial Chemical Industries in the UK; Philip S. Nutman and associates at Rothamsted Research in the UK; Franklin D. Jones and associates at the American Chemical Paint Company; and Ezra Kraus, John W. Mitchell, and associates at the University of Chicago and the United States Department of Agriculture...
William Tempelman found that when indole-3-acetic acid (IAA), the naturally occurring auxin, was used at high concentrations, it could stop plant growth. In 1940, he published his finding that IAA killed broadleaf plants within a cereal field. The related compound, MCPA, was discovered at about the same time by other UK scientists.
The search for an acid with a longer half life, i.e., a metabolically and environmentally more stable compound, led to 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), both phenoxy herbicides and analogs of IAA. Robert Pokorny, an industrial chemist for the C.B. Dolge Company in Westport, Connecticut, published their synthesis in 1941.
Both compounds were developed as part of a clandestine wartime effort to create chemical warfare agents for use in World War II; although 2,4-D was not used this way during the war. Britain and the United States were looking for a chemical to starve Germany and Japan into submission by killing their potato and rice crops, but 2,4-D was found to be ineffective for that purpose, because both crops are tolerant of it. Within a year after the war ended, 2,4-D was commercially released as an herbicide to control broadleaf weeds in grain crops such as rice, and in the 1950s it was registered in the United States to control size and enhance skin colour in potatoes without affecting yields.
The first publication of 2,4-D's use as a selective herbicide came in 1944. The ability of 2,4-D to control broadleaf weeds in turf was documented soon thereafter, in 1944. Starting in 1945, the American Chemical Paint Company brought 2,4-D to market as an herbicide called "Weedone". It revolutionized weed control, as it was the first compound that, at low doses, could selectively control dicotyledons (broadleaf plants), but not most monocotyledons — narrowleaf crops, such as wheat, maize (corn), rice, and similar cereal grass crops. At a time when labor was scarce and the need for increased food production was large, it literally "replaced the hoe".
2,4-D is one of the ingredients in Agent Orange, an herbicide that was widely used during the Vietnam War. However, 2,3,7,8-Tetrachlorodibenzodioxin (TCDD), a contaminant in the production of another ingredient in Agent Orange, 2,4,5-T, was the cause of the adverse health effects associated with Agent Orange...
