|
Diquat Dibromide
Diquat is the ISO common name for an organic dication that, as a salt with counterions such as bromide or chloride is used as a contact herbicide that produces desiccation and defoliation. Diquat is no longer approved for use in the European Union, although its registration in many other countries including the USA is still valid. Synthesis Pyridine is oxidatively coupled to form 2,2′-bipyridine over a heated Raney nickel catalyst. The ethylene bridge is formed by the reaction with 1,2-dibromoethane : History Diquat's herbicidal properties were recognized in 1955 in the Imperial Chemical Industries (ICI) laboratories at Jealott's Hill, following its first synthesis at ICI's Dyestuffs Division in Blackley, England. It was active on test plants at application rates as low as 0.1 lb/acre. It was found that only those quaternary salts which were capable of being converted by reducing agents to radical cations had herbicidal activity and another of these was paraquat, which w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Organization For Standardization
The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in Article 3 of the ISO Statutes. ISO was founded on 23 February 1947, and (as of November 2022) it has published over 24,500 international standards covering almost all aspects of technology and manufacturing. It has 809 Technical committees and sub committees to take care of standards development. The organization develops and publishes standardization in all technical and nontechnical fields other than electrical and electronic engineering, which is handled by the IEC.Editors of Encyclopedia Britannica. 3 June 2021.International Organization for Standardization" ''Encyclopedia Britannica''. Retrieved 2022-04-26. It is headquartered in Geneva, Switzerland, and works in 167 countries . The three official languages of the ISO are English, Fren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imperial Chemical Industries
Imperial Chemical Industries (ICI) was a British chemical company. It was, for much of its history, the largest manufacturer in Britain. It was formed by the merger of four leading British chemical companies in 1926. Its headquarters were at Millbank in London. ICI was a constituent of the FT 30 and later the FTSE 100 indices. ICI made general chemicals, plastics, paints, pharmaceuticals and speciality products, including food ingredients, speciality polymers, electronic materials, fragrances and flavourings. In 2008, it was acquired by AkzoNobel, which immediately sold parts of ICI to Henkel and integrated ICI's remaining operations within its existing organisation. History Development of the business (1926–1944) The company was founded in December 1926 from the merger of four companies: Brunner Mond, Nobel Explosives, the United Alkali Company, and British Dyestuffs Corporation. It established its head office at Millbank in London in 1928. Competing with DuPont a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Insecticide, Fungicide, And Rodenticide Act
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) is a United States federal law that set up the basic U.S. system of pesticide regulation to protect applicators, consumers, and the environment. It is administered and regulated by the United States Environmental Protection Agency (EPA) and the appropriate environmental agencies of the respective states. FIFRA has undergone several important amendments since its inception. A significant revision in 1972 by the Federal Environmental Pesticide Control Act (FEPCA) and several others have expanded EPA's present authority to oversee the sales and use of pesticides with emphasis on the preservation of human health and protection of the environment by "(1) strengthening the registration process by shifting the burden of proof to the chemical manufacturer, (2) enforcing compliance against banned and unregistered products, and (3) promulgating the regulatory framework missing from the original law". History The Federal I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Environmental Protection Agency
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it began operation on December 2, 1970, after Nixon signed an executive order. The order establishing the EPA was ratified by committee hearings in the House and Senate. The agency is led by its administrator, who is appointed by the president and approved by the Senate. The current administrator is Michael S. Regan. The EPA is not a Cabinet department, but the administrator is normally given cabinet rank. The EPA has its headquarters in Washington, D.C., regional offices for each of the agency's ten regions and 27 laboratories. The agency conducts environmental assessment, research, and education. It has the responsibility of maintaining and enforcing national standards under a variety of environmental laws, in consultation with state, tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pesticide Regulation In The United States
Pesticide regulation in the United States is primarily a responsibility of the Environmental Protection Agency (EPA). In America, it was not till the 1950s that pesticides were regulated in terms of their safety. The Pesticides Control Amendment (PCA) of 1954 was the first time Congress passed guidance regarding the establishment of safe limits for pesticide residues on food. It authorized the Food and Drug Administration (FDA) to ban pesticides they determined to be unsafe if they were sprayed directly on food. The Food Additives Amendment, which included the Delaney Clause, prohibited the pesticide residues from any carcinogenic pesticides in processed food. In 1959, pesticides were required to be registered. In 1970, President Richard Nixon created the EPA and shifted control of pesticide regulation from the US Department of Agriculture (USDA), the US Department of the Interior (DOI), and FDA to the newly created agency. By this time, public awareness of potential human health an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pesticide Formulation
The biological activity of a pesticide, be it chemical or biological in nature, is determined by its active ingredient (AI - also called the ''active substance''). Pesticide products very rarely consist of pure technical material. The AI is usually formulated with other materials and this is the product as sold, but it may be further diluted in use. Formulations improves the properties of a chemical for handling, storage, application and may substantially influence effectiveness and safety. Formulation terminology follows a 2-letter convention: (''e.g.'' GR: granules) listed by CropLife International (formerly GIFAP then GCPF) in the ''Catalogue of Pesticide Formulation Types'' (Monograph 2); see download page Some manufacturers do not follow these industry standards, which can cause confusion for users. Water-miscible formulations By far the most frequently used products are formulations for mixing with water then applying as sprays. Water miscible, older formulations include: * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reactive Oxygen Species
In chemistry, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (). Examples of ROS include peroxides, superoxide, hydroxyl radical, singlet oxygen, and alpha-oxygen. The reduction of molecular oxygen () produces superoxide (), which is the precursor to most other reactive oxygen species: :O2 + e^- -> \ ^\bullet O2- Dismutation of superoxide produces hydrogen peroxide (): :2 H+ + \ ^\bullet O2^- + \ ^\bullet O2^- -> H2O2 + O2 Hydrogen peroxide in turn may be partially reduced, thus forming hydroxide ions and hydroxyl radicals (), or fully reduced to water: :H2O2 + e^- -> HO^- + \ ^\bullet OH :2 H+ + 2 e- + H2O2 -> 2 H2O In a biological context, ROS are byproducts of the normal metabolism of oxygen. ROS have roles in cell signaling and homeostasis. ROS are intrinsic to cellular functioning, and are present at low and stationary levels in normal cells. In plants, ROS are involved in metabolic processes related to photoprotection and toleran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferredoxin
Ferredoxins (from Latin ''ferrum'': iron + redox, often abbreviated "fd") are iron–sulfur proteins that mediate electron transfer in a range of metabolic reactions. The term "ferredoxin" was coined by D.C. Wharton of the DuPont Co. and applied to the "iron protein" first purified in 1962 by Mortenson, Valentine, and Carnahan from the anaerobic bacterium '' Clostridium pasteurianum''. Another redox protein, isolated from spinach chloroplasts, was termed "chloroplast ferredoxin". The chloroplast ferredoxin is involved in both cyclic and non-cyclic photophosphorylation reactions of photosynthesis. In non-cyclic photophosphorylation, ferredoxin is the last electron acceptor thus reducing the enzyme NADP+ reductase. It accepts electrons produced from sunlight- excited chlorophyll and transfers them to the enzyme ferredoxin: NADP+ oxidoreductase . Ferredoxins are small proteins containing iron and sulfur atoms organized as iron–sulfur clusters. These biological " capacitors" can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosystem I
Photosystem I (PSI, or plastocyanin–ferredoxin oxidoreductase) is one of two photosystems in the photosynthetic light reactions of algae, plants, and cyanobacteria. Photosystem I is an integral membrane protein complex that uses light energy to catalyze the transfer of electrons across the thylakoid membrane from plastocyanin to ferredoxin. Ultimately, the electrons that are transferred by Photosystem I are used to produce the moderate-energy hydrogen carrier NADPH. The photon energy absorbed by Photosystem I also produces a proton-motive force that is used to generate ATP. PSI is composed of more than 110 cofactors, significantly more than Photosystem II. History This photosystem is known as PSI because it was discovered before Photosystem II, although future experiments showed that Photosystem II is actually the first enzyme of the photosynthetic electron transport chain. Aspects of PSI were discovered in the 1950s, but the significance of these discoverie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Rot
Black rot is a name used for various diseases of cultivated plants caused by fungi or bacteria, producing dark brown discoloration and decay in the leaves of fruit and vegetables: * A disease of the apple, pear and quince caused by a fungus (''Botryosphaeria obtusa'' or ''Physalospora cydoniae'') * A disease of grape vines caused by a fungus (''Guignardia bidwellii''), affecting the aboveground part of the vine, and favored by warm, humid weather; also called grape rot * A disease of cabbage and related plants caused by a bacterium (''Xanthomonas campestris pv. campestris''). Occurring around the world, it affects primarily the aboveground parts of plants. Vegetables in the crucifer family are susceptible, including broccoli, Brussels sprouts, cabbage, cauliflower, Chinese cabbage, kale, mustard, radish, rutabaga, and turnip. Many weeds may host this pathogen including Shepherd's Purse, wild mustard, and yellow rocket. * A disease of the potato caused by a bacterium (''Erwinia atrose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MCPA
MCPA (2-methyl-4-chlorophenoxyacetic acid) is a powerful, selective, widely used phenoxy herbicide. The pure compound is a brown-colored powder. MCPA has been extensively used in agriculture to control broad-leaf weeds as a growth regulator primarily in pasture and cereal crops field since 1945. The mode of action of MCPA is as an auxin, which are growth hormones that naturally exist in plants. Overdose application of MCPA acts as an herbicide and results in abnormal growth. History In 1936 investigations began at ICIs Jealott's Hill research center into the effects of auxins on plant growth looking specifically for a way to kill weeds without harming crops such as wheat and oats. William Templeman 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. Templeman and the ICI group were searching for compounds w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auxin
Auxins (plural of auxin ) are a class of plant hormones (or plant-growth regulators) with some morphogen-like characteristics. Auxins play a cardinal role in coordination of many growth and behavioral processes in plant life cycles and are essential for plant body development. The Dutch biologist Frits Warmolt Went first described auxins and their role in plant growth in the 1920s. Kenneth V. Thimann became the first to isolate one of these phytohormones and to determine its chemical structure as indole-3-acetic acid (IAA). Went and Thimann co-authored a book on plant hormones, ''Phytohormones'', in 1937. Overview Auxins were the first of the major plant hormones to be discovered. They derive their name from the Greek word αυξειν (''auxein'' – "to grow/increase"). Auxin is present in all parts of a plant, although in very different concentrations. The concentration in each position is crucial developmental information, so it is subject to tight regulation through both meta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
