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Herbicides
Herbicides (, ), also commonly known as weed killers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page for EPA reports on pesticide use ihere Selective herbicides control specific weed species while leaving the desired crop relatively unharmed, while non-selective herbicides (sometimes called "total weed killers") kill plants indiscriminately. The combined effects of herbicides, nitrogen fertilizer, and improved cultivars has increased yields (per acre) of major crops by three to six times from 1900 to 2000. In the United States in 2012, about 91% of all herbicide usage, was determined by weight applied, in agriculture. In 2012, world pesticide expenditures totaled nearly US$24.7 billion; herbicides were about 44% of those sales and constituted the biggest portion, followed by insecticides, fungicides, and fumigants. Herbicide is also used i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbicidal Warfare
Herbicidal warfare is the use of substances primarily designed to destroy the plant-based ecosystem of an area. Although herbicidal warfare use chemical substances, its main purpose is to disrupt agricultural food production and/or to destroy plants which provide cover or concealment to the enemy, not to asphyxiate or poison humans and/or destroy human-made structures. Herbicidal warfare has been forbidden by the Environmental Modification Convention since 1978, which bans "any technique for changing the composition or structure of the Earth's Biota (ecology), biota". History Modern day herbicidal warfare resulted from military research discoveries of plant growth regulators during World War II, and is therefore a technological advance on the scorched earth practices by armies throughout history to deprive the enemy of food and cover. Work on military herbicides began in England in 1940, and by 1944, the United States joined in the effort. Even though herbicides are chemicals, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2,4-D
2,4-Dichlorophenoxyacetic acid is an organic compound with the chemical formula . It is usually referred to by its ISO common name 2,4-D. It is a systemic herbicide that kills most broadleaf weeds by causing uncontrolled growth, but most grasses such as cereals, lawn turf, and grassland are 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. History 2,4-D was first reported in 1944 by Franklin D. Jones at the C. B. Dolge Company in Connecticut. The biological activity of 2,4-D as well as the similar hormone herbicides 2,4,5-T, and MCPA were discovered during World W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weed
A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. Plants with characteristics that make them hazardous, aesthetically unappealing, difficult to control in managed environments, or otherwise unwanted in agriculture, farm land, Orchard, orchards, gardens, lawns, Park, parks, recreational spaces, residential and industrial areas, may all be considered weeds.Holzner, W., & Numata, M. (Eds.). (2013). ''Biology and ecology of weeds'' (Vol. 2). Springer Science & Business Media. The concept of weeds is particularly significant in agriculture, where the presence of weeds in fields used to grow crops may cause major losses in yields. Invasive species, plants introduced to an environment where their presence negatively impacts the overall functioning and biodiversity of the ecosystem, may also sometime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Chlorate
Sodium chlorate is an inorganic compound with the chemical formula Na ClO3. It is a white crystalline powder that is readily soluble in water. It is hygroscopic. It decomposes above 300 °C to release oxygen and leaves sodium chloride. Several hundred million tons are produced annually, mainly for applications in bleaching pulp to produce high brightness paper. Synthesis Industrially, sodium chlorate is produced by the electrolysis of concentrated sodium chloride solutions. All other processes are obsolete. The sodium chlorate process is not to be confused with the chloralkali process, which is an industrial process for the electrolytic production of sodium hydroxide and chlorine gas. The overall reaction can be simplified to the equation: First, chloride is oxidised to form intermediate hypochlorite, ClO−, which undergoes further oxidation to chlorate along two competing reaction paths: (1) Anodic chlorate formation at the boundary layer between the electrolyte and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerosene
Kerosene, or paraffin, is a combustibility, combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in Aviation fuel, aviation as well as households. Its name derives from the Greek (''kērós'') meaning "wax"; it was registered as a trademark by Nova Scotian, Nova Scotia geologist and inventor Abraham Pineo Gesner, Abraham Gesner in 1854 before evolving into a generic trademark. It is sometimes spelled kerosine in scientific and industrial usage. Kerosene is widely used to power jet engines of aircraft (jet fuel), as well as some rocket engines in a highly refined form called RP-1. It is also commonly used as a cooking and lighting fuel, and for fire toys such as Poi (performance art)#Fire poi, poi. In parts of Asia, kerosene is sometimes used as fuel for small outboard motors or even motorcycles. World total kerosene consumption for all purposes is equivalent to about 5,500,000 barrels per day as of July 2023. The term "kerosene" is comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfusion
Perfusion is the passage of fluid through the circulatory system or lymphatic system to an organ (anatomy), organ or a tissue (biology), tissue, usually referring to the delivery of blood to a capillary bed in tissue. Perfusion may also refer to fixation via perfusion, used in histological studies. Perfusion is measured as the rate at which blood is delivered to tissue, or volume of blood per unit time (blood volumetric flow rate, flow) per unit tissue mass. The SI unit is m3/(s·kg), although for human organs perfusion is typically reported in ml/min/g. The word is derived from the French verb ''perfuser'', meaning to "pour over or through". All animal tissues require an adequate blood supply for health and life. Poor perfusion (malperfusion), that is, ischemia, causes health problems, as seen in cardiovascular disease, including coronary artery disease, cerebrovascular disease, peripheral artery disease, and many other conditions. Tests verifying that adequate perfusion exists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agricultural And Food Research Council
The Agricultural and Food Research Council (AFRC) was a British Research Council responsible for funding and managing scientific and technological developments in farming and horticulture. History The AFRC was formed in 1983 from its predecessor, the Agricultural Research Council (ARC). It was replaced by the Biotechnology and Biological Sciences Research Council Biotechnology and Biological Sciences Research Council (BBSRC), part of UK Research and Innovation, is a non-departmental public body (NDPB), and is the largest UK public funder of non-medical bioscience. It predominantly funds science, scient ... (BBSRC) as a result of government reorganisation in 1994. At that time, Sir William Henderson who was secretary to the AFRC claimed that "agriculture was a success story" hence the AFRC could be closed and a new vision for research was envisaged in the creation of the BBSRC. With this shift in emphasis, there also followed the closure of several educational and research o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rothamsted Research
Rothamsted Research, previously known as the Rothamsted Experimental Station and then the Institute of Arable Crops Research, is one of the oldest agricultural experiment station, agricultural research institutions in the world, having been founded in 1843. It is located at Harpenden in the English county of Hertfordshire and is a Charitable organization, registered charity under English law. Two of the station's best known and longest-running experiments are the Broadbalk Experiment, planted annually with winter wheat since 1843, and the Park Grass Experiment, a biological study that started in 1856 and has been continuously monitored ever since. History The Rothamsted Experimental Station was founded in 1843 by John Bennet Lawes, a noted Victorian era entrepreneur and scientist who had founded one of the first artificial fertilizer manufacturing factories in 1842, on his 16th-century estate, Rothamsted Manor, to investigate the impact of inorganic and organic fertilizers on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juda Hirsch Quastel
Juda Hirsch Quastel, (October 2, 1899 – October 15, 1987) was a British-Canadian biochemist who pioneered diverse research in neurochemistry, soil metabolism, cellular metabolism, and cancer. Biography Quastel, also known as "Harry" or "Q," was born at Ecclesall Road in Sheffield the son of Jonas Quastel, a confectioner, and his wife, Flora Itcovitz. His parents had come to Britain in 1897 from Tarnopol in Galicia (Eastern Europe) and were married in Britain. He was named after his grandfather, Juda Quastel, a chemist in Tarnapol. He was educated at Sheffield Central Secondary School. In the First World War, he served with the British Army as a Laboratory Assistant at St George's Hospital from 1917 to 1919. Electing to study chemistry, Quastel received a baccalaureate from Imperial College London in 1921. Pursuing graduate work at the University of Cambridge, Quastel studied with Frederick Gowland Hopkins, the leading figure in British biochemistry and a future Nobe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microorganism
A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in Jain literature authored in 6th-century BC India. The scientific study of microorganisms began with their observation under the microscope in the 1670s by Anton van Leeuwenhoek. In the 1850s, Louis Pasteur found that microorganisms caused food spoilage, debunking the theory of spontaneous generation. In the 1880s, Robert Koch discovered that microorganisms caused the diseases tuberculosis, cholera, diphtheria, and anthrax. Microorganisms are extremely diverse, representing most unicellular organisms in all three domains of life: two of the three domains, Archaea and Bacteria, only contain microorganisms. The third domain, Eukaryota, includes all multicellular o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1-Naphthaleneacetic Acid
1-Naphthaleneacetic acid (NAA) is an organic compound with the formula C10H7CH2CO2H. This colorless solid is soluble in organic solvents. It features a carboxylmethyl group (CH2CO2H) linked to the "1-position" of naphthalene. Use and regulation NAA is a synthetic plant hormone in the auxin family and is an ingredient in many commercial horticultural products; it is a rooting agent and used for the vegetative propagation of plants from stem and leaf cuttings. It is also used for plant tissue culture. The hormone NAA does not occur naturally, and, like all auxins, is toxic to plants at high concentrations. In the United States, under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), products containing NAA require registration with the Environmental Protection Agency (EPA) as pesticides. Use and analysis NAA is widely used in agriculture for various purposes. It is considered to be only slightly toxic but when at higher concentrations it can be toxic to animals. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
