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Pepper Mild Mottle Virus
''Pepper mild mottle virus'' (PMMoV) is a plant pathogenic virus that occurs worldwide on species of field grown bell, hot and ornamental pepper species. It is caused by members of the plant virus genus ''Tobamovirus''- otherwise known as the tobacco mosaic virus family. ''Tobamovirus'' are viruses that contain positive sense RNA genomes that infect plants. Symptoms of the disease vary depending on the cultivar. Typical symptoms include the chlorosis of leaves, stunting, and distorted and lumpy fruiting structures. The virus is spread by mechanical transmission and infected seeds. Avoidance is the best means of controlling the disease because once a plant is infected it cannot be treated. Only seeds that have been tested and treated for the pathogen should be planted. History The origin of PMMoV has been linked to ''Tomato mosaic virus'', as they both reside in the ''Tobacco mosaic virus'' family. The ''Tunisian Journal of Plant Protection'' brought about the link between PMMoV to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobamovirus
''Tobamovirus'' is a genus of positive-strand RNA viruses in the family '' Virgaviridae.'' Many plants, including tobacco, potato, tomato, and squash, serve as natural hosts. Diseases associated with this genus include: necrotic lesions on leaves. The name ''Tobamovirus'' comes from the host and symptoms of the first virus discovered (''Tobacco mosaic virus''). There are four informal subgroups within this genus: these are the tobamoviruses that infect the brassicas, cucurbits, malvaceous, and solanaceous plants. The main differences between these groups are genome sequences, and respective range of host plants. There are 37 species in this genus. Structure Tobamoviruses are non-enveloped, with helical rod geometries, and helical symmetry. The diameter is around 18 nm, with a length of 300–310 nm. Genomes are linear and non-segmented, around 6.3–6.5kb in length. Genome The RNA genome encodes at least four polypeptides: these are the non-structural protein and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georgia (U
Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the country in the Caucasus ** Kingdom of Georgia, a medieval kingdom ** Georgia within the Russian Empire ** Democratic Republic of Georgia, established following the Russian Revolution ** Georgian Soviet Socialist Republic, a constituent of the Soviet Union * Related to the US state ** Province of Georgia, one of the thirteen American colonies established by Great Britain in what became the United States ** Georgia in the American Civil War, the State of Georgia within the Confederate States of America. Other places * 359 Georgia, an asteroid * New Georgia, Solomon Islands * South Georgia and the South Sandwich Islands Canada * Georgia Street, in Vancouver, British Columbia, Canada * Strait of Georgia, British Columbia, Canada United K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volunteer (botany)
In gardening and agronomic terminology, a volunteer is a plant that grows on its own, rather than being deliberately planted by a farmer or gardener. Volunteers often grow from seeds that float in on the wind, are dropped by birds, or are inadvertently mixed into compost. Some volunteers may be encouraged by gardeners once they appear, being watered, fertilized, or otherwise cared for, unlike weeds, which are unwanted volunteers. The action of such plants – to sprout or grow in this fashion – may also be described as volunteering. Volunteers that grow from the seeds of specific cultivars are not reliably identical or similar to their parent and often differ significantly from it. Such open pollinated plants, if they show desirable characteristics, may be selected to become new cultivars. Law This definition also has the meaning in the law context, defining the drug-producing plant like cannabis as a "volunteer" if it grows of its own accord from seeds or roots and is not inten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crop Rotation
Crop rotation is the practice of growing a series of different types of crops in the same area across a sequence of growing seasons. It reduces reliance on one set of nutrients, pest and weed pressure, and the probability of developing resistant pests and weeds. Growing the same crop in the same place for many years in a row, known as monocropping, gradually depletes the soil of certain nutrients and selects for a highly competitive pest and weed community. Without balancing nutrient use and diversifying pest and weed communities, the productivity of monocultures is highly dependent on external inputs. Conversely, a well-designed crop rotation can reduce the need for synthetic fertilizers and herbicides by better using ecosystem services from a diverse set of crops. Additionally, crop rotations can improve soil structure and organic matter, which reduces erosion and increases farm system resilience. History Agriculturalists have long recognized that suitable rotations — such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromomethane
Bromomethane, commonly known as methyl bromide, is an organobromine compound with formula C H3 Br. This colorless, odorless, nonflammable gas is produced both industrially and biologically. It has a tetrahedral shape and it is a recognized ozone-depleting chemical. It was used extensively as a pesticide until being phased out by most countries in the early 2000s. Occurrence and manufacture Bromomethane originates from both natural and human sources. In the ocean, marine organisms are estimated to produce 56,000 tonnes annually. It is also produced in small quantities by certain terrestrial plants, such as members of the family Brassicaceae. It is manufactured for agricultural and industrial use by treating methanol with bromine in the presence of sulfur or hydrogen sulfide: :6 CH3OH + 3 Br2 + S → 6 CH3Br + 2 H2O + H2SO4 Uses In 1999, an estimated 71,500 tonnes of synthetic methyl bromide were used annually worldwide. 97% of this estimate was used for fumigation purposes, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Bromide
Bromomethane, commonly known as methyl bromide, is an organobromine compound with formula C H3 Br. This colorless, odorless, nonflammable gas is produced both industrially and biologically. It has a tetrahedral shape and it is a recognized ozone-depleting chemical. It was used extensively as a pesticide until being phased out by most countries in the early 2000s. Occurrence and manufacture Bromomethane originates from both natural and human sources. In the ocean, marine organisms are estimated to produce 56,000 tonnes annually. It is also produced in small quantities by certain terrestrial plants, such as members of the family Brassicaceae. It is manufactured for agricultural and industrial use by treating methanol with bromine in the presence of sulfur or hydrogen sulfide: :6 CH3OH + 3 Br2 + S → 6 CH3Br + 2 H2O + H2SO4 Uses In 1999, an estimated 71,500 tonnes of synthetic methyl bromide were used annually worldwide. 97% of this estimate was used for fumigation purposes, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allophane
Allophane is an amorphous to poorly crystalline hydrous aluminium silicate clay mineraloid. Its chemical formula is Al2O3·(SiO2)1.3-2·(2.5-3)H2O. Since it has short-range atomic order, it is a mineraloid, rather than a mineral, and can be identified by its distinctive infrared spectrum and its X-ray diffraction pattern. It was first described in 1816 in Gräfenthal, Thuringia, Germany. Allophane is a weathering or hydrothermal alteration product of volcanic glass and feldspars and sometimes has a composition similar to kaolinite but generally has a molar ratio of Al:Si = 2. It typically forms under mildly acidic to neutral pH (5–7). Its structure has been debated, but it is similar to clay minerals and is composed of curved alumina octahedral and silica tetrahedral layers.Smalley, I.J. 1979. A spherical structure for allophane. Nature 281, 339 only Transmission electron micrographs show that it is generally made up of aggregates of hollow spherules ~3–5 nm in diameter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humus
In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Latin word for "earth" or "ground". In agriculture, "humus" sometimes also is used to describe mature or natural compost extracted from a woodland or other spontaneous source for use as a soil conditioner. It is also used to describe a topsoil horizon that contains organic matter (''humus type'', ''humus form'', or ''humus profile''). Humus has many nutrients that improve the health of soil, nitrogen being the most important. The ratio of carbon to nitrogen (C:N) of humus commonly ranges between eight and fifteen with the median being about twelve. It also significantly affects the bulk density of soil. Humus is amorphous and lacks the "cellular cake structure characteristic of plants, micro-organisms or animals". Description The primary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect Vector
In epidemiology, a disease vector is any living agent that carries and transmits an infectious pathogen to another living organism; agents regarded as vectors are organisms, such as parasites or microbes. The first major discovery of a disease vector came from Ronald Ross in 1897, who discovered the malaria pathogen when he dissected a mosquito. Arthropods Arthropods form a major group of pathogen vectors with mosquitoes, flies, sand flies, lice, fleas, ticks, and mites transmitting a huge number of pathogens. Many such vectors are haematophagous, which feed on blood at some or all stages of their lives. When the insects feed on blood, the pathogen enters the blood stream of the host. This can happen in different ways. The ''Anopheles'' mosquito, a vector for malaria, filariasis, and various arthropod-borne-viruses (arboviruses), inserts its delicate mouthpart under the skin and feeds on its host's blood. The parasites the mosquito carries are usually located in its salivary gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and its subdisciplines are traditionally done in labware such as test tubes, flasks, Petri dishes, and microtiter plates. Studies conducted using components of an organism that have been isolated from their usual biological surroundings permit a more detailed or more convenient analysis than can be done with whole organisms; however, results obtained from ''in vitro'' experiments may not fully or accurately predict the effects on a whole organism. In contrast to ''in vitro'' experiments, ''in vivo'' studies are those conducted in living organisms, including humans, and whole plants. Definition ''In vitro'' ( la, in glass; often not italicized in English usage) studies are conducted using components of an organism that have been isolated fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endosperm
The endosperm is a tissue produced inside the seeds of most of the flowering plants following double fertilization. It is triploid (meaning three chromosome sets per nucleus) in most species, which may be auxin-driven. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This can make endosperm a source of nutrition in animal diet. For example, wheat endosperm is ground into flour for bread (the rest of the grain is included as well in whole wheat flour), while barley endosperm is the main source of sugars for beer production. Other examples of endosperm that forms the bulk of the edible portion are coconut "meat" and coconut "water", and corn. Some plants, such as orchids, lack endosperm in their seeds. Origin of endosperm Ancestral flowering plants have seeds with small embryos and abundant endosperm. The evolutionary development of flowering plants trends towards plants with mature seeds with little or no endosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
