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Weed Of Cultivation
A weed of cultivation is any plant that is well-adapted to environments in which land is cultivated for growing some other plant. Many such weeds are quite specialised and can only thrive and reproduce where the ground has been broken by plough or spade. They are invariably annual and reproduction is by seed alone, which can in many species lie dormant for years in the soil until brought to the surface during cultivation. They have fast reproduction cycles, usually in one year from seed to seed, though some species can have more than one generation in one season. A few species such as groundsel (''Senecio vulgaris''), shepherd's purse (''Capsella bursa-pastoris''), red deadnettle (''Lamium purpureum'') and chickweed ('' Stellaria media'') can survive unharmed through very cold weather and are often able to seed even in winter. See also * Crop weed Crop weeds are weeds that grow amongst crops. Despite the potential for some crop weeds to be used as a food source, many can also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerastium Arvense Subsp
''Cerastium'' is a genus of annual, winter annual, or perennial plants belonging to the family (biology), family Caryophyllaceae. They are commonly called mouse-ear chickweed. Species are found nearly worldwide but the greatest concentration is in the northern temperate regions. There are about 200 species. A number are common weeds in fields and on disturbed ground. ''Cerastium'' species are used as food plants by the larvae of some Lepidoptera species including ''Coleophora chalcogrammella'' (which feeds exclusively on ''Cerastium arvense'') and ''Coleophora striatipennella'' (which has been recorded on ''Cerastium fontanum''). Selected species *''Cerastium aleuticum'' – Aleutian chickweed *''Cerastium alpinum'' – alpine chickweed *''Cerastium arcticum'' – arctic mouse-ear chickweed *''Cerastium arvense'' – field chickweed *''Cerastium axillare'' – Trans-Pecos chickweed *''Cerastium beeringinanum'' – Bering chickweed *''Cerastium bialynickii'' *''Cerastium biebers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tillage
Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and overturning. Examples of human-powered tilling methods using hand tools include shoveling, picking, mattock work, hoeing, and raking. Examples of draft-animal-powered or mechanized work include ploughing (overturning with moldboards or chiseling with chisel shanks), rototilling, rolling with cultipackers or other rollers, harrowing, and cultivating with cultivator shanks (teeth). Tillage that is deeper and more thorough is classified as primary, and tillage that is shallower and sometimes more selective of location is secondary. Primary tillage such as ploughing tends to produce a rough surface finish, whereas secondary tillage tends to produce a smoother surface finish, such as that required to make a good seedbed for many crops. Harrowing and rototilling often combine primary and secondary tillage into one operation. "Tillage" can also mean the lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weed
A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. This introduces the concept of humans and their goals in a particular setting.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 aim is growing crops or pastures of a single species, or a mixture of a few desired species. In such environments, other plant species are considered undesirable and therefore a weed. Besides, some weeds have undesirable characteristics making them a plant pest in most human settings.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24.Holzner, W., & Numata, M. (Eds.). (2013). ''Biology and ecology of weeds'' (Vol. 2). Spri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annual Plant
An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. The length of growing seasons and period in which they take place vary according to geographical location, and may not correspond to the four traditional seasonal divisions of the year. With respect to the traditional seasons, annual plants are generally categorized into summer annuals and winter annuals. Summer annuals germinate during spring or early summer and mature by autumn of the same year. Winter annuals germinate during the autumn and mature during the spring or summer of the following calendar year. One seed-to-seed life cycle for an annual plant can occur in as little as a month in some species, though most last several months. Oilseed rapa can go from seed-to-seed in about five weeks under a bank of fluorescent lamps. This style of growing is often used in classrooms for education. Many desert annuals are therophytes, be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproduction
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction. There are two forms of reproduction: asexual and sexual. In asexual reproduction, an organism can reproduce without the involvement of another organism. Asexual reproduction is not limited to single-celled organisms. The cloning of an organism is a form of asexual reproduction. By asexual reproduction, an organism creates a genetically similar or identical copy of itself. The evolution of sexual reproduction is a major puzzle for biologists. The two-fold cost of sexual reproduction is that only 50% of organisms reproduce and organisms only pass on 50% of their genes.John Maynard Smith ''The Evolution of Sex'' 1978. Sexual reproduction typically requires the sexual interaction of two specializ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosperm plants. Seeds are the product of the ripened ovule, after the embryo sac is fertilized by sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote, and grows within the mother plant to a certain size before growth is halted. The seed coat arises from the integuments of the ovule. Seeds have been an important development in the reproduction and success of vegetable gymnosperm and angiosperm plants, relative to more primitive plants such as ferns, mosses and liverworts, which do not have seeds and use water-dependent means to propagate themselves. Seed plants now dominate biological niches on land, from forests to grasslands both in hot and cold climates. The term "seed" also has a general me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dormancy
Dormancy is a period in an organism's life cycle when growth, development, and (in animals) physical activity are temporarily stopped. This minimizes metabolic activity and therefore helps an organism to conserve energy. Dormancy tends to be closely associated with environmental conditions. Organisms can synchronize entry to a dormant phase with their environment through predictive or consequential means. Predictive dormancy occurs when an organism enters a dormant phase ''before'' the onset of adverse conditions. For example, photoperiod and decreasing temperature are used by many plants to predict the onset of winter. Consequential dormancy occurs when organisms enter a dormant phase ''after'' adverse conditions have arisen. This is commonly found in areas with an unpredictable climate. While very sudden changes in conditions may lead to a high mortality rate among animals relying on consequential dormancy, its use can be advantageous, as organisms remain active longer and are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former term specifically to displaced soil. Soil consists of a solid phase of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three-state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists regard soil as an ecosystem. Most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Senecio Vulgaris
''Senecio vulgaris'', often known by the common names groundsel and old-man-in-the-spring, is a flowering plant in the family Asteraceae. It is an annual herb, native to Europe and widely naturalised as a ruderal species in suitable disturbed habitats worldwide. Description ''Senecio vulgaris'' is an erect herbaceous annual growing up to 16 inches (45 cm) tall. The inflorescences usually lack ray florets, the yellow disc florets mostly hidden by the bracts giving the flowers an inconspicuous appearance. ''Senecio vulgaris'' is very similar to ''Senecio viscosus'' but ''S. vulgaris'' does not have the glandular hairs and ray florets found in ''S. viscosus''. Leaves and stems Upper leaves of ''Senecio vulgaris'' are sessile, lacking their own stem ( petiole), alternating in direction along the length of the plant, two rounded lobes at the base of the stem ( auriculate) and sub-clasping above. Leaves are pinnately lobed and + long and wide, smaller towards the top of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsella Bursa-pastoris
''Capsella bursa-pastoris'', known as shepherd's purse because of its triangular flat fruits, which are purse-like, is a small annual and ruderal flowering plant in the mustard family (Brassicaceae). It is native to eastern Europe and Asia minor, but is naturalized and considered a common weed in many parts of the world, especially in colder climates, including British Isles, where it is regarded as an archaeophyte,Preston CD, Pearman DA & Dines TD (2002) New Atlas of the British Flora. Oxford University Press North America and China, but also in the Mediterranean and North Africa. ''C. bursa-pastoris'' is the second-most prolific wild plant in the world, and is common on cultivated ground and waysides and meadows. Scientists have referred to this species as a 'protocarnivore', since it has been found that its seeds attract and kill nematodes as a means to locally enrich the soil. History Pictured and published in 1486. Description ''Capsella bursa-pastoris'' plants grow from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamium Purpureum
''Lamium purpureum'', known as red dead-nettle, purple dead-nettle, or purple archangel, is an annual herbaceous flowering plant native to Europe and Asia. Varieties: * ''Lamium purpureum'' var. ''hybridum'' (Vill.) Vill. (synonym: ''Lamium hybridum'' Vill.) Description ''Lamium purpureum'' grows with square stems to 5–20 cm Parnell, J. and Curtis, T. 2012. ''Webb's An Irish Flora.'' Cork University Press. (rarely 30 cm) in height. The leaf, leaves have fine hairs, are green at the bottom and shade to purplish at the top; they are 2–4 cm long and broad, with a 1–2 cm petiole (leaf stalk), and wavy to serrated margins. The Floral symmetry, zygomorphic flowers are bright red-purple, with a top hood-like petal, two lower lip petal lobes and minute fang-like lobes between. The Petal, corolla shows a line of hairs near the base of the tube. They may be produced throughout the year, including mild weather in winter. This allows bees to gather its nectar for f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellaria Media
''Stellaria media'', chickweed, is an annual and perennial flowering plant in the family Caryophyllaceae.Fernald, M. L. 1950. “Gray's Manual of Botany”. Eight Edition. American Book Company, New York, NY. 1632 pp. It is native to Eurasia and naturalized throughout the world. This species is used as a cooling herbal remedy, and grown as a vegetable crop and ground cover for both human and poultry consumption. It is sometimes called common chickweed to distinguish it from other plants called chickweed. Other common names include chickenwort, craches, maruns, and winterweed. The plant germinates in autumn or late winter, then forms large mats of foliage. Description This species is an annual in colder climates, becoming evergreen and perennial in warmer zones, with weak slender stems, up to . Plants are sparsely hairy. ''Stellaria media'' has one line of fine hairs on the stem. The leaves are oval and opposite, the lower ones with stalks. Flowers are white and small with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
