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Crop Weeds
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 prove harmful to crops, both directly and indirectly. Crop weeds can inhibit the growth of crops, contaminate harvested crops and often spread rapidly. They can also host crop pests such as aphids, fungal rots and viruses. Cost increases and yield losses occur as a result. ''Striga'', one of the main cereal crop weeds in Sub-Saharan Africa, commonly causes yield losses of 40–100% and accounts for around $7 billion in losses annually. Around 100 million hectares of land in Sub-Saharan Africa are affected by ''striga''. Barnyard grass has been identified as a culprit in global rice yield losses and certain species have been known to mimic rice. Examples of crop weeds include chickweed, barnyard grass, dandelion, ''striga'' and ''Japanese knotweed''. See also *Weed of cultivation A weed of cultivation is any plant that is well-adapted to environmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinochloa Crusgalli Habit3 - Flickr - Macleay Grass Man
''Echinochloa'' is a very widespread genus of plants in the grass family and tribe Paniceae. Some of the species are known by the common names barnyard grass or cockspur grass. Some of the species within this genus are millets that are grown as cereal or fodder crops. The most notable of these are Japanese millet (''E. esculenta'') in East Asia, Indian barnyard millet (''E. frumentacea'') in South Asia, and burgu millet (''E. stagnina'') in West Africa. Collectively, the members of this genus are called barnyard grasses (though this may also refer to '' E. crus-galli'' specifically), and are also known as barnyard millets or billion-dollar grasses. When not grown on purpose, these grasses may become a nuisance to farmers. In particular, common barnyard grass (''E. crus-galli'') is notorious as a weed. It is not easily suppressed with living mulches such as velvet bean (''Mucuna pruriens'' var. ''utilis''). Early barnyard grass (''E. oryzoides'') is a well-known example of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chickweed
''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] |
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] |
Reynoutria Japonica
''Reynoutria japonica'', synonyms ''Fallopia japonica'' and ''Polygonum cuspidatum'', is a species of herbaceous perennial plant in the knotweed and buckwheat family Polygonaceae. Common names include Japanese knotweed and Asian knotweed. It is native to East Asia in Japan, China and Korea. In North America and Europe, the species has successfully established itself in numerous habitats, and is classified as a pest and invasive species in several countries. Japanese knotweed has hollow stems with distinct raised nodes that give it the appearance of bamboo, though it is not related. While stems may reach a maximum height of each growing season, it is typical to see much smaller plants in places where they sprout through cracks in the pavement or are repeatedly cut down. The leaves are broad oval with a truncated base, long and broad, with an entire margin. The flowers are small, cream or white, produced in erect racemes long in late summer and early autumn. Related species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Striga
''Striga'', commonly known as witchweed, is a genus of parasitic plants that occur naturally in parts of Africa, Asia, and Australia. It is currently classified in the family Orobanchaceae, although older classifications place it in the Scrophulariaceae. Some species are serious pathogens of cereal crops, with the greatest effects being in savanna agriculture in Africa. It also causes considerable crop losses in other regions, including other tropical and subtropical crops in its native range and in the Americas. Witchweeds are characterized by bright-green stems and leaves and small, brightly colored and attractive flowers.Sand, Paul, Robert Eplee, and Randy Westbrooks. Witchweed Research and Control in the United States. Champaign, IL: Weed Science Society of America, 1990. They are obligate parasite, obligate hemiparasites of roots and require a living host for germination and initial development, though they can then survive on their own. The number of species is uncertain, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dandelion
''Taraxacum'' () is a large genus of flowering plants in the family Asteraceae, which consists of species commonly known as dandelions. The scientific and hobby study of the genus is known as taraxacology. The genus is native to Eurasia and North America, but the two most commonplace species worldwide, ''Taraxacum officinale, T. officinale'' (the common dandelion) and ''Taraxacum erythrospermum, T. erythrospermum'' (the red-seeded dandelion), were introduced from Europe into North America, where they now propagate as wildflowers. Both species are List of leaf vegetables, edible in their entirety. The common name ''dandelion'' ( , from French language, French , meaning 'lion's tooth') is also given to specific members of the genus. Like other members of the family Asteraceae, they have very small flowers collected together into a composite Head (botany), flower head. Each single flower in a head is called a ''floret''. In part due to their abundance, along with being a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnyard Grass
''Echinochloa'' is a very widespread genus of plants in the grass family and tribe Paniceae. Some of the species are known by the common names barnyard grass or cockspur grass. Some of the species within this genus are millets that are grown as cereal or fodder crops. The most notable of these are Japanese millet (''E. esculenta'') in East Asia, Indian barnyard millet (''E. frumentacea'') in South Asia, and burgu millet (''E. stagnina'') in West Africa. Collectively, the members of this genus are called barnyard grasses (though this may also refer to '' E. crus-galli'' specifically), and are also known as barnyard millets or billion-dollar grasses. When not grown on purpose, these grasses may become a nuisance to farmers. In particular, common barnyard grass (''E. crus-galli'') is notorious as a weed. It is not easily suppressed with living mulches such as velvet bean (''Mucuna pruriens'' var. ''utilis''). Early barnyard grass (''E. oryzoides'') is a well-known examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vavilovian Mimicry
In plant biology, Vavilovian mimicry (also crop mimicry or weed mimicry) is a form of mimicry in plants where a weed evolves to share one or more characteristics with a domesticated plant through generations of artificial selection. It is named after Nikolai Vavilov, a prominent Russian plant geneticist. Selection against the weed may occur by killing a young or adult weed, separating its seeds from those of the crop (winnowing), or both. This has been done manually since Neolithic times, and in more recent years by agricultural machinery. Vavilovian mimicry is a good illustration of unintentional selection by humans. Although the human selective agents might be conscious of their impact on the local weed gene pool, such effects go against the goals of those growing crops. Weeders do not want to select for weeds that are increasingly similar to the cultivated plant, yet the only other option is to let the weeds grow and compete with crops for sunlight and nutrients. Similar s ... [...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] |
Rice
Rice is the seed of the grass species ''Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima ''Oryza glaberrima'', commonly known as African rice, is one of the two domesticated rice species. It was first domesticated and grown in West Africa around 3,000 years ago. In agriculture, it has largely been replaced by higher-yielding Asian r ...'' (African rice). The name wild rice is usually used for species of the genera ''Zizania (genus), Zizania'' and ''Porteresia'', both wild and domesticated, although the term may also be used for primitive or uncultivated varieties of ''Oryza''. As a cereal, cereal grain, domesticated rice is the most widely consumed staple food for over half of the world's World population, human population,Abstract, "Rice feeds more than half the world's population." especially in Asia and Africa. It is the agricultural commodity with the third-highest worldwide production, after sugarcane and maize. Since sizable portions of sugarcane and ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnyard Grass
''Echinochloa'' is a very widespread genus of plants in the grass family and tribe Paniceae. Some of the species are known by the common names barnyard grass or cockspur grass. Some of the species within this genus are millets that are grown as cereal or fodder crops. The most notable of these are Japanese millet (''E. esculenta'') in East Asia, Indian barnyard millet (''E. frumentacea'') in South Asia, and burgu millet (''E. stagnina'') in West Africa. Collectively, the members of this genus are called barnyard grasses (though this may also refer to '' E. crus-galli'' specifically), and are also known as barnyard millets or billion-dollar grasses. When not grown on purpose, these grasses may become a nuisance to farmers. In particular, common barnyard grass (''E. crus-galli'') is notorious as a weed. It is not easily suppressed with living mulches such as velvet bean (''Mucuna pruriens'' var. ''utilis''). Early barnyard grass (''E. oryzoides'') is a well-known examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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