|
Peronospora Destructor
''Peronospora destructor'' is a plant pathogen. It causes downy mildew on leaves of cultivated and wild ''Allium''. '' Allium cepa'' (onion and shallot) is most often affected, while '' Allium schoenoprasum'' (chives) and '' Allium porrum'' (leek) are only occasionally affected. Downy mildew is a major disease of onion. The pathogen persists as mycelium systemically infecting onion bulbs, but is not known to be transmitted in onion seed. The pathogen can persist in the soil for several years as oospores. Systemically infected plants are dwarfed and pale green. Under moist conditions, the pathogen sporulates on the affected tissues and spreads to other plants, on the leaves and stalks of which it forms greyish-violet local lesions. Infected leaves are often entirely killed. Critical periods for infection have been determined. Infected crops yield poorly, and produce distorted bulbs. Control is by crop rotation (at least 3 years between successive onion crops), use of healthy bulbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allium Cepa
An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus ''Allium''. The shallot is a botanical variety of the onion which was classified as a separate species until 2010. Its close relatives include garlic, scallion, leek, and chive. This genus also contains several other species variously referred to as onions and cultivated for food, such as the Japanese bunching onion (''Allium fistulosum''), the tree onion (''A.'' × ''proliferum''), and the Canada onion (''Allium canadense''). The name '' wild onion'' is applied to a number of ''Allium'' species, but ''A. cepa'' is exclusively known from cultivation. Its ancestral wild original form is not known, although escapes from cultivation have become established in some regions. The onion is most frequently a biennial or a perennial plant, but is usually treated as an annual and harvested in its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allium Schoenoprasum
Chives, scientific name ''Allium schoenoprasum'', is a species of flowering plant in the family Amaryllidaceae that produces edible leaves and flowers. Their close relatives include the common onions, garlic, shallot, leek, scallion, and Chinese onion. A perennial plant, it is widespread in nature across much of Europe, Asia, and North America. ''A. schoenoprasum'' is the only species of ''Allium'' native to both the New and the Old Worlds.Ernest Small James Cullen, Sabina G. Knees, H. Suzanne Cubey (Editors) Chives are a commonly used herb and can be found in grocery stores or grown in home gardens. In culinary use, the green stalks (scapes) and the unopened, immature flower buds are diced and used as an ingredient for omelettes, fish, potatoes, soups, and many other dishes. The edible flowers can be used in salads. Chives have insect-repelling properties that can be used in gardens to control pests. The plant provides a great deal of nectar for pollinators. It was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allium Porrum
The leek is a vegetable, a cultivar of ''Allium ampeloprasum'', the broadleaf wild leek (syn. ''Allium porrum''). The edible part of the plant is a bundle of leaf sheaths that is sometimes erroneously called a stem or stalk. The genus ''Allium'' also contains the onion, garlic, shallot, scallion, chive, and Chinese onion. Three closely related vegetables, elephant garlic, kurrat and Persian leek or ''tareh'', are also cultivars of ''A. ampeloprasum'', although different in their uses as food. Etymology Historically, many scientific names were used for leeks, but they are now all treated as cultivars of ''A. ampeloprasum''. The name ''leek'' developed from the Old English word , from which the modern English name for garlic also derives. means 'onion' in Old English and is a cognate with languages based on Old Norse; Danish ', Icelandic ', Norwegian ' and Swedish '. German uses ' for leek, but in Dutch, ' is used for the whole onion genus, Allium. Form Rather than fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peronosporales
The Peronosporales are an order of water moulds (class Oomycetes) which can be pathogenic. Many diseases of plants are sometimes classified under this order, but are sometimes considered members of order Pythiales. Some of these pathogenic protists include the organisms responsible for potato blight ''Phytophthora infestans'' is an oomycete or water mold, a fungus-like microorganism that causes the serious potato and tomato disease known as late blight or potato blight. Early blight, caused by '' Alternaria solani'', is also often called ..., eucalyptus dieback, sudden oak death, and blue mold. Further genetic studies may place these organisms more definitively in one order or another. References Heterokont orders {{plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protists Described In 1849
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exclusion of other eukaryotes means that protists do not form a natural group, or clade. Therefore, some protists may be more closely related to animals, plants, or fungi than they are to other protists. However, like the groups ''algae'', ''invertebrates'', and ''protozoans'', the biological category ''protist'' is used for convenience. Others classify any unicellular eukaryotic microorganism as a protist. The study of protists is termed protistology. History The classification of a third kingdom separate from animals and plants was first proposed by John Hogg in 1860 as the kingdom Protoctista; in 1866 Ernst Haeckel also proposed a third kingdom Protista as "the kingdom of primitive forms". Originally these also included prokaryotes, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Mould Plant Pathogens And Diseases
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, despite not providing food, energy or organic micronutrients. Its chemical formula, H2O, indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. "Water" is also the name of the liquid state of H2O at standard temperature and pressure. A number of natural states of water exist. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is steam or water vapor. Water covers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vegetable Diseases
Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is applied to plants collectively to refer to all edible plant matter, including the flowers, fruits, stems, leaves, roots, and seeds. An alternative definition of the term is applied somewhat arbitrarily, often by culinary and cultural tradition. It may exclude foods derived from some plants that are fruits, flowers, nuts, and cereal grains, but include savoury fruits such as tomatoes and courgettes, flowers such as broccoli, and seeds such as pulses. Originally, vegetables were collected from the wild by hunter-gatherers and entered cultivation in several parts of the world, probably during the period 10,000 BC to 7,000 BC, when a new agricultural way of life developed. At first, plants which grew locally would have been cultivated, but as time went on, trade brought exotic crops from elsewhere to add to domestic types. Nowadays, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Water Mould Plant Pathogens And Diseases")
