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Mildews
Mildew is a form of fungus. It is distinguished from its closely related counterpart, mold, largely by its colour: molds appear in shades of black, blue, red, and green, whereas mildew is white. It appears as a thin, superficial growth consisting of minute hyphae (fungal filaments) produced especially on living plants or organic matter such as wood, paper or leather. Both mold and mildew produce distinct offensive odours, and both have been identified as the cause of certain human ailments. In horticulture, mildews are species of fungus in the order Erysiphales, or fungus-like organisms in the family ''Peronosporaceae''. It is also used more generally to mean mold growth. In Old English, mildew meant honeydew (a substance secreted by aphids on leaves, formerly thought to distill from the air like dew), and later came to mean mold or fungus. Household varieties The term mildew is often used generically to refer to mold growth, usually with a flat growth habit. Molds can thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downy Mildew
Downy mildew refers to any of several types of oomycete microbes that are obligate parasites of plants. Downy mildews exclusively belong to the Peronosporaceae family. In commercial agriculture, they are a particular problem for growers of crucifers, grapes and vegetables that grow on vines. The prime example is '' Peronospora farinosa'' featured in NCBI-Taxonomy and HYP3. This pathogen does not produce survival structures in the northern states of the United States, and overwinters as live mildew colonies in Gulf Coast states. It progresses northward with cucurbit production each spring. Yield loss associated with downy mildew is most likely related to soft rots that occur after plant canopies collapse and sunburn occurs on fruit. Cucurbit downy mildew only affects leaves of cucurbit plants. Symptoms Initial symptoms include large, angular or blocky, yellow areas visible on the upper surface. They can also be distinguished by their sporadic yellow patch appearance. As le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peronosporaceae
Peronosporaceae are a family of water moulds that contains 21 genera, comprising more than 600 species. Most of them are called downy mildews. Many species of Peronosporaceae are obligate biotrophic plant pathogens. They parasitise their host plants as an intercellular mycelium using haustoria to penetrate the host cells. The downy mildews reproduce asexually by forming sporangia on distinctive white sporangiophores usually formed on the lower surface of infected leaves. These constitute the "downy mildew". The sporangia are wind-dispersed to the surface of other leaves. According to the genus concerned, the sporangia may then germinate by forming zoospores, thus resembling ''Phytophthora'', or by germ-tube. In the latter case, the sporangia behave as conidia and are often referred to as such. Sexual reproduction is via oospores. The parasitised plants are angiosperms or gymnosperms, and most Peronosporaceae are pathogens of herbaceous dicots. Some downy mildew genera have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Powdery Mildew
Powdery mildew is a fungus, fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of Ascomycota, ascomycete fungi in the order Erysiphales. Powdery mildew is one of the easier plant diseases to identify, as the signs of the causal pathogen are quite distinctive. Infected plants display white powdery spots on the leaves and stems. This mycelial layer may quickly spread to cover all of the leaves. The lower leaves are the most affected, but the mildew can appear on any above-ground part of the plant. As the disease progresses, the spots get larger and denser as large numbers of asexual spores are formed, and the mildew may spread up and down the length of the plant. Powdery mildew grows well in environments with high humidity and moderate temperatures; greenhouses provide an ideal moist, temperate environment for the spread of the disease. This causes harm to agricultural and horticultural practices where powdery mildew may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erysiphales
Erysiphales are an order of ascomycete fungi. The order contains one family, Erysiphaceae. Many of them cause plant diseases called powdery mildew. Systematics The order contains one family (Erysiphaceae), 28 genera and around 1000 species. Many imperfect fungi (fungi whose sexual reproduction is unknown) belong here, especially the genus '' Oidium''. Recent molecular data have revealed the existence of six main evolutionary lineages. Clade 1 consists of '' Erysiphe'', '' Microsphaera'', and '' Uncinula'', all of which have an ''Oidium'' subgenus ''Pseudoidium'' mitosporic state. Clade 2 consists of '' Erysiphe galeopsidis'' and '' Erysiphe cumminsiana'' ( anamorphs in ''Oidium'' subgenus ''Striatoidium''). Clade 3 consists of ''Erysiphe'' species with anamorphs in ''Oidium'' subgenus ''Reticuloidium''. Clade 4 consists of ''Leveillula'' and ''Phyllactinia'', which have ''Oidiopsis'' and ''Ovulariopsis'' mitosporic states, respectively. Clade 5 consists of '' Sphaerotheca'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downy And Powdery Mildew On Grape Leaf
Downy, also known as Lenor in Europe, Taiwan and Japan, is an American brand of fabric softener produced by Procter & Gamble that was introduced in 1960. Brand history Lenor is a brand name of fabric softener and dryer sheets, also produced by P&G, sold in Europe, Russia and Japan. Lenor fabric softener had entered China in 2007 but was subsequently discontinued. Scent beads under the brand Downy have been sold in China since December 2017. Plans to rebrand Lenor as Downy in the UK were dropped in 2002. Awards For the company's national and international experience in sustainable development, and eco-friendly products, the Environment Possibility Award conferred the "Environmental Heroes of the Year" to Downy in 2012. Advertising Amy Sedaris and Tituss Burgess are the talents hired to promote the Downy/Lenor ''Unstopables'' In-Wash Scent Boosters range in both the US and the UK. The commercials were filmed by Grey Advertising. Its most recent television commercial feature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspergillus
'''' () is a genus consisting of several hundred mold species found in various climates worldwide. ''Aspergillus'' was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Micheli was reminded of the shape of an '' aspergillum'' (holy water sprinkler), from Latin ''spargere'' (to sprinkle), and named the genus accordingly. Aspergillum is an asexual spore-forming structure common to all ''Aspergillus'' species; around one-third of species are also known to have a sexual stage. While some species of ''Aspergillus'' are known to cause fungal infections, others are of commercial importance. Taxonomy Species In March 2010, ''Aspergillus'' covered 837 species of fungi. Notable species placed in Aspergillus include: * '' Aspergillus flavus'' is a notable plant pathogen impacting crop yields and a common cause of aspergillosis. * '' Aspergillus fumigatus'' is the most common cause of aspergillosis in individuals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Building Defects
A building or edifice is an enclosed structure with a roof, walls and windows, usually standing permanently in one place, such as a house or factory. Buildings come in a variety of sizes, shapes, and functions, and have been adapted throughout history for numerous factors, from building materials available, to weather conditions, land prices, ground conditions, specific uses, prestige, and aesthetic reasons. To better understand the concept, see ''Nonbuilding structure'' for contrast. Buildings serve several societal needs – occupancy, primarily as shelter from weather, security, living space, privacy, to store belongings, and to comfortably live and work. A building as a shelter represents a physical separation of the human habitat (a place of comfort and safety) from the ''outside'' (a place that may be harsh and harmful at times). buildings have been objects or canvasses of much artistic expression. In recent years, interest in sustainable planning and building pract ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obligate Parasite
An obligate parasite or holoparasite is a parasitic organism that cannot complete its life-cycle without exploiting a suitable host. If an obligate parasite cannot obtain a host it will fail to reproduce. This is opposed to a facultative parasite, which can act as a parasite but does not rely on its host to continue its life-cycle. Obligate parasites have evolved a variety of parasitic strategies to exploit their hosts. It is advantageous for the parasite to preserve the health of its host when this is compatible with its nutritional and reproductive requirements, except when the death of the host is necessary for transmission.Combes, C. (1997) Fitness of Parasites: Pathology and Selection ''International Journal for Parasitology'' 27 (1): 1–10. Species Obligate parasitism is exhibited in a range of organisms, with examples in viruses, bacteria, fungi, plants, and animals.Balashov, Yu.S. (2011) Parasitism and Ecological Parasitology. ''Entomological Review'' 91 (9): 1216–1223. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dew Point
The dew point is the temperature the air needs to be cooled to (at constant pressure) in order to produce a relative humidity of 100%. This temperature depends on the pressure and water content of the air. When the air at a temperature above the dewpoint is cooled, its moisture capacity is reduced and airborne water vapor will Condensation, condense to form liquid water known as dew. When this occurs through the air's contact with a colder surface, dew will form on that surface. The dew point is affected by the air's humidity. The more moisture the air contains, the higher its dew point. When the temperature is below the freezing point of water, the dew point is called the frost point, as frost is formed via deposition (phase transition), deposition rather than condensation. In liquids, the analog to the dew point is the cloud point. Humidity If all the other factors influencing humidity remain constant, at ground level the relative humidity rises as the temperature falls; this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Temperature
Atmospheric temperature is a measure of temperature at different levels of the Earth's atmosphere. It is governed by many factors, including incoming solar radiation, humidity, and altitude. The abbreviation MAAT is often used for Mean Annual Air Temperature of a geographical location. Near-surface air temperature The temperature of the air near the surface of the Earth is measured at meteorological observatories and weather stations, usually using thermometers placed in a shelter such as a Stevenson screen—a standardized, well-ventilated, white-painted instrument shelter. The thermometers should be positioned 1.25–2 m above the ground. Details of this setup are defined by the World Meteorological Organization (WMO). A true daily mean could be obtained from a continuously recording thermograph. Commonly, it is approximated by the mean of discrete readings (e.g. 24 hourly readings, four 6-hourly readings, etc.) or by the mean of the daily minimum and maximum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relative Humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest. The same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is the dew point. The amount of water vapor needed to achieve saturation increases as the temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 8 g of water per cubic metre of air at , and 28 g of water per cubic metre of air at Three primary measurements of humidity are widely employed: abso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
