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Canker Sores
A plant canker is a small area of dead tissue, which grows slowly, often over years. Some cankers are of only minor consequence, but others are ultimately lethal and therefore can have major economic implications for agriculture and horticulture. Their causes include a wide range of organisms as fungi, bacteria, mycoplasmas and viruses. The majority of canker-causing organisms are bound to a unique host species or genus, but a few will attack other plants. Weather (via frost or windstorm damage) and animal damage can also cause stress to the plant resulting in cankers. Other causes of cankers is pruning when the bark is wet or using un-sterilized tools. Although fungicides or bactericides can treat some cankers, often the only available treatment is to destroy the infected plant to contain the disease. Examples * Apple canker, caused by the fungus '' Neonectria galligena'' formerly Nectria galligena. * Ash bacterial canker, now understood to be caused by the bacterium '' Pseu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butternut Canker
''Ophiognomonia clavigignenti-juglandacearum'' is a mitosporic fungus that causes the butternut canker, a lethal disease of butternut (tree), butternut trees (''Juglans cinerea''). It is also known to parasitize other members of the genus ''Walnut, Juglans'' on occasion, and very rarely other related trees including Hickory, hickories. The fungus is found throughout North America, occurring on up to 91% of butternut trees, and may be threatening the viability of butternut as a species. Distribution Butternut, the primary host of ''O. clavigignenti-juglandacearum'', is found in mixed hardwood forests throughout central North America, from New Brunswick to North Carolina. The pathogen was identified as an invasive species in 1967. It was first discovered in Wisconsin, but has since spread to other states and into Canada, making the butternut an endangered species in Ontario. Its native origin is unknown, but possibly in Asia given the resistance of Asian walnuts to the disease. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butternut (tree)
''Juglans cinerea'', commonly known as butternut or white walnut,Snow, Charles Henry ''The Principal Species of Wood: Their Characteristic Properties'' 2nd ed. New York: John Wiley & Sons, 1908. p. 56. is a species of walnut native to the eastern United States and southeast Canada. Description ''J. cinerea'' is a deciduous tree growing to tall, rarely more. Butternut is a slow-growing species, and rarely lives longer than 75 years. It has a stem diameter, with light gray Bark (botany), bark. The leaves are alternate (botany), alternate and pinnate, long, with 11–17 leaflets, each leaflet long and broad. Leaves have a terminal leaflet at the end of the leafstalk and have an odd number of leaflets. The whole leaf is downy-pubescent, and a somewhat brighter, yellower green than many other tree leaves. Flowering and fruiting Like other members of the family Juglandaceae, butternut's leafout in spring is tied to photoperiod rather than air temperature and occurs whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honey Locust
The honey locust (''Gleditsia triacanthos''), also known as the thorny locust or thorny honeylocust, is a deciduous tree in the family Fabaceae, native to central North America where it is mostly found in the moist soil of river valleys. Honey locust trees are highly adaptable to different environments, and the species has been introduced worldwide. Outside its natural range it can be an aggressive, damaging invasive species. Description The honey locust, ''Gleditsia triacanthos'', can reach a height of . They exhibit fast growth, but live a medium life span, as long as 125 years. The leaves are pinnately compound on older trees but bipinnately compound on vigorous young trees. The leaflets are long when compound and very slightly smaller when bipinnate. The leaves are green in summer and turn yellow in autumn in shades ranging from cream and tan to golden yellow. Honey locusts leaf out relatively late in spring, but generally slightly earlier than the black locust (''Robin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutypa Lata
''Eutypa lata'' is a fungal plant pathogen of grapevines. The fungus also attacks many other hosts such as cherry trees, most other ''Prunus'' species, as well as apples, pears and walnuts. In apricots, the fungus reveals a canker surrounding a pruning wound. ''Eutypa lata'' was first found in Californian grapevines by English ''et al.''1962, a few years after its discovery elsewhere. Travadon ''et al.'', 2011 finds that ''E. lata'' is an entirely or almost entirely sexual population here but asexual reproduction may be a rare occurrence. It causes 'Eutypa dieback' in New Zealand grapevines as well. The fungus was difficult to identify on the basis of colony morphology and could be out-competed by other fungi when isolated from wood. DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dead Arm (grapes)
Phomopsis cane and leaf spot occurs wherever grapes are grown. Phomopsis cane and leaf spot is more severe in grape-growing regions characterized by a humid temperate climate through the growing season. Crop losses up to 30% have been reported to be caused by Phomopsis cane and leaf spot.Úrbez-Torres, J. R., Peduto, F., Smith, R. J., and Gubler, W. D. 2013. Phomopsis dieback: A grapevine trunk disease caused by Phomopsis viticola in California. Plant Dis. 97:1571–1579. Hosts and symptoms Phomopsis cane and leaf spot is a disease that causes symptoms in the common grapevine species, ''Vitis vinifera'', in many regions of the world. This disease is mainly caused by the fungal pathogen, ''Phomopsis viticola'', and is known to affect many cultivars of table grapes, such as Thompson Seedless, Red Globe, and Flame Seedless. Also in vines of oenological interest, such as Cabernet Sauvignon, Zinfandel, Syrah, Barbera, Chardonnay and Merlot. Spots or lesions on shoots and leaves are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discula Destructiva
''Discula destructiva'' is a fungus in the family Gnomoniaceae which causes dogwood anthracnose, affecting populations of dogwood trees native to North America. It was introduced to the United States in 1978 and is distributed throughout the Eastern United States and the Pacific Northwest. Its origins are unknown. It typically occurs in cool, wet spring and fall weather. One can avoid this fungus by watering dogwoods during drought and general cultural control care. Species affected: ''Cornus florida'' and ''Cornus nuttallii''. References External links Species Profile- Dogwood Anthracnose (''Discula destructiva'') National Invasive Species Information Center, United States National Agricultural Library The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Locate .... Lists general informa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flowering Dogwood
''Cornus florida'', the flowering dogwood, is a species of flowering tree in the family Cornaceae native to eastern North America and northern Mexico. An endemic population once spanned from southernmost coastal Maine south to northern Florida and west to the Mississippi River. The tree is commonly planted as an ornamental in residential and public areas because of its showy bracts and interesting bark structure. Description Flowering dogwood is a small deciduous tree growing to high, often wider than it is tall when mature, with a trunk diameter of up to . A 10-year-old tree will stand about tall. The leaves are opposite, simple, ovate, long and broad, with an apparently entire margin (actually very finely toothed, under a lens); they turn a rich red-brown in fall. Flowering dogwood attains its greatest size and growth potential in the Upper South, sometimes up to 40 feet in height. At the northern end of its range, heights of 30–33 feet are more typical. Hot, humid su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geosmithia Putterillii
The foamy bark canker is a disease affecting oak trees in California caused by the fungus ''Geosmithia sp. #41'' and spread by the Western oak bark beetle ('' Pseudopityophthorus pubipennis''). This disease is only seen through the symbiosis of the bark beetles and the fungal pathogen. The bark beetles target oak trees and bore holes through the peridermal tissues, making tunnels within the phloem. The fungal spores are brought into these tunnels by the beetles and begin to colonize the damaged cells inside the tunnels. Symptoms of the developing fungus include wet discoloration seeping from the beetle entry holes as the fungus begins to consume phloem and likely other tissues. If bark is removed, necrosis of the phloem can be observed surrounding the entry hole(s). As the disease progresses, a reddish sap and foamy liquid oozes from entry holes, thus giving the disease the name foamy bark canker. Eventually, after the disease has progressed, the tree dies. This disease is impor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seiridium
''Seiridium'' is a genus of plant pathogens in the family Sporocadaceae. The genus '' Lepteutypa'' is teleomorphic (reproducing sexually) and the corresponding anamorphic name, used to describe the asexual form, is ''Seiridium'' (formerly ''Coryneum''). For instance, the name ''Seiridium cupressi'' is still be used for the anamorphic form of that species, but now that it is known that a sexual stage exists, the name ''Lepteutypa cupressi''. On the other hand, no sexual stage of species '' Seiridium cardinale'' is known, so that is its only name. '' Seiridium cardinale'' is important to gardeners and foresters as they cause the devastating Cypress canker disease on ''Cupressus'', ''Thuja'', and related conifers in Northern Europe, America, Australia, and New Zealand. ''Seiridium cardinale'' is from California and was introduced to Europe around the 1930s, probably from infected nursery stock. A separate introduction affected the southern hemisphere. Species As accepted by Spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cypress Canker
Cypress canker is a disease affecting ''Cupressus'' species, caused by one of several species of fungus in the genus ''Seiridium''. Infection causes die-back of twigs and branches in susceptible cypress trees, with rapidly increasing amounts of damage and the death of the tree. History The first epidemic of cypress canker was recorded in California in 1928, with Monterey cypress (''Cupressus macrocarpa'') being affected. Within a few years the local populations of this tree had been killed. The species is widely traded as an ornamental tree and the disease had soon spread worldwide, probably with nursery stock. Within five decades the disease had reached New Zealand, France, Chile, Italy, Argentina, Greece, most of Europe, Canada, North Africa, South Africa and Australia. The causal agent of this pandemic spread was the pathogenic fungus '' Seiridium cardinale'', with '' Seiridium cupressi'' and '' Seiridium unicorne'' sometimes being involved, but being less aggressive; other pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthomonas Axonopodis
''Xanthomonas'' (from greek: ''xanthos'' – "yellow"; ''monas'' – "entity") is a genus of bacteria, many of which cause plant diseases. There are at least 27 plant associated ''Xanthomonas spp.'', that all together infect at least 400 plant species. Different species typically have specific host and/or tissue range and colonization strategies. Taxonomy The genus ''Xanthomonas'' has been subject of numerous taxonomic and phylogenetic studies and was first described as ''Bacterium vesicatorium'' as a pathogen of pepper and tomato in 1921. Dowson later reclassified the bacterium as ''Xanthomonas campestris'' and proposed the genus ''Xanthomonas''.''Xanthomonas'' was first described as a monotypic genus and further research resulted in the division into two groups, A and B. Later work using DNA:DNA hybridization has served as a framework for the general ''Xanthomonas'' species classification. Other tools, including multilocus sequence analysis and amplified fragment-length polymor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
