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 Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...

and

horticulture Horticulture is the branch of agriculture that deals with the art, science, technology, and business of plant cultivation. It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds and no ...

. Their causes include a wide range of organisms as

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

mycoplasma ''Mycoplasma'' is a genus of bacteria that, like the other members of the class ''Mollicutes'', lack a cell wall around their cell membranes. Peptidoglycan (murein) is absent. This characteristic makes them naturally resistant to antibiotics ...

s and

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...

es. The majority of canker-causing organisms are bound to a unique host

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

, but a few will attack other plants. Weather and animals can spread canker, thereby endangering areas that have only slight amount of canker. Although

fungicide Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, ...

s or

bactericide A bactericide or bacteriocide, sometimes abbreviated Bcidal, is a substance which kills bacteria. Bactericides are disinfectants, antiseptics, or antibiotics. However, material surfaces can also have bactericidal properties based solely on their ...

s can treat some cankers, often the only available treatment is to destroy the infected plant to contain the disease.

Examples

Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...

canker, caused by the fungus ''

Neonectria galligena ''Neonectria ditissima'' (syn. ''Neonectria galligena'') is a fungal plant pathogen. It causes cankers that can kill branches of trees by choking them off. Apple and beech trees are two susceptible species. Host range ''Neonectria ditissima ...

'' *

Ash Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...

bacterial canker, now understood to be caused by the bacterium ''

Pseudomonas savastanoi ''Pseudomonas savastanoi'' is a gram-negative plant pathogenic bacterium that infects a variety of plants. It was once considered a pathovar of ''Pseudomonas syringae,'' but following DNA-relatedness studies, it was instated as a new species. It ...

'', rather than ''

Pseudomonas syringae ''Pseudomonas syringae'' is a rod-shaped, Gram-negative bacterium with polar flagella. As a plant pathogen, it can infect a wide range of species, and exists as over 50 different pathovars, all of which are available to researchers from internat ...

''. After DNA-relatedness studies ''Pseudomonas savastanoi'' has been instated as a new species. * Butternut canker, caused by the fungus ''

Sirococcus clavigignenti-juglandacearum ''Ophiognomonia clavigignenti-juglandacearum'' is a mitosporic fungus that causes the lethal disease of butternut trees (''Juglans cinerea''), butternut canker. It is also known to parasitize other members of the genus ''Juglans'' on occasion, ...

'' *

Bleeding canker of horse chestnut Bleeding canker of horse chestnut is a common canker of horse chestnut trees (''Aesculus hippocastanum'', also known as conker trees) that is known to be caused by infection with several different pathogens. Infections by the gram-negative fluoresc ...

, caused by the bacterium ''

'' pv. ''aesculi'' *

Citrus canker Citrus canker is a disease affecting ''Citrus'' species caused by the bacterium ''Xanthomonas'' (''X.axonopodis; X. campestris''). Infection causes lesions on the leaves, stems, and fruit of citrus trees, including lime, oranges, and grapefruit ...

, caused by the bacterium ''

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 ...

'' *

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 d ...

, caused by the fungus ''

Seiridium ''Lepteutypa'' is a genus of plant pathogens in the family Amphisphaeriaceae. First described by the Austrian mycologist Franz Petrak in 1923, the genus contains 10 species according to a 2008 estimate. The genus ''Lepteutypa'' is teleomorphi ...

cardinale'' *

Foamy bark canker The foamy bark canker is a disease affecting oak trees in California caused by the fungus ''Geosmithia pallida'' and spread by the Western oak bark beetle ('' Pseudopityopthorus pubipennis''). This disease is only seen through the symbiosis of ...

of oaks in California, caused by the fungus ''

Geosmithia putterillii The foamy bark canker is a disease affecting oak trees in California caused by the fungus ''Geosmithia pallida'' and spread by the Western oak bark beetle ('' Pseudopityopthorus pubipennis''). This disease is only seen through the symbiosis of ...

'' *

Dogwood ''Cornus'' is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous trees or shrub ...

anthracnose, caused by the fungus ''

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 Ea ...

'' * Grape canker, caused by the fungus ''

Eutypa lata 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 ...

'' *

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 ...

canker, caused by the fungus '' Thyronectria austro-americana'' *

Larch Larches are deciduous conifers in the genus ''Larix'', of the family Pinaceae (subfamily Laricoideae). Growing from tall, they are native to much of the cooler temperate northern hemisphere, on lowlands in the north and high on mountains furt ...

canker, caused by the fungus '' Lachnellula willkommii'' *

Mulberry ''Morus'', a genus of flowering plants in the family Moraceae, consists of diverse species of deciduous trees commonly known as mulberries, growing wild and under cultivation in many temperate world regions. Generally, the genus has 64 identif ...

canker, caused by the fungus '' Gibberella baccata'' *

Oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

canker, caused by the fungus '' Diplodia quercina'' * Pine pitch canker, caused by the fungus ''

Fusarium circinatum ''Fusarium circinatum'' is a fungal plant pathogen that causes the serious disease pitch canker on pine trees and Douglas firs (''Pseudotsuga menziesii''). The most common hosts of the pathogen include slash pine ('' Pinus elliottii''), loblolly ...

'' *

Plane Plane(s) most often refers to: * Aero- or airplane, a powered, fixed-wing aircraft * Plane (geometry), a flat, 2-dimensional surface Plane or planes may also refer to: Biology * Plane (tree) or ''Platanus'', wetland native plant * ''Planes' ...

anthracnose, caused by the fungus ''

Apiognomonia veneta ''Apiognomonia veneta'' is a plant pathogen which causes anthracnose 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 there ...

'' * Poplar canker, caused by the bacterium '' Xanthomonas populi'' *

Rapeseed Rapeseed (''Brassica napus ''subsp.'' napus''), also known as rape, or oilseed rape, is a bright-yellow flowering member of the family Brassicaceae (mustard or cabbage family), cultivated mainly for its oil-rich seed, which naturally contains a ...

stem canker, caused by the blackleg fungus ''

Leptosphaeria maculans ''Leptosphaeria maculans'' (anamorph ''Phoma lingam'') is a fungal pathogen of the phylum Ascomycota that is the causal agent of blackleg disease on ''Brassica'' crops. Its genome has been sequenced, and ''L. maculans'' is a well-studied model ph ...

'' *

Rose A rose is either a woody perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred species and tens of thousands of cultivars. They form a group of plants that can be ...

cankers, caused by the fungus '' Leptosphaeria coniothyrium'' and '' Cryptosporella umbrina'' * Scleroderris canker, caused by the fungus '' Gremmeniella abietina'' * Southwest canker, caused by environmental conditions (cold and sun)Southwest Canker
/ref> *

Tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

anthracnose, caused by the fungus ''

Colletotrichum coccodes ''Colletotrichum coccodes'' is a plant pathogen, which causes anthracnose on tomato and black dot disease of potato The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. ...

'' *

Willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...

anthracnose, caused by the fungus '' Marssonina salicicola'' Image:Baumkrebs-Birke.jpg, Canker on a birch Image:Beech bark burrs and canker.JPG, Canker on a beech tree Image:Canker on Ash.JPG, Canker on an ash tree in North Ayrshire, Scotland

References

External links

Canker Diseases of Trees {{Authority control Plant pathogens and diseases

Examples

See also

References

External links