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 encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...

and

horticulture Horticulture (from ) is the art and science of growing fruits, vegetables, flowers, trees, shrubs and ornamental plants. Horticulture is commonly associated with the more professional and technical aspects of plant cultivation on a smaller and mo ...

. Their causes include a wide range of organisms as

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

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

mycoplasma ''Mycoplasma'' is a genus of bacteria that, like the other members of the class ''Mollicutes'', lack a cell wall, and its peptidoglycan, around their cell membrane. The absence of peptidoglycan makes them naturally resistant to antibiotics ...

s and

virus A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are ...

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

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

, 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

fungicide Fungicides are pesticides used to kill parasitic fungi or their spores. Fungi can cause serious damage in agriculture, resulting in losses of yield and quality. Fungicides are used both in agriculture and to fight fungal infections in animals, ...

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 p ...

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 a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

canker, caused by the fungus '' Neonectria galligena'' formerly Nectria galligena. * Ash bacterial canker, now understood to be caused by the bacterium '' Pseudomonas savastanoi'', rather than ''

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

''. After DNA-relatedness studies ''Pseudomonas savastanoi'' has been instated as a new species. * Butternut canker, caused by the fungus '' Sirococcus clavigignenti-juglandacearum'' * Bleeding canker of horse chestnut, caused by the bacterium ''

'' pv. ''aesculi'' *

Citrus canker Citrus canker is a disease affecting ''Citrus'' species caused by the bacterium '' Xanthomonas citri''. Infection causes lesions on the leaves, stems, and fruit of citrus trees, including lime, oranges, and grapefruit. While not harmful to huma ...

, caused by the bacterium '' Xanthomonas axonopodis'' * Cypress canker, caused by the fungus '' Seiridium cardinale'' * Foamy bark canker of oaks in California, caused by the fungus '' Geosmithia putterillii'' *

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

anthracnose, caused by the fungus '' Discula destructiva'' * Grape canker, caused by the fungus '' Eutypa lata'' * Honey locust 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 the cooler regions of the northern hemisphere, where they are found in lowland forests in the high la ...

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

Mulberry ''Morus'', a genus of flowering plants in the family Moraceae, consists of 19 species of deciduous trees commonly known as mulberries, growing wild and under cultivation in many temperate world regions. Generally, the genus has 64 subordinat ...

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

Oak An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

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 anthracnose, caused by the fungus '' Apiognomonia veneta'' * Poplar canker, caused by the bacterium '' Xanthomonas populi'' *

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

stem canker, caused by the blackleg fungus '' Leptosphaeria maculans'' *

Rose A rose is either a woody perennial plant, perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred Rose species, species and Garden roses, tens of thousands of cultivar ...

cankers, caused by the fungus '' Leptosphaeria coniothyrium'' and '' Cryptosporella umbrina'' * Scleroderris canker, caused by the fungus '' Gremmeniella abietina'' * Southwest canker, caused by environmental conditions (frost damage and sun-scalding) *

Strawberry The garden strawberry (or simply strawberry; ''Fragaria × ananassa'') is a widely grown Hybrid (biology), hybrid plant cultivated worldwide for its fruit. The genus ''Fragaria'', the strawberries, is in the rose family, Rosaceae. The fruit ...

anthracnose, caused by the fungus species complexes '' Colletotrichum acutatum'' and '' C. gloeosporioides'' (incl. '' C. fragariae'') *

Tomato The tomato (, ), ''Solanum lycopersicum'', is a plant whose fruit is an edible Berry (botany), berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originate ...

anthracnose, caused by the fungus '' Colletotrichum coccodes'' *

Willow Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known ...

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