Canker
Canker and anthracnose are general terms for a large number of different plant diseases, characterised by broadly similar symptoms including the appearance of small areas of dead tissue, which grow slowly, often over a period of years. Some are of only minor consequence, but others are ultimately lethal, and of major economic importance in agriculture and horticulture. Different cankers and anthracnoses are caused by a wide range of organisms, including fungi, bacteria, mycoplasmas and viruses. The majority of canker-causing organisms are tied obligately to a single host species or genus, but a few will attack a wider range of plants. Canker can be spread by weather and animals, making an area that even has a slight amount of canker hazardous.
Some cankers are treatable with fungicides or bactericides, but many are not; often the only treatment available is to destroy the infected plant to prevent the disease from spreading to other plants.
Examples
- Apple canker, caused by the fungus Nectria galligena
- Ash bacterial canker, now understood to be caused by the bacterium Pseudomonas savastanoi, rather than Pseudomonas syringae. After DNA-relatedness studies Pseudomonas savastanoi has been instated as a new species.[1]
- Butternut canker, caused by the fungus Sirococcus clavigignenti-juglandacearum
- Bleeding Canker of Horse Chestnut, caused by the bacterium Pseudomonas syringae pv. aesculi
- Citrus canker, caused by the bacterium Xanthomonas axonopodis
- Cypress canker, caused by the fungus Seiridium cardinale
- Dogwood 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
- Mulberry canker, caused by the fungus Gibberella baccata
- Oak canker, caused by the fungus Diplodia quercina
- Pine pitch canker, caused by the fungus Fusarium pini
- Plane anthracnose, caused by the fungus Apiognomonia veneta
- Poplar canker, caused by the bacterium Xanthomonas populi
- Rapeseed stem canker, caused by the blackleg fungus Leptosphaeria maculans
- Rose cankers, caused by the fungus Leptosphaeria coniothyrium and Cryptosporella umbrina
- Scleroderris canker, caused by the fungus Gremmeniella abietina
- Willow anthracnose, caused by the fungus Marssonina salicicola
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Canker on a birch
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Canker on a Beech tree.
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Canker on an Ash tree in North Ayrshire, Scotland.
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Birch canker discovered by Grey Bruce Tree Workers in Port Elgin, Ontario.
References
- ^ Gardan, L.; Shafik, H.; Belouin, S.; Broch, R.; Grimont, F.; Grimont, P. A. D. (1999). "DNA relatedness among the pathovars of Pseudomonas syringae and description of Pseudomonas tremae sp. nov. and Pseudomonas cannabina sp. nov. (ex Sutic and Dowson 1959)". International Journal of Systematic Bacteriology 49: 469–78. DOI Digital object identifier:10.1099/00207713-49-2-469. http://ijs.sgmjournals.org/content/49/2/469 PMID 10319466.
