Canker

Butternut canker is a lethal disease of Butternut trees, and has no cure.

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 of major economic importance in agriculture and horticulture. Their causes include such 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 and animals can spread canker, thereby endangering areas that have only slight amount of canker.^{[citation needed]}

Although fungicides or bactericides can treat some cankers, often the only available treatment is to destroy the infected plant to contain the disease.

Examples[]

Tree cankers (right) are caused by injuries to the bark that allow pathogens or insects in to infect the tree. Compared above is a healthy tree and segment (left) to a tree infected and containing a canker.

Apple canker, caused by the fungus Neonectria 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
Foamy bark canker of oaks in California, caused by the fungus Geosmithia putterillii
Dogwood anthracnose, caused by the fungus Discula destructiva
Grape canker, caused by the fungus Eutypa lata
Honey locust canker, caused by the fungus
Larch canker, caused by the fungus Lachnellula willkommii
Mulberry canker, caused by the fungus Gibberella baccata
Oak canker, caused by the fungus Diplodia quercina
Pine pitch canker, caused by the fungus Fusarium circinatum
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
Southwest canker, caused by environmental conditions (cold and sun)^[2]
Tomato anthracnose, caused by the fungus Colletotrichum coccodes
Willow anthracnose, caused by the fungus Marssonina salicicola