Some common or important canker diseases
| Disease |
Pathogen |
Fruiting |
Hosts |
Comments |
| Nectria canker |
Nectria galligena |
<-superficial red perithecia |
many hdwds., esp. birches, walnut |
quintessential target canker; fruits fall-spring |
| Cylindrocarpon mali |
<-sporodochia |
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| Diplodia shoot blight |
Diplodia pinea (= Sphaeropsis sapinea) |
pycnidia |
pines |
Can cause "collar rot" of seedlings in addition to shoot blight. |
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Diplodia scrobiculata |
This recently segregated species (®) was formerly referred to as D. pinea type B. It is less aggressive than D. pinea. Difficult to distinguish without molecular methods. |
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| Eutypella canker |
Eutypella parasitica |
black perithecia embedded in bark |
maples |
large flaring canker, fans |
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Hypoxylon canker
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Hypoxylon mammatum |
conidia first on mat and pillars, then perithecia in stroma |
aspens |
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Other cankers on aspen
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| Cytospora cankers |
Leucostoma, Valsa spp. |
<-perithecia united in small stroma |
various |
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| Leucocytospora, Cytospora spp. |
<-pycnidia united in small stroma |
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| Pitch canker |
Fusarium circinatum (Fusarium subglutinans f.sp. pini) |
sporodochia |
various pines |
SE epidemic in '70s, to CA in '80s |
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Scleroderris canker
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Gremenniella (Ascocalyx) abietina |
<-small brown apothecia |
red (+jack, Scots) pine, other conifers |
Disease can be shoot dieback or canker. There is a complex history of varieties, races and types of the pathogen. Briefly, European and NA races. Gremenniella abietina var. abietina has A (can attack large trees and seedlings) and B (attacks seedlings) types.
Additional unpublished information |
| Brunchorstia pinea |
<-pycnidia |
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| Beech bark disease |
Cryptococcus fagisuga |
<-cottony scale |
Am. + Eur. beech |
Scale was introduced |
| Nectria spp., esp. coccinea var. faginata |
<-superficial red perithecia |
| Cylindrocarpon faginatum |
<-sporodochia |
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Butternut canker
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Sirococcus clavigignenti-juglandacearum |
pycnidia |
butternut, Juglans cinerea; black walnut, J. nigra; heartnut, J. ailantifolia var. cordiformis (introduced to North America) |
Disease first detected about 1967, killing large numbers of butternut, pathogen apparently non-native but origin unknown |
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| Sirococcus shoot blight |
Sirococcus conigenus sensu stricto (= S. strobilinus, Ascochyta piniperda in part) |
pycnidia |
Larch (Larix laricina), cedar (Cedrus deodora), and spruces (Picea abies, P. pungens, P. spinulosa, P. contorta) in much of northern hemisphere. |
Some reports may be recently segregated species below. |
| S. piceicola |
Spruces (Picea abies, P. sitchensis and P. glauca) in western Canada and Switzerland |
Recently segregated species (®) |
| S. tsugae |
Cedrus and Tsuga spp. in western North America from Oregon to Alaska |
Recently segregated species (®) |
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| Chestnut blight |
Cryphonectria parasitica |
perithecia and pycnidia like Cytospora cankers |
chestnut |
Introduced, drastically changed eastern forests |
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| Septoria canker |
Mycosphaerella populorum |
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Populus species |
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| Septoria musiva |
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| Black knot |
Apiosporina morbosa |
pseudothecia on hard black stroma |
cherries |
gall covered with stroma |
