Scleroderris canker (

America The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

n name), or Brunchorstia disease (

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

an name),Data Sheets on Quarantine Pests - Gremmeniella abietina
/ref> ''Gremmeniella abietina'', is a

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 ...

fungal 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 th ...

diseases infecting

conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...

ous forests. The main symptom is the death of the needles, leading to the death of the tree. In the forest industry, fighting off an infection of Scleroderris canker is usually not cost-effective. Clearing is often preferred over

fungicidal 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, ...

methods, as the latter is harmful to other living organisms.

Geographical distribution

The European strain is present throughout all of Europe, including the European part of

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

. The American strain limits itself to north of 44° N.

Cause and symptoms

There are two strains of the fungus in existence, the North American and European. The latter is more virulent, capable of infecting an entire tree and killing it over a few years time, whereas the North American strain limits itself to the first few metres of the stem. Another reason behind the high potency of the European strain is that trees are unable to defend themselves from the fungus during winters, as the fungus can remain active at temperatures as low as -5° C Early signs of a Scleroderris canker infection includes a purple tint in the needles and, more evidently, the falling off the needles in the wrong season. A severe Scleroderris canker infection can sometimes be disastrous, as the fungus survives on the

pine cone A conifer cone (in formal botanical usage: strobilus, plural strobili) is a seed-bearing organ on gymnosperm plants. It is usually woody, ovoid to globular, including scales and bracts arranged around a central axis, especially in conifers a ...

s, killing any new seedlings within two years. Chances of infection increase greatly if the previous winter has been mild and the spring season is cool and wet, due to the active temperature. Infection occurs in damaged

bud In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of a stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be spec ...

s and proceeds downwards into the stem, and ascospores are released from November to July.Gremmen, J. (1968) ontribution to the biology of Brunchorstia pinea, cause of shoot dieback in Austrian and Corsican pine Nederlands Bosbouw Tijdschrift 40, 221-231.

Control

Chemical

The fungicide

Chlorothalonil Chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile) is an organic compound mainly used as a broad spectrum, nonsystemic fungicide, with other uses as a wood protectant, pesticide, acaricide, and to control mold, mildew, bacteria, algae. Chlor ...

can be used to ward off the disease in nurseries. However, it is ineffective in adult populations.Scleroderris Canker of Northern Conifers
from the

U.S. Department of Agriculture The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...

Resistance

Resistant species of

Jack pine Jack pine (''Pinus banksiana'') is an eastern North American pine. Its native range in Canada is east of the Rocky Mountains from the Mackenzie River in the Northwest Territories to Cape Breton Island in Nova Scotia, and the north-central and ...

have been observed in

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...

Regulatory

It has been found that the European strain can spread via the import of

Christmas tree A Christmas tree is a decorated tree, usually an evergreen conifer, such as a spruce, pine or fir, or an artificial tree of similar appearance, associated with the celebration of Christmas. The custom was further developed in early modern ...

s. Regulating such imports can limit the spread of the disease.

Main host genera

Abies Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family Pinaceae. They are found on mountains throughout much of North and Central America, Europe, Asia, and North Africa. The genus is most closely related to ...

Picea A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

Pinus A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accep ...

Synonyms

*''Lagerbergia abietina (Lagerberg)'' *''Ascocalyx abietina (Lagerberg)'' *''Scleroderris abietina (Lagerberg)'' *''Scleroderris lagerbergii''

References

External links

Forest Insect & Disease Leaflet 130 - Scleroderris Canker of Northern Conifers
{{Taxonbar, from=Q147369 Parasitic fungi Forest pathology Helotiaceae Fungal tree pathogens and diseases