Mycologia, ASCOMYCOTINA, HYPOCREALES, HYPOCREACEAE .
Identification, Description, Biology, Epidemiology, Treatement, Possible misleading, Images
This disease mainly attacks the apple but also occurs in pear trees neighbouring infected apple.
In spring, reddish sunken lesions occur on the young shoots or the one year old twigs. They are centered around a pruning wound, a frost bite or stone crack in the bark or a leaf scar. The lesion grows into a canker girdling the twig.
On the large older branches the development of the lesion can take several years. It digs deeper and deeper and forms several concentric ridges. The swellings of the bark can shelter wood and Sesie larvae. The twigs growing on the cankered area die.
Apples and pears can also show dry "eye rot" around the calyx in unripe or stored fruits.
The fungus overwinters as perithecia (small red granulations) which occur in the folds of the 3 -4 years old cankers. Ascospores are released at the end of winter and during spring.
On younger lesions conidial cushions occur in spring.
On older cankers, conidia and ascospores can be seen year round but their production and germination depend on the climate conditions. Ascospores and conidia contaminate the wounds. Leaf to leaf contamination is also possible.
The optimum temperature for an outbreak of the disease is 14 - 15.5 °C.
The tree must have been moist for at least six hours before the penetration of thepathogen. Incubation can take a few days, a few weeks or even a few months.
Ascospores and conidia are dispersed by rain. The existence of wounds on the bark facilitates the development of cankers.
Eliminate and burn the infected twigs.
Check periodically the plants since nursery stage.
Protect the pruning wounds.
Apply copper treatment during leaf fall and bud swelling.
Protect the wounds with healing paints.
HYP3 on line : Species (scientific name), Diseases (common names), Glossary, Crops.