Neonectria is caused by the same fungus responsible for Nectria canker.
The fungus Neonectria ditissima causes:
Apple canker – also known as: Nectria canker
End rot and rotten spots: Neonectria
Neonectria (Neonectria ditissima) is caused by the same fungus that is also responsible for Apple canker. Apples are more sensitive to it than pears and there are major differences in susceptibility between the apple varieties.
The fungus spreads via spores in wet and humid weather. The fungus is a wound parasite that usually enters the tree in the fall through leaf scars and pruning wounds.
The fungus can also be spread by the Woolly apple aphid (Eriosoma lanigerum).
The fungus can also infect apples and pears through the lenticels or through cracks around the stem. Infections during the blossoming season cause rotten spots on the noses; infections in (late) summer cause rotten spots around the stems (stem rot). The infection may already be visible on the tree in the autumn through rotten spots on the noses. If the infection only becomes visible after picking, it usually concerns rotten spots around the stem.
Neonectria neomacrospora can cause canker spots on Nordmann spruce.
Bron foto: Biology and control of the fungus Neonectria ditissima (syn. N. galligena) from a Northwestern European perspective
Where to find
Control
Remove affected branches, cut affected areas on the trunk and bearing branches. Protect pruning and cutting wounds with wound balm.
Prevention
Ensure good drainage and keep the heart of fruit trees open so that the wind has free rein. Prevent branches from rubbing past each other causing damage. Decontaminate used pruning tools.
Earwigs, parasitoid wasps and gall midges are the natural enemies of the woolly apple aphid, the insect that helps spread fungus. So do not destroy these insects.
