Bursting bulges, bizarre deformations – everyone knows these strange brown bumps on tree bark and branches. The culprit is a harmful fungus that prefers to attack fruit trees. This is the so-called fruit tree canker. How to recognize and fight it.
Especially in the cold season, the deformations of diseased, bare fruit trees become easily visible. Especially apple trees and pear trees are attacked by fruit tree canker. Rings then form on the trunk and branches of diseased trees, constricting, thickening and cracking the bark. What follows, are unsightly brown growths of the tree tie.
What causes fruit tree canker?
Trigger is the harmful fungus Nectria galligena. Its spores penetrate into the wood through wounds on the tree bark. Particularly cut wounds and bark tears are typical gateways for the fungus. Leaf scars during leaf fall are also dangerous.
Once it has penetrated the wood, the fungus carries out its destructive work: the supply of water and nutrients is impeded, branches and shoots above the infested areas grow less well and wither. If it goes very badly, even the whole tree will die.
What can be done against fruit tree canker?
The areas infected by Nectria galligena must be removed as soon as possible. Use a sickle-shaped pruning knife to cut the bulges down to the healthy wood and then scrape the area clean. Smaller shoots should be cut off completely.
Then the wound must be generously coated with a fungus-repellent tree wax. The "Landwirtschaftskammer Nordrhein-Westfalen" recommends using wound closure products such as "Celaflor Wundbalsam Plus", "Lac Balsam" or "Tervanol F". It is also best to treat infected trees in dry weather.
What are the preventive measures against fruit tree canker??
The harmful fungus likes it moist. That's why you should watch apple-. Do not plant pear trees in wet places. Also unfavorable are higher altitudes with a lot of fog and early frost. The following apple varieties are particularly susceptible to fruit tree canker:
– Berlepsch – Braedburn – Cox-Orange – Elstar – Fiesta – Gala – Goldparmane – Idared – Rubens – Topaz
Can you put the cut wood on the compost??
Just not! There the fungus would infect in shortest time the whole compost. When spreading the compost, it would spread in the garden and then infest the tree again. Cut shoots, twigs as well as branches should not be left on the meadow either. Growing in wet grass. If the fungus thrives particularly well. Ideally, burn the infested wood. If this is not possible, the waste should be placed in the residual waste.