Help the development of the site, sharing the article with friends!
Recognizing the damage caused by fruit tree canker and combating it at an early stage is crucial in order to save the affected plants. You can find out how fruit tree cancer is treated here.
In a nutshell
- Apple trees are particularly affected
- caused by fungal infestation
- first signs are often growths
- Yield is reduced
- Plant becomes more susceptible to other diseases and pests
Affected fruit trees
Apple trees are most commonly affected. However, other species can also be infested. These include, for example:
- apricot
- pear
- plum
- quince
Fruit tree canker on apple trees
However, it is by no means only fruit trees that can fall victim to the disease. The following are also affected with increasing frequency:
- birches
- Book
- alders
- ash trees
- poplars
- holly
- walnuts
- hawthorns
Notice: Tree canker can break out in both cultivated and ornamental plants. A completely resistant variety has not yet been found. However, there are variants that are more resilient. Therefore, you should recognize fruit tree cancer early and initiate treatment.
root cause
The cause of the so-called tree canker or fruit tree canker is the fungus Neonectria ditissima. This is a so-called pustule fungus. It spreads primarily in wounds in the bark and is found primarily in regions with a high rainfall rate or a dense population. Litter meadows and plantations are therefore more frequently affected.
Source: Sternrenette, Neonectria ditissima - fresh wound, edited from Plantopedia, CC BY 3.0
damage picture
The damage caused by Neonectria ditissima includes various signs by which you can recognize the fruit tree canker. It refers to:
- dying of the bark
- brownish ulcers and spots on young shoots
- Early ripening of the fruit, stunted plant parts and fruit
- tiny red fruiting bodies of the fungi on affected areas
- growths on the bark
The signs are often very pronounced, especially in young trees.
Source: Abrahami, Nectria galligena, edited by Plantopedia, CC BY-SA 4.0
Notice: So-called open tree canker is accompanied by a partial fall off of the bark. Closed tree canker, on the other hand, shows clear growths in the affected areas.
treatment
Recognizing fruit tree canker by the symptoms and starting the fight as early as possible is crucial for success. The treatment of fruit tree cancer must be done in several steps. These include:
- controls: Check the trees regularly for changes in the bark, young shoots and buds and fruit.
- Removal of affected plant parts: Using a clean and sharp cutting tool, cut off the affected sections as quickly as possible. Make sure you cut directly into the healthy wood and clean the blades with disinfectant after or before each cut. In this way you can prevent the spores of the fungi from getting back onto the plant.
3. Disposal: The clippings must not be disposed of in the compost. Otherwise, the fungal spores could spread again through wind, rain or the compost soil itself.
Tip: Also collect infested fruits and dispose of them either in organic waste or household waste. Otherwise, renewed distribution cannot be ruled out.
prevention
The best treatment for fruit tree canker is to prevent an infestation. Several measures are also necessary for this. These include:
- Choosing the right varieties: Choose resistant varieties. Although these are not completely immune, they are more resistant to the fungus.
- Keep your distance: Give the trees enough space. This ensures the necessary ventilation.
- Prevent waterlogging: Waterlogging and soil that tends to be compacted are ideal conditions for the spread of the fungus. You should therefore prevent these conditions as well as over-fertilizing the plants.
- waste: Avoid crossing branches and make regular trimmings. This keeps the crown airy and rain or dew dries off faster.
- Prevent damage: Frost cracks, an existing disease or a pest infestation can promote fruit tree cancer. Because it is precisely in these wounds that it spreads. However, immediate care or treatment can prevent the infection.
Source: Sternrenette, Neonectria ditissima - old wound, edited from Plantopedia, CC BY 3.0
frequently asked Questions
Does the fungus spread quickly?Even with preferred hosts, such as apples and pears, the fungus only spreads quickly if there is damage and unfavorable care conditions or unsuitable locations. However, a renewed infestation can be prevented by appropriate preventive measures.
When is the best time to trim?Here the opinions differ. Infested parts should be cut off as soon as possible to prevent further spread. However, only on days without frost or strong blazing sun. The best time is just before flowering.
Are there also fungicides against tree cancer?These are available, but are only available for commercial use. They are not allowed in private gardens. However, cutting the trees is usually sufficient if it is done in good time.