AT A GLANCE
Which leaf spot diseases are there in apples?
Spots and discoloration of the apple leaves are mostly caused by Mushrooms the genus Phyllosticta caused. Only found in America and Asia until a few years ago marssonina leaf fall disease, triggered by the introduced Diplocarpon sac fungus, also occurs more and more often in the home garden.
How do I recognize Phyllosticta leaf spots?
Appear on the leaves of the apple bright spots with irregular edges, which stand out clearly from the surrounding tissue. Later, dark dots appear in the middle. These are the fruiting of the fungi.
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Since the foliage can no longer perform good photosynthesis, the tree releases plant hormones and the affected leaves are shed. Humidity favors the spread of fungal pathogens.
How can I get this leaf spot disease under control?
The distribution of Phyllosticta can be done by different measures effective prevent and fight:
- Cut the apple trees back regularly and ensure a loose build-up of the crown. This will dry the foliage faster.
- Remove fallen and infested leaves and dispose of with household waste.
- Unfortunately, there are currently no home remedies for this leaf spot disease.
- Commercially available broad spectrum fungicides are effective but should be used with caution.
How do I recognize Marssonina leaf fall disease?
In rainy summers, already in the June on the top of leafgrey-black spots, that of one red-purple border are surrounded. The entire leaf turns intense yellow. Also noticeable is a high leaf loss of the apple tree.
The fruits are not attacked by this fungus. However, as a result of premature leaf loss, the apples remain smaller. In the next year you have to reckon with an affected tree with a significantly reduced number of blossoms and thus also fruit set.
How can I prevent or fight Marssonina fungus?
Since moisture promotes the spread of the fungus, you should get through regular cuts for one loose crown structure care for. The following measures are also helpful:
- Cut off affected foliage.
- Collect fallen leaves immediately.
- Dispose of all plant parts in household waste.
One Combat with home remedies is unfortunately not possible in most cases. Preparations effective against scab Although they also work against Marssonina leaf fall disease, they should only be used in exceptional cases for ecological reasons.
Tip
An optimal location prevents leaf spots
In a place where the sun plays around the apple tree in the morning hours, the dew-covered leaves dry much faster. If you also keep the crown structure loose and ensure a good supply of nutrients, the fruit tree can better defend itself against fungal diseases.