Mildew is one of the most well-known diseases of apple trees in this country. If you notice signs of this disease on an apple tree, you should act quickly.
How do I recognize and combat powdery mildew on apple trees?
Mildew on apple trees can be recognized by a mealy coating on branches, white spots on leaves and web-like cracks on fruits. In order to contain fungal infestation, affected areas should be cut out early and precautionary measures should be taken through targeted pruning.
Small mushroom with big damage
The mildew fungus, also known by the scientific name Podosphaera leucotricha, is not without good reason very feared in hobby gardening circles. This is primarily due to the massive speed with which the fungus can spread after the initial infection on a tree or in the neighborhood. If the fungal networks spread extensively on the leaves and shoot tips of the apple tree, this can sometimes lead to a total failure of the harvest or even the entire tree.
Recognizing powdery mildew as a disease on apple trees
Mildew can be recognized by the following symptoms on the tree and on the fruits of the apple tree:
- due to mealy coating on the branches
- due to white, mealy spots on the leaves
- with net-like cracks in the color of the fruit
On closer inspection, the first signs of a primary infection with mildew can be seen with the winter pruning. The fungus that hibernates on the buds and shoot tips causes the scales of the buds to stick out somewhat spread apart. Infected areas should always be cut out into the wood as soon as possible and something removed from the tree. However, the cut material can be composted in your own garden without any problems. In spring, signs of powdery mildew appear with a mealy coating on buds, young shoots and leaves. If left untreated, these areas spread quickly and gradually affect the entire tree.
Tackling the mildew fungus
Treating powdery mildew on apple trees is generally possible with fungicides, but due to the high effort and the damage to the fruit and garden with the fungicides, this is only a last resort to save the trees in the event of severe infestation. In the private garden, precaution and containment through targeted pruning are much more important. That's why you should regularly take a close look at your apple trees after winter pruning and cut out any infestations early.
Tips & Tricks
If the primary infection is extensively excised early on, the secondary infection can spread far less strongly during periods of summer wind and rain.