Leaves curl up and change color - a clear indication of the so-called curl disease. It is particularly common in peach trees. In our latitudes it is basically the biggest problem you can have with fruit trees. Although other diseases and pests can also pose a threat to it, they play a relatively minor role compared to curl disease.
Background
Peach trees are strange plants. On the one hand, they need a lot of light and sun so that they can produce sweet, juicy fruits. On the other hand, this only works if they are exposed to the winter cold for several hundred hours over the course of a year. The reason for this is the so-called vernalization. This refers to the fact that a whole range of plants only shoot and bloom if they have to survive a long period of cold in winter. At the same time, however, relatively mild and therefore often too wet winters pose a problem for them. The wetness creates the best conditions for later being attacked by a fungus. And in the worst case, such a fungal infection can even lead to the death of the plant or tree.
Frizz disease
This disease of peach trees is nothing other than an infestation with the fungus Taphrina deformans, an ascomycete. It penetrates the buds of the tree and infects the leaves that have not yet been able to unfold. It also overgrows the flower buds. Once this has happened, it is very difficult to stop the infestation. Without the massive use of fungicides, the disease can usually no longer be combated. Infestations typically occur in spring if the previous winter was particularly wet. Taphrina deformans requires 12.5 hours of continuous wetness on the tree bark in order to develop. The temperatures must not exceed 16 degrees Celsius.
Malicious images
Since the fungus is initially washed from the bark by the rain into the leaf buds of the tree, an infestation can also be seen on the leaves. They curl up as soon as they sprout in spring. The young, green leaves also have light green or red bubbles. As the disease progresses, the leaves turn whitish-green and yellowish. When the final stage of the infestation has finally been reached, they appear greatly enlarged, are brittle or even rubbery. Eventually they fall off. The associated high loss of leaves leads to a reduction in the overall photosynthesis performance of the tree and can cause it to die.
Note:
Curled leaves without color changes have nothing to do with curl disease, but rather indicate an insect infestation. Checking the undersides of the leaves, where aphids can be found, for example, provides clarity.
Combat
Combating curl disease on peach trees is problematic. There are no home remedies or biological remedies for this. The disease cannot be controlled without the use of fungicides. The problem is that the treatment must be carried out before the buds break open. Once this has happened, even fungicides no longer help. In professional peach cultivation, the trees are often sprayed prophylactically with appropriate sprays before the buds open. This can also be transferred to private cultivation. If the winter is particularly mild and wet, the garden should also be sprayed. This must be done at the end of January and then repeated three times at intervals of about a week.
Prevention
Since combating leaf curl disease in the home garden is often difficult, preventive measures play a crucial role. These begin before the tree is planted with the selection of the most resistant variety possible. These are special breeds that are extremely robust and resilient. Among others, these include:
- Alexandra Zainara
- Amsden
- Benedict
- Revita
- Red Vineyard Peach
It is also recommended to plant the peach tree near a house wall or below a roof overhang. Winter rain is then at least partially kept away from the tree. Wrapping the entire tree with a sturdy plastic baffle can also be helpful, but is very time-consuming.
Other diseases
Curly disease is the most common and dangerous disease in peach trees. But of course there are other threats to the tree. One example ispeach scab, in which hardening dark spots quickly form on leaves and fruits. It can be easily controlled with organic fungicidal products. There is also often an infestation withpeach powdery mildewThis appears as a whitish coating on leaves and fruits. To combat it, infected areas should definitely be cut off and a suitable fungicide should be used. This also applies ifshotgun disease occurs. It is shown by small reddish spots on the leaves. After a certain time, these spots fall out of the leaf, which then looks like it has been riddled with shotgun pellets.
Pests
The typical diseases of peach trees are fungal infections. However, an infestation with animal pests or insects can also occur. The aphid appears most frequently. Leaves curling up? As already suggested, this can also indicate these little beasts. The only way to combat a larger infestation is to use a chemical insecticide that must be sprayed on the tree. This is also how the fruit tree spider mite occurs. An infestation with these tiny insects can be recognized by the whitish spots that appear on the leaves and a subsequent bronze-colored discoloration.
