Depending on the location, yellow spots occasionally appear on the trunk of the apple tree, which are located on the bark. You can find out in this article what this phenomenon is all about and whether this growth harms the fruit tree.
What are those yellow spots on the trunk of the apple tree?
The yellow spots that youcommonly see on older treesarelichens. These can give the layperson the impression that they remove nutrients from the fruit tree. However, this is not the case, which is why control is rarely necessary.
Where do the yellow spots come from?
The yellow spots are not pests or plants that feed on tree sap, buta collective of algae and fungi,thatTree used as a growth base.
These so-called lichens colonize not only the bark of older trees but also stones, rocks and sandy soils. They are among the longest-lived creatures and can live for several thousand years.
Does yellow lichen harm the apple tree?
Since lichens only use the apple tree as a base, but absorb water and nutrients from the air,damageThey usually do not damagethe fruit tree. On the contrary: As long as the vegetation does not get out of hand, they even protect the trunk and branches from invading fungi and bacteria.
If the lichens also overgrow the buds and prevent them from breaking open in an old, already weakened apple tree, this can have a negative impact on the vitality of the tree.
Do I have to do something about the yellow spots on the trunk?
Since codling moths and tree lice often overwinter in the rough surface of the vegetation, you shouldif the vegetation is too dense,you should at least partially removeusing lichens:
- The loose bark and lichen can be easily brushed off with a soft brush.
- You can then apply a protective glue ring or a coat of white paint to the tree.
- For old apple trees, rejuvenation pruning can also be helpful.
- Cut off those branches where the buds are densely covered with lichen.
Tip
Lichens indicate clean air
Lichens are found on trees far less frequently in big cities than in the countryside. The reason: The rootless plants feed exclusively on water and nutrients from the air. Since they do not have an excretory system, they react very sensitively to impurities. Therefore, they are important indicators that can be used to determine the level of air pollutants and heavy metals.
