While there are a number of fungal infections that can plague trees, and many of them show similar symptoms, one that really does stand out from the crowd is powdery mildew disease. If your tree's leaves have a baby powder-like substance on their undersides, then it is almost certainly infected with powdery mildew. Here's a closer look at this condition and what you can do about it.
What causes powdery mildew disease, and how is it spread?
There are several related species of fungi that can cause this disease. It affects a wide array of plants, from trees to vegetables. Some forms of the disease also cause yellowish spots to appear on the leaves, while others only present themselves as white powder. Often, the condition starts off pretty mild, causing a light coating of white powder, and then as it becomes more severe, the powdery coating becomes thicker.
How does powdery mildew disease harm the tree?
Unlike more severe fungal infections that tend to kill off trees in a number of years, powdery mildew disease itself will not cause your tree to die back. However, it does weaken your tree and make it more susceptible to other fungal infections that may, in fact, kill it. Thus, it's important to treat powdery mildew disease rather than ignore it.
How is powdery mildew disease treated?
When the condition is first detected, the tree should be sprayed with fungicides to get the condition under control. Potassium bicarbonate is a popular fungicide to use for this purpose, as it tends to be less hazardous than other choices while still strong enough to kill the fungus.
After the tree has been treated with fungicides, the fungus should disappear. However, you will want to take measures to prevent powdery mildew from coming back. These include:
- Having the tree pruned to thin the branches, so less moisture becomes trapped between them. (Fungi thrive in moist areas).
- Cleaning up any fallen leaves, fruits and twigs promptly. (These can harbor the fungal spores and cause the tree to become re-infected).
If your tree has powdery mildew disease, you should take the precautions above with all of the trees on your property in order to prevent them from also contracting the disease.
Of all of the fungal infections that your tree can develop, powdery mildew disease is probably the least concerning. However, you do not want to ignore this infection – or else you could end up dealing with a tree suffering from deadly root rot or canker diseases down the road. For more information, contact a landscape company like Ironwood Earthcare.