Impacts of root diseases on trees
Root diseases in trees can be elusive as they conceal themselves deep within the soil. Additionally, there are usually no early symptoms that a tree is infected with a pathogen until the damage is severe.
Tree root disease not only begins in the root system but also remains in the root system and the lower stem of the host tree. This is one of the reasons why proper diagnosis is challenging.
How susceptible a tree is to a root disease varies by its genetics, location history, and the type of pathogen. Still, trees of all ages can be affected by at least one root disease type under the right circumstances.
Causes
Overwatering, poor soil conditions, ineffective drainage systems, tree root damage, pest or fungus infestations, and drought.
Symptoms
The sudden wilting or drooping of leaves on the tree’s overall canopy is a clear symptom that root disease may be present from above the ground. Better identification is made by inspecting the roots themselves or the root collar region of the tree for the presence of fruiting bodies (part of the reproductive phase of a fungal life cycle) or other signs of infection. Additional symptoms include yellowing or brown leaves, declining health for no apparent reason, and a failure to grow.
Treatment
There are no guaranteed treatment options for root diseases once the roots are infected. Because root systems are so expansive, root disease can often impact nearby trees by spreading outward. While some might assume that removing the infected tree will prevent future infestations, root disease fungi can remain active in dead roots and soil for many years.
While soil fumigation is possible, it uses chemicals that may adversely affect the environment, humans, and surrounding plant matter.
However, a non-chemical option, such as solarization, provides the most negligible impacts. Soil solarization is a method of controlling pests and pathogens using solar power to increase the temperature levels of the soil high enough to kill or severely weaken the pathogen.
Replanting a new tree in the same location is only recommended if much of the dead stump, adjoining root systems, and soil has been removed or treated. Even then, a different species with natural resistance to the root disease should be chosen.
Prevention and Management
Proper planting and maintenance practices are your best defense against tree root diseases. For example, avoid planting trees in poorly drained soil or low areas where water collects, as this encourages fungi growth. In addition, damage from improper pruning, lawnmowers, and other excavation equipment within the root zone should be avoided to prevent infestations from open wounds. If you think your tree may be damaged, it’s best to contact a professional immediately.
