ISA Certified Arborist Practice Exam

Which of the following are symptoms of root rot in trees?

1. Brown leaves and early flowering.

2. Yellowing leaves, stunted growth, and decline in health.

3. Increased leaf size and dark green color.

4. Abnormal growths on the trunk.

The correct answer is: Yellowing leaves, stunted growth, and decline in health.

The symptoms of root rot in trees primarily include yellowing leaves, stunted growth, and a general decline in health. When a tree experiences root rot, the affected roots are unable to uptake water and essential nutrients effectively, leading to stress that manifests in several ways. Yellowing leaves occur as a response to nutrient deficiencies, particularly nitrogen, which gives rise to poor foliage coloration and vitality. Stunted growth results from the tree’s compromised ability to sustain itself, causing fewer new leaves and overall growth to occur. Furthermore, a decline in health can encompass a variety of symptoms such as wilting, branch dieback, and an overall decline in vigor, indicating that the tree is not thriving. In contrast, other options present symptoms that do not align with root rot conditions, further reinforcing the accuracy of this diagnosis. For instance, early flowering and brown leaves, while potentially indicating other stress factors, do not typically correlate with root rot symptoms. Increased leaf size with a dark green color generally suggests an overabundance of nutrients and healthy growth, which is the opposite of what one would expect in the face of root rot. Lastly, abnormal growths on the trunk could point to other issues such as pests or diseases impacting woody tissue but are not characteristic of root rot