Which of the following lists three signs of root disease in trees?

• A. Reduced vigor or yellowing
• B. Dieback
• C. Visible decay or girdling roots at or near the root crown
• D. Reduced vigor or yellowing, dieback, and visible decay or girdling roots at or near the root crown

Answer: (D)

Root diseases disrupt the tree’s ability to take up water and nutrients, so signs show up both in the canopy and at the root zone. When a root problem is present, you’ll often see canopy decline first—reduced vigor or yellowing—as the tree struggles to fuel growth. As the issue progresses, dieback becomes evident in twigs and small branches. At the same time, there are physical root-zone signs: decay in the roots and roots that girdle or constrict near the root crown, which directly interferes with transport to the crown. Seeing all three signs together—reduced vigor or yellowing, dieback, and visible decay or girdling roots near the root crown—provides the strongest indication of a root disease. Each sign alone can have other causes, but their combination strongly points to a root-related problem.