Certified Arborist Practice Exam

Name 2 vascular diseases:

1. Dutch Elm Disease

2. Verticillium Wilt

3. Laurel Wilt

4. Oak Wilt

The correct answer is: Dutch Elm Disease

The correct answer identifies a vascular disease that primarily affects the water transport system of trees. Dutch Elm Disease is caused by a fungus that primarily operates through the vascular system of the elm. This disease leads to the blockage of xylem vessels, which in turn disrupts the flow of water and nutrients within the tree, ultimately causing wilting, leaf drop, and often death. While the answer provided identifies one vascular disease accurately, Verticillium Wilt, Laurel Wilt, and Oak Wilt are also considered vascular diseases as they similarly disrupt the vascular system of various tree species. For example, Verticillium Wilt is caused by the Verticillium fungus, which invades the vascular tissues and leads to symptoms such as wilting and dieback. Laurel Wilt attacks members of the Lauraceae family and is caused by a fungal pathogen spread by ambrosia beetles, affecting their vascular integrity. Oak Wilt, caused by the fungus Ceratocystis fagacearum, affects oak trees by spreading through their vascular system. All these diseases adversely impact tree health through vascular dysfunction. In summary, while Dutch Elm Disease is indeed a significant vascular disease, the other choices also represent vascular diseases that affect trees in similar ways. It's essential to recognize that