Certified Arborist Test Tree Diagnosis and Treatment 2

Question 1

What is the primary symptom pattern that differentiates verticillium wilt from other causes of canopy dieback in susceptible tree species?

Accepted Answer

Sudden wilting and dieback of individual branches ('flagging') while adjacent branches remain healthy, often with green streaking in the sapwood

Answer

Uniform yellowing and drop of all leaves simultaneously throughout the entire crown

Answer

Progressive dieback from branch tips inward and from bottom of crown upward over several years

Answer

Tan or orange discoloration of all leaves followed by complete defoliation in a single event

Question 2

What are the diagnostic symptoms of anthracnose on sycamore, and how is it distinguished from more serious diseases?

Accepted Answer

Blotchy brown leaf spots following vein patterns, shoot blight in spring, and twig dieback — primarily a cosmetic problem in most years

Answer

Small pustules on the upper leaf surface with yellowing halos, similar to fire blight on apples

Answer

Sooty black coating on leaves caused by fungal growth on insect honeydew deposits

Answer

White powdery coating on new leaves that causes them to distort and drop prematurely

Question 3

What is the significance of 'yellownecked caterpillar' and similar defoliating insects in tree health, and when does defoliation become a threat to tree survival?

Accepted Answer

Single-year complete defoliation rarely kills healthy trees, but repeated defoliation over consecutive years depletes NSC reserves and can lead to mortality, particularly combined with drought or other stresses

Answer

Defoliating caterpillars are never significant as trees immediately replace all lost foliage within days

Answer

Complete defoliation in summer always kills the tree within that season due to photosynthesis loss

Answer

Defoliating caterpillars only damage ornamental value — they have no physiological effect on tree health

Question 4

What are the symptoms and transmission mechanism of Dutch elm disease, and what management strategies are available?

Accepted Answer

A vascular wilt caused by Ophiostoma novo-ulmi transmitted by bark beetles, causing yellowing and wilting flagging in the crown — managed through sanitation, fungicide injection, and pheromone traps

Answer

Root-to-root transmission of a bacterial canker that causes bark cracking — managed by removing infected bark with sanitized tools

Answer

A foliar fungal disease spread by wind-borne spores causing premature defoliation — managed by fall fungicide application

Answer

A root rot caused by Phytophthora species transmitted through contaminated soil and water — managed through drainage improvement and phosphonate applications

Question 5

What is the purpose of a tree health assessment using canopy transparency, and what does it measure?

Accepted Answer

An estimate of overall crown density and vitality by evaluating the proportion of sky visible through the live crown compared to a full, healthy crown of the same species

Answer

The amount of sunlight reaching the ground beneath the canopy for understory management

Answer

The distance between leaves and the observer, which correlates with photosynthetic efficiency

Answer

The opacity of individual leaves as an indicator of chlorophyll content and nitrogen status

Question 6

What systemic pesticide application method involves drilling small holes into the root flare area and applying material into the holes, and what are its primary applications?

Accepted Answer

Trunk injection (basal trunk injection/soil injection) — placing systemic material directly into the vascular system via drilled wounds for high-efficiency uptake with minimal environmental exposure

Answer

Basal bark spray — applying concentrated product to the lower trunk and allowing it to absorb through the bark

Answer

Chemigation — applying systemic material dissolved in irrigation water for soil uptake by roots

Answer

Foliar application of systemic material that is absorbed through leaves and translocated throughout the tree