Certified Arborist Practice Test

Nitrogen fertilization can lead to excessive growth in trees, promoting leafy canopies and a lush appearance. While this may seem beneficial at first glance, it can significantly compromise a tree's natural defense mechanisms against pests and diseases.

When trees receive high levels of nitrogen, they often allocate more energy towards vegetative growth rather than the production of secondary metabolites that are crucial for defense. These metabolites include tannins, phenolics, and other compounds that enhance a tree's ability to fend off insect pests and combat pathogens. As a result, while the tree may grow faster and appear healthier, it becomes more susceptible to infestations and infections because it lacks the necessary defensive compounds that help protect against these threats.

This understanding underscores the importance of balanced fertilization practices that consider the overall health and ecological interactions of trees, which extends beyond just promoting rapid growth.