Certified Arborist Test 2025 – 400 Free Practice Questions to Pass the Exam

In the context of disease development, a susceptible host, a pathogen, and various environmental conditions are all critical factors. A susceptible host is necessary for a pathogen to infect and establish a disease because the host's immune response will play a significant role in determining whether a disease manifests. The pathogen is the organism that causes the disease, which can include fungi, bacteria, viruses, or nematodes. Environmental conditions encompass a range of factors that can affect the disease cycle, including moisture, temperature, and soil conditions, which can either promote or inhibit disease development.

Inadequate sunlight does not directly contribute to the development of disease in the same way. While it can affect plant health and vigor, making them more prone to stress and potentially more susceptible to various problems, inadequate sunlight itself is not considered a factor in the disease's development. Diseases are primarily linked to the interaction between hosts, pathogens, and environmental factors, rather than simply the availability of sunlight.