What is the role of a pathogen?

A pathogen is an organism that causes disease in its host, which can include plants, animals, and humans. By living off a host organism, pathogens disrupt normal physiological processes, leading to symptoms of disease such as wilting, discoloration, or death of the host plant. In the realm of turf and ornamental pest control, understanding the role of pathogens is crucial for managing plant health and preventing disease outbreaks.

The other options reflect processes or interactions that are generally beneficial for plant health but are not applicable to the role of pathogens. Nutrients are vital for plant growth, and while some organisms play important roles in enhancing growth or stimulating root development, pathogens are not among them; rather, they can hinder these processes significantly. Therefore, recognizing that the primary role of a pathogen is to cause disease by exploiting a host is essential knowledge in pest management and plant disease control strategies.