What are pathogens in the context of plant health?

Pathogens, in the context of plant health, refer specifically to disease-causing organisms that can negatively impact plants. These pathogens include various types of microorganisms such as fungi, bacteria, viruses, and nematodes. They can invade plant tissues, disrupt normal physiological functions, and lead to symptoms such as wilting, discoloration, decay, and ultimately affect plant growth, yield, and health.

Understanding pathogens is critical for managing plant health effectively. Effective control measures, like proper sanitation, disease-resistant plant varieties, and integrated pest management, can help mitigate the impacts of these harmful organisms. In contrast, the other choices describe beneficial roles or support systems for plants, which do not align with the definition of pathogens.