How is 'infestation' defined in the context of plant pathology?

In the context of plant pathology, 'infestation' refers specifically to a scenario where there are large numbers of pathogens present that lead to observable damage to the plant. This definition emphasizes the quantity of the pathogens and their capacity to harm the plant tissues, which can manifest as stunted growth, wilting, leaf spots, and overall decline in plant health. Infestation typically indicates an advanced stage of infection where the pathogen population is significant enough to elicit a detrimental response from the host plant, impacting its vigor and productivity.

The notion of infestation implies not just the presence of pathogens, but a relationship where the pathogens overwhelm the plant's defenses, leading to clear symptoms of disease. This contrasts with a scenario where only a few pathogens are present, which might not result in noticeable damage, or where the plant might be in recovery from a disease state. Understanding infestation is crucial for effective pest management and disease control strategies, as it guides the need for intervention based on the severity of the pathogen presence and its impact on plant health.