Which type of disease occurs when a host plant is invaded by a pathogen?

The type of disease that occurs when a host plant is invaded by a pathogen is referred to as a pathogenic disease. Pathogenic diseases are caused by various organisms, including fungi, bacteria, viruses, and nematodes, which can infect plants and lead to symptoms such as wilting, stunted growth, discoloration, or decay. These organisms can disrupt a plant’s normal physiological processes and often spread from infected to healthy plants.

Pathogenic diseases are characterized by their direct role in causing harm to the plant, differentiating them from other types of issues that can affect plant health, such as nutrient deficiencies or environmental stressors. Nutrient deficiencies arise from an insufficient supply of essential nutrients, while environmental stress involves adverse conditions like drought or extreme temperatures impacting plant health. These factors do not involve a pathogen actively causing a disease in the plant, which is a key aspect of pathogenic diseases. Understanding the nature of these pathogens and their effects on plants is crucial for managing plant health and implementing effective disease control measures.