That portion of individual pathogens that are brought into contact with the host. The state in which a host is infected with a pathogen but does not show any symptoms. Dead or discolored areas on the leaf tissue that are fairly small and are usually circular. A localized area of discolored, diseased tissue. Grey or white powdery growth on the plant surface.
Leaves are the most common place to see mildew.
Also characterized by intermingled patches of normal and light green or yellowish color. A common symptom of many viruses. Necrosis is dead tissue or plant parts. A chemical compound or physical agent that kills or inhibits nematodes. Microscopic, wormlike animals that live saprophytically in water or soil, or as parasites of plants and animals.