Define Sign.

Define Sign.

• A. A sign of the actual pathogen
• B. Alterations of turf grass as a result of disease
• C. Visible symptoms of disease
• D. Disease transmitted by vector

Answer: (B)

Signs are direct evidence of the pathogen itself. They are things you can observe that come from the organism causing the disease, such as fungal spores or structures, mycelium, fruiting bodies, cysts, or even viral particles seen in plant tissue. Symptoms, on the other hand, are how the plant responds to the infection—discoloration, spots, wilting, stunted growth, and similar changes in appearance. So, the statement that describes evidence of the actual pathogen fits the concept of a sign. Descriptions of alterations in the turfgrass (how the plant looks or behaves) are symptoms, and discussions about transmission by a vector relate to spread, not to signs.

Signs are direct evidence of the pathogen itself. They are things you can observe that come from the organism causing the disease, such as fungal spores or structures, mycelium, fruiting bodies, cysts, or even viral particles seen in plant tissue. Symptoms, on the other hand, are how the plant responds to the infection—discoloration, spots, wilting, stunted growth, and similar changes in appearance.

So, the statement that describes evidence of the actual pathogen fits the concept of a sign. Descriptions of alterations in the turfgrass (how the plant looks or behaves) are symptoms, and discussions about transmission by a vector relate to spread, not to signs.