Which turf disease is commonly associated with wet, dewy mornings and narrow leaf spots?

• A. Brown patch.
• B. Pythium blight.
• C. Summer patch.
• D. Dollar spot.

Answer: (D)

This item tests matching symptoms with the environmental pattern that favors a turf disease. When mornings are wet and dewy, you’ll often see small, narrow leaf spots on cool-season grasses, and that pattern points to dollar spot. Dollar spot lesions are tiny, tan to straw-colored spots that can run along the blade as narrow streaks, giving the appearance of small “dollar-sized” spots as they spread. It thrives with leaf wetness from dew and cooler temperatures, and is a common problem on greens and fairways when conditions stay moist and fertility is off.

Other diseases tend to produce different symptoms under similar conditions: brown patch forms larger circular patches, not narrow spots; Pythium blight causes greasy, rapidly expanding lesions during wet heat; summer patch shows different patterns like patchy yellowing with white mycelial mats in stressed turf. So the combination of dew-driven leaf wetness and small, narrow leaf spots is most characteristic of dollar spot.