Pythium blight can decimate a sunny site even with good management.

• A. True
• B. False
• C. Only in shade
• D. Not a real disease

Answer: (A)

Pythium blight is a fast-moving turf disease that needs leaf wetness to infect. Sunlight itself doesn’t stop it—what matters is whether the leaf blades stay wet long enough after dew, rain, or overhead irrigation. In warm, humid conditions, blades can remain wet for hours even on a sunny site, allowing rapid infection and rapid spread across the turf. The result can be large, greasy-looking patches that darken and collapse in a short time, killing turf quickly.

Good management helps a lot—drainage that reduces saturated soils, irrigation practices that minimize leaf wetness (watering early or late to avoid overnight moisture), good air movement, proper mowing height, timely fungicide use if appropriate, and clean-up of clippings to reduce inoculum. But if weather patterns bring persistent moisture and favorable temperatures, outbreaks can still occur and cause substantial damage despite diligent turf care. That combination of biology and conditions is why Pythium blight can decimate a sunny site even with good management.