Outbreaks of which disease can be predicted by monitoring nighttime minimum temperatures?

• A. Rhizoctonia blight
• B. Fusarium blight
• C. Red thread
• D. Pythium blight

Answer: (B)

Fungus outbreaks like Fusarium patch are driven by cool, wet nights. When nighttime temperatures drop, dew forms and stays on the leaf surfaces for longer periods, creating leaf wetness that the Fusarium patch pathogen needs to infect and spread. By watching the nighttime minimum temperatures, you can predict when those cool, damp overnight conditions are likely to occur and anticipate higher disease risk. This makes nightly minima a useful predictor for Fusarium patch outbreaks.

Other diseases don’t depend as specifically on how cool the nights get. Red thread is more about low nitrogen and damp, mild weather; Pythium blight is tied to hot, wet conditions and rapid, saturated irrigation; Rhizoctonia blight tends to follow warm, humid weather with leaf wetness but isn’t best predicted by night-time minima alone.