Disease Risk Maps Explained:

On the weekly maps, red dots indicate high risk (generally 4 or more days during the week conducive to disease infection). Moderate risk (yellow dots) generally indicates between 2 and 3 days per week of exposure. Fewer exposure days indicate low risk.

Forecast maps are based on National Weather Service forecast guidance, with daily risk based on the numeric value of the index.

Dollarspot Risk: Using the models of Mills and Rothwell (1982) and Hall (1984) with slight modifications for compatibility with the available regional weather observations, these maps highlight the risk of dollar spot infection. Dollar spot risk is a function of relative humidity, temperature, leaf wetness hours and days with rain.

Pythium Blight Risk: Using the model of Nutter et al. (1983) with slight modifications for compatibility with the available regional weather observations, these maps highlight the risk of pythium blight infection. The index is a function of air temperature and relative humidity.

Brown Patch Risk: Using the model of Fidanza et al. (1996) with slight modifications for compatibility with the available regional weather observations, these maps highlight the risk of brown patch infection. The index is a function of relative humidity, leaf wetness and minimum daily air temperature.

Anthracnose Risk: Using the model of Danneberger et al. (1984) with slight modifications for compatibility with the available regional weather observations, these maps highlight the risk of anthracnose infection. The index is a function of leaf wetness and temperature.

References