Threshold Charts

Select a location to review the following list of threshold charts.

  • Soil Temperature: Daily average 2-inch soil temperature and the 2-inch soil temperature averaged over 5 days are key indicators of plant growth stage (weeds and turfgrass) and soilborne disease development (see Turf Path update, April 1, 2011). The highlighted 55-60° F threshold indicates the appropriate threshold to initiate prevention for fairy ring and other soilborne diseases on golf putting greens.

  • Smith-Kerns Model for Dollar Spot Prediction: The Smith-Kerns Model is based on 5-day rolling averages of air temperature and relative humidity with a 20% model threshold. Tracking for this model begins April 1.
    • 2-month: This chart will display the past 60-days of probabilities.
    • Annual: This chart will display all probabilities for the year, it will not be available until June.