What is the variance in the growth potential (GP) equation?

I’ve been asked about the variance in PACE Turf’s growth potential (GP) equation. The variance adjusts the shape of the curve, as the chart above shows. With a lower variance, the GP drops quickly as t moves away from t_o. With a higher variance, the GP stays higher with temperatures moving away from t_o.

For more about GP, see:

• Improved overseeding programs 1. The role of weather A mathematical model helps explain the role of weather in the outcome of overseeding programs

• Using temperature to predict turfgrass growth potential (GP) and to estimate turfgrass nitrogen use

• PACE Turf’s climate appraisal forms