Temperature and leaf age are generally recognized as the driving force for pathogen development (growth and sporulation of lesions), whilst wind factors (direction,
speed) dictate inoculum (spore) dispersal In the model presented here, the dynamics
of the pathogen population on leaves were split into three key processes: (a) infection, (b) colony or mycelium growth, and (c) sporulation and dispersion. The time between infection
and sporulation was described as the latent period,and the duration of sporulation as the infectious period.The standard formula of Analytis was used to describe the effect of temperature on the rate of spore infection and on the rate of mycelium growth.
F was a function of a normalized temperature