Development of hypothetical infection model based on environmental variables for Plasmopara viticola (Berk. & M.A. Curtis) Berl. & De Ton

Development of a hypothetical infection model for Plasmopara viticola based on environmental variables was applied to black grape variety Vranec. The infected leaves were digitally quantified using the software platform 'ImageJ' to determine disease severity. The resulting data, along with inputs of average temperature and leaf wetness duration, were used to establish a regression relationship. Downy mildew infection reaches its maximum when we have an average of 2 hours and 29 minutes of leaf wetness duration and an average daily temperature of 26.8 ° C. The regression relationship then by used to describe the results, and based on this, a hypothetical infection model for P. viticola was developed