Factors influencing the airborne sporangia concentration of Phytophthora infestans and its relationship with potato disease severity

Forecasting systems are widely used to predict the application of fungicides for managing late blight. However, airborne inoculum has rarely been included in these forecasting systems. Monitoring sporangia crop environments may offer an opportunity improve blight forecast by integrating pathogen pressure. Hence, this experiment aiming analyze relationships between weather based risk and levels atmosphere potato crops. The experiments were conducted during two growing seasons a field. During study, concentration Phytophthora infestans air, conditions, phenology cultivars r-AUPDC cycle recorded. weather-based was estimated using infection pressure (IP) daily value (DRV) on hourly relative humidity (RH) temperature (T). effect parameters analyzed. IP DRV showed strong positive correlation with concentration, standing out pronounced RH levels. Analysis within day increase from 9 h 18 h. This linked T, spore release, decrease RH. Our results identified T 10 °C 80% as minimum threshold significant air. maximum level found air at 88% (average humidity) 17 temperature). Finally, weekly P. observed different susceptibility