Ecology and Seasonal Dynamics of Erysiphe necator Conidia Dispersal in Vineyards Under Mediterranean Climate

Abstract

Powdery mildew caused by Erysiphe necator is a major fungal disease affecting grapevine production in Mediterranean viticultural regions, resulting in significant reductions in fruit quality and yield. Understanding the ecology and seasonal dispersal dynamics of airborne conidia is essential for improving disease forecasting and management strategies. The present study investigated the seasonal patterns of E. necator conidia dispersal in vineyards under Mediterranean climatic conditions and evaluated the influence of environmental factors on pathogen dissemination. Airborne conidia were monitored throughout the growing season using volumetric spore traps installed in commercial vineyards. Meteorological parameters including temperature, relative humidity, rainfall, wind speed, and solar radiation were simultaneously recorded to determine their relationship with spore abundance and disease development. Results indicated that conidial dispersal varied significantly during different phenological stages of grapevine growth, with peak concentrations occurring during warm and moderately humid periods favorable for pathogen sporulation and infection. Temperature and relative humidity showed strong positive correlations with conidial release, whereas heavy rainfall events reduced airborne spore concentrations due to wash-off effects. Seasonal fluctuations in spore density were closely associated with disease incidence and canopy microclimate conditions within vineyards. The study demonstrated that Mediterranean environmental conditions strongly influence the epidemiology and dispersal behavior of E. necator. Continuous monitoring of airborne inoculum combined with climatic data can improve early disease prediction and optimize fungicide application timing. The findings contribute valuable information for developing integrated disease management programs aimed at sustainable grapevine protection under Mediterranean production systems.