Effects of elevated CO2 and temperature on interactions of grapevine and powdery mildew: first results under phytotron conditions

This study reports the effect of increased CO2 and temperature on powdery mildew (Erysiphe necatrix) of grapevine evaluated under controlled conditions. Grapevine potted plants, belonging to the cv Moscato and Barbera, were grown in phytotrons under four different simulated climatic conditions: standard CO2 concentration for the area (450 ppm) with standard (ranging from 22 to 26°C) and elevated temperature (4°C higher than standard), elevated CO2 (800 ppm) with standard and elevated temperature. Physiological responses of grapevine and pathogen development were studied. Results showed an increase of the chlorophyll content with higher temperatures and CO2 concentration, to which consequently corresponded an higher fluorescence index. Disease incidence did not significantly vary between cultivars. In conclusion, an increase in CO2 did not affect powdery mildew incidence, probably due to the increased photosynthetic activity of plants under such conditions.