Effect of a climate change scenario on Fusarium equiseti leaf spot on wild rocket and radish under phytotron simulation

This study was undertaken by simulating the effects of increasing the temperature and CO2 values on the incidence and severity of F. equiseti on wild rocket (Diplotaxis tenuifolia) and radish (Raphanus sativus), under phytotron conditions. Two sets of 3 trials were carried out in which eight different temperature and CO2 combinations were tested:1) 400-450 ppm CO2, 18-22 A degrees C; 2) 800-850 ppm CO2, 18-22 A degrees C; 3) 400-450 ppm CO2, 22-26 A degrees C, 4) 800-850 ppm CO2, 22-26 A degrees C, 5) 400-450 ppm CO2, 26-30 A degrees C; 6) 800-850 ppm CO2, 26-30 A degrees C; 7) 400-450 ppm CO2, 14-18 A degrees C; 8) 800-850 ppm CO2, 14-18 A degrees C. The temperature and CO2 levels were significant factors of influence on disease incidence (DI) and severity (DS) in all the trials, and their combination significantly influenced the DI and DS of F. equiseti leaf spot on both hosts. Disease incidence and severity increased on wild rocket at 850 ppm of CO2, in comparison to 450 ppm, in each tested temperature range. The highest CO2 value on radish, for all the tested temperature regimes, caused an increase in DI and DS, which resulted statistically significant at the highest tested temperature range. The results obtained in this study add more concern to the possible negative effects of the spread of F. equiseti on vegetables in Italy as well as in other areas suffering from increased temperatures as a consequence of climate changes.