Experimental trials to control strawberry powdery mildew in Italy

Powdery mildew (Podosphaera aphanis) is the main pathogen of strawberry (Fragaria x ananassa) grown under high tunnels and can infect all the aerial parts of the plant. Increasing restrictions on the use of chemical fungicides make necessary to develop new technologies and to evaluate the efficacy of alternative substances such as natural, microbial or low-impact products. Starting from 2013, greenhouse and field trials have been carried out in Trentino region (Northeastern Italy) to evaluate the efficacy of alternatives to chemical fungicides on strawberry. Their integration into strategies against powdery mildew was also tested. On the June-bearing cultivar Elsanta, repeated applications of products based on potassium bicarbonate and orange essential oil showed a good efficacy against powdery mildew, both in field and in semi-field trials. Other substances such as vegetal extracts, whey and fertilizers were not sufficiently effective in controlling P. aphanis. Everbearing varieties, given the long production cycle and susceptibility, showed greater problems in containing the disease. Further trials, integrating different agronomical and disease management practices, will be necessary to achieve an effective control of powdery mildew on these cultivars