Could wasted food be useful to control phytopathogenic fungi? Effect of humic and fulvic acids extracts from different composts in phytophthora cinnamomi growth

Abstract

The enormous amount of daily wasted food became a major social and environmental issue. Furthermore, the extensive use of agrochemicals is increasing agricultural and health problems. Composting can be an effective way of reuse the organic waste to produce an organic fertilizer with benefits for crops, environment and public health. In the present work, the antifungal effect of humic (HA) and fulvic acids (FA) extracted from four different organic composts was evaluated against Phytophthora cinnamomi, a phytopathogenic fungus. The activity of the extracts at 250, 500, 750 and 1000 μg/mL were evaluated using the Poisoned Food method. Interestingly, both extracts affected mycelium growth, FAs appearing more effective than HAs, with a dose-response relationship. FAs obtained from vermicompost at 1000 μg/mL induced a 22% inhibition, suggesting to be environmentally-friendly good candidates for prophylaxis and control of P. cinnamomi infections. Keywords: Biopesticides, humic acids, fulvic acids, fungal diseases, plant disease control