Application of Fungicides and Microalgal Phenolic Extracts for the Direct Control of Fumonisin Contamination in Maize

Fungicides and, for the first time, microalgal phenolic extracts (MPE) from Spirulina sp. and Nannochloropsis sp. were applied on maize culture media and under field conditions to evaluate their ability to minimize Fusarium species development and fumonisin production. An in vitro assay against an F. verticillioides was carried out, using maize grains as culture medium. An open field experiment was carried out in North West Italy under naturally-infected conditions. The compared treatments were factorial combinations of: two insecticide applications (untreated control and pyrethroid against European Corn Borer), four antifungal compounds (untreated control, MPE from Spirulina sp. and Nannochloropsis sp., synthetic fungicide) and two timings of application of the antifungal compounds (maize flowering and milk stage). The MPE were capable to inhibit fumonisin production in vitro more efficiently than tebuconazole. Insecticide application reduced the infection by Fusarium species and subsequent fumonisin contamination. However, fumonisins in maize fields were not significantly controlled with both fungicide and MPE application.