Use of microwaves in the prevention of Fusarium oxysporum f. sp. melonis infection during the commercial production of melon plantlets

One of the main ways in which Fusarium oxysporum f. sp. melonis—the causal agent of fusarium wilt in melon—is transferred, is the re-use of propagation trays by greenhouse personnel. The aim of this work was to investigate the effects of different levels of microwave energy, produced by a commercial microwave oven, on suspensions of the microconidia of this fungus. The viability of the fungus in the substrate normally used in nurseries for plantlet production was also tested following its experimental contamination and irradiation. Microconidial viability declined as the energy applied increased, and total eradication was achieved at low levels of irradiation in both the suspension and the substrate. The increase in the price of melon plantlets resulting from such a treatment would only be about €2.6×10−4, a tiny increment over the current sale price to growers of €0.19.