New alternatives for postharvest control of rots in citrus fruit

摘要

The inclusion of new molecules in the postharvest of citrus fruit opens a new stage where it is possible to control almost all pathogens causers of decays and losses after harvest, with active ingredients alternatives to the traditional fungicides. The use of both Fludioxonil and Propiconazole assures, with only two active ingredients, the control of the postharvest diseases in citrus fruits during the whole season. Fludioxonil, active ingredient recently registered in the European Union for postharvest use in citrus fruits, is a wide spectrum fungicide, with low risk and belongs to the family of the fenilpirroles, presents high efficacy against Pénicillium spp. (green and blue mold), Alternaria spp., Botrytis spp., and Rhizopus spp. Propiconazole,belonging to the family of the triazoles, is the unique authorized ingredient which controls and prevents, with high efficacy, the diseases caused by Galactomyces citri-aurantii (sour rot), also presenting efficacy against Pénicillium spp. After inoculation, the application of 690 ppm of FDX and 600 ppm of PROP, by drench or by dip in a tank, reduced around 90% infections caused by Pénicillium spp. and Galactomyces citri-aurantii and more than 85% infections caused by secondary moulds such as Botrytis spp. and Rhizopus spp. In pack-house trials the treatment efficacy was up to 95% against the mentioned moulds. The application of FDX (2880 ppm) and PROP (1200 ppm) by on-line spray, in water or in wax mix, reduced the sour rot and the green and blue moulds to more than 85% after inoculation and 95% in pack-house trials under commercial conditions.