Influence of post-harvest treatments with fludioxonil and soy lecithin co-application in controlling blue and grey mould and fludioxonil residues in Coscia pears

Abstract

The residue levels of fludioxonil (FLU) were determined in Coscia pear following a 1-, 2- or 4-min dip in an aqueous mixture of FLU containing 300 or 100 mg l⁻¹ (active ingredient, a.i.) at 20 and 50°C, respectively, with or without 2% soy lecithin. The efficacy of heat treatment with water and FLU mixtures was investigated on artificially inoculated pears for the control of post-harvest decay caused by blue (Penicillium expansum Link) and grey (Botrytis cinerea Pers. ex Fr.) mould. Treatment with 300 mg l⁻¹ FLU at 20°C increased residues significantly when treatment time rose from 1 to 2 min; no further increase was recorded when dip time raised from 2 to 4 min. FLU residue rates were unaffected by treatment time when 300 mg l⁻¹ a.i. was applied in combination with lecithin at 20°C. While treatment with 100 mg l⁻¹ a.i. at 50°C for 1 and 2 min resulted in similar residue levels, significantly higher residues were detected when dip time increased from 1 to 4 min. Co-application of lecithin significantly decreased FLU residues with respect to fruit treated with FLU alone. Treatments with FLU at 20 or 50°C effectively controlled decay over 10 days of incubation. While co-application of lecithin did not affect the efficacy of FLU at 300 mg l⁻¹and 20°C, treatment efficacy decreased when lecithin was applied in combination with 100 mg l⁻¹ FLU and 50°C for 4 min and to a greater extent when dip time was 1–2 min.

Keywords:

• Pyrus communis L.
• disease control
• hot water dip
• fludioxonil
• residues
• lecithin

Acknowledgements

The authors gratefully acknowledge the Syngenta Crop Protection, Italy, and the CEDAX s.r.l., Italy, for kindly supplying the fungicide Fludioxonil and the soy lecithin, Xedabio®, respectively. Research was supported by MiPAF, ‘Sviluppo delle Esportazioni di Prodotti Agroalimentari del Mezzogiorno’.