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

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 50C, 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 20C 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 20C. While treatment with 100 mg l-1 a.i. at 50C 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 50C 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 20C, treatment efficacy decreased when lecithin was applied in combination with 100 mg l-1 FLU and 50C for 4 min and to a greater extent when dip time was 1-2 min.