THIABENDAZOLE UPTAKE AND PERSISTENCE IN LEMONS FOLLOWING POSTHARVEST DIPS AT 50-DEGREES-C

Thiabendazole (TBZ) uptake and degradation rate in lemon fruits, follo wing prestorage dipping at 50 degrees C in mixtures containing differe nt amounts of fungicide, was compared with those measured after treatm ent at standard room temperature. TBZ residues were strictly dependent upon the amount of fungicide. Following 1,200 ppm TBZ dipping at 20 d egrees C residue uptake in fruit was the same that would have been acc umulated with ca. 150 ppm fungicide at 50 degrees C, a value that can be calculated due to the linear relationship between the residue in fr uit after treatment and fungicide concentration TBZ residues showed gr eat persistence during fruit storage: after 13 weeks at 8 degrees C an d 1 week at 20 degrees C residues in fruit averaged ca. 70% of their i nitial values. In this study it was shown that it is possible to emplo y remarkably low amounts of TBZ (ca. 150 mg kg(-1)), when applied in c ombination with water at 50 degrees C, and keep the same residues of f ruit treated at room temperature with high amounts of TBZ (1,200 mg kg (-1)).