Degradation of Pyrethrin Residues on Stored Durum Wheat after Postharvest Treatment

In this paper, pyrethrin levels during a postharvest treatment on stored durum wheat were studied. Two experiments were carried out at single and double the dose recommended by the manufacturer. In all trials, the initial deposition of pyrethrins levels was below the fixed maximum residue level of 3 mg/kg. The fate of pyrethrins in the two experiments was similar, and the total content of pyrethrins remained unchanged for 22 days with a complete dissipation in 8 months. In the single dose experiment, half-life times of pyrethrins I and II were 46 and 72 days, while for the double dose, pyrethrins I and II were 41 and 53 days, respectively.