AbstractThe effects of low‐volume ventilation on the persistence and biological efficacy of chlorpyrifos‐methyl applied to English wheat were investigated. Four 20‐tonne batches of wheat were treated with a dose of 2.5 mg kg−1chlorpyrifos‐methyl. After treatment, two of the batches were aerated continuously at a rate of 17 m3h−1tonne−1(10 cfm tonne−1) for 16 weeks. The remaining two batches were not aerated. Samples were collected from both aerated and non‐aerated wheat at intervals over the 16‐week storage period and subjected to biological assay using laboratory multi‐organophosphorus‐resistant strains of Tribolium castaneum, Sitophilus granarius, Sitophilus oryzae and Oryzaephilus surinamensis. The samples were also analysed for chlorpyrifos‐methyl residues. No differences in either the biological efficacy or the rate of chemical decomposition were detected between the aera
展开▼
