Sorption of sulfuryl fluoride into wheat and its impact on efficacy, fluoride residues and product quality

Abstract

This work was carried to investigate sorption of sulfuryl fluoride (SF) and its impact on efficacy, residues and technological quality of wheat and its products. An important factor to consider in the practical application of fumigants is the impact of sorption of the gas into the commodity during fumigation. Sorption may reduce the biological activity of a fumigant by reducing the concentration of gas available to target insects and no information is available on the impact of sorption on the biological efficacy of this fumigant against target pests. Information on the efficacy of SF against insect pests is generally limited to fumigation times of 48 h or less. The aim of this work was to provide more detailed information about the sorption behaviours of SF when wheat, semolina and flour are fumigated at three concentration x time exposures under different conditions (temperature, grain moisture content), filling ratio and repeated fumigation. The impact of fumigating with SF under these conditions on the efficacy against lesser grain borer in the presence of bread wheat, effects on the technological properties of durum wheat and the presence of fluoride residue in selected grain fractions were studied.