Behaviour of fumigants during vacuum fumigation. IV.-Sorption of fumigants by wheat and wheat feed under atmospheric and reduced pressure

In assessing the effectiveness of reduced pressure fumigation compared with fumigation at atmospheric pressure a knowledge of the effect of reduced pressures on the sorption equilibrium between fumigant and commodity is necessary. Experiments are described in which sorption isotherms for wheat feed/hydrogen cyanide and wheat feed/methyl bromide were determined at atmospheric and at 5 cm. Hg pressure and rates of sorption are deduced. In small‐scale chamber fumigations of whole wheat with methyl bromide at atmospheric pressure and at 5 cm. Hg, amounts of gas sorbed and bromide residues were determined. The results of the experiments are discussed with reference to effects in full‐scale fumigations.