Malathion Residues On and In the Leaves of Phaseolus vulgaris1

Abstract

By using P-32 labeled malathion, the speed of migration of malathion in the tissues of P. vulgaris L. was measured. Speed of migration was found to be very low in leaves. Malathion was taken up by the leaf tissues very rapidly, and the rate of entry of malathion into the tissue was found to satisfy Langmuir’s adsorption equation. It was found also that the slow dissipation of malathion residues in the later stage (persistence stage) in this experiment was owing to the lower rate of evaporation effected by absorption of the insecticide by plant tissue.