Loss of Phorate from a Granular Formulation Applied in the Soil

Abstract

In experiments conducted out of doors, most of the toxic residue from granular phorate in the soil had disappeared in the summer after 2 months. During the fall the residue persisted longer, and in the winter when the soil was frozen there was almost no loss of the residue. As indicated, phorate degradation or loss in the soil was dependent on the temperature. As the temperature of the soil was increased, the rate of disappearance of the phorate increased. Moisture does not affect the loss of granular phorate as much as the temperature. Regardless of the soil type, very little phorate translocated through more than 3 inches of soil. By increasing the amount of water added to the soil, an increasing amount of residue was lost by translocation. However, it represented only a small fraction of the total residue. Likewise, barley plants absorbed only a very small percentage of the phorate which was present in either sandy loam or muck.