Factors Affecting the Practical Employment of Systemic Insecticides. II.

Abstract

In the two years which have elapsed since I last wrote (Martin, 1950) of the potential uses of systemic insecticides, a deeper knowledge of the properties of these materials has become available to provide a sounder basis for their practical employment. A wide use of these materials has so far been hindered by scant information, particularly of the risks of harm following the consumption of treated food crops plants. Poisonous residues of the older insecticides which, by accident, remain on the plant surface are largely removed in the usual processes of preparation for the table such as washing, peeling, or discarding the outer leaves. These precautions fail with systemic compounds which not only pass into the plant tissue but which tend to accumulate in the storage organs and in the tenderer new growth, the very parts of the plant which serve for food. Clearly then an accurate and complete knowledge of the fate of the poisonous systemic insecticide must be available before its use on food crops can be recommended.