Effect of Hydrogen Cyanide and Carbonyl Sulphide on the Germination and Plumule Vigour of Wheat

Abstract

Several factors which may influence the germination of wheat fumigated with hydrogen cyanide or carbonyl sulphide were investigated. Dosages of hydrogen cyanide ranged from 10 mg litre−1 for 24-h exposure up to 150 mg litre−1 for 96-h exposure. Dosages of carbonyl sulphide ranged from 25 mg litre−1 for 24-h exposure up to 500 mg litre−1 for 72-h exposure. The experiments were conducted on wheat of 11·4, 13·8 and 15·7% moisture content. The higher levels of these fumigants exceed those needed for control of insects in wheat. Germination was not diminished and may have been slightly enhanced with hydrogen cyanide, but was diminished by high levels of carbonyl sulphide in the drier wheat. The plumule length was reduced following all dosages of hydrogen cyanide, but only after high dosages of carbonyl sulphide, especially on the driest wheat. It is concluded that hydrogen cyanide and carbonyl sulphide could be used to control insects in wheat without affecting seed viability, provided that concentrations are carefully controlled.