Herbicidal Interactions of Potassium Azide with Calcium Cyanamid

Abstract
The herblcidal activity of potassium azide and calcium cyanamld, applied singly and in combination, was evaluated in greenhouse and field experiments. In the greenhouse, the combinations were synerglstlc against several plant species including yellow nutsedge (Cyperus esculentus L.) and crabgrass (Digitaria sanguinalis (L.) Scop). The combinations also were synerglstlc in 2 field experiments at different locations. In the field, the combinations reduced the number of weed seeds germinating from treated soil over a 6-mo. period; potassium azide or calcium cyanamid applied singly were not effective. In the laboratory, calcium cyanamid reduced the rate of disappearance of potassium azide from the soil.