Abstract

The calcium (Ca)-cyanamide is a nitrogen fertilizer with herbicide and fungicide side effects. Hydrogen cyanamide is absorbed as a molecule by roots and shoots of plants. It will be decomposed rapidly by the enzyme cyanamide hydratase to urea followed by urease to ammonium. From cyanamide decomposition mainly glutamate and alanine are built and the basic amino acids such as arginine, lysine and histidine are increased. The most dramatic effect of cyanamide is the strong inhibition of catalase and cytochromoxidase and the blocked thiols of redox systems. Cyanamide applied to dormant buds of fruit trees inhibits catalase activity and increases H₂O₂-content. Prior to bud break, arginine content decreases and associated with increase of polyamines such as putrescine, spermine, spermidine, histamine and cadaverine. These sharply decrease again at fully blooming stage.

Key words: Cyanamide, enzymatic break down, reaction with plant constituents and enzymes, amino acid metabolism, polyamines, dormancy break.