Organic acids as seed germination inhibitors.

Abstract

Phytotoxicity of aromatic and aliphatic acids was tested by a wheat seed bioassay. Wheat seed germination was found to be influenced by the number of hydroxy and methoxy groups, the molecular position of single and double hydroxy groups, the length of the aliphatic chain, as well as by the pK_a of the acid solutions. Orto and meta coumaric, ferulic and orto hydroxybenzoic among phenolic acids, and butyric acid among aliphatic acids showed the most inhibitory activity; toxicity was found to increase exponentially with the increasing acid concentrations. Levels of 0.25 and 1.8mM resulted in a 10 and 50% toxicity, respectively.