ORGANIC-ACIDS AS SEED-GERMINATION INHIBITORS

Phytotoxicity of aromatic and aliphatic acids was tested by a wheat se ed 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, feruli c and orto hydroxybenzoic among phenolic acids, and butyric acid among aliphatic acids showed the most inhibitory activity; toxicity was fou nd to increase exponentially with the increasing acid concentrations. Levels of 0.25 and 1.8mM resulted in a 10 and 50% toxicity, respective ly.