Effects of walnut phenolics on germination of dandelion seeds

The effects of walnut phenolics were determined on the seeds germination of dandelion. The walnut methanolic extract contained eight phenolic compounds: catechin, chlorogenic acid, p- and o-coumaric acids, ferulic acid, tannic acid, caffeic acid and syringic acid. The catechin was the major phenolic compound in all the organs of walnut. The application of walnut extracts in the soil, reduced the seeds germination of dandelion (Taraxacum officinale Web). While comparing the effects of extract on other monocotyledonous and dicotyledonous plants, the germination of wheat and bluebottle seeds was slightly inhibited, but that of corn poppy and red deadnettle seeds was drastically inhibited than dandelion seeds. Moreover some identified phenolics present in walnut tissues, also reduced the germination of dandelion seeds and the catechin was most strongest inhibitor. Possible role of walnut phenolics as allelopathic agents against dandelion is discussed.