use of allelopathic traits of several medicinal plants on some germination characteristics and early growth of wheat and wild oat

ecosystem pollution and weed resistance to herbicides have led researchers to pay more attention to natural herbicides. to examine allelopathic effects of liquorice, rosemary, chamomile and eucalypt on germination characteristics and early growth of wheat (triticum aestivum l.) and wild oat (avena fatua l.), a factorial experiment based on completely randomized design with 20 treatments and four replicates was conducted at cereal laboratory of college of agricultural, shiraz university, iran in 2010. the results showed that rosemary essential oil had most negative effect on germination percentage (g%), seedling length (sl), radicle length (rl), shoot to root length ratio (s/r), relative water content (rwc) and total water content (twc). the lowest negative effect on g%, sl, rl and twc was obtained from eucalypt essential oil and the least effect on rwc was observed from liquorice essential oil treatments. most reduction on s/r was obtained from chamomile essential oil. the effect of stem essential oil on all measured traits, except g%, was more than leaf essential oil. also wild oat was found to be more responsive than wheat to rosemary and chamomile essential oils. considering these results, it appeared that control of wild oat by using such essential oil as rosemary and chamomile might be possible under some conditions with appropriate cautions.