Effect of Essential Oil Extracted from Acorus tatarinowii Rhizomes on Germination and Growth of Barnyardgrass, Eclipta and Rice(Oryza sativa)

The laboratory and glasshouse experiments were conducted to evaluate the effect of fraction 4 on seed germination and seedling growth of barnyardgrass (Echinochloa crusgalli (L.) Beauv.), eclipta(Eclipta prostrata(L.) L.) and rice(Oryza sativa L.), which was separated from the essential oil of rhizomes of grass-leaved sweetflag(Acorus tatarinowii) that was dephlegmated at low pressure. A common phenomenon was observed in both laboratory and greenhouse trials, that is, seed germination and seedling growth was inhibited at higher concentration but slightly increased at 50 mg/L or lower concentration. Under laboratory conditions, inhibition was observed at concentration from 50～400 mg/L and more than 90% inhibition with >400 mg/L. However, under glasshouse conditions, inhibition occurred at 3000 mg/L or higher while increase of the growth was observed at 1000 mg/L or lower concentration.