| Abstract: | The use of Eucalyptus trees, in association with other plants, has the potential to reduce the growth of neighbouring plants or grasses by competing for resources or releasing allelochemicals that may cause other plants to grow slowly. Our purpose here is to assess whether border planting of Eucalyptus is harmful to the establishment,growth, and production of Cymbopogon winterianus at various distances from tree lines in the Wondo Genet Agricultural Research Center in Southern Ethiopia. Several factors were studied: growth performances and yield of aromatic grasses; soil properties, including total nitrogen,organic carbon, and moisture content; and plant leaf nutrient content(NPK) at various distances away from the Eucalyptus citriodora border line were studied. Chemical compositions of hydro-distilled essential oils obtained from selected C. winterianus grasses leaves were analysed by gas chromatography. Plant height, biomass yield, amount of essential oil yield, and essential oil composition all were significantly affected due to Eucalyptus effect in the first10-m distance as compared to beyond 10 m from the tree border line. There were increases in soil total nitrogen,organic carbon, and moisture content with decreasing distances to the Eucalyptus tree border. The result of plant leaf nutrient content(NPK) differed across treatment and distance. The pot experiment(15 cm 9 20 cm), shoot length,and number of leaves of aromatic plants varied in the degree of inhibition based on the concentration of the aqueous extract. Significantly higher inhibitions of the shoot length and number of leaf parameters were observed when using 25% fresh leaf extract compared to other extract levels. |
