Allelopathic Effect of Eucalyptus globulus on Seed Germination and Seedling Growth of Highland Teff (Eragrotis tef)and Barely(Hordeum vulgare L.)

ABSTRACT

The phenomenon of allelopathy, whereby a plant species chemically interferes with the

germination, growth or development of other plant species has been known and documented for

over 2000years.Allelochemicals are plant secondary metabolites normally released into the

environment through volatilization, leaching, root exudation and decomposition of plant residues

in the soil. The study was conducted at Kulumsa Agricultural Research Center to examine the

allelopathic effect of Eucalyptus globulus on seed germination and early growth stages of

highland Teff (Eragrostis tef) and Barley (Hordeum vulgare L.).Fresh leaf, juvenile stems, root

and mixtures of (fresh leaf, juvenile stems, root) aqueous extracts at 0%,5%, 10%, 15%, 25%,

and 50%concentrations were used to run the experiment under Laboratory condition. The

research design used in this study was factorial Complete Randomized Design (CRD) with three

replications. The quantitative data was collected, coded and then subjected to two way ANOVA

analysis of variance procedure with SAS Version 9.1 and the means compared by using least

Significant difference test (LSD) at the 5% level of probability. The allelopathic influence of

aqueous extracts of Eucalyptus globulus on the germination and seedling growth was examined.

It was noted that aqueous extract of fresh leaf at 25% and 50% had inhibitory effect on

germination on Petri dish and root seedling growth of both crop. At 25% of fresh leaf extract

seed germination on Petri dish of teff inhibited at about 36.3% and barely at about 55.5%

inhibited ,while root length of teff and barely inhibited by 69.20%(which is almost the same

effect) under the highest level of concentration(50%)of fresh leaf extract. These finding indicates

that teff and barely seed germination, early seedling growth affected by allelochemials in fresh

leaf compared to other plant parts of Eucalyptus globulus. Therefore it is recommended to stop

Eucalyptus globulus plantation expansion near the land of economically important crop plants of

teff and barely.7