Allelopathic Effects of Introduced Eucalyptus Gomphocephala Extracts on Germination and Seedling Growth of Native Ceratonia siliqua in Libya

Abstract

<jats:p>The present study aimed to investigate the allelopathic effects of leaf aqueous extracts of introduced Eucalyptus gomphocephala L. (donor species) were collected during different growing seasons at different concentrations (0, 25, 50, 75, and 100% v/v) on germination percentage, average germination time, plumule and radical length, dry weight of radical and plumule and seedling vigor index (SVI) of native Ceratonia siliqua L. (recipient species) seedlings under laboratory conditions. Results suggested that the germination percentage and all growth parameters of C. siliqua were significantly reduced gradually with the increase of aqueous extract concentration levels and the reduction was varied and could be extract concentration and growing season dependent. The highest phytotoxic effect on germination and seedling growth was exhibited by E. gomphocephala aqueous extract at 100% concentration, followed by 50% concentration. Generally, it is concluded that the allelopathic effect of introduced E. gomphoracephala trees on native Ceratonia siliqua trees has been weak or no effectiveness in some cases under laboratory conditions.
Keywords: Eucalyptus gomphocephala; Introduced species; Libya; Allelopathy; Ceratonia siliqua</jats:p>