Comparative Evaluation of the Allelopathic Effects of Eucalyptus Leaf, Sunflower Seed Coat, and Rice Husk Extracts on Germination and Seedling Growth of Cereal Crops and Weeds

• Parez Ahmed Taha1 and Sonia Hiwa Othman2

  Author

Allelopathy is crucial biological phenomenon through which certain plants release compounds that can affect the germination and early growth of neighboring plant species. The experiment was carried out in a laboratory in the College of Agricultural Engineering Sciences, University of Sulaimani, Sulaymaniyah City, Kurdistan Region of Iraq, in autumn 2025. The study was designed to evaluate the effect of some aqueous plant extracts such as eucalyptus leaves (Eucalyptus camaldulensis), sunflower seed coats (Helianthus annuus) and rice husks (Oryza sativa) on seed germination such as germination percentage (G%), mean germination time (MGT, days), and coefficient of variation of germination velocity (CVG%) and radical and coleoptile length (cm) of seedling properties of cereal crops (Triticum aestivum and Hordeum vulgare) and weed plants (Lolium rigidum and Cephalaria syriaca) at concentration of 10% and 25 % plus to control. The experiment was conducted using a factorial-completely randomized design (CRD) using two-way ANOVA. Comparisons among means of the parameters were carried out using were carried out by Duncan’s multiple range test at P≤0.05. The results showed that the extract of eucalyptus leaf extract had the strongest activity, particularly at 25%, where germination was completely inhibited in all tested species, followed by sunflower seed coat extract. Thus, the results concluded that plant derived extracts offer the more and effective environmental compatibility on inhibiting seed germination and seedlings properties can be used as alternative of conventional synthetic herbicides.

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