Seedling growth response of two durum wheat genotypes to the allelopathic activity of (Avena sterilis l.)

The study evaluated the allelopathic effects of aqueous extracts of wild oat (Avena sterilis L.) on seedling growth of two durum wheat genotypes: a landrace (MBB) and an introduced genotype (Waha). Experiments used seeds and envelopes (glumes and lemma) at concentrations of 0%, 25%, 50%, 75%, and 100% in a controlled laboratory environment. Results showed that genotype significantly affected most growth parameters, except root length, while extract type influenced all parameters. Concentration significantly affected only root and leaf lengths. Interactions between genotype and concentration, as well as extract and concentration, were observed. Correlation analysis revealed positive and negative relationships among growth traits and extract types. Notably, grain extracts stimulated root number in MBB, reaching a maximum of 4.91 roots at 25–50% concentrations, whereas envelope extracts inhibited coleoptile length in Waha, with a minimum of 3.70 cm at 25%. Leaf length decreased significantly under high grain extract concentrations (75–100%). These findings highlight genotype-specific allelopathic responses of durum wheat to A. sterilis extracts.