Allelopathy in two durum wheat ( Triticum durum L.) varieties

Two varieties of durum wheat ( Triticum durum L.), ‘Karim’ and ‘Om rabii’ commonly used in northern Tunisia were grown to maturity. Their allelopathic effects were measured in terms of germination rate and radicel length of a barley variety ‘Manel’ ( Hordeum vulgare L.) and a bread wheat variety ‘Ariana’ ( Triticum aestivum L.). Diluted extracts of roots, leaves and stems of durum wheat were applied to seeds of the test varieties. Leaf extracts of durum wheat depressed the germination rate, radicels also being susceptible to durum wheat extracts. The allelopathy of durum wheat varied with the source of extracts, leaf extracts being the most active. Results suggest that durum wheat allelopathy takes the form of heterotoxicity, depressive to crops in a sequence.