Abstract :
The effect of different sources of rice (Oryza sativa cv. Ember) residues; straw, dry root, burned straw, and burned root on wheat (Triticum aestivum cv. IPA) and barley (Hordeum vulgare cv. Local) germination and seedling growth was investigated. Extracts of residues were used at concentrations of 1%, 2%, and 4% (w:v). Whole residues were used at rates of 10, 20, and 40 g/kg soil. Seed germination, shoot and root length, reduction in dry weight , chlorophyll content, and electrolyte leakage from leaf cells expressed as injury were measured. The results showed as the concentration of the extracts or rate of whole residues increased, all the growth parameters studied decreased also in both crops except injury to seedling which increased in proportional to increasing concentrations. Ground root extracts and whole residues were the most effective in reducing germination, root length , shoot length, chlorophyll content and dry weight. For whole residues, burned root was superior in increasing injury to wheat leaves while ground root was more effective in increasing injury to barley leaves. For the interaction, ground root extract at 4% or ground root of whole residues at 40g/kg soil had the most inhibitory effect in most cases.
