Allelophatic Effects of Cicer arietinum L. Cultivars Straw on Seedling Growth of Helianthus annus L. and Zea mays L.

Where crop residues are left on the soil surface to avoid soil erosion, preserve moisture, increase nutrient balance and a number of other benefits. The residues of preceding crops affect the germination of other crops through the release of allelochemicals. Thus, we investigated the allelopathic effects of straw aqueous extract of four chickpea cultivars on germination and seedling growth of corn and sunflower. Two separate experiments were conducted as the factorial experiments based on completely randomized design with extract of four chickpea cultivars (Karaj‚ Jam‚ Flip and Ilc480) and concentrations at (0, 5‚ 10‚ 20 and 40 %) with 3 replicates. Results indicated that, the degree of inhibition was largely dependent on the concentration of the extracts. Corn was more sensitive to different levels of extracts than Sunflower. Chickpea cultivars extracts had not significant difference on sunflower but showed significant inhibition in the case of Corn. The interaction effect had no significant effect in both crop plants. In general, there was a considerable response by sunflower and corn seeds to extract of chickpea cultivars that show chickpea straw not only had negative effect on seed germination, but also vegetative growth was relatively more sensitive to allelochemicals than germination.