Differences in allelopathic effect of tree of heaven root extracts and isolated ailanthone on test-species/Razlike u alelopatskom ucinku ekstrakata korijena pajasena i izoliranog ailantona na test-biljne vrste

The objective of this paper was to analyse allelopathic effect of 3 different aqueous solutions from tree of heaven's (Ailanthus altissima (Mill.) Swingle) root extract and their dilutions on common wheat (Triticum aestivum L.), pigweed (Amaranthus retroflexus L.) and red bristlegrass (Setaria pumila L.). Investigated aqueous solutions obtained from tree of heaven's root extract were root aqueous solution, aqueous solution with isolated ailanthone and root aqueous solution without ailanthone. Each of these solutions was diluted with water in ratio 1:4 and 1:16 before application on seeds of 3 test-plant species. Concentrated root and ailanthone aqueous solution and dilutions were equivalent to concentration of 0.48 mg/mL ailanthone. High allelopathic effect on radicle and shoot length of all test-species was proven for all investigated aqueous solution and their dilutions. Inhibitory effect on initial growth of all test-species was proportional to the increase in concentration in all treatments. The effect on initial growth was stronger in relation to the effect on germination of test-species. Lower concentrations caused stimulation of red bristlegrass germination. Pigweed was the most sensitive and common wheat the least sensitive test-species. The least significant effect was measured in the aqueous solution of isolated ailanthone.