Ibrahim S. Alsaadawi1, Tamara A. Al-Khateeb2, Hameed A. Hadwan2 and Nabil R. Lahmood3
1 Department of Biology, College of Science, Baghdad University, Baghdad, Iraq
2 National Center for Organic Farming, Ministry of Agriculture, Baghdad, Iraq.
3 Department of Agronomy, College of agriculture, Waset University, Waset, Iraq.
Study was conducted to test if the variationin weed population and biomass between the stands of Enkathand Rabeh sorghum cultivars, which was observed in the field, was due to differences in their allelopathic potential. Field experiment revealed that Enkath cultivar significantly suppressed weed density and dry weight biomass over Rabeh cultivar by 34 and 29% after 35 days after sowing (DAS), and 22 and 24% after 65 DAS. Stair case experiment indicatedthat root exudates of Enkath cultivar showed more suppression to weeds than Rabeh giving additional evidence for the superiority of Enkath indicated that in its allelopathic weed suppression. Chemical analysis revealed that sorgoleone and several phenolic acids were present in higher concentrations in root exudates of Enkath compared to Rabeh. The results recommend screening more sorghum cultivars in order to offer a potential source of allelopathic germplasm that could be manipulated to enhance weed suppression in an effective and environmentally sustainable approach.
Keywords: Allelopathy, sorghum cultivars, weeds, root exudates, phytotoxins.
RECEIVED: June 15, 2014
ACCEPTED: June 26, 2014