Investigating the possibilities of using some manures and plant extract for weed control in corn

This study was conducted between 2015 and 2016 in corn production areas of Igdir province to investigate allelopathic potential of different crop/plant species for weed management under laboratuary and field conditions. The experiment was carried out in Herbology Laboratory of Iğdır University, Faculty of Agriculture, Department of Plant Protection under laboratory condition and East Anatolian Agricultural Research Institute of Iğdır Experimental areas under field conditions. Field studies were carried out with three replications according to randomized block design. Sunflower, vetch, hazelnut radish and wheat plants were used as green manure. Aqueous extracts were obtained from above ground plant parts of same crop plants(sunflower, vetch, hazelnut radish and wheat) in order to determine the allelopathic effects on germination of redroot pigweed(Amaranhtus retroflexus L.) in petri dishes under laboratuvary condition with four replications in concentrations of 2%, 5% and 10%. The highest fresh weight of corns (13,133 kg da-1) were obtained from wheat green manure application and the lowest fresh weight of corns (6,866 kg da-1) were obtained from hazelnut radish green manure application under field conditions. The maximum corn dry weight was obtained from the application of vetch green manure (3,466 kg da-1), and the minimum corn dry weight (1,733 kg da-1) was obtained from the application of poultry manure. No significant statistical difference was found between the fresh and dry weight of weeds and plant height of maize at maturity between different applications. In laboratory studies, the best results (98,4%) were obtained from the extract concentration of 5% of the vetch in preventing the germination of the redroot pigweed seeds while the lowest effect (64%) were also obtained from the 2% extract concentration of vetch. Extracts obtained from sunflower, vetch, hazelnut radish and wheat plants prevented the germination of the seeds of the redroot pigweed at the 10% extract concentrations.