Controlling weeds in Chickpea through Allelopathy.

To reduce chemical herbicides application side effects, such as environmental pollution, but to increase checkpea grain production, this study was carried out by using different residues of Wheat, Barley, Sunflower, Safflower, Rape seed and regional dominant weeds, hand weeding and without hand weeding methods for controlling weed growths in checkpea field. Different crop residues as mentioned above were crashed and added to soil 0.25 and 0.5 kg per meter square in late of autumn and early spring 20days before planting and mixed with soil in 7-10cm deep. In order to do this study, experiments were conducted with Randomized Complete Block Design(RCBD) with 4 replications in 3 locations (Maragheh, Ardabil and Ghachsaran) for 3 years (2001- 2003) with 14 treatments as mentioned above for first and second year and 10 treatments for third year. Data of weed numbers were collected. Weed density species at early growth and maturity stages, weed biomass and plant height were determined and analyzed. In addition, chevkpea biomass and grain yield and H.K.V were determined and analyzed. The results of first year in Maragheh showed that hand weeding had greater effects in controlling weed growths, second greater controlling effects were belong to wheat residues 0.25kg/m2 , sunflower 0.25 and 0.5kg/m2 s weed. In second year, and weeding, barley 0.5, rapeseed and barley 0.25kg/m2 had second greater effects on weed controlling compared to other treatments, which increased growths and grain yield, but decreased weed densities. In third year, results were similar to second year results. However, the results were differed in Gachsaran, where showed that wheat residues had greater effects on controlling weed growthsdecreased weed densities and increased grain yield, compared to other treatments. The effects of amount of different residues were not significant, which produced grain yield at the same level. In Ardabil, the results were similar to Maragheh results in first year, but in second year, after hand weeding, using of residues of convulvulus arvensess controlled weed growth leading to increased grain yield. However, in third year after hand weeding using of rapeseed residues (0.25kg/m2) and sunflower (0.25kg/m2) decreased weed growths, leading to increased grain yield compared to the other treatments. It could be concluded that different techniques of weed controlling depending on different areas were differed. After hand weeding, residue of wheat, sunflower and barley in Maragheh, Wheat in Gachsaran and In Ardabil wheat, convulvulus arvensess and rapeseed residues had greater effects on controlling weed growthsdecreased weed densities and increased grain yield.