Evaluate of changes in the vertical distribution of leaf area of dryland wheat cultivars in competition with wild mustard in Gorgan

In order to evaluate changes in the vertical distribution of leaf area and dry matter of wheat different cultivars in different densities of wild mustard, a field experiment was conducted in Agricultural Research Station Gorgan depended on Agriculture Research Center of Golestan Province during 2010-2012. The experiment design consisted of four randomized complete blocks in a factorial arrangement. The design consisted of two factors, four wheat cultivars (Arta, Tajan, Mogan and Morvarid) and 5 levels of wild mustard densities (0, 4, 8, 16 and 32 plants.m-2). The results of combined analysis showed year effect wasn’t significant on light extinction coefficient, light use efficiency, vertical distribution of leaf area and dry matter, but cultivar×wild mustard density interaction effect was significant. In this research distinguished dry matter accumulation and too leaf area amount in all of evaluated layers in Morvarid cultivar was higher than other cultivars in competition and pure conditions. Also, wheat cultivars in competition conditions assigned higher of leaf area and dry matter to the upper layers of canopy that this event was more evident in Morvarid and Moghan. In this research, the means of light extinction coefficient in the maximum of wild mustard density in Morvarid, Moghan, Arta and Tajan was 0.23, 0.51, 0.63 and 0.65, respectively. The highest and lowest of light extinction coefficient observed in Tajan and Morvarid, respectively. Totally, the results of this experiment in two years showed Morvarid had the highest of seed yield for the reason that the most of vertical distribution of leaf area and light use efficiency and too, the lowest of light extinction coefficient in compared to other cultivars, and was the more of succeed in competition with wild mustard.