Redistribution Response of Photosynthetic Assimilates of Different Spring Bread Wheat Cultivars in Different Densities of Wild Oat

In order to study the redistribution response of photosynthetic assimilates of different spring bread wheat cultivars in different densities of wild oat, an experiment was conducted based on a strip block experiment with three replications at the Research Farm of Ramin Agriculture and Natural Resources University, Ahwaz, Iran during 2012. Treatments were four oat densities (0, 40, 80 and 120 plants m-2) in horizontal strips and 10 spring bread wheat cultivars (Chamran, Baz, Atrak, Arvand, Maroon, Shoeleh, Chenab, Veree/Nak and Falat) in vertical strips. Results showed that with increase in oat density up to 120 plants m-2, efficiency and percentage of the assimilates redistribution was increased, but current assimilates contributed less to the grain filling and grain yield. However, dwarf and early maturing cultivars of Veree/Nak and Atrak, with 2400 Kg ha-1 and Chenab with 2200 Kg ha-1 of redistribution appeared to benefit from an efficient transport system against the weed (wild oat). In contrast to the dwarf cultivars, the tall cultivar of Arvand with minimum assimilates redistribution of 600 Kg ha-1 and maximum amount of current assimilates of 3700 Kg ha-1 and also Shoeleh and Maroon were less dependent on their stem reserves at the grain filling stage.