S. H. Mousavi, S. A. Siadat, Kh. Alami-Saeid, E. Zand , A. M. Bakhshandeh,
Volume 4, Issue 12 (8-2014)
Abstract
In order to study the tolerance mechanism of spring bread cultivars to wild oat competition, an experiment was conducted in research farm of Ramin Agricultural and Natural Resources University of Khouzestan as strip block with three replications during 2010-2011 growing season. Experimental factors were wild oat densities includ 0 (as control) and 80 plant/m2 as horizontal plots and ten wheat cultivars include Chamran (Atila), Baz, Atrak, Arvand, Maroon, Shoeleh, Chenab, Veree/Nak and Falat (Seri 82) as vertical plots. By using competition index, cultivars divided in four groups of mid-susceptible, medium, mid-tolerant and tolerant. Also modeling of competition of wheat cultivars with wild oat, between measured traits, trait of weed biomass has highest direct reduction effect (-0.609) on competition index. Also, wheat traits such as grain number in spikelet has highest direct reduction effect (0.498) and death plant percent has highest indirect reduction effect (-0.307) on competition effect. But wheat biomass although indirect increase effect by effect on weed biomass and thousand grains weight of wheat, has highest direct and positive effect (-0.395) on competition index. Other effective trait was thousand grain weight of wheat that by direct and positive effect (0.270) resulted in increase in competition effect of cultivars.
S. H. Mousavi, S. A. Siadat, Kh. Alami-Saeid, E. Zand, A. M. Bakhshandeh,
Volume 5, Issue 18 (2-2016)
Abstract
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.
