Effect of Density and Root-shoot interference on wheat (Triticum aestivum L.) and wild oat (Avena fatua L.) performance

ABSTRACT: Two pot experiments were designed to investigate above- and below-ground interactions and plant density effect on wheat and wild oat performance. Theses experiments were conducted as factorial based on randomized complete design with four replications. The treatments of first experiment included four interference level (above-ground, below-ground, full and no interaction of wheat and wild oat) and four wild Oat densities (2,4,6 and 8 plant/pot) and for second experiment were four densities of wheat and Avena fatua (0, 2, 5 and 8 plants per pot). In both plants, full and belowground interaction decreased plant height, number of leaves, flag leaf area, chlorophyll content of flag leaf, biomass and grain yield compared to aboveground interaction and control, significantly. All traits of wild oat reduced by aboveground interaction compared to control. In full interaction, flag leaf chlorophyll content of wheat and wild oat were reduced about 10.7% and 6.9% compared to control, respectively. Number of leaves, biomass and grain yield of wheat and wild oat showed greatest susceptibility to interaction treatments. When wild Oat density increased the biomass, grain yield, plant height, number of leaves, flag leaf area, chlorophyll content of flag leaf of wheat decreased. Increasing of wheat density reduced root volume, root dry weight, grain and biological yield and 100 seed weight of Avena fatua, significantly. Maximum grain yield, biological yield, 100 seed weight, root dry weight and root volume loss of A. fatua were 78.22%, 67.11%, 41.90%, 52.82% and 43.75% compared with the control, respectively.