The study of ecological indicators on wheat in agricultural biome

In order to study the effect of plant density and plant orientation on receiving and using of radiation in wheat cultivars, an experiment was conducted at the research farm of Gonbad Kavous University in 2012. The experiment was carried out as factorial based on completely randomized design with three replications. The factors were including: orientation with four levels (North-South, East- West, North East- South West and North West- South East), plant density with three levels (250, 300 and 350 plant per square meter) and wheat cultivars (Kouhdasht and line 17). Variance analysis results showed that that ecological indicators study (consisting of leaf area index, dry matter accumulation, canopy extinction coefficient and Radiation use efficiency) were affected by interaction effect on orientation and plant density, but cultivars had no significant effect on ecological indicators. Leaf area index (LAI) and dry matter accumulation increased with the increase of plant density; in such as a way that plant density, the highest LAI (8.33) and dry matter accumulation (2294±357.3 g/m2) were obtained in East-West orientation. The increase of dry matter accumulation due to the interception of photo synthetically active radiation was resulted in the increase of leaf area index in East-West orientation. Canopy extinction coefficient (K) was affected by plant densities of 300 and 350 plants per square meter and in plant densities 250 plant per square meter no significant difference in plant orientations was observed. Average of canopy extinction coefficient in this study 0.63 was measured. Radiation use efficiency (RUE) was affected by interaction effect of plant density and orientation. The maximum of RUE was observed in the high plant density and East-West orientation.