Determination of the Best Intercropping Combination of Wheat and Rapeseed Based on Agronomic indices, Total Yield and Landuse Equivalent Ratio

In order to determine the best intercropping combination of wheat (Triticum aestivum) and rapeseed (Brassica napus) based on total yield and landuse efficiency, an experiment was conducted during 2010-2011 growing season at Agricultural Research Farm of Faculty of Agriculture, Bu-Ali Sina University. This experiment used randomized complete blocks design and three replications. Treatments included sole cropping of wheat (T), sole cropping of rapeseed (B), intercropping of two rows of rapeseed with one row of wheat (BB1), two rows of rapeseed and two rows of wheat (BB2), two rows of rapeseed and three rows of wheat (BB3), two rows of wheat and one row of rapeseed (TT1), two rows of wheat and two rows of rapeseed (TT2), and two rows of wheat and three rows of rapeseed (TT3). The results showed that plant height, number of spikes/m2, 1000-seed weight, and grain and biological yields for wheat were significantly affected by experimental treatments. By shifting planting pattern from sole cropping to intercropping, plant height and 1000-seed weight increased, but other traits decreased. Maximum and minimum values of wheat grain yield (545 g/m2 and 225 g/m2, respectively) were achieved at T and BB1 treatments, respectively. The effect of experimental treatments on all rapeseed traits was significant. Similar to wheat treatments, by shifting the planting pattern from sole cropping to intercropping, plant height and 1000-seed weight for rapeseed increased but other traits decreased. Maximum grain yield of rapeseed (398 g/m2) was revealed at B treatments. In general, based on the results, values of land equivalent ratio (LER) in all intercropping treatments was higher than unity and competition index (CI) was less than unity. The TT3 treatment had the least CI (0.05) and the highest value of LER (1.5). Therefore, the TT3 treatment was the most suitable intercropping combination of wheat and rapeseed