Evaluation compatibility of old and new wheat varieties with canola in additive series of combination

Introduction Wheat breeders have been constantly working to develop new varieties with improved productivity and yield and resistance to pests and diseases. These varieties are being released frequently and are replaced existing ones over and released on basis of their performance under open conditions. Intercropping has been widely applied to reduce soil erosion and water loss, restoring ecological balance, improving radiation and nutrient use efficiency, raising land equivalent rate and increasing economic benefits. The objective of the present work was to determine the effect of row intercropping of old and newwheat cultivars and canola as additive series on the yield, yield components, radiation use efficiency and land equivalent ratio under climatic conditions of Mashhad. Materials and Methods This experiment was conducted as factorial layout based on a randomized complete block design with three replications at the Agricultural Research Ftation of Ferdowsi University of Mashhad, Iran during two growing season of 2014-2015 and 2015-2016. The first and the second factors were wheat varieties (the old: Roshan and Tabasi and the new: Parsi and Sirvan) and intercropping ratios of wheat and canola in additive series (0:100, 25:100, 50:100, 75:100, 100:100 and 100:0), respectively. Investigated traits were seed, biological and straw yield of wheat and number of pods per plant, number of seeds per plant, 1000-seed weight, seed, biological and straw yield of canola, radiation use efficiency based on seed yield and total dry matter land equivalent ratio. For analysis of variance SAS 9.1 was used. All the means were compared according to least significant test (p≤0.05) Results and discussion Results showed that the highest wheat yield and yield components, except for 1000-seed weight, were obtained for under monoculture and by increasing the proportion of canola to 75%, significant decrease was observed in seed yield and biological yield of wheat. There was a significant increase in seed yield of new wheat varieties compared to Tabasi as an old variety while the biological yield was not affected by the variety. As compared to other wheat variety, in the presence of the new variety Sirvan, seed and biological yield and radiation use efficiency of canola were significantly increased. However, between different wheat varieties there was no significant difference in radiation use efficiency. The maximum land equivalent ratio (1.41) was calculated with 25% canola+100% wheat. Conclusion Results revealed that yield of wheat and canola were significantly affected by intercropping ratio and wheat varieties in which yield of both crops due to competition was reduced. However due to different criteria of these species associated with better use of water, radiation and nutrient resources when they are intercropped, land use efficiency was increased. New varieties of wheat seems to preform better when intercropped with canola. However, there was no significant differences in radiation use efficiency and land equivalent ratio between the old and the new wheat varieties. Acknowledgement This research (32693) was funded by Vice Chancellor for Research of Ferdowsi University of Mashhad, which is hereby acknowledged.