Regression and Path Analysis of the Relationship Between Seed Yield and the Most Important Yield Components of Sesame

In order to study the correlation between yield component and seed yield of sesame and to determine the relationships between shoot length, capsules per plant, seeds per capsule, 1000-seed weight, biological yield and harvest index, in 2013 an experiment was conducted based on RCBD design with ten treatments (including different biological and chemical fertilizers) in experimental field of Ferdowsi university of Mashhad. Results showed that there was a positive and significant correlation between seed yield and plant height, but much of the efficacy of plant height on seed yield was by influencing capsules per plant. Biological and seed yield had a positive and significant correlation (0.81 and 0.87, respectively) with capsules per plant. The highest direct effect of components on seed yield was belonged to “capsules per plant” and the least belonged to “plant height”. Analysis of regression showed that capsules per plant and biological yield had the most effect on seed yield and their partial regression coefficient was 10.7 and 0.134, respectively. The partial regression coefficient for standardized data of these two traits showed the priority of biological yield in comparison with capsules per plant. Yield function that is a function of capsules per plant and biological yield, with the coefficient of determination of 0.96 justified a large part of seed yield. So biological yield and capsules per plant were the most important traits of sesame that can be considered by researchers. Also, after calibration of yield function, it can be used for estimating the production of sesame.