Evaluation of six sesame varieties for yield variability in relation to their physiological traits in South Kordofan

A field experiment was conducted for two seasons (2006/07 - 2007/08) under rain-fed conditions at Kadugli Research Station Farm in South Kordofan State. The experiment was undertaken to evaluate six sesame (Sesamum indicum L.) varieties of diverse genetic background for growth, yield and yield component. Physiological traits for yield variation among these varieties were also investigated. Sesame varieties used were two local (Gabaroak and Jebeli) and four introduced (Gedarif-l, Promo, Um shagara and Kenana-2). The varieties were arranged in a randomized complete block design with 4 replications. The parameters studied included yield and yield components and some morph-physiological traits. Oil and protein content of sesame genotypes were also measured. Analysis of variance was carried out for each season and combined over seasons. The combined analysis showed that seed yield differences among varieties were highly significant (P 0.01). The highest seed yield of 800kg/ha was recorded by Um shagara variety, while the lowest yield of less than 300kg/ha was obtained from the two local varieties. Differences among varieties in oil and protein content were not significant. Seed oil content ranged from 47 to 55%. Highly significant differences for number of capsules per plant, number of seeds per capsule, secondary branches per plant and plant height at first capsule as well as harvest index were observed. Harvest index ranged from 18 to 38% and its trend was almost commensurate with yield ranking. Total dry weight, leaf area index, crop growth rate, relative growth rate and net assimilation rate did not show significant variation among varieties. These results indicated that differences in yield are more related to harvest index i.e. Significant and high positive correlations were recorded for seed yield with plant secondary branches, plant height at harvest, capsule number per plant and harvest index. Among morph-physiological traits only leaf area index and crop growth rate showed a significant and positive association with yield per plant. The results of this study indicated that the most important traits affecting sesame yield are dry matter production, capsules number per plant, plant height at harvest, secondary branches per plant, leaf area index and crop growth rate. This result suggests that seed yield could be improved by selecting for such characters