Performance and stability of seed yield in rainfed sesame genotypes as influenced by plant population density
Department of Plant Breeding and Seed Technology, University of Agriculture, Abeokuta P.M.B. 2240, Abeokuta, Ogun State, Nigeria
A study was conducted to determine the performance and stability of seed yield in 14 sesame (Sesamum indicum L.) genotypes which were grown in a randomized complete block design with three replications at three plant population densities in South-West Nigeria in each of two years. Two stability parameters were obtained (i) as the linear regression (b value) of genotype mean yield in each environment and the deviations from the regression (S 2d). The genotypes evaluated differed significantly for seed yield and genotype x environment (G x E) interactions. Regression coefficients ranged from 0.65-1.25 and were statistically close to unity. One genotype, 530-3, with a regression coefficient value of 1.01 and smaller S2d value and a relatively high seed yield, could be considered the most widely-adapted genotype. Deviations from the regression were significant in all the genotypes. The highest-yielding genotypes appeared less stable than the average of all entries. Three genotypes, Type A, 530-6-1, and Pbtill No. 1 were identified as suitable for cultivation in all the environments. Genotypes E8 and 69B-88Z were identified as desirable genotypes for cultivation in any of the three plant populations. The result pointed out Goza as being most appropriate for cultivation in 133 333 plants ha-1 and 73A-11 and C-K-Z in 266667 plants ha-1, while Domu would be appropriate in 266667 plants ha -1. These genotypes were distinct and therefore deserve a place in commercial seed production and future breeding programmes. ©2006 Trop. Agric. (Trinidad).