Stability assessment of soybean varieties in Kenya

(Received 23 January, 2001; accepted 5 August, 2001) ABSTRACT Soybean (Glycine Max (L.) Merr.) varieties grown in Kenya are imported from different countries and there is a renewed interest in the cultivation and utilisation of the crop for both home and industrial use. The objective of this study was to screen soybean varieties for yield stability in different environments in Kenya and compare their performance under these environments. The overall aim was to identify appropriate and high yielding varieties of soybeans for production in diverse agro-ecological zones. These trials were conducted at four sites located at Busia and Homabay in western Kenya and Gachoka and Thika in central Kenya, over a five year period. Ten varieties were tested and the trials were set up in a randomised complete block design, with each variety replicated four times at each site. Cultivar yield stability at the environments, yielding ability, height at maturity as well as days to maturity formed the basis for assessing cultivar suitability for a given environment. There were significant cultivar x environment interactions for all the response variables tested. Four cultivars, EAI3600, Gazelle, Nyala and Sable were identified to be stable in the different environments and were consistently observed to be high yielding and of appropriate height, maturity period and highly adaptable to the sites. Key Words: Days to maturity, Glycine max resume Les varieties de soja (Glycine Max (L.) Merr) plantees au Kenya sont importees de differents pays. Il y a un renouvellement d'interet a la culture et a l'utilisation a la fois domestique et industrielle de la plante. L'objectif de cette etude etait de tester les varieties du soja pour un rendement stable dans les differents environnements du Kenya et comparer leurs performances dans ces derniers. Le principal vise etait d'identifier les varieties ameliorees appropriees du soja et leur augmentation de rendement pour la production dans diverses zones agro-ecologiques. Ces essais etaient conduit dans quatre sites differents dont Busia et Homabag dans l'ouest , Gashoka et Thika au centre, du Kenya pendant une periode de plus de cinq ans. Dix varieties etaient testees dans un block completement pris au hazard avec chaque variete repetee quatre fois a chaque site. La stabilite de rendement d'une variete, l'abilite de rendement, la taille a maturation aussi bien que la date de maturation ont forme la base de l'etude de convenance d'une variete pour un environnement donne. Les interactions varietes x environnements etaient significatives pour toutes les variables reponses testees. Quatre varietes EAI 3600, Gazelle, Nyala et Sable etaient identifiees stables dans les differents environnements, et observees de maniere consistante a rendement eleve, de taille et periode de maturate appropriees, et adaptable aux sites. Mots Cles: Jours de maturite, Glycine max (Af Crop Sci J 2002 Vol 10 No 2 pp139-144)