Njuguna, J. K.Wanjala, S.Wepukhulu, B.Gatambia, E.2015-08-122015-08-122012East African Agricultural And Forestry Journal, 78 (1), p. 117-1200012-8325http://localhost:8080/dspace/handle/0/9217Mango is one of the most widely grown fruit crops in the world. In Kenya, mango is an important fruit crop in terms of area under cultivation, volume and value of the product. However, despite the importance of this crop, its potential has not been fully exploited due to constraints such as diseases, insect pest infestations, poor crop husbandry and usage of inappropriate rootstocks among other factors. The two commonly used rootstocks in Kenya namely Sabre and Peach were adopted from South Africa which is a subtropical country. Their characteristics and their influence on improved cultivars in Kenya have not been documented. A study was therefore initiated to detennine the effect of the two rootstocks on three improved cultivars namely Glenn, Irwin and Tommy Atkins. Results showed that Irwin and Tommy Atkins grafted on Peach rootstock out yielded Glenn grafted on the same rootstock. There was a difference (P<0.5) between cultivars for fruit number and fruit weight. All the three cultivars produced more and heavier fruits when grafted on Sabre rootstock than when grafted on peach rootstock. Cultivar Irwin had the highest fruit number and weight followed by Tommy Atkins while Glenn had the lowest. This could be attributed to faster and vigorous growth of cultivar Irwin thus establishing a large canopy earlier than other cultivars. It can be concluded that Sabre is a more superior rootstock than Peach and of the three cultivars; Irwin has the greatest yield potential particularly when grafted on Sabre rootstock.enhttp://creativecommons.org/licenses/by/3.0/Journal ContributionCultivarsMangoesRootstocksFood securitymaterialsMethods