Evaluation of the American yam bean (Pachyrhizus spp.) for storage root yield across varying eco-geographic conditions in Uganda

Open Access Article; Published online: 15 June 2019The American yam bean (Pachyrhizus spp.) is a legume crop that is exclusively used for its storage roots. The seeds are inedible due to presence of toxic rotenone. It produces high storage root yields comparable of major root crops like cassava or sweetpotato. And flower pruning more than doubles its root yield performance. Using twenty five yam bean accessions, the current study aimed to determine root yield stability and adaptability, and presence of yam bean production mega environments in Uganda. Trials were planted at three stations, Namulonge, Serere, and Kachwekano during two consecutive seasons of 2011. Fresh storage root yields were significantly different (p < 0.05) across locations with the ideal location being Namulonge (fresh storage root yield of 10.1 t ha-1), followed by Serere (8.0 t ha-1), and Kachwekano (3.1 t ha-1). Results of AMMI analysis indicated the presence of genotype-by-environment interaction for fresh storage root yield. Through AMMI estimates and GGE visual assessment, genotype 209017 was the highest yielding with mean yield of 20.7 t ha-1. Genotype 209018 with mean yield of 15.5 t ha-1 was the most stable and adapted accession in the entire discriminating environment in Uganda. From the environmental focusing plot, the six environments were grouped into two putative mega environments for yam bean production

Proliferation and shoot recovery among the East African highland banana

Production of East African highland banana (EA-AAA banana) ( Musa spp.) is limited by scarcity of planting materials, attributable to their low natural proliferation ability. Under natural field conditions, the EA-AAA bananas greatly differ in suckering ability. In vitro micropropagation has been adopted as an alternative means for production of banana planting materials. In this study, the in vitro proliferation potential of seven EA-AAA banana cultivars, with different suckering ability was determined on Murashige and Skoog (MS) medium, to enhance development of micropropagation protocols for their multiplication. Commonly cultivated non EA-AAA banana cultivars were used to compare proliferation of the seven EA-AAA cultivars. There was a wide variation in the number and morphology of shoots and buds produced by the different cultivars. The EA-AAA banana cultivars produced 3-4 new shoots in each subculture cycle, and 57-169 recoverable shoots from one starting shoot-tip explant in 18 weeks. Non-EA-AAA banana cultivars, namely Sukali Ndizi (AAB) and Yangambi Km5 (AAA), showed higher proliferation levels, 5 and 9 shoots, from each subculture cycle and 322 and 352 recoverable shoots, respectively. The EA-AAA banana cultivars showed higher efficiency to produce recoverable shoots from shoot buds (53 - 66% except for cv. Kabula at 36%) compared to Sukali Ndizi (52%) and Yangambi Km5 (32%). The study demonstrates the potential of in vitro approach for production of banana planting materials. In vitro proliferation ability and in particualr efficiency to produce recoverable shoots of the different EA-AAA banana cultivars could be improved by varying the culture conditions during the subsequent subculture cycles.La production de la banane (EA-AAA banana) ( Musa spp.) dans les montagnes de l\u2019Afrique de l\u2019Est est limit\ue9e par le manque du mat\ue9riel de plantation suite \ue0 leur base capacit\ue9 de prolif\ue9ration. En conditions naturelles au champs, les bananes EA-AAA different consid\ue9rablement en leur capacit\ue9 de succion. La propagation in vitro a \ue9t\ue9 adopt\ue9e comme moyen alt\ue9rnatif pour la production du mat\ue9riel de plantation de la banana. Dans cette \ue9tude, le potentiel de prolif\ue9ration in vitro de sept cultivars de banana EA-AAA de capacit\ue9 de succion diff\ue9rente, \ue9tait d\ue9termin\ue9 sur les media de Murashige et Skoog (MS), afin d\u2019am\ue9liorer le d\ue9veloppement de protocoles de micropropagation pour leur multiplication. Des cultivars commun\ue9ment cultiv\ue9s autre que la banana EA-AAA \ue9taient utilis\ue9s pour faire la comparaison avec la proliferation des sept cultivars EA-AAA. Il y\u2019avait eu une large variation dans le nombre et la morphologie des pousses et bourgeons de diff\ue9rents cultivars. Les cultivars de bananes EA-AAA ont produit 3-4 nouvelles pousses dans chaque cycle de sous culture et 57-169 pousses recouvrables d\u2019un explant de pousse dans 18 semaines. Les cultivars de bananes non-EA-AAA nom\ue9ment Sukali Ndizi (AAB) and Yangambi Km5 (AAA), ont montr\ue9 de niveaux \ue9lev\ue9s de proliferation, 5 et 9 pousses de chaque cycle de sous culture et 322 et 352 pousses recouvrables, respectivement. Les cultivars de bananes EA-AAA ont montr\ue9 un niveau d\u2019efficacit\ue9 \ue9lev\ue9 quant \ue0 la production de de pousses recouvrables \ue0 partir de bourgeons (3566% except\ue9 pour cv. Kabula \ue0 36%) en comparaison avec Sukali Ndizi (52% et Yangambi km5 (32%). Cette \ue9tude d\ue9montre le potentiel de production du mat\ue9riel de plantation de la banana par l\u2019approche in vitro. La capacit\ue9 de proliferation in vitro et en particulier l\u2019efficacit\ue9 de produire de pousses recouvrables de diff\ue9rents cultivars pourrait \ueatre am\ue9lior\ue9 en variant les conditions de cultrure Durant les cycles sous culturales

Performance and Acceptability of Orange Fleshed Sweetpotato Cultivars in Eastern Uganda

White fleshed sweetpotato ( Ipomea batatus ) cultivars are an important staple and source of carbohydrates in Uganda. However, their orange fleshed sweetpotato (OFSP) counterparts are less common. The OFSP varieties can offset Vitamin A deficiency (VAD). Increased consumption of the OFSP cultivars could contribute to alleviation of VAD a common problem in Uganda. Research was conducted on-farm in twenty parishes of Iganga and Kamuli districts of eastern Uganda to evaluate the agronomic performance, consumer acceptability, dry matter and beta carotene content of 4 OFSP cultivars. The OFSP cultivars gave lower yield than the local white fleshed cultivars. Beta carotene content was generally higher in OFSP cultivars than in white fleshed ones. Ejumula, and SPK004 in Iganga, as well as kala in kamuli district gave more yield than the other orange fleshed cultivars. Children expressed preference for the OFSP compared to the white fleshed ones. Farmers who participated in on farm trials with OFSP cultivars continued to plant the OFSP cultivars after the trial indicating good potential for adoption. Farmer selection criteria were identified to include high yield, resistance to disease and pests, fast growth rate, good taste and nutritive value. Given the higher nutritional value, children&apos;s taste preference and willingness of farmers to grow OFSP cultivars, it is concluded that the production and distribution of planting material should be facilitated especially for cultivars Ejumula, Kala and SPK004

Proliferation and shoot recovery among the East African highland banana

Production of East African highland banana (EA-AAA banana) ( Musa spp.) is limited by scarcity of planting materials, attributable to their low natural proliferation ability. Under natural field conditions, the EA-AAA bananas greatly differ in suckering ability. In vitro micropropagation has been adopted as an alternative means for production of banana planting materials. In this study, the in vitro proliferation potential of seven EA-AAA banana cultivars, with different suckering ability was determined on Murashige and Skoog (MS) medium, to enhance development of micropropagation protocols for their multiplication. Commonly cultivated non EA-AAA banana cultivars were used to compare proliferation of the seven EA-AAA cultivars. There was a wide variation in the number and morphology of shoots and buds produced by the different cultivars. The EA-AAA banana cultivars produced 3-4 new shoots in each subculture cycle, and 57-169 recoverable shoots from one starting shoot-tip explant in 18 weeks. Non-EA-AAA banana cultivars, namely Sukali Ndizi (AAB) and Yangambi Km5 (AAA), showed higher proliferation levels, 5 and 9 shoots, from each subculture cycle and 322 and 352 recoverable shoots, respectively. The EA-AAA banana cultivars showed higher efficiency to produce recoverable shoots from shoot buds (53 - 66% except for cv. Kabula at 36%) compared to Sukali Ndizi (52%) and Yangambi Km5 (32%). The study demonstrates the potential of in vitro approach for production of banana planting materials. In vitro proliferation ability and in particualr efficiency to produce recoverable shoots of the different EA-AAA banana cultivars could be improved by varying the culture conditions during the subsequent subculture cycles.La production de la banane (EA-AAA banana) ( Musa spp.) dans les montagnes de l’Afrique de l’Est est limitée par le manque du matériel de plantation suite à leur base capacité de prolifération. En conditions naturelles au champs, les bananes EA-AAA different considérablement en leur capacité de succion. La propagation in vitro a été adoptée comme moyen altérnatif pour la production du matériel de plantation de la banana. Dans cette étude, le potentiel de prolifération in vitro de sept cultivars de banana EA-AAA de capacité de succion différente, était déterminé sur les media de Murashige et Skoog (MS), afin d’améliorer le développement de protocoles de micropropagation pour leur multiplication. Des cultivars communément cultivés autre que la banana EA-AAA étaient utilisés pour faire la comparaison avec la proliferation des sept cultivars EA-AAA. Il y’avait eu une large variation dans le nombre et la morphologie des pousses et bourgeons de différents cultivars. Les cultivars de bananes EA-AAA ont produit 3-4 nouvelles pousses dans chaque cycle de sous culture et 57-169 pousses recouvrables d’un explant de pousse dans 18 semaines. Les cultivars de bananes non-EA-AAA nomément Sukali Ndizi (AAB) and Yangambi Km5 (AAA), ont montré de niveaux élevés de proliferation, 5 et 9 pousses de chaque cycle de sous culture et 322 et 352 pousses recouvrables, respectivement. Les cultivars de bananes EA-AAA ont montré un niveau d’efficacité élevé quant à la production de de pousses recouvrables à partir de bourgeons (3566% excepté pour cv. Kabula à 36%) en comparaison avec Sukali Ndizi (52% et Yangambi km5 (32%). Cette étude démontre le potentiel de production du matériel de plantation de la banana par l’approche in vitro. La capacité de proliferation in vitro et en particulier l’efficacité de produire de pousses recouvrables de différents cultivars pourrait être amélioré en variant les conditions de cultrure Durant les cycles sous culturales