Browsing by Author "Wesonga, John"
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Publication Indigenous leafy vegetables of Eastern Africa — A source of extraordinary secondary plant metabolites(Elsevier, 2017-10-01) Neugart, Susanne; Baldermann, Susanne; Ngwene, Benard; Wesonga, John; Schreiner, MonikaIndigenous African leafy vegetables vary enormously in their secondary plant metabolites whereat genus and the species have a great impact. In African nightshade (Solanum scabrum), spiderplant (Cleome gynandra), amaranth (Amaranthus cruentus), cowpea (Vigna unguiculata), Ethiopian kale (Brassica carinata) and common kale (Brassica oleracea) the specific secondary metabolite profile was elucidated and gained detailed data about carotenoids, chlorophylls, glucosinolates and phenolic compounds all having an appropriate contribution to health beneficial properties of indigenous African leafy vegetables. Exemplarily, various quercetin glycosides such as quercetin-3-rutinoside occur in high concentrations in African nightshade, spiderplant, and amaranth between ~1400–3300μg/g DW. Additionally the extraordinary hydroxycinnamic acid derivatives such as glucaric isomers and isocitric acid isomers are found especially in amaranth (up to ~1250μg/g DW) and spiderplant (up to 120μg/g DW). Carotenoids concentrations are high in amaranth (up to101.7μg/g DW) and spiderplants (up to 64.7μg/g DW) showing high concentrations of β-carotene, the pro-vitamin A. In contrast to the ubiquitous occurring phenolics and carotenoids, glucosinolates are only present in the Brassicales species Ethiopian kale, common kale and spiderplant characterized by diverse glucosinolate profiles. Generally, the consumption of a variety of these indigenous African leafy vegetables can be recommended to contribute to different benefits such as antioxidant activity, increase pro-vitamin A and anticancerogenic compounds in a healthy diet.Publication Is Partial Root Zone Drying Irrigation A Feasible Water Saving Strategy In African Leafy Vegetable Production? A Review.(Afr. J. Hort. Sci., 2016) Odula, Osia; Wesonga, John; Masinde, Peter; Stützel, HartmutKenya is considered a water deficit countrywith an annual water recharge of 640m 3per capita.Water saving irrigation technologies such as partial root zone drying (PRD) are important means to sustainability produce high yield and quality African leafy vegetables under water limited conditions.PRD is a novel and innovative approach in which half of the root zone is irrigated interchangeably in a planned irrigation schedule.Several researchersin developed countries,particularly those from arid and semiarid,have extensively evaluated PRD as a water saving irrigation strategy on field and horticultural crops without significant influence on both crop yield and quality.PRD actually improves product quality in several crop species as partial root zone drying exploits the drought induced abscisic acid root to shoot signalling to limit stomatal conductance which ultimately saves water.In this paper we reviewPRD results on various field and horticultural crops around the globe with the view of assessing the potential of its implementation in productionof African leafy vegetables in urban and periurban areas in Kenya.Publication Leadership and change management to transform tertiary agricultural education institutions.(Transforming tertiary agricultural education in Africa, 2021-12) Imbuga, Mabel; Wesonga, John; Sila, Daniel N.This chapter explores the concepts of leadership and change management within the context of transforming Africa's tertiary agricultural education (TAE) sector, and more specifically its universities. Sections 6.2 and 6.3 focus on existing leadership practices in African TAE institutions and a vision for their future transformation. Sections 6.4 and 6.5 more specifically address the role of leadership in effecting this transformation, and best practices for such leadership. Section 6.6 analyses the challenges associated with successfully managing organizational change. Section 6.7 provides a brief conclusion.Publication Mainstreaming Efficient Legume Seed Systems in Eastern Africa: Challenges, opportunities and contributions towards improved livelihoods(Food and Agriculture Organization of the United Nations, 2018) Ojiewo, Christopher Ochieng; Rubyogo, Jean-Claude; Wesonga, John; Bishaw, Zewdie; Abang, Mathew M.; Gelalcha, SolomonLegumes are important components of sustainable farming systems. They are useful to diversify and intensify cropping systems as double, catch, relay and intercrops; fix ‘free’ nitrogen to soils from the atmosphere and improve soil health that boost cereal crop yields; act as rotation crops for breaking disease and pest cycles; increase and diversify smallholder incomes (and hence buffer them from the effects of price, pest and climate-related production fluctuations); enhance quality of household diets because of their higher protein and micro-nutrient content compared with starch-based staple cereal crops; and provide good sources of animal feed (high protein crop residues and byproducts) and low carbon footprint, mitigating climate change...