PhD Graduands 2020

Samuel Aringo Were

Degree Programme
PHD in Crop Protection
Samuel Aringo Were
Biography

Samuel Aringo Were, received MSc. in Crop Protection from the University of Nairobi in 2012. In the Thesis titled, “Distribution of Potato Tuber moth (Ptheromeae opercullela) in Kenya and Management strategies in Kenya” I sought to determine the distribution of potato tuber moth in potato growing areas of Kenya. I also determined the varietal resistance to potato tuber moth in locally grown potatoes. My research interests include sustainable management of plant pest and diseases; plant microbe interaction and the pathways of these interactions leading to enhanced plant resistance to biotic stresses. In line with these, i pursued a doctorate degree in Crop Protection. My thesis titled “Characterisation of Bean root rot fungi from soils in Western Kenya and their management with biochar and vermicompost” sought to identify the different bean root rot pathogens in Western Kenya using different techniques. I also sought determine the effect of the soil amendments in management of root rot as well as elucidate the mechanism by which these amendments enabled the suppression of disease and increase bean productivity.

Abstract

Abstract

The root rot disease complex has continued to be a major constraint in the production of common beans (Phaseolus vulgaris) resulting in losses of up to 70% in Kenya. The aim of this study was to establish (i) the occurrence and quantification of root rot fungal pathogens of common bean in Western Kenya and (ii) the effect of farming practices on the populations of the pathogens. A survey was conducted in Western Kenya’s LM1 LM2 UN1 and UM3 AEZ’s to obtain data on different farming practices and soil characteristics. Pathogens were isolated and identified using morphological and molecular techniques. Soil pH ranged from 4.59 to 6.01, Percent carbon and nitrogen ranged from 9.8 g/Kg0 to 19 g/Kg and 0.8 g/Kg to 1.5 g/Kg. All farms were infected with root rot fungi, including Fusarium solani, Pythium ultimum, Rhizoctonia solani and Macrophomina phaseolina. Fusarium spp. was the most abundant with the highest populations of 62 X 103 cfu/g soil recorded in lower midland zone 2. The isolation frequency of Fusarium spp., Pythium spp. and Rhizoctonia spp. was high in upper midland zone 1. Quantification of genomic DNA from soil by qPCR was highest for Rhizoctonia solani (2.23 X 100 pg µL-1). Sand had a positive correlation with Pythium ultimum DNA and Rhizoctonia solani DNA while clay had a negative correlation with Fusarium spp. and Rhizoctonia solani DNA. In conclusion, soil properties, management practices and elevation affected root rot pathogen populations and should be considered when developing management strategies. 

 

Research Supervisors

Research Supervisors

Prof. Rama D. Narla,

Prof. Eunice W. Mutitu

 Prof. James W. Muthomi

Jane Jerono Cheserek

Degree Programme
PHD in Genetics and plant breeding
Research Topic:
PERFORMANCE OF INTERSPECIFIC ARABUSTA COFFEE HYBRIDS FOR YIELD, CUP QUALITY, AND DISEASE RESISTANCE.
 Jane Jerono Cheserek
Biography

I currently work for the Kenya Agricultural and Livestock Research Organization-Coffee Research Institute as a coffee breeder.  I studied at the University of Nairobi for my BSc. Agriculture, MSc. Plant breeding and genetics and currently I have been awarded the Doctor of Philosophy (PhD) in plant breeding and genetics at the same University. I have worked in the coffee breeding department for the last 9 years bringing in vast experience in coffee improvement. The objective of my breeding work is development of coffee varieties that combine both high yield, disease resistance, drought tolerance and good cup quality. The ongoing breeding programs are geared towards development of coffee varieties are at different development stages. One of the programs includes search for markers associated with Coffee Berry Disease resistance using SNPs with GWAS and QTL mapping. The molecular work would enhance our breeding activities and shorten the breeding time for coffee varieties. Other related work includes germplasm conservation and the production of coffee planting materials in form of seed and seedlings for distribution to farmers. Currently, I am evaluating coffee genotypes that have been received from different parts of the world for adaptability trials under the International Multi-Location Variety Trial (IMVLT) in collaboration with World Coffee Research (WCR) as the Principal Investigator. The trials sites are located in Ruiru and Koru sites in Kenya. 

Abstract

Abstract

The Kenya annual coffee production has in recent years declined due to different factors such as change of land use and biotic stresses, despite the country being one of the world’s producers of high-quality coffee. This study analysed the agronomic potential of Arabusta hybrids developed from C. arabica and C. canephora for their bean yield, quality, and disease resistance. Nineteen Arabusta genotypes were assessed in two different locations (Siaya ATC and KALRO-Alupe) for growth and bean yield during the second and third years after establishment in the year 2017 and 2018 respectively. Arabusta hybrids that had higher yields when compared to other genotypes in Busia were ARH1, ARH4, and ARH5 whereas in Siaya it was ARH4.The polymorphism between the Arabusta genotypes and the Arabica coffee varied, with 72% polymorphism calculated among Arabusta genotypes and 46.8% among the Arabica genotypes. The SSR marker SAT 235 was able to identify genotypes that have the CK-1 gene for coffee berry disease resistance. Significant variation in sensory and bean grade traits showed that Arabusta hybrids gave higher scores than backcrosses and Robusta. Acidity showed significant positive correlation with aroma (r=0.84), balance (r=0.85), flavour (r=0.96) and preference (r=0.96).  The 100 berry weight showed a positive correlation with the AA bean size indicating that berry weight can be used to predict AA bean size. Arabusta hybrids, backcrosses, and Arabica coffee on average had higher levels of sucrose, oil, and trigonelline when compared to Robusta which was responsible for the improved liquor quality.

 

Important Links

Research Supervisors

Research Supervisors

Prof.  Kahiu E Ngugi

Prof. James W Muthomi

Dr. Chrispine O. Omondi

 

PENINAH MUENI YUMBYA

Degree Programme
PHD in Horticulture
Research Topic:
EFFECTIVENESS OF HEXANAL AND ITS MODE OF ACTION ON THE POST-HARVEST QUALITY OF BANANA FRUITS (MUSA SPP)
PENINAH MUENI YUMBYA
Biography

Ms. Peninah Yumbya, PhD research topic is on; Effectiveness of Hexanal and Its Mode of Action on the Post-Harvest Quality of Banana Fruits (Musa Spp). Peninah’s PhD research was funded by International Development Research Center, Canada under the enhanced preservation of fruits using nanotechnology project. Peninah got more funding from the National Research Fund (NRF), Kenya, which supported her PhD research.  Peninah further won the African Bioscience Challenge Fund (ABCF) in the year 2017/2018 which sponsored the molecular analysis work. Peninah did her Msc. in Horticulture in the University of Nairobi between 2010 and 2012. Her Msc. thesis was on; Effect of 1-Methylcyclopropene (1-MCP) and Activebag® Packaging on Postharvest Shelf Life and Quality of Purple Passion Fruit (Passiflora Edulis Sims). She did her BSc in Agriculture (Crop Science option) from the University of Nairobi between 2006 and 2010.

 

Abstract

Abstract

Banana is one of the major fruits produced in Kenya. However, its full potential is not fully exploited due to several constraints including high postharvest losses. The present study was conducted to assess the effectiveness of hexanal, a naturally occurring compound in prolonging the shelf-life of ‘Grand nain’ and ‘sweet banana’ varieties produced under two agro-ecological zones (AEZ) of Kenya.  Further, the study sought to validate the effect of hexanal treatments on the fruits’ postharvest quality and elucidate the molecular basis of its mode of action. To realize these objectives, three separate but related experiments were conducted. 

In the first objective, the best method of hexanal application, the effective concentration and treatment duration were evaluated. In the second objective, the effect of hexanal treatment on selected quality attributes was analyzed. In the third objective, mature-green ‘Grand nain’ banana fruits were treated with either hexanal, ethylene, 1-Methylcyclopropene (1-MCP), a combination of 1-MCP and hexanal or left untreated. The fruits were left to undergo normal ripening. Three fruits from each treatment combination were randomly sampled at two-day interval for analysis of selected physical and physiological parameters as well as molecular analysis.

Hexanal applied twice as a pre-harvest spray significantly (p < 0.05) delayed time to fruit harvesting compared to the controls. Effectiveness of hexanal was significantly affected by duration of application with the post-harvest dip for 5 minutes being more effective than 2.5 minutes. Hexanal treatment did not have any significant effect on the various quality attribute parameters analyzed. Hexanal and 1-MCP treatments suppressed the expression of various cell wall genes compared to fruits treated with ethylene and the controls. These results indicate that hexanal technology is effective to delay ripening and extend the shelf-life of banana fruit without affecting the quality attributes of the fruits. Further, hexanal mode of action is through temporal suppression of ripening genes.

 

Research Supervisors

Research Supervisors

Prof. Jane Ambuko

Prof. Margaret J. Hutchinson

Prof. Willis Owino

 

Samuel Kimaru Linguya

Degree Programme
PHD in Crop Protection
Research Topic:
Detection of Plant Pathogens Associated with African Nightshade Seed and Methods of Seed Processing to Reduce Infection
 Samuel Kimaru  Linguya
Biography

Samuel Kimaru Linguya is a holder of PhD from the University of Nairobi in Crop Protection in 2020.He graduated with Msc in crop Protection from the same institution in 2013 and from Egerton University with a Bachelor of Science Degree in Agriculture Education and Extension. He joined Equity Bank after graduation as an Agriculture credit officer upto to 2010.Currently he is a high school teacher and part time lecturer teaching Agricultural Sciences. He has published eight papers in referred journals and presented four papers in different conferences. His research interest is in crop diseases diagnosis and management. In Ph.D research he has isolated three potyviruses and deposited their sequences in the gene bank as Kenyan isolates infecting African nightshades. He is a member of African crop science society and St. John Ambulance.

He loves inspiring farmers to grow African nightshades to curb malnutrition and improve food security.

Abstract

Abstract

 

African nightshade (ANS) is known for high micronutrient content, medicinal properties and fast growth with low production costs. The challenges facing its production include low quality seed, low leaf/seed yields per hectare, pests and diseases, poor harvesting and processing methods. The objectives of this study were to evaluate the quality status of African nightshade seed, detect seed borne pathogens, identify the most prevalent viral pathogens and determine a suitable seed processing method for clean ANS seed production. A household survey was conducted in 240 farms in Nyanza and Western Kenya where ANS is grown in abundance and seed samples were collected from farms and local markets. Certified seed samples were purchased for comparison. Quality and purity tests were done following International Standard Testing Association rules (ISTA). Purity was determined by separating seed samples into pure, discoloured, weed, other crop seeds and other foreign matter. Germination percentage was obtained by planting lots of 100 seeds on paper towel where number of germinated seeds, normal seedlings and infected seedlings were counted. Seedling vigour index was assessed by measuring seedling length and seedling dry weight. Fungal and bacterial pathogens were isolated and identified using appropriate methods to species level. Serology and molecular techniques were used to identify viruses and the major viruses were sequenced using next generation sequencing. Certified seeds were used as a standard check.  The seed processing methods used by farmers were evaluated. Data was analyzed and treatment means compared using the fisher’s protected LSD test at 5% probability level.

Seed quality tests showed that farm saved seed was of poor quality compared to seed obtained from the local market and certified seed. Farm saved and local market seed had low seed purity of 68.6% and 74%, respectively compared to certified seed at 94.4%. In addition, only certified seeds met the recommended moisture and germination percentage as per ISTA rules. There was a significant (p≤ 0.05) correlation between seed quality and germination parameters. For example seed purity had significant positive correlation (r=0.76**) with germination percentage. The following major pathogens were detected in African nightshade: Aspergillus flavus (42.4%), Aspergillus niger (32.5%), Xanthomonas campestris pv. vesicatoria (31%), Potato virus Y (26%), Penicillium chrysogenum (23.5%), Cucumber mosaic virus (21%) and Pseudomonas syringae pv. tomato (17%). Three major viruses namely Potato virus Y (PVY), Cucumber mosaic virus (CMV) and Tobacco mosaic virus (TMV) were confirmed by next generation sequencing revealing genomic homology of more than 90% with 22 isolates from all over the world. Three strains of Potato virus Y were identified as PVYNTN, PVYO and PVYN:O. Evaluation of seed processing methods revealed that wet seed fermentation method, produced seeds with the highest purity of 96.3% and yielded more (913.8 kg/ha) compared to other processing methods. The high level of ANS seed infection, contributes to poor seed quality leading to poor plant growth and low yields. There is need to train farmers on appropriate processing methods for clean seed production to increase ANS productivity. The current study recommends routine inspection of seeds by seed producers to ensure that the seed is of acceptable quality and within the tolerable levels of infection. 

Research Supervisors

Research Supervisors

Dr.Dora C. Kilalo, Dr. William M. Muiru & Prof. John W. Kimenju

Sokame, Bonoukpoè Mawuko

Degree Programme
PHD in Crop Protection
Research Topic:
Functioning of a community of lepidopteran maize stemborers and associated parasitoids following the Fall Armyworm invasion in Kenya
Sokame, Bonoukpoè Mawuko
Biography

Sokame has currently completed his PhD in Crop Protection from the university of Nairobi, Kenya in partnership with the International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya. He is a national of Togo and did his previous studies at school of Agriculture University of Lomé, Togo, where he obtained BSc and MSc degrees in Agricultural Engineer, majoring plant production in 2012. His research interests include all aspects of crop production and pest management. He previously worked on Maruca multi-nucleopolyhedrovirus, MaviMNPV and vegetable oils for cowpea pests control at IITA-Benin, 2011-2012. Later on, he moved to the University of Lomé as researcher assistant where he was involved in several projects aimed at crop pests IPM control by a means of insect pheromones, mychorrizal fungals, plant extracts. In 2016, Sokame joined ICIPE to conduct a PhD where he registered in Crop Protection from the University of Nairobi, Kenya in 2017. Therefore, he looked at chemical ecology mechanisms underlying oviposition choice in maize lepidopteran stemborers and the interfering of the invasion of the Fall ArmyWorm. Currently, Sokame is under Data Management, Modelling and Geoinformation Unit at icipe where he is involved in climate model applications in agricutural cropping systems and methodological approach for predicting and mapping the phenological adaptation of tropical cereal crops using multi-environment trials. He has over ten publications in scientific peer-review journals.

Abstract

Abstract

Lepidopteran stemborers are still among the most important pests that are reported to cause maize yield losses in sub-Saharan Africa. In Kenya, they seriously limit potential maize yield. The recent invasion of the fall armyworm in the maize growing region of the country has further complicated the management of stemborer pests in maize fields. For proper management of maize pests, the knowledge of the behavioural and chemical ecology, eco-environmental factors and interaction among various pests species in the field is essential. Therefore, this study aimed to identify the main reservoir source of maize stemborers and associated parasitoids that give rise to new populations in succeeding cropping season and evaluate the chemical basis of the female moth oviposition site preference. Furthermore, the communal larval interactions among the stemborer species and FAW larvae and the factors such as larval dispersal potential, environment temperature, larval density and duration of the interactions as well as the susceptibility of FAW larvae to the stemborer associated parasitoids were also studied. The study showed that maize residues constituted their carry-over niches during off-season that give rise to new habitat management considerations in IPM strategies. The chemical basis highlighted specific attractant volatiles compounds that generate applications in the development of a multi-species lure targeting female moths. FAW constitutes an additional production constraint of cereal crops that can co-exist with stemborer species along different temperature gradients. In addition, the nonreproductive mortality induced by common stemborer specific parasitoids can be explored further as part of FAW biological control contribution.

Research Supervisors

Research Supervisors

 

Dr. Dora Chao Kilalo,

Dr. Gerald Juma  

Dr. Paul-André Calatayud

MARY MWAURA

Degree Programme
PhD Agricultural Information And Communication Management (By Research)
Research Topic:
Influence of Technology Transfer methods and Extension Workers characteristics on sustainability of Urban and Peri-urban Agriculture in Nairobi City County
Mary Mwaura
Biography

Mary Njoki Mwaura is an Agri-Nutrionist and Extensionist. She obtained her PhD Degree at the University of Nairobi in the area of Agricultural Information and Communication Management. She obtained her Master’s degree in the area of Agricultural Extension, a Bachelor of Science Degree in Agriculture and Human Ecology Extension and a Diploma in Agriculture and Home Economics all from Egerton University.

 

Abstract

Abstract

Urban and Peri urban agriculture contributes substantially to food and nutritional security to approximately 60 percent of Nairobi residents directly or indirectly. The current study was necessitated by the emerging and dynamic challenges affecting the sustainability of urban and peri urban agriculture such as the competition of resources, inadequate policies and a declining extension system. The purpose of the study was to provide an understanding on the influence of technology transfer methods and extension worker characteristics on the empowerment of farmers for sustainability of urban and peri urban agriculture. The study utilised a cross-sectional survey method and used questionnaires to collect data. The study sampled 149 farmers and 64 extension workers. Descriptive and Multiple Linear Regressions were used to analyse data. Technology transfer methods of ICT, farm visits, office visits, trainings and demonstrations and field days had a positive and significant (P<.05) influence on the sustainability of urban and peri urban agriculture. Extension worker characteristics of age, gender, educational levels and work experiences were found to positively and significantly influence the empowerment of the urban and peri urban farmers. The study concluded that the choice of technology transfer methods and extension worker characteristics influenced farmer empowerment and consequent sustainability of urban and peri urban agriculture. The study recommended empowerment of extension workers on the adult learning principles for farmer empowerment and the transformation of the extension system to a more “integrated digitized and individualized method.

 

Research Supervisors

Research Supervisors

Dr. Sabina Mukoya-Wangia, 

Dr Japheth O. Origa and 

Professor O. L. E. Mbatia

 

Davis Nguthi Muthini

Degree Programme
PHD in Agricultural Economics
Research Topic:
FARM PRODUCTION DIVERSITY AND ITS ASSOCIATION WITH DIETARY DIVERSITY AMONG SMALLHOLDER FARMERS IN KISII AND NYAMIRA COUNTIES, KENYA
Davis Nguthi Muthini
Biography

Muthini possesses over 6 years’ experience in research activities that include: project design; proposal development; planning, supervising and undertaking field work/ data collection using various applications such as ODK and CSPro; undertaking data analysis using various software such as STATA, R and SPSS; synthesizing research findings; writing reports. Mr Muthini has authored various articles in peer reviewed journals and made presentations in international conferences in Germany and Canada. 

Currently employed as a Senior Economist at the National Treasury and Planning, undertaking assignments such as: coordinating policy dialogues with relevant local, national and international stakeholders; designing and analyzing projects against criteria that includes project impact potential, cost effectiveness, paradigm shift potential, theory of change and value for money (cost benefit analysis). He has been significantly involved in development of the National Policy on Climate Finance, Kenya’s Nationally Determined Contributions on Climate Change; Climate Finance Training Manual; Kenya Climate Finance Landscape Report; among other policy documents.

 

Abstract

Abstract

Undernutrition and micronutrient malnutrition affect close to one billion people globally.  Interventions such as biofortification, farm production diversity, and market linkages target to  exploit farming and marketing systems to reduce undernutrition. The impact of consumption  of biofortified crops on nutrition has been studied extensively. However, the impact of  awareness of varieties and knowledge of nutrition qualities of biofortified crops on adoption is  not well understood. Similarly, whereas a direct link between farm production diversity and  household dietary diversity is well established in literature, a similar link has not been  sufficiently established for women and children.  

The effect of increasing production diversity on dietary diversity was found to be small in many  of the previous studies, which could be explained by the partial effect of diets sourced from the  market. There are no studies in literature that have expressly differentiated diets by sources,  that is, subsistence and market pathways. This study evaluates the effect of farm production  diversity and food sourcing pathways on diet diversity using panel data collected from 808 respondents selected through multistage sampling in Kisii and Nyamira Counties, Kenya. The  two counties were selected based on the prevailing high malnutrition rates in the face of thriving agriculture. Data were analyzed through descriptive and inferential statistical methods  using Stata 14 software. The results from the study have been presented in the form of three  papers that are discussed hereafter. 

The first paper evaluates the impact of variety awareness and nutrition knowledge on the  adoption of KK15 bean variety which contains high levels of zinc and iron. The Average Treatment Effect (ATE) framework was applied to control for variety awareness and  knowledge of variety nutrition attributes among respondents.  

The results show that farmers who had knowledge of the nutrition attributes of KK15 beans  were more likely to adopt the variety. The potential adoption loss due to lack of knowledge of  the nutritional benefits was 8 percent. Adoption of biofortified crops can therefore be enhanced  if information on the nutrition characteristics of the varieties is widely disseminated in the  population.  

The second paper applies the Poisson model to evaluate the association between farm  production diversity and diet diversity at household and individual levels. The study findings  indicate that farm production diversity is significantly associated with the diet diversity of  women and that of the entire household, but not with the diet diversity of children. Animal  species diversity has the highest magnitude of association with dietary diversity in this study.  Every additional animal species kept leads to a 0.33 and 0.13 increase in household dietary  diversity and the dietary diversity of women respectively. Children’s diet diversity is associated  with household size and education of the mother. The study highlights the need to incorporate  individual dietary requirements in policy and nutrition interventions. 

The third paper also applies the Poisson model to examine the effect of different food sourcing  pathways on the household’s and individual’s diet diversity. In particular, the analysis focusses  on the dietary diversity from subsistence and the market. The findings show that farm  production diversity is positively associated with dietary diversity obtained from subsistence, 

but negatively associated with dietary diversity obtained from the market. The results  underscore the important role of markets for the diets of smallholder farmers, even in  subsistence-oriented settings, possibly because they are not able to produce enough food from  their small farms. Thus, while farm diversification is an important step towards nutrition,  improving market access for smallholders may deliver more benefits. 

 

Research Supervisors

Research Supervisors

Prof. Rose Nyikal

Seth Ooko Onyango

Degree Programme
PHD in Agricultural Economics
Research Topic:
Impact of choice and integration of tsetse fly and trypanosomiasis control methods on household income in Lamu County, Kenya.
Seth Ooko Onyango
Biography

Seth Ooko Onyango holds a BSc. Degree in Agricultural Economics and a MSc. Degree in Agricultural Economics both from Egerton University, Kenya. He is graduating with a PhD in Agricultural Economics from the University of Nairobi. 

He is currently serving as an Assistant Director of Livestock Production in the Ministry of Agriculture, Livestock, Fisheries and Cooperatives and head of Monitoring and Evaluation at the Kenya Tsetse and Trypanosomiasis Eradication Council (KENTTEC). 

His study looked at the Impact of choice and integration of tsetse fly and trypanosomiasis control methods on household income in Lamu County, Kenya. 

The research was funded by the National Research Fund (NRF) and the Kenya Tsetse and Trypanosomiasis Eradication Council. 

 

Abstract

Abstract

The farm households in Lamu County had participated in the control of tsetse flies and trypanosomiasis using insecticide treated livestock, insecticide treated targets and trypanocidal drugs. However, full uptake of the control methods had not been realized possibly due to how household characteristics, technological and institutional factors affected farmers’ decisions to adopt the control methods. Further, the impact of the control of tsetse flies and the disease on household income had not been estimated to aid resource mobilization for the control of tsetse flies in the vast infested areas of Kenya. The study applied quasi-experimental research design with treatment and control groups from a sample of 536 livestock rearing households in Lamu County. Analysis using a Multivariate Probit model revealed that household socio-economic characteristics and technological attributes were the major factors that influenced the choice of tsetse and trypanosomiasis control methods. The level of integration of the methods of tsetse control improved the herd structure of cattle and donkeys as a pathway to possible increase in household income. Endogenous Switching Regression results showed that the control of tsetse fly and trypanosomiasis in Lamu County had a positive impact on household income and that the effects of control varied depending on the method or combination of methods used. The study recommends that the national institutions and devolved units of government designs farmer outreach programs that take into consideration key household socio-economic characteristics as well as technological attributes which may stimulate up-take of appropriate technologies for increased household income hence poverty alleviation. National and county governments to prepare bankable proposals for resource mobilization to roll out the control of tsetse fly and trypanosomiasis in all the infested land areas of Kenya

BULLE HALLO DABASSO

Degree Programme
PHD in Range Management
Research Topic:
Analysis of stratified livestock production as an option for enhancing commercial off-take of pastoral cattle in Kenya’s drylands
Bulle Hallo Dabasso
Biography

Dabasso holds a BSc. degree in natural resource management from Egerton University, Kenya, a MSc. degree in natural resource management and sustainable agriculture from the Norwegian University of Life Sciences, and a Ph.D degree in range management from the University Nairobi. His Ph.D research, funded by the German Federal Ministry for Economic Cooperation and Development (BMZ), under the collaborative research project, ‘Reduction of Post-Harvest Losses and Value Addition in East African Food value chains’ (RELOAD), focuses on reducing losses in pastoral cattle value chains.

 

Dabasso currently work for the Kenya Agricultural and Livestock Research Organization as senior research officer. He research interest include; rangeland management, pastoralism and pastoral livelihoods. His research activities in the drylands of northern Kenya have immensely contributed to scientific knowledge and widely published in peer refereed journals.

Abstract

Abstract

Livestock production in Kenya accounts for 10–15 % of the country’s gross domestic product (GDP) and about 42% of the agricultural GDP. The production mainly occurs in pastoral areas, where approximately 70% of the national large ruminant herd is reared. The areas are characterized by high seasonal and inter-annual rainfall variability that influences pasture availability−during the dry season, the pasture is scarce and limited in nutrient concentrations. Consequently, animals become lean in the dry season and fall short of terminal markets’ quality requirements. A system that geographically stratifies livestock production so that breeding takes place in pastoral areas, followed by fattening in areas with better eco-climatic conditions and more grazing and water resources is a potential option for ensuring lean animals from drylands meet the quality requirements of terminal markets. This livestock production approach is re-emerging in Kenya’s drylands despite its discontinuation in 1970s, but its potential in adding value to pastoral cattle and thus enhance their commercial off-take, has not been comprehensively analysed. Against this background, this thesis analysis the existing stratified livestock production (SCP) system as an option enhance sale of pastoral cattle in Kenya’s drylands. Narrative interviews were conducted with thirty-four (34) purposively selected respondents. Cattle fattening performance and profitability were done by collecting data on animal weights at purchase and at sale points, costs of purchase and fattening, the cattle selling prices. Requirements for pastoralists to use the production system as marketing avenue were investigated.

The results revealed three forms of SCP practised by ranchers, by traders, and by agro-pastoralists, which differed with respect to access to grazing resources, herd size, and fattening period. Fattened animals had average daily weight gain of 0.24 ± 0.07kg (n = 601), 0.39 ± 0.13kg (n = 240), 0.24 ± 0.08kg (n = 140) under the SCP by ranchers, traders and agro-pastoralists, respectively. On average, the practitioners earned USD 61.7 ± 34.2 (ranchers), USD 81.3 ± 44.0 (traders), and USD 55.9 ± 36.6 (agro-pastoralists) as net revenues after selling the animals. Under the SCP systems practiced by traders and ranchers, pastoralists were required to sell 3-4 year bulls or steers of Borana or Sahiwal breed in secondary markets or near urban centres, use sale agents to ensure the traceability of the animals whenever necessary, and comply with unpredictable supply orders. In response to these requirements, the pastoralists were slowly changing their animal husbandry practices to produce the required type of animals, keeping “emergency” animals in the home-based herds to target the unpredictable market demands, arranging with sale agents to sell in the secondary markets, and establishing buyer-seller trust.

The study concludes that different forms of SCP, with varying management practices, exist in Kenya’s drylands. The forms of SCP are economically attractive to the practitioners, and appealing to the pastoralists as they are integrating their production and marketing practices to meet the requirements of using the system as a marketing channel. The study recommends promoting and strengthening SLP in Kenya’s drylands by addressing the existing challenges. This study did not determine the type of cattle (in terms of genetic make-up, age, sex, and body condition) that had the highest weight gain and returns under the SCP systems, and therefore, further research that fills this gap is recommended

Important Links

Research Supervisors

Research Supervisors
  1. Dr. Oliver Wasonga
  2. Dr. Patrick Irungu
  3. Prof. Brigitte Kaufmann

SHADRACK OTIENO NYAWADE

Degree Programme
PHD in Soil Science
Research Topic:
Diversification of potato farming systems through legume intercropping for improved resource use efficiency
Shadrack Nyawade
Biography

Shadrack Nyawade is a specialist in Soil and Water Resource Management with several years of experience in on-farm research, and is currently working for the International Potato Center (CIP) as a Research Associate tasked with designing and monitoring sustainable soil and water conservation practices. He holds BSc in Range Management, MSc in Land and Water Management and PhD in Soil Science (a graduand), both from the University of Nairobi, Kenya. Shadrack has a wide range of publications in high impact journals. In his career, Shadrack has been a visiting scholar in Austria, Germany, UK, Sweden and South Africa. He has learned and applied both qualitative and quantitative methodologies that combine field trial and case study analysis, with fuzzy-set qualitative comparative analysis. He is a fluent and passionate team builder who is self-driven and adaptable to new undertakings. Shadrack is a public motivational speaker who has changed lives of many young innovators

Abstract

Abstract

Expanding production of potato to the midlands and lowlands of Kenya is only possible if the effect of water deficit, high temperatures and nutrient limitation on potato growth is well understood. Potato (Solanum tuberosum L.) was grown singly and intercropped with lima bean (Phaseolus lunatus L.) or dolichos (Lablab purpureus L.), and the respective single crop of the legumes in three agro-ecological zones (AEZs) of Kenya; upper-midland (1552 meters above sea level (masl), lower-highland (1894 masl) and upper-highland (2552 masl). The objectives were to i) determine the interrelationships between soil water balance, soil temperatures and crop nutrient (NPK) uptake under potato-legume intercropping ii) assess the short-term effect of potato-legume intercropping on dynamics of microbial activity and SOM fractions, iii) evaluate the effect of potato-legume intercropping on soil nitrogen balance and iv) quantify the radiation and crop water productivity of potato-legume intercropping system. Intercropping increased SWC by up to 38%, thus increasing RUE by 56–78%, CWP by 45–67% and nutrient use efficiency by 4067%. Compared with the sole potato, intercropping increased the contents of labile fraction organic matter by 12–28% and microbial biomass by 15–38%. The residue mixture of potato and legume intercrops enhanced N mineralization with peak N release of 5 to 9 kg N ha-1 occurring within 8 to 10 weeks of residue decomposition. This period coincided with the peak N uptake by potato (19.9 to 31.2 kg N ha-1) thus showing a close synchrony of N supply and potato N demand.

Important Links

Research Supervisors

Research Supervisors
  1. Professor Nancy Karanja
  2. Professor Charles Gachene
  3. Dr Monica Lyn Parker