Master Graduands 2020

Thuku Linet Njeri

Degree Programme
Master of Science in Applied Human Nutrition
Research Topic:
Role of kitchen gardens in diversifying diets among semi-arid inhabitants of Igamba Ngombe in Tharaka Nithi county, Kenya
Thuku Linet Njeri
Biography

Thuku Linet Njeri is a nutritionist by profession with a BSc in Food science Nutrition and Dietetics and an MSc in Applied Human Nutrition both from the University of Nairobi. She is registered with the Kenya Nutritionist and Dietetics Institute a regulatory body of nutritionists and dieticians in Kenya.

She is highly self-driven and can work well in a team set-up. With the knowledge acquired from the University, she endeavors to be of help to the local and global community.

Abstract

Abstract

Achieving dietary diversity in Arid and Semi-Arid lands is a big challenge due to the weather patterns experienced in this climatic zone. The low amounts of rainfall and high temperature levels negatively affect food production as well as livestock in these areas. Kitchen gardens are known to directly improve food security at household levels by ensuring access to nutritious and diversified foods; information on the role they play in Arid and Semi-arid lands is scanty. A comparative study was conducted between August and September 2019 to determine dietary diversity among 98 practicing and 221 non-practicing households. Data entry and analysis were performed using Statistical Package for Social Sciences (SPSS) version 20 and Microsoft excel. Results showed that kitchen garden practicing and non-practicing households had similar characteristics in age, sex, main occupation, and type of contribution to household (p >0.05) but differed significantly (p <0.05) in level of education and gender of the household head. The study showed significant difference (p<0.05) in the dietary diversity scores between the two groups. Kitchen gardening practicing households had a more diversified diet compared to the non-practicing households. This could be contributed by the fact that all the households that practiced kitchen gardening had planted more than one type of vegetable while majority of the participants, 71%, had more than two types of vegetables. Out of all the four indicators of sustainability used in the study, source of water was the biggest setback faced. In conclusion, kitchen gardens have an influence on dietary diversity of households.

Research Supervisors

Research Supervisors

Professor Wambui Kogi-Makau

Dr George Abong

Abdirizack Aftin Hussein

Degree Programme
Master of Science in Food Safety and Quality
Research Topic:
CONSUMPTION PATTERNS, QUALITY CHARACTERISTICS AND ACRYLAMIDE CONTENT OF BREAD COMMERCIALLY TRADED IN NAIROBI, KENYA
Abdirizack Aftin Hussein
Biography

Abdirizack Aftin Hussein has been working at Kenya Bureau of standards as a market Surveillance officer since 2017. He received his undergraduate degree From Jomo Kenyatta University of Agriculture and Technology in June 2016. Abdirizack Currently lives in Nairobi and enjoys travelling, making new friends  and Reading.

Abstract

Abstract

Bread consumption in Kenya has recently been on the rise especially in urban and peri-urban areas. This trend is influenced by consumption patterns and the purchasing power of bread consumers. The current study sought to assess bread consumption patterns, quality and safety of bread in Nairobi, Kenya. The study employed a combination of field study and laboratory analysis of bread samples traded in the urban supermarkets in Nairobi County.

Results indicated that majority of bread consumers are the middle aged group and two thirds of them consumed bread daily. Urban consumption of bread in Nairobi reported an increasing trend. The logit model revealed gender as a significant (p<0.001, R2=0.426) predictor factor of the trends of consumption of bread in the urban area whereby the males were less likely (odds 0.143) than the females to increase their intake of bread.

The investigation of physicochemical and microbiological characteristics of bread sold in supermarkets along Nairobi business district revealed that brown bread had significantly (p<0.001) higher moisture and water activity, however, the fibre and total solids in the brown bread were significantly (p<0.01) lower than the white bread. The highest variability was found in acid insoluble ash. Acrylamide content was within the required levels. Additionally, the bread samples were found to be free of yeasts and moulds. In conclusion, bread consumption is on the rise and quality and safety of the bread is compromised exposing consumers to health risks. However, there is need to increase the surveillance on the bread due to the trading of bread in sub-optimal physico-chemical quality, less optimal than the stipulation in the national standards, in these retail stores.

Important Links

Research Supervisors

Research Supervisors
  1. Dr. George O. Abong’ 
  2. Prof. Michael W. Okoth 

STEPHEN KIMANI NJOROGE

Degree Programme
Master of Science in Food Safety and Quality
Research Topic:
Effect of dairy farming practices on intake of antibiotic residues in milk consumed in Kiambu County, Kenya
STEPHEN KIMANI NJOROGE

Abstract

Abstract

 

The current study evaluated dairy practices that compromise milk quality and safety along the dairy supply chain. The main risk factor being antibiotics residue in raw milk consumed in Kiambu County. A cross-sectional survey was conducted using a structured questionnaire to determine the suitability of milk equipment, storage of milk, health management and animal treatment at farms, the level of knowledge of risks associated with antibiotics residue in milk, and farm management. Raw milk samples were also collected and analyzed to determine the levels of antibiotic residues.  

The results showed that small scale farmers keep 2 to 3 cows, which accounted for 98% of the respondents. The record management at the farm level was done by less than 40% of the respondents. Hygiene and poor storage highly contributed to milk rejection, as reported by 97% of the respondents. The buyers lacked testing gargets for determining contaminants such as antibiotics and preservatives. According to the present study, brokers who accounted for 14% of the respondents play a significant role in milk vending in the sub-urban centers in Thika town, Ruiru town, and Nairobi. The use of health records was not a priority among the farmers, coupled with irregular withdrawal periods ranging from 48 hours to 72 hours.

Additionally, the present study found the presence of antibiotics in raw milk. Among the samples, 10 % tested beta-lactam positive on screening through the rapid test; namely: Gatei 11.7%, Gatundu 6%, and Kiganjo 12.1%. Consequently, eight derivatives were quantified and identified as follows: Ampicillin 0.007±0.0 µg/ml, Amoxicillin 0.02±0.022 µg/ml, and Penicillin G 0.016±0.017 µg/ml were above 0.004µg/ml recommended MRLs. However, Cloxacillin (0.008±0.004 µg/ml), Dicloxacillin (0.007±0.0 µg/ml), Nafcillin (0.010±0.004 µg/ml), Oxacillin (0.009±0.0.002 µg/ml), and Phenoxymethyl-penicillin (0.009±0.005 µg/ml) were below 0.030µg/ml recommended MRLs. The exposure assessment for the antibiotic residues, revealed that consumer under the study were safe, having ADI below the set standard by Codex. The levels of antibiotics residues quantified, including ampicillin, amoxicillin, and penicillin G were above the Codex standards maximum recommended levels, hence posing a food safety risk to the consumer. The study concluded that the prevalence of antibiotic residues in raw milk is 10%; this poses a high food safety risks to the milk consumers. Inappropriate dairy farming practices on food safety have heightened the situation. The creation of food safety awareness and improvement in dairy practices can mitigate the situation.

 

Research Supervisors

Research Supervisors

PROF. MICHAEL W. OKOTH

DR. LUCY NJUE

JUDITH KATUMBI NDEME

Degree Programme
MSc Food Safety and Quality
Research Topic:
Harvesting, postharvest handling and the Physicochemical changes during storage of guavas in two Counties of Kenya.
JUDITH KATUMBI NDEME
Biography

Judith Katumbi Ndeme (MSc. Food Safety and Quality), BSc. Food Science and Technology (University of Nairobi), 2018. Judith comes from Makueni County. Her MSc. Research focused on postharvest management of guava fruit in Kitui and Taita Taveta counties, Kenya. Currently, she works with the Ministry of Education under the state department of Technical and vocational education and Training (TVET). She aspires to grow as an academia focusing on research, University and college training/ lecturing. Additionally, she is looking forward to becoming a Food safety and quality lead consultant.

Abstract

Abstract

The guava (Psidium guajava) fruit is highly nutritious and common in almost all ecological regions in Kenya. The fruit suffers huge losses attributed to the low consumption and marketability as it neglected by farmers and consumers. Standard postharvest handling, storage and marketing are not practiced and most of it is left to rot in the farm. The current findings indicate that guava harvesting practices are substandard and skin colour was the main maturity index in Kitui and Taita Taveta, 98.6% and 92.1% respectively. There was no organized storage and packaging of guavas as farmers harvested just enough for household consumption hence no bulk handling of the fruit. A cluster analysis of hygiene knowledge of farmers revealed that Kitui farmers had higher knowledge scores (71.9%) as compared to those from Taita Taveta (49.8%). Lack of postharvest handling practices has contributed to the huge guava losses incurred in Kenya.

The effect of storage conditions on the physicochemical changes of guava during storage was evaluated by analysing changes in moisture, weight, beta carotene, ascorbic acid, total soluble solids, total titratable acidity and pH as influenced by storage factors specifically washing, modified atmosphere packaging and temperature. Temperature of storage significantly (p<0.05) accelerated the rate of physicochemical changes of the net bags as compared to modified atmosphere. Fruits stored at 20-25℃ and 28-30℃ recorded the higher change in weight loss, moisture content, vitamin C and beta carotene as compared to those at 8-10℃. The study concluded that storage at 8-10℃ afforded the fruits a shelf life of 11 days. Modified atmosphere packages best lowered the rate of deterioration based on the changes in ascorbic acid, beta carotene. Guava shelf life can be extended Best storage is obtained by storing in modified atmosphere packaging at 8-10℃.

 

Research Supervisors

Research Supervisors
  1. Prof. Jasper K. Imungi
  2. Dr. George Ooko Abong’
  3. Prof. Charles Gachuiri

Ann Karimi Murithi

Degree Programme
Master of Science in Plant breeding
Research Topic:
MAPPING AND VALIDATION OF MAJOR QUANTITATIVE TRAIT LOCI (QTL) FOR MAIZE LETHAL NECROSIS (MLN) RESISTANCE IN MAIZE
Ann Karimi Murithi
Biography

I am plant breeding and biotechnology student. My thesis research goal was to identify genomic regions associated with Maize Lethal Necrosis (MLN). My work was able to identify candidate genes that are potentially associated with resistance to this disease. This project was done at CIMMYT. Previously, I did my undergraduate, Bsc. Biochemistry, at Kenyatta University. 

My career objectives are to be part of a system that is involved in identification of novel genes important for improvement of crop production while utilizing both new and novel genomic tools. 

Currently, I am enrolled as a Ph.D. student at Iowa State University (ISU), where I am working under MLN gene editing program, sponsored by CIMMYT

 

Abstract

Abstract

Maize lethal necrosis (MLN) is a viral disease caused by dual infection of two viruses Maize chlorotic mottle virus and Sugarcane mosaic virus resulting in devastating effects on maize production. Maize is susceptible to MLN from the seedling stage to maturity, and the management and control of the disease is costly to smallholder farmers. Development of host plant resistance will be an effective method of MLN control. Little is known about the causal genes and molecular mechanisms underlying the resistance. To identify genetic loci associated with MLN resistance, two independent sets of mapping populations were developed. From a set five F2 bi-parental mapping populations, the most resistant and most susceptible individuals were genotyped and marker-trait association analysis was performed through Genome Wide Association Study. GWAS revealed a major effect QTL on chromosome 6 (qMLN_06.157) that was significantly associated (P < 1 X 10-8) with MLN resistance. While using seven independent segregating populations, the favourable allele from KS23 at qMLN_06.157 was validated and fine-mapped to a 0.4cM interval. Candidate gene analysis using maize reference genome, B73, revealed a eukaryotic transcription initiation factor (elF) in this interval. elFs have previously been shown to be involved in plant viral resistance. Eight SNPs within/adjacent to the target window have been identified which co-segregate with MLN. This study provides important insights into the genetic architecture underlying resistance to MLN, establishes a tenable target for gene editing in GRMZM2G073535, and presents a useful set of polymorphic SNPs to be used in breeding for MLN resistance.  

 

Research Supervisors

Research Supervisors

 

University Supervisors:

Prof. Kahiu Ngugi

Dr. Evans Nyaboga

External Supervisor:

Dr. Michael S. Olsen

CAROLYNE WAMBUI NGURE

Degree Programme
MSc Plant Pathology
Research Topic:
Effectiveness of Density Sorting in Reducing Aflatoxin B1 and Fumonisins in Maize Grains
CAROLYNE WAMBUI NGURE
Biography

Ngure Carolyne is a Kenyan born scientist with key specialization in plant pathology and biotechnology. Over the past 5 years, she has worked professionally both in the public and private sector. Currently, she is attached to Kenya Plant Health Inspectorate Services (KEPHIS) on a temporary basis.

Carolyne is set to earn her MSc. in Plant Pathology on the 11th of December 2020. Having come from a background of academicians, she has consistently worked towards achieving great academic heights despite all odds of balancing between work and family and financing part of the research work. 

She is a very hardworking and resilient person, with great determination to achieve the tasks set before her. 

Her goal is to achieve the highest academic level that one can achieve and offer solutions to the community especially in the area of plant disease diagnosis, prevention and management as well as enhancing food safety. 

Abstract

Abstract

Mycotoxins such as aflatoxins and fumonisins are prevalent contaminants of maize, which is a major staple food in Kenya. Aspergillus flavus, Aspergillus parasiticus and Fusarium verticilloides are the major producers of carcinogenic aflatoxins and fumonisins respectively. Currently there are no effective methods of decontaminating grains and whole consignments have to be destroyed. This study sought to determine the effectiveness of density sorting in reducing aflatoxin B1, fumonisins, Aspergillus spp. and Fusarium spp. populations in maize grains. 

Samples (n=206) were collected during the 2017 harvest crop from markets in eight counties in Western and Nyanza regions of Kenya. Sample numbers differed across counties ranging from 10-30 per county. All samples were analyzed for mycotoxins using an ELISA assay. Ten samples with more than 50 ppb of aflatoxin B1 and 4 ppm of fumonisins were weighed into 300 g with two replicates and sorted using a density sorter into heavy and light fractions constituting 65-75% and 25-35% of the original weight respectively. The effectiveness of density sorting in reducing mycotoxin-producing fungi was determined by isolation from 20 samples of the unsorted and 80 samples of the sorted heavy and light fractions.

Mycotoxin-producing fungi isolated from unsorted and sorted samples were Aspergillus spp., Fusarium spp. and Penicillium spp.  Prevalence of Aspergillus flavus was higher in 93% of the samples followed by Penicillium. at 85% and Fusarium verticilloides at 67%. Density sorting reduced fumonisins in 100% of the samples with an average of 71% reduction and aflatoxin B1 in 50% of the samples while the levels increased in the rest of the samples averaging the percentage change at -12.8%.

Density sorting can be used to reduce fumonisins and aflatoxin B1 effectively in maize grain but had no effect on mycotoxin-producing fungi. The density sorter machine should be improved for large scale use at a commercial level.

 

Research Supervisors

Research Supervisors

Prof. James   W. Muthomi

Prof. Rebecca J.  Nelson

 

Arnet Nyambura Kuria

Degree Programme
Master of Science in Plant breeding and biotechnology
Research Topic:
Imagery phenotyping and mapping quantitative trait loci for northern leaf blight (NLB) resistance in maize
Arnet Nyambura Kuria
Biography

Arnet Nyambura Kuria was born on May 30th 1988 in Embu County.  She attended her O levels at Kigari Secondary School where she attained a K.C.S.E certificate. Later in the year 2008, she attended Paramilitary training at The National Youth Service where she also underwent a Diploma course in general agriculture at Yatta School of Agriculture. After completion of the diploma course in 2012 she worked at KALRO Embu under maize breeding program for one year. 

In 2013 she enrolled for her undergraduate course; BSc. Agriculture at Kenya Methodist University. In the year 2015 September, she enrolled for a Master’s Degree in Plant Breeding and Biotechnology at the University of Nairobi.

Abstract

Abstract

Northern leaf blight (NLB) is a major foliar disease caused by fungus Exserohilum turcicum that leads to limited production of cereals in the Sub-Saharan Africa. The disease lowers production of maize up to 80%, threatening food security in the region. Currently, new technologies have been incorporated where digital imagery tools are used for detecting foliar diseases in the field earlier enough before the severity is high. To curb this major problem of foliar diseases in maize quantitative trait loci (QTL) mapping is recommended and adopted to assist as an effective and efficient tool in breeding to generate resistant host plants. This study was implemented to; i) compare the visual scoring method of phenotyping foliar diseases with the digital imagery methodology ii) Identifying the genomic regions associated with resistance to Northern leaf blight disease through quantitative trait loci mapping. Data was collected where the disease severity was scored using a CIMMYT scoring scale. All data collected was analyzed using Meta-R software. It was concluded from the studies that digital imagery analysis led to more efficient and effective breeding. To identify genomic loci associated with NLB resistance, double haploid (DH) lines from two bi-parental mapping populations were genotyped and marker trait association analysis carried out. Genome-Wide Association Study (GWAS) revealed a major quantitative trait locus (QTL) on chromosome 5 and chromosome 7 that were significantly associated with NLB resistance. This study provides important insights into the genetic architecture underlying resistance to NLB.

 

Research Supervisors

Research Supervisors

Dr. Felister Nzuve

Dr.Douglas Miano

Dr.Gowda Manje

 

Rachael Wambui Wachira

Degree Programme
MSc Plant Pathology
Research Topic:
Effect of Soil Amendment with Biochar.Lime and Compost on Soil Acidity and Root Rot in Common Bean (Phasolus vulgaris L.) in Western Kenya
 Rachael Wambui Wachira
Biography

Rachael Wachira is a degree holder of Bachelor of Science in Microbiology and Biotechnology in the University of Nairobi where she attained First Class Honors.  She enrolled for her Master of Science in Plant Pathology in September 2017 at the College of Agriculture and Veterinary Sciences in University of Nairobi and is a beneficiary of Gandhi Smarak Nidhi Scholarship for the academic year 2017/2018 and 2018/2019. Her project work was funded by the McKnight Foundation through KALRO-Kibos. She is an aspiring research scientist in mycology and is currently working as a research assistant in the Efficacy Unit co-ordinated by Professor Eunice Mutitu in the University of Nairobi. Rachael Wachira is thrilled to graduate with a Masters degree on 11th December 2020.

Abstract

Abstract

 

Root rot complex is a major biotic constraint to bean productivity in Western Kenya caused by synergistic associations of different soil borne fungal pathogens. It is aggravated by infestations of bean stem maggot and is severe in acidic soils whose fertility is low. The disease causes poor seedling emergence, low plant establishment and yield losses of up to 70%. Management of root rot by seed dressing with fungicides has a short-lived effect of two to three weeks after sowing while disease tolerant varieties are few. Thus, the study evaluated the effect of biochar, lime, compost and DAP as soil amendments on soil acidity and bean root rot. Field experiments were conducted in farms whose soil pH was less than 5.5 at Nandi South within Kapkerer, Kiptaruswo and Koibem characterized as low, medium and high soil fertility sites respectively. The treatments used were biochar, lime, compost, diammonium phosphate and their combinations and were laid out in a Randomized Complete Block Design. The field experiment was carried out during the short rains of 2018 with a repeat in the long rains of 2019. Biochar, compost, lime and diammonium phosphate were applied at rates of 1t/ha, 2t/ha, 2t/ha and 67kg/ha respectively. Soil samples were analyzed for pH, nutrient content and quantification of root rot pathogens. Bean root rot, stem maggot incidences and plant mortality were assessed at two, four and six weeks after emergence and expressed into percentages while yield and yield components were assessed at physiological maturity. Combined application of biochar, lime, compost and DAP had significantly higher effects than their sole application on soil acidity and bean root rot. Sole application of lime, two-way combination of biochar with lime and three-way combination of biochar with lime and compost, significantly (p≤0.05) soil pH by 0.6 to 0.8 units. Prevalent root rot pathogens isolated from soil were Rhizoctonia solani, Fusarium oxysporum and Fusarium solani. The effect of the amendments 5 on population of root rot pathogens, varied per pathogen. Both an increase and a decrease in population of Rhizoctonia solani was noted among the treatments. All the treatments had significantly (p≤0.05) higher population of F. oxysporum and lower population of F. solani compared to non-amended soils. In both seasons, non-amended plots had significantly higher percentage plant emergence and stand counts than amended plots. This effect was mostly noted in treatments containing DAP. The effect of the treatments on plant mortality varied in season whereby, the treatments had significantly higher plant mortality in the short rains of 2018 and significantly low plant mortality in the long rains of 2019. In both seasons, most of the treatments had significantly reduced incidence of bean root rot by 52% to 77% compared to non-amended soils. This was noted in treatments of lime, biochar +lime, biochar +lime+ DAP and biochar + lime + compost, biochar + compost +lime + DAP, lime + DAP and biochar + DAP. Incidences of bean stem maggot were significantly (P≤0.05) reduced in application of biochar + compost +lime + DAP, biochar + lime and biochar + compost by 52% to 77%. Application of biochar + lime+ compost resulted in a significant increase on biomass by up to 30% while application of biochar + lime+ DAP significantly increased the number of pods per plant and seeds per pod by 63 and 77% respectively. Additionally, application of biochar + lime, biochar + lime +DAP and biochar + lime +compost significantly increased grain yield by 204%, 201% and 217% respectively. The study shows that the effect of biochar, lime and compost on soil acidity and bean root rot varied in combination. Application of biochar with lime and biochar with lime and compost reduced soil acidity. Combining biochar, lime or compost with an inorganic fertilizer reduces bean root rot and increases grain yield in acidic soils. Therefore, biochar, lime and compost can be used as liming amendments in acidic soils and combined with an inorganic fertilizer to improve bean productivity. 

Key words: Amendments, biochar, compost, lime, root rot, soil acidity

Research Supervisors

Research Supervisors

Prof. James W. Muthomi

Prof. John H. Nderitu

Dr. James Ojiem 

Gladwell Mwemba Mwasi

Degree Programme
Masters of Science in Agricultural Resource Management
Research Topic:
CONTRIBUTION OF LIVESTOCK TO THE LIVELIHOODS OF URBAN AND PERI-URBAN HOUSEHOLDS IN EMBAKASI CONSTITUENCY, NAIROBI COUNTY
Gladwell Mwemba Mwasi
Biography

Gladwell Mwasi works as the Chief Livestock Production Officer at Nairobi County, Kenya deployed at Embakasi Central and North Sub Counties. She also served as Livestock Production Officer in the Department of Livestock Production, Ministry of Agriculture, Livestock and Fisheries from 2009 to 2013.

Gladwell Mwasi completed her primary school Education at Mwakuni Primary School in 1997 and later joined Bura Girls High School, where she completed in 2001. She graduated from the University of Nairobi with a Bachelor of Science Degree in Agricultural Education and Extension. She also holds a certificate in Agricultural Marketing Management from the National Institute of Agricultural Management (NIAM) JAIPUR.

She is an experienced agricultural education expert, researcher and trainer of trainers. Her interests lies in sustainable agriculture, food security, resource mobilization, resource management and strategic planning.

Gladwell Mwasi was born in Taita/Taveta County on 8th December, 1983. She is married to Henry Chigwado and a loving Mother to Kevin, Maxwell and Larry. Her hobbies include playing volleyball and reading.

 

Abstract

Abstract

Urban Livestock keeping contributes to food security, income generation, employment creation, insurance and improved social status. Despite the above benefits, rapid urbanization and high population has led to high rates of urban food insecurity and malnutrition. Thus, a study was conducted to evaluate the contribution of livestock production to the livelihood of urban and peri urban households in Embakasi Constituency, Nairobi County. The objectives of the study were to assess the influence of livestock farming on the livelihood of the respondents, the institutional influence on livestock production and challenges faced by respondents in Embakasi constituency. The study targeted 780 livestock keeping households, of which, a sample size of 160 respondents was purposefully sampled. Structured questionnaire was used to collect primary and secondary data analysed using SPSS version 20. The results showed 47.5% of the household heads were aged between 36 and 50 years, 22.5% had acquired post-secondary education, though 87.5% were not in formal employment. 30% of respondents kept chicken and 25% cattle. 45% respondents sold their produce at the farm-gate and roadside stores, while 88% faced challenges in accessing feed. The age of the farmer and leadership of the household influencing livestock keeping technology adoption reflected a correlation of (r=0.74) and (r=0.80) respectively. In conclusion, respondents kept livestock in Embakasi constituency for example; cattle, poultry, pigs, rabbits and shoats. The study recommends that county government should improve provision of extension services and feed accessibility for future increased production and thus access to safe animal products.

Research Supervisors

Research Supervisors

Prof. Joseph O. Njung’a

Department of Animal Production, University of Nairobi

 

Prof. Paul N. Mbugua

Department of Animal Production, University of Nairobi

 

Dr. Josiah M. Kinama

Department of Plant Science and Crop Protection, University of Nairobi

 

OTIENO VICTOR ODHIAMBO

Degree Programme
Master of Science in Seed technology and business management
Research Topic:
Conditions for optimum germination of Sprawling bauhinia seed (Tylosema fassoglense)
OTIENO VICTOR ODHIAMBO
Biography

After earning my degree in Biochemistry and Chemistry from the University of Nairobi, I entered the research world to explore my passion for research and management. Over 10 years, I have worked on various donor funded projects collaborating with stakeholders in conservation and sustainable use of Forest Genetic Resources (FGR). In addition to project management, I write research concepts, technical reports and publication and design experiments. As seed research scientist, I backstop research activities at KEFRI besides consultancy in seed analyses.

Abstract

Abstract

Understanding seed biology and germination ecology of plants is critical for domestication of neglected and underutilized species (NUS). However, this information is not readily available for Tylosema fassoglense [Family: Fabaceae]; despite its potential as a future crop. The main objective of this study was to evaluate the germination requirements of three lots (sourced from Busia, Migori and Siaya) of T. fassoglense by determining dormancy type, the effects of light, temperature and water potential as well as correlations amongst seed traits. Scarification significantly (p<0.05) improved water uptake by 4 to 22 times as well as germination from between 30-70% to 90-100%. The relative light germination index (RLG) ranged from 0.46 to 0.57. Germination was significantly (p<0.05) reduced at 10°C and 40°C whilst germination was 0% at 45 °C. The calculated base, optimum and ceiling temperatures (Tb, To and Tc; 50th percentile) ranges were 4.05-8.0 °C, 33.61-35.75 °C and 46.54-47.24 °C respectively while thermal time (θT(50)) suboptimal ranged from 76.19 to 89.02 degree Celsius days (°C d). Low water potential of -0.5 MPa significantly (p<0.05) reduced final germination to less than 50% while germination was 0% at both -1.0 and -1.5 MPa. The base water potential (Ψb) and hydro time (θH(20)) ranges was -0.92 to -0.97 MPa and 3.95-4.11 Megapascal days (MPad) respectively. Negatively significant (p<0.05) correlations were observed between Tb and θT; Ψb and θT while non-significant correlations were observed between germination and physical traits. Scarification improved water imbibition as well as final germination percentage and seeds of T. fassoglense are probably neutral photoblastic. The optimum temperature range for germination was 30-35 °C while seed germination was tolerant to low water potential up to -0.5 MPa. The findings of this study will be useful in future research contributing towards the domestication of T. fassoglenseas a future crop to enhance a sustainable agriculture and nutrition in Kenya and potentially worldwide.

Research Supervisors

Research Supervisors

Dr. Felister M. Nzuve, Prof. John W. Kimenju, Dr. Tiziana Ulian