Research Publications

Permanent URI for this communityhttp://172.16.31.117:4000/handle/123456789/55

Browse

Now showing 1 - 20 of 256

Screening for host plant resistance to Helicoverpa armigera (Lepidoptera: Noctuidae) in selected chickpea (Cicer arientinum L.) genotypes in Kenya
(24-04) Ruttoh, E. K; Mulwa, R.M.S; Ngode, L; Gohole, L; Towett, B.; Njogu, N. Silim; Kimurto, P. K.
Helicoverpa armigera is a major pest on the chickpea (Cicer arientinum) world. In Kenya, it causes up to 80% yield losses of the crop. Control measures include application of pesticides and cultural methods which have become less feasible due to their associated costs. Host plant resistance can offer long-term benefits in managing this pest. The objective of this study was to screen and identify chickpea genotypes that are tolerant to Helicoverpa armigera infestation under field conditions. Thirty chickpea genotypes were screened at Agricultural Training Centre, Koibatek under field conditions for two seasons in RCBD design in 3 replicates. Data on larval densities, percent pod damage, and amount of leaf consumed were transformed using angular transformation and then subjected to ANOVA, while treatment means separated using Duncan’s Multiple Range Test at P≤0.05. Correlation analysis between larval densities, yield and yield components was done using Genstat 12. The genotypes were classified into various categories of resistance and susceptibility on a visual leaf damage rating scale of 1-9. The results showed that there was significant variation in larval densities among the genotypes. At vegetative stage, mean larval densities ranged from 0.15 to 1.2 Genotypes EC583250 and EC583264 had lowest larval densities while ICC4973 and ICC3137 had highest densities. Larval densities increased from 0.3 to 1.97 during flowering stage. The larvae population increased drastically to a mean of 3.58 at podding. Genotype EC583260 had the least larval density of 2.2. The genotypes, EC583318, EC583250, EC583260 and EC583264 were least infested by the larvae with percent pod damage ranged from 3% on EC583264 with high yields while ICC3137 had highest pod damage of 20.2%. EC583260 was found to be low yielding (1051kg ha-1) while ICC4958 was the high yielding Egerton J. Sci. & Technol. Volume 13: 39-55 ISSN No. 2073 - 8277 (2205kg ha-1). Genotypes EC58318, ICCV10, ICC14831, EC583260, EC583264, and EC583250 had high resistance and could be exploited to chickpea breeding programmes as source to resitance.
Electronic document delivery for supporting agricultural esearch in Kenya: the experience of egerton university library
(Journal of Information Management, 2002) Ongus, Raymond Wafula; Nyamboga, Constantine Matoke
Digitizing a research library: Egerton University- Kenya
(Journal of Information Management, 2004) Ongus, Raymond W.; Nyamboga, Constantine M.
Experiences in the Use of the Internet at Egerton University Library, Njoro-Kenya
(Bulletin of Information Technology, 2004) Nyamboga, Constantine Matoke; Ongondo, Millicent A.; Ongus, Raymond Wafula
Plant Regeneration via Somatic Embryogenesis from Leaf and Floral Explants of ‘Chancellor’ Wine Grape
(Egerton University, 2006) Mulwa, Richard M.S.; Norton, Margaret M.A.; Skirvin, Robert M.
Abundant embryogenic callus was obtained from leaf and floral explants of ʺChancellorʺ grape by continuous culture for 12 weeks on Nitsch and Nitsch basal medium supplemented with 9 μM 2, 4‐D + 17 μM IASP + either 1 μM BA or 1 μM TDZ (ECIM) in darkness. They were successfully maintained by a five to six week subculture interval on NN medium containing 2 μM 2, 4‐D + 0.2 μM TDZ + 4 μM IASP (LTMM). Near synchronous embryo developed from embryogenic callus on medium containing 10 μM IASP + 8 μM NOA + 1 μM TDZ + 1 μM ABA + 2.5 g/l AC (EDMM). Individually separated somatic embryos were germinated on both NN and half strength of MS containing 0.5 μM BA + 0.025 μM NAA, respectively; normal plantlet conversion from embryos was low (35%). Whole fruiting plants were obtained. Aberrant embryo development was characterized by failure to form functional shoot meristems following the initial cotyledon expansion during germination. These observations indicate that the embryo conversion stage of the regeneration is difficult and remains a limiting factor requiring more empirical experimentation for improvement in grape tissue culture.
Biotechnology approaches to developing herbicide tolerance/selectivity in crops
(Egerton University, 2006-01) Mulwa, Richard M.S; Mwanza, Lydia M.
Effective weed control in any crop production system is a prerequisite if high yields and good quality are to be achieved. Over the millennia that humans have practiced crop agriculture, weed control has been the most significant part of cropping operations in ensuring good quality harvests. Initially, hand weeding dominated most weeding practices but it was gradually replaced with mechanical control in the developed world. Mechanical weed control practices are now viewed to be unsatisfactory due to the high-energy requirements and other associated costs, plus the perceived facilitation of soil erosion and compaction. Mechanical weed control has now been largely replaced by chemical weed control using herbicides that can eliminate weeds from crop plantings with minimal soil disturbance. Herbicide treatment in crop plantings has allowed economically viable weed control and increased productivity. The most preferred herbicides today are those that combine weed killing potency with low- or no- environmental persistence. However, the very effective broad spectrum herbicides available also lack selectivity, thus limiting their use in some cropping operations. On the other hand, the continuous use of the few available selective herbicides is speeding up the development of herbicide resistance in weeds; hence making it difficult to achieve effective control in some crops. Herbicides generally function by disrupting unique and essential processes in plants e.g. photosynthesis, mitosis, pigment biosynthesis or essential amino acid biosynthesis. Both crops and weeds share these processes. Consequently, at present, selectivity is mostly based on differential herbicide uptake between weeds and crops, controlled timing and site of application or rapid detoxification of the herbicide by the crop plants. Reliance on these natural selective processes limits the effective use of potent herbicides; hence mechanisms to impart better herbicide selectivity in crops need to be investigated.
In vitro plant regeneration from immature cotyledon explants of macadamia (Macadamia tetraphylla L. Johnson)
(Egerton University, 2006-07) Mulwa, Richard M. S.; Bhalla, Prem L.
The macadamia tree, an Australian native, is highly valued for its nuts. Macadamia improvement pro- grams so far have relied on conventional breeding and selec- tion. The production of improved cultivars required to meet future demands could be accelerated by the application of modern biotechnological techniques, but this requires an efficient and reproducible regeneration system that has not yet been established for macadamia. We report here shoot regeneration from immature cotyledon explants of macadamia. Adventitious buds were induced on the cotyle- don explants from fruits collected at 140 and 190 days af- ter full bloom (DAFB) on MS medium supplemented with either 10 or 15 µM TDZ. The addition of 2% coconut milk (CM) to 10 µM TDZ containing media resulted in enhanced adventitious bud induction from 190 DAFB ex- plants. Further shoot development from the induced buds was depressed in media containing TDZ + CM; the addi- tion of 0.001 µM IAA to this combination doubled shoot development, from 1.9–3.9 shoots per explant. The trans- fer of bud clumps to media supplemented with 8.8 µM BA alone or in combination with either 0.14 µM GA3 or 0.001 µM IAA significantly increased shoot production from the previously induced explants by 1.5–2 times of that observed in TDZ + CM medium.
Assessment of clonal stability of in vitro regenerated shoots of Macadamia tetraphylla by RAPD analysis
(Egerton University, 2007) Mulwa, Richard M. S.; Bhalla, Prem L.
Macadamia nuts constitute an important part of the world nut industry and are highly valued for their health- promoting properties. Macadamia is an open-pollinated crop that takes 8–12 years to bear fruit when multiplied via seeds. The yield and nut quality in seedling plantations are often highly variable, and grafting is currently the most common method for producing nursery trees with reduced variability. We have previously reported on the tissue-culture propagation of macadamia, and in the present study we assessed the clonal integrity of the regenerated shoots. The RAPD proﬁles of 3 macadamia stock plants and 10 in vitro regenerated lines from each stock plant were analysed to assess the clonal integrity of the shoots regenerated in vitro for micropropagation purposes. The extent of genetic variation between the stock plants and 9 randomly selected seedlings was also assessed. There was no difference in clonal identity between the stock plants and their micropropagated progeny, indicating that clonal micropropagation was possible using enhanced axillary proliferation in macadamia. In contrast, there was a large genetic variation among the seedlings and between the seedlings and stock plants, with genetic distance estimates ranging from 0.121 to 0.637 among seedlings, indicating rampant out-crossing of the macadamia plant.
Structure, Conduct and Performance of Commodity Markets in South Sudan: Linkages Food Security
(Egerton University, 2008-07) Ngigi, Margaret
Several factor highlight food market risks and uncertainties for urban consumers in South Sudan. First, the South Sudan’s agriculture is yet to revive appreciably from severe disruptions caused by over two decades of civil conflicts. Secondly, rural and urban areas are poorly integrated, mainly due to a virtual absence of transport and communication infrastructures, as well as due to civil insecurities. As a result, major urban markets are heavily dependent on imports of most basic food staples. The major supply sources are North Sudan and Uganda. Khartoum and Kosti are the major centers of procurement transactions of North-South Sudan trade, while Kampala is the major centre of cross-border transaction of commodities flowing from Uganda. Together, North Sudan and Uganda account for the bulk of sugar, maize flour, rice, onion, wheat flour and sorghum sold in the four markets. This heavy dependence on importation of food supplies implies that any adverse events, both market and non-market, on the North- South Sudan, and/or the Kampala-South Sudan trade flows increases the vulnerability of a large percentage of urban households
Somatic Embryogenesis of Pathogen- Free Horseradish (Armoracia Rusticana) Plants in Vitro
(2009) Wannarat, Wannasiri
Illinois had been the major producer of horseradish in the United States for many years. Horseradish root production in Illinois had recently decreased due to a disease complex that causes root discoloration and rots. The use of pathogen-free (PF) horseradish planting stock was a means for the Illinois horseradish growers to restore root quality and yields. Micropropagation of PF plants through tissue culture could be used to deliver PF planting stock to growers, but it was time-consuming and has high labor costs. In addition, the growers needed millions of plants to supply their planting stock needs. It had been proposed to develop a method to produce whole plants from single cells via somatic embryogenesis. To initiate somatic embryogenesis, the Illinois Horseradish ‘Doll’ cultivar (‘Doll’) was tested with 2,4 -D (0.25 to 1.0 mg/l) and BA in vitro. Somatic embryogenic callus was successfully induced from leaf explants on MS medium supplemented with 2, 4-D. Somatic embryos (SEs) were collected from the callus, germinated, and converted to whole plants. Histological studies of SEs showed that they developed from cells near the vascular bundles. Furthermore, SEs developed through stages that mimicked normal embryo development. SEs germinated to give healthy and vigorous horseradish plants. Since cell suspensions of somatic embryogenic calli yielded plants, it raised the possibility to generate large number plantlets from suspension cultures. In addition, it was predicted that SEs could be encapsulated to make “artificial seeds” that could be used to supply a certified set program.
Eleven years of PARIMA activities in north-central Kenya: Impacts on Egerton University and neighboring communities
(Global Livestock Collaborative Research, 2009) Aboud, Abdillahi; Mutinda, Mark; Muthoka, Stellamaris; Coppock, D. Layne
Production and Marketing of African Indigenous Leafy Vegetables
(Humbuldt Universitat- Zuberline, 2010) Henze, Judith; Abukutsa-Onyango, Mary; Opiyo, Arnold
PREFACE: It is unusual for young scientists to identify so strongly with the concerns and needs of their research subjects that they want to give them something substantial to help solve their everyday problems. Instead, it is common research practice that data on smallholder farmers’ livelihoods strategies, behaviour, and working conditions are extracted for research purposes, solely to be published in articles in high-impact scientific journals. In HORTINLEA interdisciplinary research programme, the 30 predominantly Kenyan, but also German and Tanzanian doctoral students agreed that they would not use their last summer term on statistics, scientific writing, or presentation techniques, but would use the term to hold a practical field day on AIV cultivation and marketing with and for smallholder farmers. This field day was intended to showcase innovative practices that are considered promising in applied research on production, socio-economics, marketing, and consumption of AIVs. In preparation for this field day, which took place in December 2018 in Bondo, the idea of a handbook to translate scientific findings to practical farm advice in farmer-friendly language was born. It was expected that rural advisory services and trainers could use the handbook to teach improved production and marketing practices for AIVs. The most practical and important knowledge gained over the course of their research was extracted,verified, and prepared from the research findings for inclusion in the handbook. The first draft was prepared by Judith Henze based on the expert knowledge of farmers, doctoral students, and their supervisors. These recommendations were peer-reviewed by two farmer groups to check for comprehensibility and identify knowledge gaps. Subsequently, the handbook was reviewed by scientists from Humboldt-Universität zu Berlin in the fields of soil fertility (Prof. Christof Engels), post-harvest management (Prof. Dr. Susanne Huyskens-Keil), and agricultural extension (Martin Ihm). A final review was conducted by Prof. Mary Abukutsa-Onyango from Jomo Kenyatta University of Agriculture and Technology (JKUAT) who has promoted farmer-friendly research in Kenya for many years and is a figurehead for the promotion of AIV crops in smallholder systems. Dr. Arnold Opiyo contributed to the concept of this handbook and gave it a final touch. It is an art and a challenge to derive sound recommendations for upgrading smallholder production and marketing practices from scientific findings. The handbook contains the main steps for upgrading the AIV value chain from sowing and planting, tillage, pest and disease management, irrigation and water management, harvesting, and post-harvest activities. These steps are complemented by information on how to keep farm records and where farmers may obtain further information in Kenya. With this handbook, the junior scientists have not only demonstrated their excellence in the scientific community, but proved that they strive for application- and transfer-oriented results with and for smallholder farmers. We hope the practical knowledge on agro-ecological intensification of AIV cultivation will be widely disseminated and that nutrient-dense AIV crops will be included frequently in daily meals to contribute to sustainable and healthy diets in Kenya and sub-Saharan Africa.
Socio- Economic Factors Influencing Meat Value Addition by Rural Agribusiness in Kenya
(Current Research Journal of Social Sciences, 2011) Ngore, P.M.; Mshenga, P. M.; Owuor, G.; Mutai, B. K.
Socio Economic Factors Affecting Farmers Awareness of Clean Development Mechanism projects. Case of Smallholder Forest Carbon Projects.
(Current Research Journal of Social Sciences, 2011) Ayuya, O. I.; lagat, J. K.; Mironga, J. M.; Mutai,B. K.
Increasing Teacher Quantity and Quality Using School-Based ODL Instructional Delivery Mode: A Case Study of Teacher Training at Egerton University
(Research gate, 2011) Francis N. Wegulo
Characterization of Indigenous Chicken Production Systems
(Springer Science+Business Media, 2011-07) Okeno, Tobias O.; Kahi, Alexander K.; Peters, Kurt J.
Indigenous chicken (IC) and their production systems were characterized to understand how the whole system operates for purposes of identifying threats and opportunities for holistic improvement. A survey involving 594 households was conducted in six counties with the highest population of IC in Kenya using structured questionnaires. Data on IC farmers’ management practices were collected and analysed and inbreeding levels calculated based on the effective population size. Indigenous chicken were ranked highest as a source of livestock income by households in medium- to high-potential agricultural areas, but trailed goats in arid and semi-arid areas. The production system practised was mainly lowinput and small-scale free range, with mean flock size of 22.40 chickens per household. The mean effective population size was 16.02, translating to high levels of inbreeding (3.12%). Provision for food and cash income were the main reasons for raising IC, whilst high mortality due to diseases, poor nutrition, housing and marketing channels were the major constraints faced by farmers. Management strategies targeting improved healthcare, nutrition and housing require urgent mitigation measures, whilst rural access road network needs to be developed for ease of market accessibility. Sustainable genetic improvement programmes that account for farmers’ multiple objectives, market requirements and the production circumstances should be developed for a full realization of IC productivity. Keywords Characterization . Indigenous chicken . Production systems
Catechols in caffeic acid phenethyl ester are essential for inhibition of TNF-mediated IP-10 expression through NF-jB-dependent but HO-1- and p38-independent mechanisms in mouse intestinal epithelial cells
(Egerton University, 2012) Mapesa, Job O.; Waldschmitt, Nadine; Schmoeller, Ingrid; Blume, Carolin; Hofmann3, Thomas; Mahungu, Symon; Clavel, Thomas; Haller, Dirk
Scope: Caffeic acid phenethyl ester (CAPE) is an active constituent of honeybee propolis inhi- biting nuclear factor (NF)-kB. The aims of our study were to provide new data on the functional relevance and mechanisms underlying the role of CAPE in regulating inflammatory processes at the epithelial interface in the gut and to determine the structure/activity relationship of CAPE. Methods and results: CAPE significantly inhibited TNF-induced IP-10 expression in intestinal epithelial cells. Using various analogues, we demonstrated that substitution of catechol hydroxyl groups and addition of one extra hydroxyl group on ring B reversed the functional activity of CAPE to inhibit IP-10 production. The anti-inflammatory potential of CAPE was confirmed in ileal tissue explants and embryonic fibroblasts derived from TNFDARE/1 mice. Interestingly, CAPE inhibited both TNF- and LPS-induced IP-10 production in a dose- dependent manner, independently of p38 MAPK, HO-1 and Nrf2 signaling pathways. We found that CAPE did not inhibit TNF-induced IkB phosphorylation/degradation or nuclear translocation of RelA/p65, but targeted downstream signaling events at the level of tran- scription factor recruitment to the gene promoter. Conclusion: This study reveals the structure–activity effects and anti-inflammatory potential of CAPE in the intestinal epithelium.
Farm gate private standards and price premium: Evidence from the GlobalGAP scheme in Kenya’s French beans Marketing.
(Agribusiness International Journal, 2012) Kariuki, IM; Loy, J.-P.; Herzfeld, T
Determinants of Adoption of Butternut Squash (Cucurbita moscharta) Farming by Small-holders in Suba District Kenya.
(Asian Journal of Agricultural Sciences, 2012) Isaboke, H.N.; Mshenga, P.; Mutai, B.K.; Saidi, M.
Contribution of Selected indigenous Fruits and Household Income and Food security in Mwingi, Kenya
(Current Research Journal of Social Sciences, 2012) Muema, C. M.; Mutai, B. K.; Lagat, J. K.; Kibet, L. K.; Maina, M. C.

Browse

Browsing Research Publications by Issue Date