Journal Articles

Improving aquaculture productivity in Uasin Gishu County, Kenya: Addressing pathogens, water quality, and management challenges

Sat, 01 Mar 2025 00:00:00 GMT

Improving aquaculture productivity in Uasin Gishu County, Kenya: Addressing pathogens, water quality, and management challenges Mutai, E. Kipyegon; Ngeiywa, M.M.Moses; Liti, D. Aquaculture in Uasin Gishu County, Kenya, has grown significantly due to government support, favorable climatic conditions, and an increasing demand for fish as a protein source. However, fish farming in the region faces severe challenges from pathogenic parasites and microbes, which significantly impact fish health and aquaculture productivity. Poor water quality, overcrowded ponds, and agricultural runoff exacerbate the proliferation of pathogens, including protozoan parasites (Ichthyophthirius multifiliis), monogeneans (Gyrodactylus species), bacterial pathogens (Aeromonas hydrophila, Edwardsiella tarda), and fungal infections (Saprolegnia species). These pathogens cause diseases that lead to high mortality rates, reduced productivity, and economic losses. This review synthesizes current research on fish pathogens in Uasin Gishu, contextualizing the findings within regional and global frameworks, and identifies critical gaps in disease management. It also proposes strategies to mitigate disease prevalence, improve water quality, and enhance aquaculture sustainability.

Enhancing fisheries productivity through improved fish pond management in Uasin Gishu County, Kenya: A comprehensive review

Tue, 01 Jul 2025 00:00:00 GMT

Enhancing fisheries productivity through improved fish pond management in Uasin Gishu County, Kenya: A comprehensive review Kosgei, J. Patricia; Liti, David M; Chemoiwa, Emily J.; Mutai, Edwin K. Aquaculture is increasingly recognized as a cornerstone of global food security and economic development. However, its potential remains underexploited in many developing regions, including Uasin Gishu County in Kenya. This review synthesizes local and global research on the challenges and opportunities for enhancing fisheries productivity in the county through improved pond management practices. By examining production systems, water quality variables, and nutritional management, this review presents practical strategies for sustainable intensification of aquaculture in the region. The findings underscore the need for coordinated efforts among stakeholders to unlock the full potential of aquaculture in Uasin Gishu County, positioning it as a viable pathway toward rural development and long-term food security. The recommendations focus on capacity building, resource access, policy support, and integrated farming approaches aimed at improving productivity, profitability, and environmental sustainability.

Influence of Water Quality on Growth Dynamics of Nile Tilapia (Oreochromis niloticus) in Uasin Gishu Aquaculture Systems

Mon, 01 Dec 2025 00:00:00 GMT

Influence of Water Quality on Growth Dynamics of Nile Tilapia (Oreochromis niloticus) in Uasin Gishu Aquaculture Systems Kosgei, J. Patricia; Liti, M. David,; Mutai, K. Edwin; Chemoiwa, J. Emily Aquaculture in Uasin Gishu County, Kenya, supports food security and livelihoods but faces challenges from unstable water quality affecting Nile tilapia (Oreochromis niloticus) growth. This study examined the relationship between water quality and fish growth across five farms representing earthen, tank, and raised liner systems from May 2023 to April 2024. Physico-chemical parameters—dissolved oxygen (DO), temperature, pH, chemical oxygen demand (COD), and biological oxygen demand (BOD)—were measured at three-hour intervals, while fish growth was monitored monthly. Data were analyzed using ANOVA, Tukey’s HSD, and multiple regression to assess water quality effects on growth. Temperature (21–23 °C) was below the optimal 25–30 °C range; pH (8–9) was acceptable; DO occasionally dropped below 3 mg/L; and COD (32–95 mg/L) and BOD (33–103 mg/L) indicated organic loading. Significant differences occurred among farms for temperature, DO, COD, and BOD. Growth parameters derived from the von Bertalanffy Growth Function showed the best performance in raised liner systems, with Cheplaskei Farm A recording the highest growth (L∞ = 36.78 cm; W∞ = 630.02 g). COD and BOD were the strongest predictors of maximum growth rate. The findings emphasize the need for stable water quality management to enhance O. niloticus productivity and ensure sustainable aquaculture in the region.

Investigation of the morphological variation among taxa to determine species diversity within Cyperus dives complex in East Africa: a review

Tue, 01 Apr 2025 00:00:00 GMT

Investigation of the morphological variation among taxa to determine species diversity within Cyperus dives complex in East Africa: a review Tallam, Jerop; Otieno, Donald Fredrick; Musili, Paul Mutuku The Cyperus dives complex, a group within the Cyperaceae family, exhibits substantial morphological diversity across East Africa, presenting a valuable opportunity for studying species diversity and ecological adaptation. This investigation explored the morphological variation among taxa within this complex to assess species diversity and inform conservation strategies. Through a detailed examination of leaf shape, inflorescence structure, and reproductive features, the study reveals significant variations that delineate species boundaries and highlight adaptive traits. Findings from existing literature affirms the complex interplay between environmental factors and morphological characteristics, illustrating how different taxa are adapted to a range of ecological niches. The results demonstrates that morphological diversity within the Cyperus dives complex is influenced by habitat variability and evolutionary pressures. The study concludes that a comprehensive understanding of morphological variation is essential for accurate species identification and effective conservation management. This investigation contributes to the broader understanding of biodiversity in East Africa and supports the development of targeted conservation strategies to protect the diverse taxa within the Cyperus dives complex.

ANTIDIABETIC ACTIVITY OF LEAVES AND ROOT EXTRACTS OF KENYAN POPULATIONS OF DODONAEA VISCOSA ON STREPTOZOTOCIN (STZ) INDUCED DIABETIC RATS

Sun, 01 Sep 2024 00:00:00 GMT

ANTIDIABETIC ACTIVITY OF LEAVES AND ROOT EXTRACTS OF KENYAN POPULATIONS OF DODONAEA VISCOSA ON STREPTOZOTOCIN (STZ) INDUCED DIABETIC RATS Langa, Philemon Kibet; Njenga, Elizabeth Wanjiku; Jeruto, Pascaline; Lukhoba, Catherine Diabetes is a metabolic disorder affecting more than 400 million people worldwide. There are three types of diabetes which includes type I diabetes mellitus (T1D), type II diabetes mellitus (T2D) and gestational diabetes. The disease is associated with polyuria, polydipsia, and glycosuria, and many other underlying conditions. It leads to disability, high financial constraints and ultimately death of the patients. This study therefore intends to seek alternative ways of managing diabetes using herbal remedies. Dodonaea viscosa leaves and roots were collected from Baringo, Elgeyo Marakwet, Uasin Gishu and Kwale counties. They were soaked in ethanol and their antidiabetic activity done on male swiss albino rats. Antidiabetic activity was calculated by a glucometer. T-test was used to compare the activity of the roots and leaves. ANOVA was calculated using F-test to find out the activity of various populations. A comparison of activity of Insulin, 200 mg and 400 mg/kg bw extracts was determined using their means. From the results, D. viscosa has a strong antidiabetic activity. T-test revealed that there was no significant difference between their activities of roots and leaves as evidenced from p >0.05. Fstatistic (F = 0.545) indicates that the variances between the populations are not statistically different. The p-value (Sig. = 0.742) further confirms this. Insulin led to the highest decrease in blood sugar, followed by plant extract at 400 mg/kg bw and finally 200 mg/kg bw extracts. More research to isolate pure compounds from this rich plant need to be done.

Molecular phylogeny and genetic diversity of Dodonaea viscosa populations from North Rift and Coastal Kenya using ITS1 and rbcL markers

Tue, 01 Apr 2025 00:00:00 GMT

Molecular phylogeny and genetic diversity of Dodonaea viscosa populations from North Rift and Coastal Kenya using ITS1 and rbcL markers Langat, P.K.; Njenga, E.W.; Jeruto, P.; Lukhoba, C. W.; Musila, F.M. The genus Dodonaea (Sapindaceae) comprises slightly over 70 species. Dodonaea viscosa is a plant of Australian origin with seven subspecies. In Kenya, there are two subspecies. D. viscosa has been used medicinally to manage several ailments. It is considered a difficult taxonomic group due to its polymorphic nature. Owing to its uses in ethnomedicine and the taxonomic challenge of Kenyan subspecies, a molecular phylogenetic study was done using ITS1 and rbcL genes from Kenyan populations. DNA was extracted, sequenced, exported to MEGA 11, PhyloSuite, and R for analysis. Aligned sequences were subjected to evolutionary analyses and PCA while phylogeny was constructed using maximum likelihood (ML) method. Nucleotide frequency and substitution rates, nucleotide disparity index, and evolutionary divergence of the genes were very low implying a short genetic distance among the Kenyan populations. ML trees showed that the highland and coastal Dodonaea populations were closely related as they are monophyletic and have high bootstrap values. PCA showed that rbcL genes contributed to most variations in Dodonaea populations where two clusters based on rbcL genes were observed. In contrast, ITS1 genes contributed to fewer variations and grouped all Dodonaea populations into one cluster. This study provides more data to solve the taxonomic challenge of D. viscosa. There is a need for further studies targeting other gene regions to understand well the phylogenetic relationships of Kenyan populations of Dodonaea.

olecular Analyses of Genetic Variation and Phylogenetic Relationship in the Family Sapindaceae. A Review Paper

Fri, 01 Aug 2025 00:00:00 GMT

olecular Analyses of Genetic Variation and Phylogenetic Relationship in the Family Sapindaceae. A Review Paper Langat, P.K.; Njenga, E.W.; Jeruto, P.; Nyamwamu, C.N.; Lukhoba, C.W.; Musila, F.M. The Sapindaceae, commonly known as the soapberry family, is a cosmopolitan group of approximately 1900 species across 144 genera, forming part of the economically and ecologically significant angiosperm order Sapindales. Despite prior taxonomic efforts, relationships within Sapindaceae and across Sapindales have remained poorly resolved due to complex morphological variation and incomplete infra-familial classification systems. Recent advances in molecular systematics, particularly the use of nuclear ribosomal DNA internal transcribed spacer (ITS) sequences and Angiosperms353 target enrichment datasets, have enabled substantial progress in reconstructing evolutionary relationships within this group. ITS-based phylogenetic analyses have confirmed species-level resolution within Indian Sapindus, clearly distinguishing S. emarginatus from S. trifoliatus, and revealing the divergent position of S. oligophyllus, which clusters with Allophylus of tribe Thouinieae. Estimates of evolutionary divergence revealed significant variability among tribes, with the greatest divergence observed between Paullinieae and Harpullieae (0.20) and the least between Sapindeae and Lepisantheae (0.06), supporting past taxonomic hypotheses. Complementary phylogenomic analyses using Angiosperms353 markers across 123 Sapindaceae genera (86% coverage) recovered 21 clades, providing the basis for a revised classification into four subfamilies and 20 tribes, including six newly proposed tribes within Sapindoideae. Broader Sapindales-wide analyses comprising 448 samples and 85% of genera confirmed family monophyly and resolved core clades while also revealing persistent challenges in subfamily-level relationships due to paralogy, likely linked to ancient hybridisation and polyploidy events. The presence of paralogous loci, particularly in Meliaceae and Rutaceae, affirms the need for careful data curation and highlights the impact of ancient genome duplications on phylogenetic inference. This integrated molecular framework provides the most comprehensive phylogenetic resolution of Sapindaceae and Sapindales to date. It offers a robust foundation for future evolutionary, biogeographic, taxonomic, and conservation-orientated studies while emphasising the need for continued sampling and the incorporation of genomic complexity in phylogenetic reconstruction.

Screening advanced potato mutant genotypes against bacterial wilt disease under different agro-ecological zones of Kenya

Sun, 01 Jun 2025 00:00:00 GMT

Screening advanced potato mutant genotypes against bacterial wilt disease under different agro-ecological zones of Kenya Apondi, Maurine; Kinyua, Miriam G.; Were, Javan O.; Gohole, Linnet S. Host plant resistance is a key tool in the management of plant diseases. Mutant lines (IP1, IP2, IP3 and IP4) were tested against other potato varieties (Shangi, Sherehekea, K. Mpya and Unica) in different agro-ecological zones to ascertain their performance under potato bacterial wilt disease pressures. An experiment was set in an RCBD design with three replications in four different sites, namely, Nyandarua, Elgeiyo Marakwet, Burnt Forest and Moiben. Assessment was done on potato bacterial wilt disease prevalence and severities, as well as host plant status, which were rated on a scale of 1-5. Data obtained were subjected to analysis using statistical software GenStat 16th Edition VSN International Ltd. Different response levels and uniqueness were express across all AEZs, where variety, sites and time intervals (DAS) as well as their interactions had significant effects on disease severity, with different tolerance levels to the pathogen experienced in all the lines. The severity mean of four mutant lines was below 2.0 as per the days after sowing (DAS). Moreover, IP1 (2.0) and IP2 (2.1) had an overall mean across all sites; therefore, they proved a high level of tolerance to the bacterial wilt pathogen, while IP3 (2.4) and IP4 (2.5) wer the resistant check (2.8) across all the sites and the susceptible check Kenya Mpya (3.2). Hence, there is a need for regular screening of the available genotypes for R. solanacearum production. The existence of the most tolerant varieties could form a baseline in integrated disease management for sustainable potato production.

Investigation of the morphological variation among taxa to determine species diversity within Cyperus dives complex in East Africa

Tue, 01 Apr 2025 00:00:00 GMT

Investigation of the morphological variation among taxa to determine species diversity within Cyperus dives complex in East Africa Tallam, Tallam; Otieno, Donald Fredrick; Musil, Paul Mutuku The Cyperus dives complex, a group within the Cyperaceae family, exhibits substantial morphological diversity across East Africa, presenting a valuable opportunity for studying species diversity and ecological adaptation. This investigation explored the morphological variation among taxa within this complex to assess species diversity and inform conservation strategies. Through a detailed examination of leaf shape, inflorescence structure, and reproductive features, the study reveals significant variations that delineate species boundaries and highlight adaptive traits. Findings from existing literature affirms the complex interplay between environmental factors and morphological characteristics, illustrating how different taxa are adapted to a range of ecological niches. The results demonstrates that morphological diversity within the Cyperus dives complex is influenced by habitat variability and evolutionary pressures. The study concludes that a comprehensive understanding of morphological variation is essential for accurate species identification and effective conservation management. This investigation contributes to the broader understanding of biodiversity in East Africa and supports the development of targeted conservation strategies to protect the diverse taxa within the Cyperus dives complex.

Association of microclimatic and edaphic factors with sandfly abundance and distribution in Bungoma county, Kenya

Wed, 01 Jan 2025 00:00:00 GMT

Association of microclimatic and edaphic factors with sandfly abundance and distribution in Bungoma county, Kenya Mulonga, Job; Makwali, Judith; Ngeiywa, Moses Sandflies (Diptera: Psychodidae) are the only known primary vectors of leishmaniases including cutaneous leishmaniasis. Infected female phlebotomine sandflies pass Leishmania parasites to humans and animals as they bite for blood meals. Environmental microclimatic factors such as humidity, temperature, and soil characteristics affect sandfly abundance and distribution differently. Heterogenous environmental factors that pose potential disease risks exist in Bungoma County, with scanty studies documenting their relationships. The current study aimed to investigate the associations of environmental altitude, temperature, humidity and soil chemical and physical factors with sandfly abundance and distribution. A cross-sectional field survey was applied to collect sandflies from 12 cave habitats in 5 selected sub-counties in Bungoma County by use of Center for Disease Control and Prevention light traps. Cave ambient temperature, soil temperature, relative humidity, Geographical positioning system locations were measured and recorded on site, and a composited soil sample collected from each site was transported to a soil laboratory for physical-chemical analyses. Sandflies were collected once from each site every month for 24 months. Chi-square tests, one way analysis of variance (ANOVA) and Pearson’s correlation tests (p<0.05) were used for data analysis. Temperature and relative humidity significantly (p<0.05) correlated with sandfly abundance and distribution. Short rain seasons (October-December) recorded the peak abundance of sandflies (p=0.2611). soil physical and chemical factors nonsignificantly correlated with sandfly abundance in the sampled sites. Altitude, relative humidity and temperature are key determinants of sandfly abundance and distribution in Bungoma County. Vector management strategies should be planned to target the peak season of sandfly abundance (OctoberDecember) for effective cutaneous leishmaniasis control.