Journal of Science and Applied Technology
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Item Antimicrobial Activity of Kenyan Laikipia County Leonotis mollissima Plant Extract(Laikipia University, 2022) Kinuthia, Wanjiru Esther.The use of herbal medicine is expanding rapidly across the world due to the high bills involved in the importation of modern medicinal drugs. About 80 percent of the African population use traditional medicine from plants to treat common infectious diseases caused by microorganisms. The main objective of this research was to determine the antimicrobial activity of crude extracts and isolated compounds of Laikipia University Leonotis mollissima (Lion’s ear) from the Lamiaceae family. The plant was studied in this research due to its wide use by local communities of Kenya for medicinal remedies. Its decoction is used by the Marakwets of Kenya to treat microbial diseases. The plant was sampled from Laikipia University Kenya, identified, air dried and voucher specimen kept for reference in the Biological Department of Egerton University in Kenya. Crude extracts from dry powder of the leaves were successively extracted with hexane, dichloromethane, ethyl acetate and methanol for seventy-two hours. With repeated column chromatography, Leonotis mollissima dichloromethane leaves (79.69 g) crude extract yielded compounds 1 (Sederin), 2 (20-hydroxylucidenicacid D2) and 3 (labdane). Identification of pure compounds was achieved by 1H and 13C NMR (500 MHz) spectroscopy. Chemical shifts (δ) were expressed in ppm relative to tetramethylsilane (TMS) as internal standard and coupling (J) in Hz. On screening for antimicrobial activity, all crude extracts showed an MIC (Minimum Inhibition Concentration) of < 0.1 mg/mL to > 0.5 mg/mL on all test microorganism (Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium and Candidas albican. Compounds 1 and 3 had an MIC of > 0.16 mg/mL on all test microorganisms while 2 compound had an MIC of 0.10 mg/mL. The IC50 (Inhibition Concentration that reduces the effect of microorganisms by 50%) for all crude extracts and isolated compounds was less than that of Amoxil® and Doxycycline® antibiotics on all test micro-organisms on calculation with Graphpad Prism 8 free download computer program at different concentrations. This is a confirmation that Leonotis mollissima contains compounds that can be isolated and used as drugs to treat various diseases including microbial infectious diseases. Keywords: Kenya, Laikipia County, leonotis mollissima, minimum inhibition concentration (MIC)Item Genetic Diversity and Geographic Distribution of Maize Streak Virus in Kenya(Laikipia University, 2022) Pande, Daniel.Maize streak virus (MSV) is one of the most important pathogens responsible for poor maize yields in Africa. For over the past 50 years, the MSV-A1 genotype has continually been moving back and forth between southern and eastern Africa and from East to West Africa. Despite Kenya being a maize producing country, very little is known of its MSV genetic diversity and geographical distribution of the circulating variants. In this study, a sampling survey was undertaken in the farmers’ fields to collect MSV prevalence and symptom severity, where a total of 178 complete MSV genomes were sequenced from both grass and maize. Both phylogenetic and phylogenetic tools were used to illustrate the genetic diversity and geographical distribution. The results showed that the MSVA lineages had a distinct but overlapping geographical distributions in the country and noticeable relationship between the MSV symptom severity and the percentage infectivity. Keywords: Genetic distribution, geographical distribution, Kenya, Maize streak virus, MastrevirusItem The Cotton Industry in Kenya: Problems, Prospects, and Revival Strategies(Laikipia University, 2022) Rutto, Lelei Kiprono David.,; Auma, Elmada Odeny.,; Ngode, Lucas.Cotton is presently grown in twenty-two counties in Kenya spread across Central, Coast, Eastern, Nyanza, Rift Valley, and Western regions. Cotton production has been well below potential in recent years due to various constraints, including the non-availability of quality seeds and inappropriate production technologies, especially for smallholder farming, lack of access to credit, high cost of farm inputs, among other constraints. For the cotton industry to be revived, various strategies have to be put in place, including establishing efficient rural finance and credit supply system for smallholders and rural primary agro-processors; ensuring policies, institutional and legal frameworks are investor-friendly; facilitating long term investments in farm improvement technologies; and improving governance of co-operative sector by empowering farmers and farmer groups. This study is based on the principle that policy, institutional and economic content is the base upon which some of the problems in the cotton industry could be addressed in order to arrive at prospects essential in de-limiting the challenges. This will impact cotton industry revival and translate into increased incomes, thereby enhancing food security in cotton-growing areas. Primary data was obtained through field survey using questionnaires and interviews by stratified random sampling method in cotton-growing zones. Secondary data from various sources (KALRO, CODA, & MOA reports) was looked at, compared, and analysed using descriptive and qualitative methods to come up with prospects and strategies for solving production and marketing problems. The qualitative data analysed showed that the cotton industry face problems such as: lack of access to quality seeds; high cost of inputs; competition with other farm enterprises over scarce resources; and collapse of irrigation schemes and ginneries. The prospects suggested include acquisition of new seed varieties, increased employment in cotton industry, and improved economy as well as reduced poverty. The revival strategies included: maximization of African Growth Opportunity Act initiative by United States government that was extended from 2015 to 2025 to make local farmers benefit more; implementing the cotton bill and enforce cotton regulations; expanding cotton acreage/yield; and empowering cotton associations such as KCGA/HAWESA. It was concluded that there was need to address outlaid problems; avail resources for acquisition of quality seed, purchase of farm inputs and rehabilitation of collapsed irrigation schemes and ginneries; and invest in the cotton industry by the government, private sector, and the international community for cotton industry revival. Keywords: Cotton, problems, prospects, revival strategiesItem Identification of Plant Species along the Riparian Corridor of the Iguameti Stream in Laikipia County Kenya(Laikipia University, 2022) Obwanga, Ojowi Benson.,; Outa, Omondi James.,; Ngure, Veronica.Abstract This study presents the first characterization of riparian vegetation on Iguameti Stream as well as a description of anthropogenic activities within the riparian corridor. Study points fell within the upper reaches of the stream within Laikipia University and lower reaches with a high density of human settlements and farming activities. Sample plots (30m×10m) in the upper and lower reaches of the stream were selected in the phytocoenoses of the study area in such a way that each sample plot was visually homogenous and that all floristic variation in the area was sampled. Based on physiognomical classification, three types of vegetation formations were identified: afromontane forest, woodland and swamp vegetation. Human activities include: introduction of exotic species; timber harvesting; damming; stream channelization; livestock grazing; and land tillage. The upper reaches exhibited minimal disturbance, a detailed vertical stratification with ample canopy, understory, shrub, herb layer, and ground cover dominated by indigenous vegetation. Trichocladus ellipticus, Allophylus sp., Teclea sp, Dombeya goetzinii, Ficus natalensis, Rhus natalensis, Pavonia urens and Cyathula cylindrical were dominant, while in the lower reaches, Pittosporum viridiflorum, Cupressus sp., Eucalyptus sp., Crotalaria agatiflora, Rhus natalensis, Hibiscus fuscus, Hypoestis verticillaris and Rubus sp. were dominant. Species loss was reported in the lower reaches where the buffer strips ˂5m on the left and right banks compared to ˃20m in the upper reaches. Steam damming has caused replacement of riparian vegetation with wetland plants like Crassula schimperi, Hydrocotyl sp., Oenanthe palustris, Sphaeranthus steetzi, Rorippa sp., Polygonum pulchrum, Typha sp. and sedges mainly Cyperus spp. and Fimbristylis sp. Canopy cover decreased from >90% in the upper reaches to < 60% in the lower reaches. Riparian vegetation loss in the upper reaches may cause habitat loss for Colobus guereza kikuyuensis and Aonyx capensis. Urgent strategic multi-disciplinary management of the riparian zone is needed to limit biodiversity loss. Keywords: Biodiversity conservation, climate change, Laikipia County, riparian vegetation, species loss