MST-Plant and Microbial Sciences
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Item Infestation of Coffee and Other Crops by Field Dodder (Cuscuta Campestris Yunker) in Kericho County, Kenya(Kenyatta University, 2023-02) Chepkemoi, CarolineAbstractItem Impact of Salinity on Growth, Physiological Traits and Yield of Butternut Squash (Cucurbita Moschata L. Mellonia) Varieties in Mwea, Kenya(Kenyatta University, 2023-09) Njoroge, Mary NyamburaAbstractItem Effects of Neem, Garlic and Aloe Extracts on the Development of Postharvest Potato Soft Rot Caused by Erwinia Carotovora Bacteria(Kenyatta University, 2019-06) Ndivo, Felix MwanziaPotato (Solanum tuberosum L,) production in Kenya has been limited by diseases from plant pathogens especially bacterin soft rot which has led to production of poor quality tubers. Potato post harvest diseases such as bacteria soft rot caused by Erwinia caretovera have led to immense losses in stored potato tubers by smallholder farmers in Kenya. Although the use of synthetic chemicals has assisted in control of bacteria soft rot, their use has been greatly minimized due (o identifiable problems such as chemical residues, non-biodegradability, high phytotoxicity, environmental pollution and development of resistance by target organisms. Therefore, use of botanicals can be safer and better alternative on management of soft rot in potato tubers and other susceptible vegetables such as carrots and tomatoes. This is because the natural edible plant extracts have been found to be non-toxic to consumers, non pollutant to the environment and very economical as compared to the use of agrochemicals. This study was therefore designed to determine the effect of the plant extracts of neem (dzadirachia indica M.), garlic (Allium sativum M.) and aloe (dloe secundiflora Engl.) on the development of soft rot bacteria both in-vitro and in-vivo. In the in-vitro test, the effect of the extracts on the growth inhibition of Erwinia carotovora was investigated in a Muller Hinton (MH) culture media, while in the in-vivo test, the plant extracts were applied directly onto potato tuber tissue to investigate their effectiveness in inhibiting the development of soft rot in three potato varieties (Kenya Mpya, Sherekea and Purple Gold). Erwinia carotovora was isolated from diseased potato tubers and cultured in a nutrient agar medium. The treatments in the experiment were laid out in a completely randomized design (CRD) with five replicates and the data collected subjected to Analysis of Variance (ANOVA) with statistical significance PItem Infestation of Coffee and Other Crops by Field Dodder (Cuscuta Campestris Yunker) in Kericho County, Kenya(Kenyatta University, 2023-03) Chepkemoi, CarolineJixtensive eographical distribution and variable host runge make F.'u.wym campestriy (el dodder) one of the most comnion and highly (|clelI(fl!Vc invasive Nowering plant species, Cusenra campestris Is an obligate shoot parusitic weed (hat hampers growth of plants and couses loss of yield of many crops globally. It In,.u been recorded ns one of the worst weed of cropy in Turkey nnd lh_c Democratic Republic of Congo. The mte of spread and destruction in (hese countrics and others is alarming and 1€ this happens in Konya, crop yields are likely to be reduced. In Kenya the dodder weed is common in countics such as Central, Coast, Nyanza, Western and Rl valley, This study sought lo investigate the causes, extent n{u( impact of infestation and potential for management of C. campestris in Chilchila ward, Kericho County, Kenya. The study documented crops affcclcz{, lmpnc( and eflorts to monage the weed in (he arca. A semi-structured questionnaire was administered 10 60 farmers (o gel their views on the impacts of the invasive species and management efforts. Eight plots of 20 x 20 M were established along four, 3.5 km baseline transects in all the four compass direotions starting from the point of introduction of field dodder. The plots were laid al 400 m from cach other. Data that was collected in each plot included (he (ype of crops affected, levels of infestation on coffee and weight of their berries in coffee at different levels of infestation. The results were summarized using deseriptive statistics and presented using tables and charts, Analysis of variance (ANOVA) was used to invcsligg(c variation in intensity of infestalion of Cuscuia campestris on coffee plantations with distance from the point of introduction, The main crops parasitised included coffee which had the highest frequency, followed by bananas and mangoes. This was attributed to the perennial nature of the crops. Besides, the high cconomic value attached 10 the coffee necessitates frequent application of fertilizers which also benefit C. campestris. The number of infested coffee trees reduced significantly with increasing distance from the point of introduction (F= 6.41, df = 24, p < 0.05). Findings from this study indicated that ficld dodder infestation led to small berries (29.7%), reduced berry weight (35.9%), falling of leaves (3.9%) low crop yield (13.3%) and death of coffee trees (17.2%). Farmers’ management methods included hand picking (49), pruning (25), spraying (26), weeding and uprooting (3). Hand picking at an early stage, timely application of correct proportions of glyphosate, pruning lower branches and uprooting the host was reported by 6.7% of farmers as effective methods of control. On the other hand, 43% of the farmers stated that the methods were not effective, but they appreciated the fact that it lowered the infestation level. Further, 50.3% of the respondents reported that the methods were not effective at all. The findings in this study are crucial in the formulation of strategies to control the spread of C. campestris. Farmers are encouraged to get rid of weeds regularly as they were found to be primary hosts for field dodder. Use of monocotyledonous plants such as aloes and bamboo as hedge plants was recommended as these plants apparently defied infestation by the weed.Item Ecological Impacts and Utilization of Urtica Dioica L. In Nyeri County, Kenya(Kenyatta University, 2024-05) Kamicha ,Wairimu JosephThough the stinging nettle (Urtica dioica L.) is categorized globally as an invasive species, the plant is a source of vital nutrients and an ingredient in many local medicine practices. However, there is inadequate information on the edaphic factors enhancing the invasiveness of U. dioica, the subsequent impact on local flora diversity, and upcoming value-addition opportunities. Hence, this study sought to determine the invasive effects of U. dioica on herbaceous plants density and diversity. Then analyze the relationship between U. dioica density with soil mineral contents and investigate the market presence of raw and value-added products. Lastly, this study intended to document local knowledge of U. dioica in Nyeri County, Kieni Sub County areas namely; Endarasha, Charity, and Watuka. Sites with high colonization of U. dioica were purposively identified. Based on land use types, Stratified random sampling method was used to place five transects each measuring one hundred metres long. Ten quadrats each measuring one square metre in roadside, riverbank, pastureland, residential, and cropland areas were used for data collection. Fifteen soil cores were taken from each land use type and mixed to form soil samples for each land use type in Endarasha, Charity, and Watuka. Questionnaires were administered to 196 respondents from the study area. Results from Pearson correlation analysis between the density of U. dioica and other herbaceous species indicated that there was a strong negative correlation between the density of U. dioica and other herbaceous species diversity (r=-0.8). One-way ANOVA showed significant statistical differences in the concentration of nitrogen (F=4.8495, df=4, 14, p < 0.05) and phosphorous (F=4.3589, df=4, 14, p < 0.05) among different land types confirming their different impacts on U. dioica density. The study also established that locally, U. dioica is used in the food, medicine, and veterinary sector. Such consumption could indicate the economic potential of the plant species in the local cottage industries to support the government's manufacturing agenda. This study recommends increasing public awareness of the benefits of U. dioica to boost its consumption hence reducing its invasiveness.Item Efficacy of Banana Paper as a Carrier for Control Agents for the Management of Root- Knot Nematodes(Kenyatta University, 2024-06) Kamau, Dorris WanguiGlobally, potatoes, Solanum tuberosum, are a key staple food crop. In Kenya and East Africa, it is the second most important food crop after maize. Among the various constraints on potato production are plant-parasitic nematodes, RKNs are viewed as the most economically damaging group of plant-parasitic nematodes (PPNs) worldwide. Plant-parasitic nematodes are linked to reduced yields, low quality of crop produce, and high costs of production. The current study was undertaken to evaluate the efficacy of a lignocellulose fiber matrix (banana fiber paper) as a carrier for control agents in the management of RKN on potatoes in Kenya. The experiment was conducted in both field and pot trials over two consecutive cropping seasons. The experiment was conducted in Mwea, Kirinyaga County, in plots measuring 4x4 meters for two consecutive short rain cropping seasons and in pot trials in a screen-house at Kenyatta University. Mwea was chosen as the experimental site as there is a high prevalence of RKNs in the area brought about by continuous planting of RKN-susceptible crops such as tomatoes in the area. Effectively managing RKNs in Mwea may be essential in improving the yields and incomes of farmers in the region and also providing them with opportunities to successfully venture into potato farming; thus, improving food security in the country. Land preparation was done manually, and then 4x4 meters plots were marked. Treatments were distributed to the plots randomly using a completely randomized block design. The six treatments used in this study included (a) banana paper impregnated with abamectin, (b) abamectin alone, (c) Trichoderma asperellum alone, (d) banana paper impregnated with Trichoderma asperellum, (d) banana paper alone, and (e) untreated control. Seed potatoes sourced from the International Potato Centre (CIP) were planted after wrapping them with banana banana-paper. Data collection on plant height and number of stems began after the crops had germinated and was done after every two weeks throughout the cropping season (12 weeks). The data collected included a) plant height (cm), b) mass of tubers per plant (g), c) mass of the entire root system (g)/plant, d) number of stem/plant, e) number of tubers/plant, g) the reproduction factor of J2’s/200cc of soil. Data were analyzed using R (Version 4.2.3) statistical software (R Core Team, 2023). Tukey’s Honest Significant Difference (Tukey-HSD) test was done where the Analysis of Variances (ANOVA) indicated that there were significant differences (p<0.05) between the treatment means. Banana paper impregnated with abamectin (abamectin-paper) led to significantly increased crop growth, yield and the number of tubers compared to abamectin alone, paper-control and no treatment. The use of banana paper impregnated with abamectin also significantly reduced the nematode density at harvest compared with abamectin alone, paper-control, and absolute-control. However, the paper-control and abamectin alone also significantly improved potato production and nematode management compared to the untreated control. The use of abamectin-paper resulted in a 30% and 36% increase in the number of tubers per plant compared to the untreated control in Seasons 1 and 2, respectively. Additionally, abamectin-paper increased the mean tuber yield per plant by 83% in Season 1 and 148% in Season 2 compared to the untreated control. Additionally, abamectin-paper reduced nematode reduction by 96% in season 1 and 89% in season 2 compared to the untreated control. Consequently, this innovative technology, also known as 'Wrap&Plant,' provides a viable option for nematode management in potatoes under resource-constrained conditions in Sub-Saharan Africa.Item Effects of Arbuscular Mycorrhizal Fungi and Trichoderma spp. on Nutrient Uptake and Water Stress Tolerance in Vigna unguiculata (L.) Walp. (Cowpea)(Kenyatta University, 2024-07) Juma, Daniel WanjalaIn a bid to explore alternatives that mitigate effects of low water and nutrient supply for crops, the influence of arbuscular mycorrhizal fungi and Trichoderma spp. on cowpea growth and nutrient uptake at different soil water levels under greenhouse conditions was undertaken. Cowpea is an essential food crop for both humans and livestock. It’s a source of income in marginal areas and also adds nutritive value to the soil by fixing nitrogen. The experiment was arranged on a completely randomized design (CRD) with the three water levels treatment, of 90 % (no stress), 60 % (mild stress), and 30 % (severe stress) of field capacity (FC). Two cowpea varieties including KVU 27-1 and Katumani 80 (K80) that are commonly grown by farmers were used in each water level. Each water level was subjected to seven fungal inoculation treatments: I- Funneliformis mosseae (BEG 12), II- Rhizophagus irregularis (BEG 44), III- Trichoderma harzianum (Har), IV- Trichoderma asperellum (Asp), V- BEG 12 + BEG 44 (BB), VI- Har + Asp (HarS), VII- Har + BEG 12 + BEG 44 (HBB), and VIII- which was un-inoculated as control (C). Each experimental unit was replicated four times resulting in 192 pots. The variables measured included, plant height, chlorophyll content, Shoot Dry Weight, Root Dry Weight, Root Length, Leaf Area, Stem Diameter, Relative Water Content, Specific Leaf Area and root mycorrhizal colonization. The shoot tissue analysis was also done to determine the nitrogen (N), phosphorous (P) and potassium (K) contents. All data were subjected to a two-way ANOVA in R software version 4.2.1 to test levels of significance due to treatments and their interactions. Means that were significant at p ≤ 0.05 were separated using Bonferroni test. Results showed that all the growth parameters and the shoot nutrient content were statistically significant at (p ≤ 0.05) with soil water level treatment in both varieties. Water stress had a negative influence on growth and the shoot nutrient content. The fungal inoculants were significant on stem diameter (p = 0.006), relative water content (p = ˂0.001) and p = 0.002 for KVU 27-1 and K80 respectively) and Specific Leaf Area (p = 0.049) for KVU 27-1. The widest stem diameter was 0.4 cm in KVU 27-1 under Har and HarS fungal treatments. The highest Relative Water Content was 94 % in KVU 27-1 with the inoculation of HBB while the highest SLA was 657 g/cm2 in K80 with HarS inoculation. In addition, the interaction between water levels and fungal inoculations were observed in Stem Diameter, Relative Water Content and Specific Leaf Area. The combined inoculation of HarS and HBB had the greatest influence on the shoot nutrient levels for both cowpea varieties. The highest N and P shoot content were 3.7 % (in KVU 27-1) and 0.12 % (in K80) inoculated with HBB and HarS respectively. The highest K content was 2.7 % in both varieties inoculated with HarS. Mycorrhizal colonization increased with increase in soil water level with the highest root colonization percentage of 37.8 % at 90 % FC. From the study, the co-inoculation of HarS and HBB was the most appropriate to enhance growth and nutrient uptake in the cowpea varieties. Therefore, these two treatments are recommended to be incorporated on agricultural soils to enhance plant growth.Item Impacts of Landscape and Flowering Seasons on Preference, Diversity and Quality of Honeybee-Collected Pollen in Murang’a County, Kenya(Kenyatta University, 2024-09) Koech, SheilaHoneybees are eusocial insects which live in highly organized colonies. Honeybees forage on nectar and pollen from flowering plants. Corbicula pollen is the pollen found in the hind legs of honeybees. Honeybees exhibit a generalist behavior, making it relatively simple to discern a diverse array of flowering plants based on the pollen they gather. Understanding the role of landscapes and flowering seasons is essential for pollinator health, particularly in agricultural landscapes such as Murang’a (Kenya), where landscape exhibits significant fragmentation, with cultivated crops replacing the original natural vegetation. This study involved the assessment of both the quality and quantity of corbicula pollen and examining how they fluctuated across flowering seasons and landscapes. Sampling of honeybee-collected pollen from 18 apiaries occurred monthly over a period of 12 months, encompassing three distinct landscape types (low, medium and high) classified using the Normalized Difference Vegetation Index (NDVI). Floral origins were identified through palynological analysis, protein content quantified via spectrophotometric analysis, and the types and levels of pesticide residues were determined using QUECHERS method. Pollen Hazard Quotient (PHQ) was employed to assess the potential risk to honeybees posed by each identified pesticide. Results showed that plant families Lauraceae and Poaceae were the most abundant at 20.5%. The months of February, June and July exhibited the highest polled diversity. Pollen protein ranged between 0.01 - 7.11 % with the plant families Fabaceae, Lauraceae, and Solanaceae having the highest average amounts of crude protein (7.11, 6.87, & 6.66%, respectively). Cupressaceae and Rosaceae recorded lowest amounts (0.39 and 0.01, respectively). The month of November (2019), March, June and August-2020 recorded the highest amounts of protein respectively. 11 pesticide residues were detected with concentrations between 0.1 to 1203 µg kg-1. Two fungicides (Carbendazim and Trifloxystrobin) and nine insecticides (Acephate, Carbofuran, Chlorpyriphos, Imidacloprid, Spinosyn A and D, Thiamethoxam, Acetamiprid, and Indoxacarb) were detected. Insecticides (81.8%) were the most widely used, while fungicides (18.2%) were the least used. The pesticides were identified in 11 plant families, with Asteraceae and Poaceae being the most heavily contaminated, accounting for over 60% of the detected pesticides. The results suggest that honeybees collect pollen from a wide variety of flowers. Honeybee-collected pollen vary in terms of their diversity, abundance, crude protein content across the sampling time. Honeybee-collected pollen was also found to contain pesticide residues. while land use may not correlate with the quality or quantity of available pollen resources, the nutritional landscape of Murang’a is seasonally dynamic in terms of bee forage hence imposing seasonal resource limitations. There is a need to supplement domesticated bees with alternative non-contaminated pollen sources due to the seasonal resource limitations.Item Ecological Impacts and Utilization of Urtica Dioica L. In Nyeri County, Kenya(Kenyatta University, 2024-05) Wairimu, Joseph KamichaABSTRACT Though the stinging nettle (Urtica dioica L.) is categorized globally as an invasive species, the plant is a source of vital nutrients and an ingredient in many local medicine practices. However, there is inadequate information on the edaphic factors enhancing the invasiveness of U. dioica, the subsequent impact on local flora diversity, and upcoming value-addition opportunities. Hence, this study sought to determine the invasive effects of U. dioica on herbaceous plants density and diversity. Then analyze the relationship between U. dioica density with soil mineral contents and investigate the market presence of raw and value-added products. Lastly, this study intended to document local knowledge of U. dioica in Nyeri County, Kieni Sub County areas namely; Endarasha, Charity, and Watuka. Sites with high colonization of U. dioica were purposively identified. Based on land use types, Stratified random sampling method was used to place five transects each measuring one hundred metres long. Ten quadrats each measuring one square metre in roadside, riverbank, pastureland, residential, and cropland areas were used for data collection. Fifteen soil cores were taken from each land use type and mixed to form soil samples for each land use type in Endarasha, Charity, and Watuka. Questionnaires were administered to 196 respondents from the study area. Results from Pearson correlation analysis between the density of U. dioica and other herbaceous species indicated that there was a strong negative correlation between the density of U. dioica and other herbaceous species diversity (r=-0.8). One-way ANOVA showed significant statistical differences in the concentration of nitrogen (F=4.8495, df=4, 14, p < 0.05) and phosphorous (F=4.3589, df=4, 14, p < 0.05) among different land types confirming their different impacts on U. dioica density. The study also established that locally, U. dioica is used in the food, medicine, and veterinary sector. Such consumption could indicate the economic potential of the plant species in the local cottage industries to support the government's manufacturing agenda. This study recommends increasing public awareness of the benefits of U. dioica to boost its consumption hence reducing its invasiveness.Item Salinity And Sodicity Induced Responses on Germination, Growth and Phenolic Compounds Accumulation in Cowpea (Vigna unguiculata (L) Walp)(Kenyatta University, 2023-07) Mutuku, Titus; Adelaide Mutune; Edward George MamatiAbstractItem Impact of Salinity on Growth, Physiological Traits and Yield of Butternut Squash (Cucurbita Moschata L. Mellonia) Varieties in Mwea, Kenya(Kenyatta University, 2023) Njoroge, Mary Nyambura; Moses P.Hungu Gathaara; Raphael K. WanjoguKenya occupies approximately 60 million ha out of which 80% is cloaked by the arid and semi-arid lands (ASAL) which is susceptible to salinity as dryness aggravates salinity. Growth of non-staple food has been adopted by farmers in these areas with butternut squash being one of them. It is cultivated widely as it requires less rainfall and little labor yet it has a high nutritional value and a ready market contributing to the incomes of small holder farmers. Little research on butternut squash has been carried out despite its economic potential and information on growth, physiological response and yield of butternut squash varieties to salinity is scarce. This study was aimed at evaluating salinity effects on growth, selected physiological traits and yield of Waltham and Jupiter F1 hybrid butternut varieties. Waltham and Jupiter F1 hybrid were subjected to Sodium Chloride treatments of 0, 25, 50, 75 and 100 mM. A randomized complete block design was used with 3 replicates. Thirty plots each measuring 4.5 m long and 1.2 m wide were established. A net plot measuring 1.5 m long and 0.4 m wide, made of 4 plants was established in each plot from which data were collected. The data that was recorded include: germination percentage, number of leaves and leaf area, the height of plant at seedling stage and length at mature stages (vegetative stage and after harvesting), plant girth, transpiration rate, photosynthetic rate, stomatal conductance, chlorophyll concentration, fruit number per plant, fruits weight, shoots and roots fresh and dry weight. The data collected were subjected to ANOVA using SAS computer software. LSD was used to separate the means at 5 percent level (p<0.05). Salinity reduced significantly (p<0.05) the growth parameters, selected physiological traits and yield. The highest decrease was noted at 100 mM. Adverse effects of salt was low on Jupiter due to its high performance and yield hence it is more tolerant to salinity stress compared to Waltham. Jupiter may be recommended for saline affected areas. Further studies could also be done on Jupiter through future breeding programs as a source of salt tolerant genes.Item Assessment of Germination Potential and Population Status of Melia Volkensii Gürke in Kitui County, Kenya(Kenyatta University, 2022) Njehu, Jane Mukami; Emily Wabuyele; Adelaide MutuneMelia volkensii Gürke is a native tree species that grows in the arid and semi-arid areas of East Africa. There has been overutilization of this tree which may lead to risk of rapid decrease in its community and genetic diversity. Additionally, planning and implementing planting programmes and conservation plans of M. volkensii have been hindered by insufficient knowledge on its seed storage behavior. This study sought to develop optimal protocols for seed germination and assess population status of Melia volkensii to enhance conservation and supply chain management in Kitui County. Melia volkensii fruits were collected from Tiva Forest and the germination experiment was carried out in KEFRI Kitui within nursery conditions. Seed germination experiments were arranged in a completely randomized design with three factors – extraction state, storage container and storage temperature. For extraction, seeds were divided into two lots – extracted seeds and unextracted seed (nut). Two types of storage containers were used namely sealed and unsealed. The storage temperatures were room temperature (30oC) and cold storage (-20oC). Germination tests were done before storage, and later after 2, 4 and 6 months in storage from each of the storage conditions. A hundred seeds and nuts each were sown for each experimental unit. The rate of seedling sprouting was recorded for a duration of 10 days as a percentage of seeds sown. Variation in germination percentages “was tested using two-way analysis of variance (ANOVA) at 95 % confidence interval and means separated using fisher’s protected least significant difference” in R and SAS statistical software. The highest percentage (89 %) was scored in nuts kept in unsealed containers at 30oC at 6 months and the lowest (14 %) in seeds stored in similar conditions for 2 months.The differences were significant. These results indicate that the germination rates of M. volkensii seeds increased with increase in period of storage. Additionally, plant population was determined in situ across seven transect lines measuring 1050 meters in length. Sampling was carried out in five plots measuring 50 x 50 m established at intervals of 200 meters. Transect 1 and 7 were laid in farmland while the transects between these two were laid in bushland. All tree species represented in each plot were counted. “Height and diameter at breast height (DBH) were measured for all M. volkensii trees within the plots. Melia volkensii seedlings and coppices were counted in 5 x 5 m nested plots within the larger plots. One-way analysis of variance (ANOVA) at 95 % confidence interval was used to test for variance in parameters measured and means separated using Tukey’s HSD. There were significant differences in height and DBH” means of M. volkensii among transects. Transect 2 had the lowest mean height and DBH while the tallest trees were in transects 1, 3, 4, and 6. Transect 1 had highest mean DBH. Means of seedlings were not significantly different among transects. Coppicing was significantly highest in transects 1 and 4. Moreover, relative abundance, species richness and diversity of plant species observed were analyzed “using Simpson’s index of biodiversity and Shannon-Wiener species diversity index. Melia volkensii was the most frequently occurring species with 12.2% (n=67) followed by Acacia tortilis10.0 % (n=55). Calotropis strophela, Commiphora capensis, Maerua crassifolia were the least represented relative abundance of 0.18 %. Values of indices used varied among transects and did not follow the location of transect implying that diversity was not determined by land disturbance. In conclusion, nuts stored unsealed at room temperature have the highest longevity. Based on diversity and relative abundance of M. volkensii and associated tree species in the study area, tree exploitation in Kasaala Location does not cause depletion of M. volkensii.Item Mechanical, Diffusion and Degradation Behaviour oF Sausage Fruit Tree Fiber (Kigelia Africana) Reinforced Polypropylene Composites(Kenyatta University, 2022) Mueni, Nzioka Beatrice; Abdallah .S. MerengaPolypropylene is a thermoplastic polymer used in cement mortars, concrete, packaging plastics, and in re-usable containers. It is made from monomer propylene. It is economical and has a good resistance to fatigue in comparison to other polymers. Polypropylene is however non-biodegradable and liable to chain degradation especially in external applications evidenced by cracks and crazing. Previously use of U-V absorbing additives to curb external exposure degradation was increasing on cost and also unfavorable to the environment. The only solution to this is blending polypropylene with natural fiber (cellulose) to modify its structure. PP/Starch blends have poor rigidity, very low thermal stability and high diffusivity. Cellulose is rigid, has high diffusivity and thermal stability hence suitable in reinforcement of polypropylene. Research work is still going on how to improve the mechanical properties and lowering the density of the composites, as well as have biodegradable high performance engineering materials at low cost. This research investigated the mechanical properties, creep, thermal degradation, diffusion and biodegradation measurements of sausage fruit tree fiber reinforced polypropylene composites. Injection molded samples were used, where the fiber was first grinded in to fine powder. Dynamic mechanical analysis was carried out using torsion pendulum at temperature range 300 C to 100ºC. Creep measurements were performed at 30, 40, 50 and 600C .The time for deformation and recovery of sample was 12 minutes. Diffusion measurements were done at room temperature and mass difference monitored after 7, 30,60, and 90 days. Thermal degradation was done within temperature range 25 to 5500C at a heating rate 5 oC/min. Biodegrability was monitored by burying the samples 20 cm under soil. Mass difference monitored after 7, 30,60 ,and 90 days. Cellulose addition in small amounts increased the storage modulus (stiffness) and loss modulus of the polypropylene. Models of analysis for creep data were Burger model and Weibull model. Increase in cellulose loading decreased resistance to creep hence increased deformation. Water intake increased with cellulose loading. Fickian diffusion behavior was noted and diffusion coefficients increased from approximately 1.481×10-12 cm2/s to 1.646×10-10 cm2/s with cellulose loading. Thermal stability of the blends increased with cellulose loading (activation energy increased from approximately 69.22 to approximately 210.01kJ/mol). Biodegradability improved. Lifespan decreased from approximately 199 years for pure polypropylene to approximately 15 years for 20% fiber loading. When polypropylene is reinforced with cellulose the structural rigidity is improved, thermal stability, hydrophilicity and biodegradation increases. Use of SFTF particles in polypropylene matrix should be adopted since these PP blends are promising non-environmental pollutants.Item Assessment of Satisfaction with Postnatal Care Services Among Women Who Delivered In Embu Hospital, Embu County, Kenya(Kenyatta University, 2021) Wachira, Joyce W.; Harun Kimani; George OtienoSatisfaction among patients has progressively been acknowledged as a salient outcome within the delivery system of health care and there are numerous studies being done among developing countries. Majority of the women report low satisfaction with the postnatal care services compared to the other maternity care phases. The World Health Organization advocates that the women‟s satisfaction should be surveyed as a tool geared towards improvement of effectiveness and quality of maternal health care. The purpose of the study was assessment of satisfaction with the postnatal services offered in Embu Hospital among women who delivered in this facility. This study was directed by the following specific objectives; determining women‟s satisfaction with postnatal care services, determining influence of socio-demographic factors on women‟s satisfaction with postnatal care, establishing health system factors influencing satisfaction of postnatal women and establishing the influence of perceived quality of care on women‟s satisfaction. Research design used was descriptive cross-sectional. The population studied were postnatal women 15-49 years who had delivered in Embu hospital. The study applied systematic random sampling method and the sample size was 225 respondents. A structured client exit questionnaire, interviews with key informants and focused group discussion guide were used to collect data. Pretesting was done in Chuka hospital to ensure validity of the instruments. Reliability of research tools was decided through test-retest strategy. Authority to conduct this research was obtained from the Kenyatta University Ethical Review Committee and approval acquired from the National Commission for Science, Technology and Innovation. The study generated both quantitative and qualitative data. The statistical package for social scientists (SPSS version 20) was used for data coding and entry and analysis through descriptive and inferential statistics. Percentages, frequencies and cross tabulations were adopted to present data. The study outcomes uncovered that most women 54.6% were satisfied with postnatal care services provided with only 45.4% being dissatisfied. Findings from this study also showed that socio-demographic factors like age (P=0.759), marital status (P=0.667), education level (P=0.717), occupation (P=0.194) and monthly income (P=0.385) did not have a significant relationship with women‟s satisfaction with postnatal care. The study noted that the health system factor that influenced postnatal women‟s satisfaction was comfort and care (P= 0.008). Pertaining influence of perceived quality on satisfaction, it was noted that women from the FGD‟s associated quality with tangibles like clean hospital environment, availability of resources and staff. Majority of the key informants ranked the quality of postnatal services as good. The study concluded that some women 45.4% were still dissatisfied with the postnatal care services provided in this facility. The study recommends that the county government in liaison with the hospital administration should have frequent patient satisfaction surveys which can help to provide feedback to customers hence improving the satisfaction of the clients. Recruitment and employment of more qualified staff by the county government to enhance the quality of postnatal care provided.Item Assesment of Carbon Sequestration and Biomass Accumulation of Managed and Natural Mangrove Plantations of Mida Creek, Kilifi County Kenya(Kenyatta University, 2021) Omollo, Kevin, Ogolla; Najma Dharani; Benards OkeyoMangrove forests play a significant role along the coastal environment throughout the tropical coast. They provide ecosystem services that are able to sustain both flora and faunal organisms found in such ecosystems. They are stores of large quantities of carbon in their biomass hence referred to as carbon sinks. This carbon can be emitted into the atmosphere when mangrove forests are degraded through unsustainable utilization. With accurate quantification of carbon stocks in these forests, it will be easy to define their potential role in global climate regulation through their carbon sequestration ability. Since the sequestration potential of the replanted managed mangrove species of Mida Creek is unknown, this indicates an information gap which calls for bridging to help develop a baseline inventory data for effective forest conservation and management. The main objective of this study is to quantify the amount of carbon sequestered by the managed mangrove forest of the Mida Creek, Kenya. Three sites were selected for this study; 15 year-old Kibusa Plantation, 20 year-old Green Island Plantation, and a Natural Stand. Fifty Plots in the plantations and sixty plots in the natural stand of (10 x10) m2 were selected in each study site. Three carbon pools were investigated; aboveground carbon, belowground carbon, and soil organic carbon. Biomass for carbon determination in Kibusa and Natural Stands was estimated using a general allometric equation. Aboveground carbon was determined by measuring the diameter at breast height using a DBH meter. Belowground biomass and soil organic carbon was determined through root coring method using a soil corer at different depth profiles. Mean total carbon stocks in Kibusa and Green Island Plantations was 424.52±11.68 Mg C/ha and 958.57±50.01 Mg C/ha while the natural stand contained significantly higher total Carbon stocks of 2159.77±31.09Mg C/ha. There was no significant difference in the amount of soil organic carbon among the three different sites (F0.05(1)2,15=0.35, p>0.05). This study indicates that reforestation enhances structural development of replanted mangroves and that replanted mangroves are significant carbon stores. Rhizophora mucronata species was found to be the most abundant species compared to all the other species in all the three study sites, with an Importance Value Index of 117.1. In addition, Ammonium, Phosphates and Nitrates from the soil were also determined. Ammonium was the most abundant nutrient in all the three study sites. High Ammonium concentration in the mangrove sediment led to high amount of carbon sequestered in the root biomass. Therefore high ammonium concentration in the soil leads to increase in amount of carbon sequestered in the root biomass. From these results, we can deduce that awareness should be raised among the community members on the need for conservation and reforestation that will increase the amount of carbon sequestered since more mangroves increase the amount of carbon (IV) oxide capture. This will help in mitigating the issue of global warming at local levels.Item Effects of Conservation Tillage on Soil Moisture, Chemical Properties, Maize and Bean Physiological Parameters and Yields in Embu County Kenya(Kenyatta University, 2021) Kyalo, Munyao Joseph; Moses Hungu Gathaara; Alfred N. MicheniProduction of Zea mays L. and Phaseolus vulgaris L. has been lagging at 1.8 and 0.5 t/ha respectively. Yield potentials are 6.0 and 2.5 t/ha for maize and bean respectively. This is attributed to frequent dry spells and low soil fertility. Sustainable agricultural approaches such as conservation tillage (CT) have been embraced by farmers and have contributed to improvement in chemical and physical properties of soil and crop yields. However, the physiological basis of the observed yield increase due to CT practices has not yet been reported hence the study. Objectives of the study were: to assess CT practices effects on soil moisture, soil chemical properties, maize and bean physiological parameters and yields. The study was carried out in two seasons at the Kenya Agricultural and Livestock Research Organization farm in Embu County. Experimental design was a split-plot arranged in a randomized complete block design with nine treatments replicated three times. Conservation tillage practices comprised Zero tillage (ZT) and Furrows/ridges (F/R) evaluated against conventional tillage (CVT). The test crops were maize and beans grown as intercrops or monocrops. Key data sets were: soil moisture, soil chemical properties, maize and bean physiological parameters and yields. Soil moisture was measured in each plot twice per month by the use of a PR2 moisture probe. Laboratory analysis of soil samples for organic carbon followed the Walkley and Black method, whilst Nitrogen analysis followed the Kjeldahl method. Analysis of Variance (ANOVA) was used to analyze all data sets with the Statistical Analysis System computer software (SAS). Treatment means differences were compared using Fisher’s least significant difference test. The CT (ZT and F/R) practices led to increase in soil moisture content, soil organic carbon, and soil nitrogen and soil pH that was significant (p ≤ 0.05). Significantly (p ≤ 0.05) higher nodules, chlorophyll concentration, sugars and starch were obtained for the beans under CT plots compared to those under CVT. The beans grown under F/R plots had grain yields of 1.3 t/ha in SR 2015 and 1.4 t/ha in LR 2016 in comparison to those grown under CVT plots which had grain yields of 1.2 t/ha in SR 2015 and 1.3 t/ha in LR 2016. Maize under CT plots had significantly (p ≤ 0.05) higher leaf area index, chlorophyll concentration, sugars and starch compared to those grown under CVT plots. Maize grain yield under ZT plots was 1.8 t/ha in SR 2015 and 2.2 t/ha in LR 2016 and that under F/R plots was 1.7 t/ha in SR 2015 and 2.1 t/ha in LR 2016 Maize grain yield under CVT plots was 1.8 t/ha in SR 2015 and 2.3 t/ha in LR 2016. It can be concluded that CT is a suitable technique for conserving soil water for plant use, improving soil health and crop physiological parameters hence the increased crop productivity. This study recommends the adoption of CT practices to enhance production of crops and ensure security of food for the studied area and other regions with comparable agro ecological conditions.Item Economic and Ecological Valuation of Mangrove Forest at Mida Creek in Kilifi County, Kenya(Kenyatta University, 2021) Olima, Cecilia Oyuga; Paul Muoria; Margaret Awuor OwuorMangroves are considered a highly productive blue forest providing services that are important to the community both locally and globally. Increasing human population and demand for natural resources is threatening the existence of these forests. The concept of ecosystem services and its valuation helps in educating and informing people of the benefits and cost of their decisions. There is need to provide a simplified approach to identify, assess and quantify ecosystem services. This study assessed the value of harvested goods and coastal protection services provided by mangroves of Mida Creek in the current and plausible future scenarios. The study adopted the methods described in the Toolkit for Ecosystem Services Site-based Assessment (TESSA). Data was collected using primary techniques (focus group discussions, key informant interviews, spatial methods, household interviews and field measurements), and secondary data (data on wind speed and coastal protection values). Descriptive statistics was used to summarize quantitative data. The coastal protection value of mangroves was extrapolated from secondary data. This study estimated the annual current value of harvested goods in Mida Creek to US$ 11.3 million (US$ 6,869.5ha- yr.-). The value was expected to increase to US$14.2 million in the conservation scenario but reduce to US$ 10.9 million in the business-as-usual scenario. The study also established that a wider mangrove bandwidth offers better protection against coastal hazards as opposed to a narrow bandwidth. The value of coastal protection in the current scenario was estimated to be US$ 5.1 Million per year. It is likely to increase to US$ 5.7 Million per year in the conservation scenario and was estimated to reduce to approximately US$ 5.0 million in the business as usual scenario. From, these results, raising awareness among stakeholders on the importance of sustainable use of the natural resources as demonstrated by the value of ecosystems services that would be lost or gained if the mangrove of the Mida Creek is altered is necessary. These findings also add to growing literature on ecosystem services valuation and the need to use site specific non modelling tools like TESSA.Item Morphological and Molecular Characterization of Cultivated Dioscorea l. (Dioscoreaceae) from Selected Counties in Kenya(Kenyatta University, 2021) Atieno, Valentine; Grace Gatheri; Joseph W. KamauYam (Dioscorea species) is one of the underutilized and neglected tuber crops in the country. Earlier studies indicated the need for further research to establish the phylogeny of Kenyan yams through molecular methods. This study aimed to characterise Dioscorea spp. using morphological and molecular methods. Twenty-four specimens from five growing areas; Meru, Embu, Taita-Taveta, Busia and Bungoma counties were collected directly from farmer’s fields. Herbarium voucher specimens were collected and deposited at the Kenyatta University Herbarium. Morphological data were recorded in the field using characters stated in the IPGRI’s descriptor of Yams. The collected Dioscorea spp. specimens were identified into; D. minutiflora Engl., D. alata L., D. bulbifera L. and D. cayenensis Lam by twining direction, flesh colour, tuber shape, presence and absence of wings, presence and absence of spines and flowering or non-flowering. Spine density was significant in characterising D. minutiflora Engl. which had spines on the stem bases. D. alata L. was distinguished based on its four-angled stem and petioles that were all purplish-green with a purple base, elongate tuber shape and white tuber flesh colour. Dioscorea cayenensis Lam. was distinguished based on its yellow tuber flesh colour and cylindrical tuber shape. All the other species twined to the right in an anticlockwise direction except D. bulbifera L. which twined to the left in a clockwise direction and produced aerial tubers that were irregular in shape. Based on cluster analysis, all 24 specimens were grouped into three clusters. Cluster 1 had D. minutiflora Engl. Cluster 2 contained three sub-cluster groups of D. alata L., D. bulbifera L. and D. cayenensis Lam. Cluster 3 grouped a few D. minutiflora Engl. Principal Component Analysis showed the correlation between the different morphological characters, and most of the correlation was between PC-1 and PC-2. The distribution of species based on PC-1 and PC-2 showed the distantly related species in each quarter; D. alata L. (1st quarter), D. bulbifera L. (2nd quarter), D. cayenensis Lam. (3rd quarter) and D. minutiflora Engl. (4th quarter). Seventeen leaf specimens were selected for DNA extraction and observation made using rbcL marker. The genotypes were grouped to two main clusters. Dioscorea minutiflora Engl. and D. burkilliana J. Miege clustered together as one genetic group. However not all D. minutiflora Engl. species were in one specific cluster hence showing that there may be variation within the species. Dioscorea alata L. and D. bulbifera were seen to be potentially related. Generally, the rbcL marker demonstrated the phylogeny of Kenyan Dioscorea spp. Comparison of morphological and molecular data analysis gave similar results. The phylogenetic relationships of Kenyan Dioscorea spp. was established and morphological and molecular characterisation was efficient in establishing species relatedness among Dioscorea spp. Further study can be done with an emphasis on the use of more than one molecular marker.Item Prevalence of Campylobacter Jejuni and Other Bacterial Pathogens in Selected Foods and Drinks Served in Fast Food Kiosks in Ngara and Burma Markets in Nairobi(Kenyatta University, 2016) Odhiambo, Winnie AwuorEnteric pathogens such as Salmonella, Shigella, E.coli, Vibrio and Campylobacter are easily transmitted when contaminated food is consumed, ending up in outbreaks. Campylobacter is one of the most important pathogens as it can cause infections which may lead to health complications that could be fatal. Limited data exist on Campylobacter infections from fast food kiosks in Kenya. This study was aimed at determining the risk factors of campylobacteriosis, microbial load in water, milk and cooked chicken, survival rates and identify other pathogens in the food and water served at commercial catering points in Nairobi's Ngara and Burma markets. A questionnaire was administered to food vendors to obtain information on the risk factors associated with Campylobacteriosis. A total of 135 samples; chicken (45), water (45) and milk (45) were sampled and their microbial load determined by colony count. Campylobacter isolation was done using charcoal cefoperazone desoxycholate agar and confirmed by biochemical tests, while other enteric were isolated through standard bacterial culture and isolation techniques. Survivalrates of these isolates in varied temperatures were evaluated. Age, education level, occupation, undercooking of chicken, site of processing chicken, source of milk, storage of milk, source of water and method of treating drinking water were found to influence transmission of Campylobacter, while hand washing and serving of food by chicken processors were not found to influence the transmission of Campylobacter. The microbial load in chicken was 111.738 x 10 4 CFU/ml and 67.893 x 104 CFU/ml in Burma and Ngara markets respectively, while in milk, it was 115.673 xlO 4 CFU/ml and 160.354 xlO 4 CFU/ml in Burma and Ngara market respectively. Microbial load in water was determined by the most probable number technique, the load was 3.083331100 ml and 3.54167/1 00 ml in Burma and Ngara market respectively. There was no significant difference in the Microbial load across the samples; milk (p<0.0396), chicken (p<0.0053) and water (p<0.3805) in both Ngara and Burma markets. Temperatures below the optimum growth temperature for C. jejuni (42°C) generally seemed to have inhibitory effect on the population of the organism. Survival of Campylobacter was poor in water and chicken at room temperature (25°C) while in chicken and milk stored at 4°C, Campylobacter had higher survival rates. Chicken in Burma market, 6 (13.3%) had the highest prevalence of the pathogens; Salmonella, Shighella and Vibrio isolates were detected with E coli as the most prevalent npathogen. This research has shown that the food eaten in most urban centres of Ngara and Burma market pose high risk to infection hence warranting consistent surveillance. Proper storage of food and drinks after they have been thoroughly boiled is recommended.Item Human Use of Forest Trees and its Impact on Tree Diversity and Abundance in Chemususu Forest, Baringo County, Kenya(Kenyatta University, 2020) Kipkoech, Morogo HoseaTrees provide both direct and indirect benefits to humans, who depend on them for their livelihoods. Forest ecosystems are vulnerable to over-utilization and exploitation due to the sensitivity of its complex and highly diverse ecosystem. The aim of the study was to determine the human impact on tree species diversity, abundance, plant population structure and uses of forest trees by local communities adjacent to Chemususu forest Reserve in Koibatek Sub-County, Baringo County. Questionnaires and interview schedules were used to collect data on uses of trees; the target group were households within 3km stretch from the forest edge. The data on trees species, diversity, abundance and plant population structure was collected by systematic sampling using six parallel belt transects each starting from the forest edge. Sampling was conducted in quadrats of 20m x 20m (for trees) located along the transects at 500m intervals. In each of the quadrats, all the trees species were identified, counted and diameter at breast height (DBH), measured at 1.36m outside the bark to the nearest cm. Indicators of human disturbance were assessed to determine the extent of human impact. The Statistical Package for Social Sciences (SPSS) was the main tool for quantitative data analysis from both questionnaires and interview schedules. Analysis of Variance (ANOVA) was used to test whether the mean number of cut stems and debarked trees varied with distance from forest edge. ANOVA was also used to test for variation in the mean diversity indices, tree species abundance and DBH with distance from forest edge. In both cases, tukey test was used to separate the means. Shannon-Wiener Diversity index (Magurran, 1988) was computed. Pearson’s correlation was carried out to determine the relationship between abundance of cut stems and debarked trees with distance from human settlement in each study plot and to investigate the relationship between mean species abundance, diversity, and DBH with distance from human settlement. Majority of the local residents had stayed in the region for more than 15 years and perceive the forest as important for various uses, 98.4% for spiritual and cultural purposes, timber (97.52%), tourism and recreation (96.3%) and hunting (97.1%).Three trees species, Olea europaea, Dombeya torrida and Olea capensis were used for firewood as well as charcoal and formed a large proportion of used trees. Trees used for timber Juniperus procera, Podocarpus falcatus and the exotic cupressus lusitanica had been heavily extracted. There was no significant relationship between the number of charcoal kilns and distance from the forest edge (r = - 0.849; P=0.069). This also applied to the number of plots with evidence of pit sawings with distance from the forest edge (r = 0.555; P =0.333) but the number of plots with split stems decreased significantly with distance from the forest edge (r = -0.892; P = 0.043).There was no significant variation in the mean number of cut stems and mean number of debarked trees with distance from human settlement (F(4, 25) =0.082; P= 0.546) and (F (4, 25) =1.795; P=0.162), respectively. Tree diversity did not vary with distance from human settlement (F (4, 25) = 1.67; P=0.189).There was a significant difference in the mean number of trees in different DBH classes (F (4, 25) = 5.181; P =0.002). The number of trees on the lower DBH classes was more than those on the higher classes at various distance intervals, but this difference was not statistically significant. The study showed that the community role in forest degradation was significant and they highly depended on it for their livelihood. Thus, it was important to understand the relationship between the community and the forest. Alternative sources of trees used for timber and charcoal should be encouraged to reduce pressure on forest trees.