Abstract Nutrient enrichment is one of the most serious threats to wetland ecosystems. Information is lacking, particularly concerning the response of wetland plants species in Kenya in regard to nutrient enrichment of wetlands. Understanding the mechanisms and adaptations that allow only certain species to thrive in the potentially stressful wetland environment requires the study of the biology of these plants. This study was carried out to investigate the growth and nutrient uptake among s...
Abstract Physical characteristics of green coffee bean have been reported to affect beverage quality to some extent. The objective of this study was to assess the beverage quality and green bean physical characteristics of forty two arabica coffee genotypes and to determine the relationship between the two attributes. Green bean physical characteristics were assesed through actual measurements, grading and weighing while beverage quality was determined by a panel of seven judges using the pr...
Abstract Climatic variability is the main factor responsible for the fluctuations in the coffee yield in the world. The relationships between the climatic parameters and the agricultural production are quite complex, because environmental factors affect the growth and the development of plants under different forms during the phenological phases of the coffee crop. Such environmental factors include reduced rainfall and high temperatures both of which majorly contribute to drought. This pape...
Abstract Biochemical composition appears to be influenced by both genetic factors and plant growth conditions. The main objective of this study was to evaluate the biochemical composition of selected Ruiru 11 sibs and its relationship with cup quality. Thirty four (34) Ruiru 11 sibs grown in three different locations in Kenya were used in this study. The experiment was laid out in a Randomized Complete Block Design with three replications. Coffee cherries were picked during the peak harvesti...
Abstract Knowledge of the effects of environment and genotype by environment (GxE) interaction is important to breeders in making decisions regarding the release of new cultivars. Five Coffea arabica lines coded CR8, CR22, CR23, CR27 and CR30 have been developed by Coffee Research Foundation and are currently being tested for release in various coffee growing zones in Kenya. The objective of this study was to determine the performance of the five advanced breeders’ lines under varying envi...
Abstract Bacterial Blight of Coffee (BBC) caused by Pseudomonas syringae pv garcae has become of major concern in Kenya due to its increasing incidence and severity. For decades, the disease was confined within and to the west of the Great Rift Valley, but recently it has spread to reach other coffee growing areas. In order to minimize the chemical input in its management, which apart from polluting the environment have high cost implications, development of resistant/tolerant cultivars is h...
Abstract Knowledge of the effects of environment and genotype by environment (GxE) interaction is important to breeders in making decisions regarding the release of new cultivars. Five Coffea arabica lines coded CR8, CR22, CR23, CR27 and CR30 have been developed by Coffee Research Foundation and are currently being tested for release in various coffee growing zones in Kenya. The objective of this study was to determine the performance of the five advanced breeders lines under varying environ...
Abstract Roundup degrading bacteria were isolated from the soil and gut of fungus cultivating termites Macrotermes michaelseni using MM7 media supplemented with the pesticide as the sole source of carbon and energy. The isolates were gram negative rods the isolate from the soil was designated GS1 while that from termite gut was designated GT2. The 16S rRNA gene sequence of the isolates revealed that isolates Both isolates GS1 and GT2 are closely related to Enterobacter sp AY 0822447 with 99%...
Abstract Presently, the food chains of the famous saline alkaline flamingo-lakes of East Africa are the focus of intense scientific discussion as the lakes host toxic cyanobacteria, which when consumed by Lesser Flamingos, weaken the birds and therefore make them susceptible to attacks by infective diseases. The distribution, genetic and toxicological aspects of Microcystis in Kenya has been studied extensively. Although there are reports on the occurrence of Microcystis in Kenya’s hypersa...
Abstract Greywater recycling has been identified as an efficient method to conserve water. The purpose of this study was to investigate some selected hydrochemical characteristics, plant nutrients and metal content of greywater and soils in residential areas of Homa Bay town. Laundry greywater had the highest pH (9.1 ± 0.01), Electrical conductivity (2900 ± 215 S cm-1) and salinity (0.4 ± 0.02 - 0.8 ± 0.01 mg L-1). The lowest electrical conductivity (400 ± 50 S cm-1) was recorde...
Abstract A non-culture approach was used to study the archaeal diversity in Lake Elmenteita, Kenya. Five different sampling points were selected randomly within the lake. Wet sediments and water samples were collected from each sampling point. In addition, dry mud cake was collected from three points where the lake had dried. DNA was extracted from these samples and the 16S rRNA genes were amplified using primers described to be Domain-specific for Archaea. Eleven clone libraries were constr...
Abstract Africa supports a population of over 1 billion people with over half of them depending on maize for food and feed either directly or indirectly. Maize in Africa is affected by many stresses, both biotic and abiotic which significantly reduce yields and eventually lead to poor production. Due to the high demand for maize in the region, different improvement strategies have been employed in an effort to improve production. These include conventional breeding, molecular breeding, high ...
Abstract Objective: To determine the phenology, dry matter yield, grain yield and yield components of chickpea under four tillage methods and three sowing times within a semi-arid area of Kenya. Methodology and results: Field experiments were carried out at the National Animal Husbandry Research Centre, Naivasha, Kenya, between 2005 and 2007. Four tillage methods (Conventional, Strip, Furrow tillage, and double digging) and three sowing times (at onset, one week, two weeks after onset of rai...
Abstract In insect species characterized by inbreeding, limited dispersal, and a metapopulation structure, high genetic differentiation and reduced genetic diversity within local populations are expected. Using the model system Lysiphlebus hirticornis Mackauer, a specialist parasitoid of the tansy aphid, Metopeurum fuscoviride Stroyan (Hemiptera: Aphididae), we examined within-site temporal population dynamics and genetics, including molecular variation at the tansy plant level. Aphid-parasi...
Abstract The gap between maize demand and regional supply is increasing as small-holder farmers grapple with many challenges, key among them drought. Research in identifying maize lines that are tolerant to water deficit and that are amenable to A. tumefaciens-mediated transformation is a step towards enhancing food security. The objectives of this study were, to assess the physiological response of tropical maize inbred lines to water deficit, to determine whether A. tumefaciens elicits hos...