Abstract Background: Peasant agroecosystems in Kenya are considered to be a continuum of integrated traditional farming systems and natural ecosystem conservancy programs. Hyphaene compressa (doum palm) exists in arid and semi-arid lands (ASAL) of Kenya. While research in these areas is focusing on new plants to be brought to the areas, there is no focus on doum palm, which is already adapted to these areas. Scanty ethnobotanical knowledge exists in the form of unpublished material. The stud...
Abstract Named after Hermann L. F. von Helmholtz (1821-1894), Helmholtz equation has obtained application in many elds: investigation of acaustic phenomena in aeronautics, electromagnetic application, migration in 3-D geophysical application, among many other areas. As shown in [2], Helmholtz equation is used in weather prediction at the Met O ce in UK. Ine ciency, that is the bottleneck in Numerical Weather Prediction, arise partly from solving of the Helmholtz equation. This study investig...
Abstract Aims: The aim of this study was to determine the effect of different watering regimes on selected coffee genotypes and to evaluate drought tolerance among selected coffee genotypes. The study also aimed at determining the optimum watering interval for these genotypes under high temperature conditions. Study Design: Completely Randomized Design (CRD) with 3 replications. Place and Duration of Study: The experiment was conducted in a greenhouse at Coffee Research Station in Ruiru, Ken...
Abstract African nightshade, Solanum nigrum L .is one of the most important leafy vegetable rich in nutritional and medicinal value, can be used to feed people with human immune deficiency virus, HIV/AIDS in Kenya. This study was conducted to morphologically characterize thirty African nightshade accessions in order to establish the level of genetic variation amongst them. The limited information available on this species hinders their sustainable conservation and development. Existing knowl...
Abstract Irrigation water management is necessary for a successful irrigation system. Knowledge and tools on irrigation management is thus a requisite for profitable and sustainable use of the scarce water resources in Kenya. The study determined the irrigation water requirement of tomato (Solanum lycopersicum L.) crop in Rachuonyo catchment using CropWat model and the area climate, soils and tomato crop data. The study findings indicated that crop evapotranspiration (ETc) and net irrigation...
Abstract The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a worldwide pest of gramineous crops and a major pest of corn. Kenya has, in the recent years, reported massive outbreaks of this pest causing huge economic losses in maize fields. The indiscriminate use of insecticides has led to the evolution of insecticide resistance. This presents serious challenges to the control of pests including fall armyworm. The fall armyworm infestation has greatly threatened food security in Keny...
Abstract Cassava (Manihot esculenta Crantz) is a food and industrial storage root crop with substantial potential to contribute to managing risk associated with climate change due to its inherent resilience and in providing a biodegradable option in manufacturing. In Africa, cassava production is challenged by two viral diseases, cassava brown streak disease (CBSD) and cassava mosaic disease. Here we detect quantitative trait loci (QTL) associated with CBSD in a biparental mapping population...
Abstract Precision agriculture (PA) has a huge potential for growth in sub-Saharan Africa (SSA), but it faces a number of social-economic and technological challenges. This study sought to map existing PA research and application in SSA countries following the methodology for systematic mapping in environmental sciences. After screening for relevance, the initial about 7715 articles was reduced to 128. Results show that most of the studies were conducted in countries with socio-economic and ...
Abstract Majority of reported work on coffee breeding primarily concerns agronomic improvement that directly impinges on coffee quality. However, it is crucial that coffee breeding programmes for disease resistance also include coffee quality improvement since consumer awareness about the quality of different coffees has increased. The aim of this study was to determine the variation and associations of cup quality parameters and resistance against Coffee Berry Disease (CBD) in Coffea arabic...
Abstract Coffee Leaf Rust (CLR) is a fungal disease caused by Hemileia vastatrix Berk et Br. and is one of the major diseases of coffee. It causes premature leaf fall, yield loss and even death of the tree in severe cases. Coffee genotypes respond differently to biotic factors. This study was aimed at identifying potential sources of resistance genes to the disease. Forty five Coffea arabica L accessions were evaluated for their response to CLR under field conditions. CLR infection was asses...
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...