Browsing by Author "Okumu Oliver"

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    Effect of Time after Incorporation of Lablab Green Manure on Root Rot Pathogens and Establishment of Common Bean (Phaseolus vulgaris L.)
    (World Journal of Agricultural Research, 2018) Okumu Oliver; Muthomi James; Ojiem John; Narla Rama; Nderitu John
    Green manure incorporation is important for restoration of soil quality, particularly buildup of organic matter and supply of nutrients to plants. However, undecomposed plant residues reduce crop establishment and plant stand. Therefore, there is need to determine suitable time for green manure incorporation before planting. The effect of time after incorporation of lablab green manure on soilborne pathogens and bean crop establishment was evaluated by incorporating 12t/ha of lablab green manure at planting and at 7, 14, and 28 days before planting. Soil samples were collected before and after incorporation of green manure at planting, and at two, four and six weeks after planting. Data was collected on crop emergence, plant stand, yield, incidence and severity of root rot, and population of root rot pathogens. Incorporation of lablab residues 28 days before planting resulted in 21% improvement in germination, with corresponding reduction in root rot incidence and severity of 8% and 36%, respectively, compared to plots incorporated with green manure at planting. Plots incorporated with lablab green manure earlier before planting had reduced population of root rot pathogens, while those incorporation at planting excited the population of root rot pathogens and also had up to 71% reduction in grain yield compared to plots where lablab residue was incorporated 28 days before planting. The results of the study showed that a period of 28 days between Lablab green manure incorporation and planting is necessary to allow for proper decomposition, resulting in a reduction in root rot incidence and an increase in grain yield.
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    Evaluation of Common Bean Production Systems and Fertilizer Use in Nandi South
    (University of Nairobi, 2017) Okumu Oliver; Muthomi J.; Narla R.; Nderitu J.; Lauren J.; Ojiem J.
    High fertilizer cost and increased concern for ecological sustainability have led to improved interest on green manure and organic fertilizer. The study evaluated common bean production systems and organic fertilizer use by farmers in Nandi South. A semi structured questionnaire was administered to individual farmers in the form of interviews and the data was analyzed through descriptive statistics, frequency counts and percentages. Results showed that majority of the farmers were women with a mean age of 51.6 years. Many farmers 59% cultivated improved bean varieties sourced from their own farms and applied fertilizers albeit different quantities. The results further indicated that 67% of farmers in Koibem and 57% in Kapkerer applied green manure as a soil amendment. Addition of green manure to soils helps in improving soil conditions and increasing crop yields in low soil fertility areas. Green manure use as soil amendments is an ecologically sustainable way of increasing yield. Relevance to innovation. Many modern agricultural practices have unintended negative consequences and therefore there is growing concern about sustainable and better agricultural systems. It is therefore time to assess the importance and future role that soil improving legumes may play in agricultural system. Application of lablab legume species as green manure is an important practice for sustainable agriculture production as the crops fix nitrogen and has deep and extensive root system that allows for nutrients extraction and recycling. Green manure has favou..rable N to P ratios and has predictable N activity hence its application will increase yield.