Browsing by Author "Muthomi James Wanjohi"

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    Biomass Yield and Quality of Fodder from Selected Varieties Of Lablab (Lablab Purpureus L) In Nandi South Sub-County of Kenya
    (Online Journal of Animal and Feed Research, 2021) Wangila Anthony Juma; Gachuiri Charles Karuku; Muthomi James Wanjohi; Ojiem John Okeyo
    Low quality feeds is the main challenge ailing livestock production among the small-scale farmers in the tropics. Cheaper sources of alternative high quality fodder supplements are needed to improve livestock productivity. The objective of this study was to determine biomass yield and quality of fodder from selected lablab varieties. Eight lablab varieties namely, DL1002, Ngwara Nyeupe, Echo-Cream, Black-Rongai, Eldo-KtCream, Eldo-Kt-Black1, Brown Rongai and Eldo-Kt-Black2 were established in three sites of Nandi south sub county, Kenya. Randomized complete block design was used at farm level with four replications per site. Data on biomass yield, chemical composition and in vitro-dry matter digestibility of the eight lablab forages was collected. Biomass yield differed significantly among the lablab varieties ranging from 5.6-12.6 t DM/ha across the three sites. Highest biomass yield was recorded for Brown Rongai (12.6 t DM/ha) and lowest with DL1002 (5.6 t DM/ha). Crude protein (CP) content varied significantly between varieties with sites ranging from 19.6- 23.9 g/100g. Highest CP was recorded with Eldo-Kt-Cream and Black Rongai (23.9 g/100g and 23.7 g/100g) across the three sites. For all the varieties, Neutral detergent fibre (NDF) ranged from 44.4-48.6 g/100g, acid detergent fibre (ADF) 31.6-35.7 g/100g and acid detergent lignin (ADL) 9.0-11.9 g/100g across the three sites. Highest NDF was recorded with DL1002 (48.6 g/100g), ADF with Eldoret-Kitale-Black2 (35.9 g/100g) and acid detergent lignin with DL1002 (11.7 g/100g). In vitro dry matter digestibility (IVDMD) varied significantly between varieties and sites ranging from 67.6-75.7 g/100g between the varieties across the three sites. Eldo-Kt-cream and Black Rongai had the highest IVDMD (75.7 and 74.4 g/100g) across the three sites. Eldoret-Kitale-Cream and Black Rongai varieties had better dry matter yield, crude protein and low fibre fractions compared to the other varieties signifying their potential to be recommended as supplement to low quality fodder by small-scale farmers.
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    Effect of Legume Extracts on Germination, Seedling Health of Beans (Phaseolus vulgaris L.) and Soil Microorganisms
    (International Journal of Plant & Soil Science, 2019-05-10) Okumu Oliver Otieno; Muthomi James Wanjohi; Ojiem John; Narla Rama; Nderitu John Huria
    Application of undecomposed green manure has been reported to cause poor emergence and establishment of common beans in the field. Therefore, to understand the mechanisms’ contributing to the poor crop establishment, the effect of extracts from fresh and decomposed legume green manures on bean seed germination, fungal mycelial growth, spore germination and germ tube elongation were evaluated. The extracts were prepared in either ethanol or distilled water. Data was collected on percentage seed germination, seedling length, mycelial radial growth, spore germination and germ tube elongation. Ethanol extracts from fresh lablab inhibited bean germination by 56%, increased mean germination time to 8 days, and decreased germination index while ethanol extracts of groundnut and beans caused highest inhibition in bean shoot length and reduced biomass. Ethanol extracts from fresh green manures significantly inhibited fungal mycelia growth while the aqueous extracts from beans, groundnuts and soybean had significant level of antifungal activity while aqueous lablab extracts stimulated mycelial. Aqueous extract of lablab and soybean enhanced spore germination by over 70% with more pronounced effect on germ tube length and number of germ tubes by 8.0% and 13% respectively. The study comparatively reveals that the extract of lablab was inhibitory to common bean germination compared to other legume extracts and also stimulated the growth of root rot pathogens that may have resulted in poor establishment of beans.
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    In Vitro Antifungal Activity of 'Desmodium Intortum' and 'D. Uncinatum' Root Extracts against Growth of Toxigenic 'Fusarium Verticillioides' and 'Aspergillus Flavus'
    (Southern Cross Publishers, 2020-12) Njeru Nancy Karimi; Midega Charles Aura Odhiambo; Muthomi James Wanjohi; Wagacha John Maina; Khan Zeyaur Rahman
    Maize grown under push-pull cropping system has been reported to contain lower concentrations of fumonisin and aflatoxin than maize monocrop. This study determined the inhibitory effect of desmodium root extracts on spore germination and radial growth of toxigenic 'Aspergillus flavus and Fusarium verticillioides'. 'Aspergillus flavus and F. verticillioides' were isolated from maize and soil and tested for ability to produce aflatoxin and fumonisin by inoculation on mycotoxin-free maize. Aflatoxin and fuminisin were detected and quantified by direct competitive ELISA. Desmodium roots were dried, ground to fine powder and extracted with methanol and dichloromethane and evaluated for anti-fungal activity by inhibition of spores of 'A. flavus and F. verticillioides' potato dextrose agar (PDA) medium. Isolates of F. verticillioides produced up to 599,741 mug/kg fumonisin while isolates of 'A. flavus' produced up to 199,184 mug/kg aflatoxin. Desmodium root extracts reduced germination of 'A. flavus spores and F. verticillioides' by 9.6% and 43.8%, respectively and reduced their respective colony radial growth by 15% and 57%. The results suggested that desmodium roots contain chemical compounds that inhibit growth of 'A. flavus and F. verticillioides'. This may explain the reduction in infection of maize with mycotoxin-producing fungi before harvest in push-pull cropping systems by reducing the pathogen inoculum in the soils. Determination of the active compounds in the root exudates is recommended.
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    Influence of Socio-Economic and Agronomic Factors on Aflatoxin and Fumonisin Contamination of Maize in Western Kenya
    (Willley Online Library, 2019-06-11) Njeru Nancy Karimi; Midega Charles Aura Odhiambo; Muthomi James Wanjohi; Wagacha John Maina; Khan Zeyaur Rahman
    Consumption of maize contaminated with mycotoxins has been associated with detrimental health effects. A farm survey covering 116 push-pull and 139 non-push-pull cropping systems was conducted to determine the socio-economic and agronomic factors that influence farmers’ knowledge on incidence and contamination of maize by ear rots and associated mycotoxins in western Kenya. All the respondents were smallholder farmers between the ages of 23 and 80 years, with 50% of them being female. Maize samples were collected from the standing crop in the field of each interviewed farmer and analyzed for aflatoxin and fumonisin. Only a small proportion of farmers had knowledge of aflatoxin and ear rots in maize. Overall, less than 20% of maize samples were contaminated with both aflatoxin and fumonisin, and more maize samples were contaminated with fumonisin as compared to aflatoxin. Proportions of maize samples containing higher than the acceptable Kenyan regulatory threshold (10 µg/kg) for aflatoxin and European Commission regulatory threshold (1,000) µg/kg for fumonisin were lower in maize samples from push-pull cropping system. Age of farmer and county of residence were significantly and positively associated with knowledge of aflatoxin, while cropping system, county of residence, and level of education were positively associated with knowledge of maize ear rots. There was strong correlation between knowledge of maize ear rots and knowledge of aflatoxin. Levels of both aflatoxin and fumonisin were significantly and positively associated with the use of diammonium phosphate (DAP) fertilizer at planting. Aflatoxin levels were also positively associated with stemborer damage. Agronomic practices were not significantly different between push-pull and non-push-pull farmers. However, use of DAP fertilizer was the most important agronomic factor since it was associated with both aflatoxin and fumonisin contamination of maize. These results imply that creating awareness is key to mitigation of ear rots and mycotoxin contamination of maize. The results also suggest that the levels of aflatoxin and fumonisin in maize in western Kenya were influenced both by pre-harvest agronomic practices and by the cropping system adopted, push-pull or not.
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    Occurrence of Fusarium Head Blight of Wheat and Associated Mycotoxins in Narok and Nakuru Counties, Kenya
    (Science and Eduacation Publishing, 2016) Wagacha John Maina; Njeru Nancy Karimi; Okumu Oliver Otieno; Muthomi James Wanjohi; Mutegi Charity Kawira
    Fusarium head blight (FHB) is an important disease of small grain cereals. This study assessed the incidence and severity of FHB of wheat at hard dough stage, and levels of deoxynivalenol and T2-toxin at harvest by direct competitive enzyme linked immuno-sorbent assay. Wheat ears were randomly sampled from 51 farms in Narok County and 51 farms in Nakuru County at hard dough stage while wheat kernels were sampled at harvest. Prevalence of FHB in both Counties was 100%. The mean incidence of FHB was 28.4% and 20.5% in Narok and Nakuru Counties, respectively with 16.9% and 11.7% corresponding severity. Over 14 Fusarium spp. were isolated from wheat ears and kernels with F. avenaceum, F. poae and F. graminearum being isolated in the highest incidence. Levels of DON in the kernels ranged from below limit of detection n (
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    Quality of Lablab (Lablab purpureus) Forage Preserved as Hay or Silage
    (Indian Journal of Animal Nutrition, 2021) Wangila Anthony Juma; Gachuiri Charles Karuku; Muthomi James Wanjohi; Ojiem John Okeyo
    Shortage of livestock feeds during the dry season is a major constraint to livestock production in Kenya. This scenario is due to dependence on rain fed forage production resulting in shortages during the dry season and excess during the wet season. This situation can be ameliorated through conservation, but losses occur when forages are conserved. The main objective of this study was to assess the effects of on-farm conservation methods on quality of lablab fodder. Fodder from eight varieties of lablab;DL1002, Ngwara Nyeupe, Echo-Cream, Black Rongai, Eldo-Kt-Cream, Eldo-Kt-Black1, Brown Rongai and Eldo-Kt-Black2 were conserved on-farm either as hay or silage. The conserved and fresh fodder were analyzed for dry matter content, crude protein, ash content, neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and in vitro dry matter digestibility (IVDMD). Lablab silage was analyzed for pH and total ammonia nitrogen. Crude protein content declined significantly; by 4.2 g/100 g when fodder was conserved as hay and by 6.0 g/100 g in silage. The NDF content increased significantly by 7.6 g/100g in lablab hay but declined by 4.2 g/100 g in silage while ADF increased by 6.1 g/100 g in hay and declined by 5.0 g/100 g in silage. A significant decline of 3.2 g/100 g of lignin was observed in silage with no difference in the hay. The IVDMD declined significantly by2.8 g/100 g in lablab hay and increased by 4.5 g/100 g in silage. The pH of lablab silage ranged from 4.37 to 4.89 while total ammonia nitrogen ranged from 27 to 41 g/100 g for different lablab varieties. Conservation of lablab as silage was found to be a superior on-farm method compared to hay making.
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    Residual Effects of Lablab Green Manure on Root Rot Pathogens and Performance of Common Bean (Phaseolus Vulgaris L.)
    (Innovations in Agriculture, 2023-10-04) Okumu Oliver Otieno; Muthomi James Wanjohi; Ojiem John; Nderitu John Huria
    Organic manures often have considerable residual effect on the subsequent crops in the soil. Residual effects of lablab green manure on root rot pathogens and bean crop establishment was evaluated by conducting field experiments at two sites with varying soil fertility in Nandi South. Common bean varieties KK8 and GLP2 seeds were planted on plots previously treated with different soil amendments. Soil samples were collected before planting and six weeks after emergence to determine the populations of root rot pathogens. Throughout the experiment, data was collected on crop emergence, plant stand, root rot incidence and severity, as well as crop yield. There was increase in crop emergence by 40% for GLP2 and 19% for KK8 with corresponding 7% reduction in root rot incidence in plots previously treated with lablab green manure. There were variations in the population of root rot pathogens between the two studies, with Kapkerer exhibiting a higher pathogen population compared to Koibem. The primary root rot pathogens isolated and identified were F. solani, F. oxysporum and Pythium ultimum, F. solani and F. oxysporum were the most dominant species isolated in over 90% plant and soil samples. Residual plots treated with lablab green manure recorded a substantial in yield with an impressive increase of 22% when compared to other treatments. Correlation analysis established that disease incidence, and severity was negatively correlated with yield while plant stand was positively correlated with yield. Our research highlights the long-term benefits of lablab green manure as an organic soil amendment, showcasing its ability to improve crop emergence, reduce root rot incidence, and boost overall crop yield. This knowledge can guide farmers in optimizing their agricultural practices for increased productivity and sustainable soil health.