Oliver Otieno | University of Nairobi, Kenya (original) (raw)

Papers by Oliver Otieno

Research paper thumbnail of Occurrence of Fusarium Head Blight of Wheat and Associated Mycotoxins in Narok and Nakuru Counties, Kenya

World Journal of Agricultural Research, 2016

Fusarium head blight (FHB) is an important disease of small grain cereals. This study assessed th... more 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 ( LOD) to 623 µg/kg while the concentration of T-2 toxin ranged from LOD to 69 µg/kg. The levels of DON and T2-toxin in wheat kernels in the two Counties were within the lim...

Research paper thumbnail of Role of agronomic practices on the occurrence of Fusarium head blight in Nakuru County, Kenya

Research paper thumbnail of Resistance of Kenyan wheat germplasm to Fusarium head blight and deoxynivalenol contamination

Fusarium head blight (FHB) of wheat causes quantitative and qualitative reduction in yield. Culti... more Fusarium head blight (FHB) of wheat causes quantitative and qualitative reduction in yield. Cultivar resistance is the most effective method of managing the disease. This study evaluated the resistance of wheat germplasm currently available in Kenya to Fusarium head blight and deoxynivalenol (DON) contamination. Nine wheat varieties and four CIMMYT lines were evaluated for susceptibility to FHB under two diverse agro-ecologies in Nakuru and Narok Counties, Kenya during the 2013 cropping season and in the greenhouse. The varieties and lines were inoculated at mid-anthesis with mixed inocula of three isolates of F. graminearum. Incidence and severity of FHB were assessed weekly and data on severity used to calculate the area under disease progress curve (AUDPC). After harvest, incidence of F. graminearum in the grain was determined and DON contamination determined by direct competitive enzyme-linked immunosorbent assay (ELISA). Incidence and severity of FHB differed significantly (p ≤...

Research paper thumbnail of Occurrence of f u s a r i u m head blight, associated mycotoxins and resistance of wheat germplasm

Research paper thumbnail of Evaluation of Common Bean Production Systems and Fertilizer use in Nandi South

High fertilizer cost and increased concern for ecological sustainability have led to improved int... more 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. R...

Research paper thumbnail of Pomiar marki w świetle koncepcji tworzenia wartości dla akcjonariuszy

Research paper thumbnail of Effect of lablab green manure on population of soil microorganisms and establishment of common bean (Phaseolus vulgaris L.)

Green manures improve soil health and fertility but application of undecomposed lablab residues l... more Green manures improve soil health and fertility but application of undecomposed lablab residues lead to low crop establishment. The study was carried out to determine the effect of green manure on microbial population and establishment of bean crop. Bean varieties were planted on plots each treated with lablab green manure at one ton ha -1 over whole plots and in rows, DAP fertilizer was applied at 75 kg/ha. Data was collected on microbial population, crop emergence, root rot incidence and severity, and yield. Green manure incorporation increased soil organic carbon, nitrogen, phosphorus and potassium but reduced germination percentage by about 35% and increased incidences of root rot by 30% compared to plots without green manure. The population of root rot pathogens was significantly higher in plots treated with green manure two weeks after emergence while the population of saprophytic fungi was low. Plots treated with lablab green manure reduced grain and biomass yields by 25%. Gr...

Research paper thumbnail of 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

Green manure incorporation is important for restoration of soil quality, particularly buildup of ... more 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...

Research paper thumbnail of Coffee Production Challenges and Opportunities in Tanzania: The Case Study of Coffee Farmers in Iwindi, Msia and Lwati Villages in Mbeya Region

Asian Journal of Agricultural and Horticultural Research

Coffee is one of the most popular cash crops grown in Tanzania. However, its productivity has rem... more Coffee is one of the most popular cash crops grown in Tanzania. However, its productivity has remained low due to various biotic, abiotic and socio-economic factors prevailing in Mbeya Region. These production challenges have never been properly and intensively documented for better decision making. Therefore, this study was set to assess and provide a better understanding of the current production situation and available technologies and practices for enhancing coffee production in the region. The research was carried out in Iwindi, Msia and Lwati villages located in Mbeya Region. Two sources of data were used; (a) primary data collected through focus group discussion; and (b) secondary data collected through a systematic and intensive process that involved searching and collecting relevant publications. From the research, farmers were found to grow very old trees that were more than 20 years. The soils were found to have low levels of nutrients and organic matter. Soils are also a...

Research paper thumbnail of Improving Sugarcane (Saccharum officinarum L.) yields in Sub-Sahara Africa through the use of existing technologies: Sugarcane agronomy

World Journal of Advanced Research and Reviews

Research paper thumbnail of Occurrence of Fusarium Head Blight, Associated Mycotoxins and of Resistance of Wheat Germplasm

Research paper thumbnail of Effect of Lablab (Lablab Purpureus L.) Green Manure on Population of Pathogenic and Non-pathogenic Soil Microorganisms and Bean (Phaseolus Vulgaris L.) Crop Establishment

Research paper thumbnail of Occurrence of f u s a r i u m head blight, associated mycotoxins and resistance of wheat germplasm

Research paper thumbnail of Effect of Legume Extracts on Germination, Seedling Health of Beans (Phaseolus vulgaris L.) and Soil Microorganisms

International Journal of Plant & Soil Science

Application of undecomposed green manure has been reported to cause poor emergence and establishm... more 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 mycelial growth while the aqueous extracts from beans, groundnuts an...

Research paper thumbnail of Coffee Production Challenges and Opportunities in Tanzania The Case Study of Coffee Farmers in Iwindi, Msia and Lwati Villages in Mbeya Region

Coffee is one of the most popular cash crops grown in Tanzania. However, its productivity has rem... more Coffee is one of the most popular cash crops grown in Tanzania. However, its productivity has
remained low due to various biotic, abiotic and socio-economic factors prevailing in Mbeya Region. These production challenges have never been properly and intensively documented for better decision making. Therefore, this study was set to assess and provide a better understanding of the current production situation and available technologies and practices for enhancing coffee production in the region. The research was carried out in Iwindi, Msia and Lwati villages located in Mbeya Region. Two sources of data were used; (a) primary data collected through focus group discussion; and (b) secondary data collected through a systematic and intensive process that involved searching and collecting relevant publications.
From the research, farmers were found to grow very old trees that were more than 20 years. The
soils were found to have low levels of nutrients and organic matter. Soils are also acidic, a pH below 5.5. High prevalence of pests such as coffee berry and stem borers and diseases like coffee leaf rust, Fusarium spp., bacterial blight, and red blister were reported in the region. Poor agronomic practices involving intensive intercropping of coffee with trees, other food crops like banana, beans and using generally low tree densities per hectare was observed. Poor extension services due to unbalanced extension agent to farmer ratio (about 1:1800) were found to be one of the causes for poor adoption of best coffee agronomy. Lack of market information and low coffee prices were found to demoralize farmers as it leads to a low return on investment. When asked about their ‘priority training and input support requirements’, all farmers mentioned best coffee agronomy and fertilizer use training. They also mentioned fertilizers (especially Urea or Yara Mila Java blend products) and pesticides (for berry borer, stem borer, Coffee berry disease, and coffee leaf rust) inputs as key for better yields. All these inputs and training require money and service provider. Bundling of training and inputs together could make it easier for any service provider to help farmers increase their yields.

Research paper thumbnail of Coffee Production Challenges and Opportunities in Tanzania: The Case Study of Coffee Farmers in Iwindi, Msia and Lwati Villages in Mbeya Region

Asian Journal of Agricultural and Horticultural Research, 2019

Coffee is one of the most popularcash crops grown in Tanzania. However, its productivi... more Coffee is one of the most popularcash crops grown in Tanzania. However, its productivity has remained low due to various biotic, abiotic and socio-economic factors prevailing in MbeyaRegion. These production challenges have never been properly and intensively documented for better decision making. Therefore, this studywas set to assess and provide a betterunderstanding of the current production situation andavailabletechnologies and practicesfor enhancingcoffee production in the region.The research was carried out in Iwindi, Msia and Lwativillageslocated in Mbeya Region. Two sources of data were used; (a) primary data collected through focus group discussion;and (b) secondary data collected through a systematic and intensive process that involved searching and collecting relevant publications.From the research, farmers were found to grow very old treesthat were more than 20years. The soils were found to have low levels of nutrientsand organicmatter. Soilsarealso acidic, a pH below 5.5. High prevalenceof pests such ascoffee berry and stem borersand diseases likecoffee leaf rust, Fusariumspp., bacterial blight,andred blisterwere reported in the region. Poor agronomic practices involving intensive intercropping of coffee with trees, other food cropslike banana, beansand using generally low tree densities per hectare wasobserved.Poor extension servicesdue to unbalanced extension agent to farmer ratio (about 1:1800) werefound to be one of the causes for poor adoption of best coffee agronomy. Lack of market information andlow coffee prices were found to demoralize farmers as it leads to a low return on investment. When asked about their ‘priority training and input support requirements’, all farmers mentioned best coffee agronomy and fertilizer use training. They also mentionedfertilizers (especially Urea orYara Mila Java blend products) andpesticides(for berry borer, stem borer, Coffee berry disease, andcoffee leaf rust) inputs askeyfor better yields. All these inputs and training require money and service provider. Bundling of training and inputs together could make it easier for any service provider to help farmers increase their yields.

Research paper thumbnail of Effect of Time after Incorporation of Lablab Green Manure on Root Rot Pathogens and Establishment of Common Bean (Phaseolus vulgaris L.) " Effect of Time after Incorporation of Lablab Green Manure on Root Rot Pathogens and Establishment of Common

Green manure incorporation is important for restoration of soil quality, particularly buildup of ... more 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.

Research paper thumbnail of Effect of Lablab Green Manure on Population of Soil Microorganisms and Establishment of Common Bean (Phaseolus vulgaris L

Green manures improve soil health and fertility but application of undecomposed lablab residues l... more Green manures improve soil health and fertility but application of undecomposed lablab residues lead to low crop establishment. The study was carried out to determine the effect of green manure on microbial population and establishment of bean crop. Bean varieties were planted on plots each treated with lablab green manure at one ton ha-1 over whole plots and in rows, DAP fertilizer was applied at 75 kg/ha. Data was collected on microbial population, crop emergence, root rot incidence and severity, and yield. Green manure incorporation increased soil organic carbon, nitrogen, phosphorus and potassium but reduced germination percentage by about 35% and increased incidences of root rot by 30% compared to plots without green manure. The population of root rot pathogens was significantly higher in plots treated with green manure two weeks after emergence while the population of saprophytic fungi was low. Plots treated with lablab green manure reduced grain and biomass yields by 25%. Green manure increases soil nutrients directly and improves crop establishment after decomposition. Results of the study revealed a considerable increase in the population of root rot pathogens with corresponding decrease in the population of antagonistic fungi thus the poor emergence and crop establishment can be associated with increase in population of root rot pathogens and stress experienced by seeds during decomposition

Research paper thumbnail of Evaluation of Common Bean Production Systems and Fertilizer use in Nandi South

High fertilizer cost and increased concern for ecological sustainability have led to improved int... more 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 favourable N to P ratios and has predictable N activity hence its application will increase yield.

Research paper thumbnail of Resistance of Kenyan wheat germplasm to Fusarium head blight and deoxynivalenol contamination International Journal of Agronomy and Agricultural Research (IJAAR

Fusarium head blight (FHB) of wheat causes quantitative and qualitative reduction in yield. Culti... more Fusarium head blight (FHB) of wheat causes quantitative and qualitative reduction in yield. Cultivar resistance is the most effective method of managing the disease. This study evaluated the resistance of wheat germplasm currently available in Kenya to Fusarium head blight and deoxynivalenol (DON) contamination. Nine wheat varieties and four CIMMYT lines were evaluated for susceptibility to FHB under two diverse agro-ecologies in Nakuru and Narok Counties, Kenya during the 2013 cropping season and in the greenhouse. The varieties and lines were inoculated at mid-anthesis with mixed inocula of three isolates of F. graminearum. Incidence and severity of FHB were assessed weekly and data on severity used to calculate the area under disease progress curve (AUDPC). After harvest, incidence of F. graminearum in the grain was determined and DON contamination determined by direct competitive enzyme-linked immunosorbent assay (ELISA). Incidence and severity of FHB differed significantly (p ≤ 0.05) among the varieties and lines with variety Kwale showing the least disease while line 10155 had the highest FHB levels. The AUDPC ranged from 69.8 to 120.1 for the least and most susceptible varieties, respectively. All the wheat lines and varieties accumulated DON ranging from 442 to 748 ng/g (Mean = 572 ng/g). There was a positive correlation between FHB severity, AUDPC, re-isolation frequency of F. graminearum and DON accumulation. The assessed wheat varieties and lines could be grouped into two categories: moderately tolerant and susceptible. Wheat varieties and lines available in Kenya are susceptible to FHB and DON contamination implying need for considering other strategies for managing FHB.

Research paper thumbnail of Occurrence of Fusarium Head Blight of Wheat and Associated Mycotoxins in Narok and Nakuru Counties, Kenya

World Journal of Agricultural Research, 2016

Fusarium head blight (FHB) is an important disease of small grain cereals. This study assessed th... more 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 ( LOD) to 623 µg/kg while the concentration of T-2 toxin ranged from LOD to 69 µg/kg. The levels of DON and T2-toxin in wheat kernels in the two Counties were within the lim...

Research paper thumbnail of Role of agronomic practices on the occurrence of Fusarium head blight in Nakuru County, Kenya

Research paper thumbnail of Resistance of Kenyan wheat germplasm to Fusarium head blight and deoxynivalenol contamination

Fusarium head blight (FHB) of wheat causes quantitative and qualitative reduction in yield. Culti... more Fusarium head blight (FHB) of wheat causes quantitative and qualitative reduction in yield. Cultivar resistance is the most effective method of managing the disease. This study evaluated the resistance of wheat germplasm currently available in Kenya to Fusarium head blight and deoxynivalenol (DON) contamination. Nine wheat varieties and four CIMMYT lines were evaluated for susceptibility to FHB under two diverse agro-ecologies in Nakuru and Narok Counties, Kenya during the 2013 cropping season and in the greenhouse. The varieties and lines were inoculated at mid-anthesis with mixed inocula of three isolates of F. graminearum. Incidence and severity of FHB were assessed weekly and data on severity used to calculate the area under disease progress curve (AUDPC). After harvest, incidence of F. graminearum in the grain was determined and DON contamination determined by direct competitive enzyme-linked immunosorbent assay (ELISA). Incidence and severity of FHB differed significantly (p ≤...

Research paper thumbnail of Occurrence of f u s a r i u m head blight, associated mycotoxins and resistance of wheat germplasm

Research paper thumbnail of Evaluation of Common Bean Production Systems and Fertilizer use in Nandi South

High fertilizer cost and increased concern for ecological sustainability have led to improved int... more 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. R...

Research paper thumbnail of Pomiar marki w świetle koncepcji tworzenia wartości dla akcjonariuszy

Research paper thumbnail of Effect of lablab green manure on population of soil microorganisms and establishment of common bean (Phaseolus vulgaris L.)

Green manures improve soil health and fertility but application of undecomposed lablab residues l... more Green manures improve soil health and fertility but application of undecomposed lablab residues lead to low crop establishment. The study was carried out to determine the effect of green manure on microbial population and establishment of bean crop. Bean varieties were planted on plots each treated with lablab green manure at one ton ha -1 over whole plots and in rows, DAP fertilizer was applied at 75 kg/ha. Data was collected on microbial population, crop emergence, root rot incidence and severity, and yield. Green manure incorporation increased soil organic carbon, nitrogen, phosphorus and potassium but reduced germination percentage by about 35% and increased incidences of root rot by 30% compared to plots without green manure. The population of root rot pathogens was significantly higher in plots treated with green manure two weeks after emergence while the population of saprophytic fungi was low. Plots treated with lablab green manure reduced grain and biomass yields by 25%. Gr...

Research paper thumbnail of 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

Green manure incorporation is important for restoration of soil quality, particularly buildup of ... more 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...

Research paper thumbnail of Coffee Production Challenges and Opportunities in Tanzania: The Case Study of Coffee Farmers in Iwindi, Msia and Lwati Villages in Mbeya Region

Asian Journal of Agricultural and Horticultural Research

Coffee is one of the most popular cash crops grown in Tanzania. However, its productivity has rem... more Coffee is one of the most popular cash crops grown in Tanzania. However, its productivity has remained low due to various biotic, abiotic and socio-economic factors prevailing in Mbeya Region. These production challenges have never been properly and intensively documented for better decision making. Therefore, this study was set to assess and provide a better understanding of the current production situation and available technologies and practices for enhancing coffee production in the region. The research was carried out in Iwindi, Msia and Lwati villages located in Mbeya Region. Two sources of data were used; (a) primary data collected through focus group discussion; and (b) secondary data collected through a systematic and intensive process that involved searching and collecting relevant publications. From the research, farmers were found to grow very old trees that were more than 20 years. The soils were found to have low levels of nutrients and organic matter. Soils are also a...

Research paper thumbnail of Improving Sugarcane (Saccharum officinarum L.) yields in Sub-Sahara Africa through the use of existing technologies: Sugarcane agronomy

World Journal of Advanced Research and Reviews

Research paper thumbnail of Occurrence of Fusarium Head Blight, Associated Mycotoxins and of Resistance of Wheat Germplasm

Research paper thumbnail of Effect of Lablab (Lablab Purpureus L.) Green Manure on Population of Pathogenic and Non-pathogenic Soil Microorganisms and Bean (Phaseolus Vulgaris L.) Crop Establishment

Research paper thumbnail of Occurrence of f u s a r i u m head blight, associated mycotoxins and resistance of wheat germplasm

Research paper thumbnail of Effect of Legume Extracts on Germination, Seedling Health of Beans (Phaseolus vulgaris L.) and Soil Microorganisms

International Journal of Plant & Soil Science

Application of undecomposed green manure has been reported to cause poor emergence and establishm... more 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 mycelial growth while the aqueous extracts from beans, groundnuts an...

Research paper thumbnail of Coffee Production Challenges and Opportunities in Tanzania The Case Study of Coffee Farmers in Iwindi, Msia and Lwati Villages in Mbeya Region

Coffee is one of the most popular cash crops grown in Tanzania. However, its productivity has rem... more Coffee is one of the most popular cash crops grown in Tanzania. However, its productivity has
remained low due to various biotic, abiotic and socio-economic factors prevailing in Mbeya Region. These production challenges have never been properly and intensively documented for better decision making. Therefore, this study was set to assess and provide a better understanding of the current production situation and available technologies and practices for enhancing coffee production in the region. The research was carried out in Iwindi, Msia and Lwati villages located in Mbeya Region. Two sources of data were used; (a) primary data collected through focus group discussion; and (b) secondary data collected through a systematic and intensive process that involved searching and collecting relevant publications.
From the research, farmers were found to grow very old trees that were more than 20 years. The
soils were found to have low levels of nutrients and organic matter. Soils are also acidic, a pH below 5.5. High prevalence of pests such as coffee berry and stem borers and diseases like coffee leaf rust, Fusarium spp., bacterial blight, and red blister were reported in the region. Poor agronomic practices involving intensive intercropping of coffee with trees, other food crops like banana, beans and using generally low tree densities per hectare was observed. Poor extension services due to unbalanced extension agent to farmer ratio (about 1:1800) were found to be one of the causes for poor adoption of best coffee agronomy. Lack of market information and low coffee prices were found to demoralize farmers as it leads to a low return on investment. When asked about their ‘priority training and input support requirements’, all farmers mentioned best coffee agronomy and fertilizer use training. They also mentioned fertilizers (especially Urea or Yara Mila Java blend products) and pesticides (for berry borer, stem borer, Coffee berry disease, and coffee leaf rust) inputs as key for better yields. All these inputs and training require money and service provider. Bundling of training and inputs together could make it easier for any service provider to help farmers increase their yields.

Research paper thumbnail of Coffee Production Challenges and Opportunities in Tanzania: The Case Study of Coffee Farmers in Iwindi, Msia and Lwati Villages in Mbeya Region

Asian Journal of Agricultural and Horticultural Research, 2019

Coffee is one of the most popularcash crops grown in Tanzania. However, its productivi... more Coffee is one of the most popularcash crops grown in Tanzania. However, its productivity has remained low due to various biotic, abiotic and socio-economic factors prevailing in MbeyaRegion. These production challenges have never been properly and intensively documented for better decision making. Therefore, this studywas set to assess and provide a betterunderstanding of the current production situation andavailabletechnologies and practicesfor enhancingcoffee production in the region.The research was carried out in Iwindi, Msia and Lwativillageslocated in Mbeya Region. Two sources of data were used; (a) primary data collected through focus group discussion;and (b) secondary data collected through a systematic and intensive process that involved searching and collecting relevant publications.From the research, farmers were found to grow very old treesthat were more than 20years. The soils were found to have low levels of nutrientsand organicmatter. Soilsarealso acidic, a pH below 5.5. High prevalenceof pests such ascoffee berry and stem borersand diseases likecoffee leaf rust, Fusariumspp., bacterial blight,andred blisterwere reported in the region. Poor agronomic practices involving intensive intercropping of coffee with trees, other food cropslike banana, beansand using generally low tree densities per hectare wasobserved.Poor extension servicesdue to unbalanced extension agent to farmer ratio (about 1:1800) werefound to be one of the causes for poor adoption of best coffee agronomy. Lack of market information andlow coffee prices were found to demoralize farmers as it leads to a low return on investment. When asked about their ‘priority training and input support requirements’, all farmers mentioned best coffee agronomy and fertilizer use training. They also mentionedfertilizers (especially Urea orYara Mila Java blend products) andpesticides(for berry borer, stem borer, Coffee berry disease, andcoffee leaf rust) inputs askeyfor better yields. All these inputs and training require money and service provider. Bundling of training and inputs together could make it easier for any service provider to help farmers increase their yields.

Research paper thumbnail of Effect of Time after Incorporation of Lablab Green Manure on Root Rot Pathogens and Establishment of Common Bean (Phaseolus vulgaris L.) " Effect of Time after Incorporation of Lablab Green Manure on Root Rot Pathogens and Establishment of Common

Green manure incorporation is important for restoration of soil quality, particularly buildup of ... more 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.

Research paper thumbnail of Effect of Lablab Green Manure on Population of Soil Microorganisms and Establishment of Common Bean (Phaseolus vulgaris L

Green manures improve soil health and fertility but application of undecomposed lablab residues l... more Green manures improve soil health and fertility but application of undecomposed lablab residues lead to low crop establishment. The study was carried out to determine the effect of green manure on microbial population and establishment of bean crop. Bean varieties were planted on plots each treated with lablab green manure at one ton ha-1 over whole plots and in rows, DAP fertilizer was applied at 75 kg/ha. Data was collected on microbial population, crop emergence, root rot incidence and severity, and yield. Green manure incorporation increased soil organic carbon, nitrogen, phosphorus and potassium but reduced germination percentage by about 35% and increased incidences of root rot by 30% compared to plots without green manure. The population of root rot pathogens was significantly higher in plots treated with green manure two weeks after emergence while the population of saprophytic fungi was low. Plots treated with lablab green manure reduced grain and biomass yields by 25%. Green manure increases soil nutrients directly and improves crop establishment after decomposition. Results of the study revealed a considerable increase in the population of root rot pathogens with corresponding decrease in the population of antagonistic fungi thus the poor emergence and crop establishment can be associated with increase in population of root rot pathogens and stress experienced by seeds during decomposition

Research paper thumbnail of Evaluation of Common Bean Production Systems and Fertilizer use in Nandi South

High fertilizer cost and increased concern for ecological sustainability have led to improved int... more 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 favourable N to P ratios and has predictable N activity hence its application will increase yield.

Research paper thumbnail of Resistance of Kenyan wheat germplasm to Fusarium head blight and deoxynivalenol contamination International Journal of Agronomy and Agricultural Research (IJAAR

Fusarium head blight (FHB) of wheat causes quantitative and qualitative reduction in yield. Culti... more Fusarium head blight (FHB) of wheat causes quantitative and qualitative reduction in yield. Cultivar resistance is the most effective method of managing the disease. This study evaluated the resistance of wheat germplasm currently available in Kenya to Fusarium head blight and deoxynivalenol (DON) contamination. Nine wheat varieties and four CIMMYT lines were evaluated for susceptibility to FHB under two diverse agro-ecologies in Nakuru and Narok Counties, Kenya during the 2013 cropping season and in the greenhouse. The varieties and lines were inoculated at mid-anthesis with mixed inocula of three isolates of F. graminearum. Incidence and severity of FHB were assessed weekly and data on severity used to calculate the area under disease progress curve (AUDPC). After harvest, incidence of F. graminearum in the grain was determined and DON contamination determined by direct competitive enzyme-linked immunosorbent assay (ELISA). Incidence and severity of FHB differed significantly (p ≤ 0.05) among the varieties and lines with variety Kwale showing the least disease while line 10155 had the highest FHB levels. The AUDPC ranged from 69.8 to 120.1 for the least and most susceptible varieties, respectively. All the wheat lines and varieties accumulated DON ranging from 442 to 748 ng/g (Mean = 572 ng/g). There was a positive correlation between FHB severity, AUDPC, re-isolation frequency of F. graminearum and DON accumulation. The assessed wheat varieties and lines could be grouped into two categories: moderately tolerant and susceptible. Wheat varieties and lines available in Kenya are susceptible to FHB and DON contamination implying need for considering other strategies for managing FHB.