ABSTRACT The purpose of this paper is to illustrate the importance of applying open-source techno... more ABSTRACT The purpose of this paper is to illustrate the importance of applying open-source technologies for mobile-based data collection for real-time tracking of seed yam (Dioscorea rotundata and Dioscorea alata) production. In the past, seed yam data in Nigeria have been predominantly collected using field notebooks, which were subsequently entered into a Microsoft Excel spreadsheet or Access database for analysis and reposition. Relevant areas of weakness within the current data systems include time delay in providing feedback and non-availability of data upon demand. As a result, this has hampered direct tracking of seeds at various stages of crop production and management. The study provided data collectors with a pre-installed yam seed tracking app for use on an Android device for data collection and management. The system architecture is based on the Open Data Kit (ODK) framework and a custom design based on requirements and lessons learned from literature. The ODK (Aggregate) made data easily accessible in minimum time possible from the point of data collection. The yam seed tracking application was developed as a result, which was field tested. The results indicated that this method improved efficiency, speed, and convenience in data collection and visualization, showing that this type of system can be used in crop management and research. The ODK was helpful to farmers in making their management decisions and ultimately boosting crop productivity. Stakeholders were able to visualize trends in yam production, which helps with marketing decisions.
Rose cut flower is one of the widely grown cut flowers in Kenya. However, most roses have a chall... more Rose cut flower is one of the widely grown cut flowers in Kenya. However, most roses have a challenge of short vase life. This study aimed at determining the efficacy of plant extracts from thyme and stevia in preservation of rose cut-flowers. Two rose cut-flower cultivars; ‘radiance and ‘high & sparkling’ were subjected to stevia and thyme extracts each at three levels (0.2, 0.4, and 0.6gL-1). Thyme extracts at a concentration of 0.2 gL-1 significantly (p≤001) extended the vase life of rose cut flower by 3.5 days and floral absorption rates by 10.4% compared to the commercial preservative (chrysal) at the same concentration rates. Application of higher doses (0.4gL-1 and 0.6gL-1) of plant extracts led to shorter vase life (6 days) of rose cut flower and maximum bent neck records at day 8. The response of rose cut flower to the treatments did not vary between cultivars. The results from this study indicate that thyme extracts offer an attractive alternative to the use of chemical fl...
Biological control agents are useful components in the enhancement of plant disease resistance an... more Biological control agents are useful components in the enhancement of plant disease resistance and improvement of soil properties. Effect of biological control agents (BCAs) as a disease control method in plants is hampered by their vulnerability to environmental and edaphic conditions. This study entailed the use of chitosan-silica nanocomposites for delivery of BCAs. Effect of BCAs-nanocomposite complexes (bionanocomposites) on resistance of tomato plants to bacterial wilt, mycorrhizal root colonization and rhizosphere soil properties were investigated. Replacement of mesoporous silica nanoparticles (MSN) in the nanocomposite with nano synthesized clay was also assessed on disease resistance. Tomato seeds and seedlings were pre-treated using bionanocomposites and then inoculated by Ralstonia solanacearum isolated from infected tomato plants in a greenhouse. Bionanocomposites treatment of tomato plants caused a significant increase (P≤0.05) in the level of pathogenesis-related bioc...
We reported a simple colorimetric probe based on gold nanoparticles (AuNPs) for detecting Ralston... more We reported a simple colorimetric probe based on gold nanoparticles (AuNPs) for detecting Ralstonia solanacearum. The AuNPs were synthesized through reduction with citrate ion and characterized by ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The freshly synthesized AuNPs were brick red due to an intense surface plasmon absorption band at 520 nm. Upon interaction with synthetic gibberellic acid (GA3), a bathochromic shift occurred in the surface plasmon resonance (SPR) peak of AuNPs to higher wavelengths. The 'eye-ball' limit of detection was 0.2 ppm. This shift was accompanied by a change in the color of the AuNPs from brick red to purple. Soil samples were collected from the rhizosphere of tomato plants, exhibiting bacterial wilt symptoms and pure cultures of Ralstonia solanacearum isolated using a modified Kelman’s TZC medium. Gibberellins (GA) were extracted from the culture of R. solanacearum u...
Finger millet blast disease, caused by Pyricularia oryzae, is a serious constrain of finger mille... more Finger millet blast disease, caused by Pyricularia oryzae, is a serious constrain of finger millet production which is threatening global food security especially to the resource poor smallholder farmers in arid and semi-arid regions. The disease adversely affects finger millet production and consumption due to its wide distribution and destruction in all finger millet growing areas of southern Asia and eastern Africa. Here, we present a study that investigated the occurrence, impact, risk factors and farmers’ knowledge and perceptions of finger millet blast in Kenya. We surveyed blast disease occurrence and interviewed farmers in Bungoma and Kisii Counties of Kenya during March–April 2019. Data were analysed using SPSS statistical program. Descriptive analysis was done by calculating means, percentages, frequencies, and standard errors. Comparative statistics, chi-square and t-tests, were used to evaluate differences existing among the farm characteristics and socio-demographics an...
Finger millet blast caused by Pyricularia oryzae is the most globally important disease of finger... more Finger millet blast caused by Pyricularia oryzae is the most globally important disease of finger millet. The disease ravages cultivated finger millet, posing a threat to one of the world’s most important, climate-resilient, and nutrient-rich cereal crops, which serves as an important source of food security. Both pathogenic and mutualistic fungi colonize plant tissues and compete for the same niche, subsequently influencing the disease pathogenesis. We analyzed the natural dynamics of the fungal community associated with finger millet blast. Fungal culture was performed on blast-diseased finger millet tissues collected from different agro-ecological regions in Kenya. Fifty-five isolates were obtained from finger, leaf and neck tissues with blast symptoms and characterized based on morphology and DNA sequencing of the internal transcribed spacer (ITS) and 28S rDNA regions. The identified fungal genera corresponded to Exserohilum, Sarocladium, Fusarium, Epicoccum, Cochliobolus, Curvularia, Bipolaris, Penicillium, Setosphaeria, Phoma, and Alternaria, in addition to two unnamed fungal species. Many fungal pathogens of other crops that are not inherently expected to be present on finger millet were encountered, including Penicillium citrinum. Multi-gene phylogenetic studies using concatenated sequences for the ITS and 28SrDNA regions were analyzed using IQ-tree on maximum likelihood basis and aligned using MAFFT to generate a tree with two distinct groups, which were further segregated into several subgroups. The outcome of this study provides useful information on the type of fungal community associated with finger millet blast, which may open avenues for understanding and protecting against finger millet blast disease in Kenya.
The United Nations classifies Kenya as a water-scarce country since it has less than 1000 m 3 per... more The United Nations classifies Kenya as a water-scarce country since it has less than 1000 m 3 per capita of renewable freshwater supplies. Numerous factors including global warming, contamination of drinking water, and a lack of investment in water resources have aggravated the water crisis in Kenya. Estimates indicate that only about 56% of its population has access to safe water supply. Like many developing countries, Kenya recognizes the crucial role of water in realizing its development goals. Its economic performance and poverty reduction are critically dependent on clean water availability for agriculture, industrialization, energy production and tourism among others. Similar to most developing countries, Kenya suffers from lack of human, monetary and institutional capabilities to efficiently provide clean and sufficient water to its citizens. The water shortage in the major cities is acute and chronic and has continued to worsen with increasing urbanization, water pollution and encroachment of water catchment areas by humans and invasive plant species. Despite the water challenges facing the urban populations, Kenya possesses sufficient water resources to meet demand if the available resources are properly managed. Several initiatives are being put in place in Kenya to mitigate the water challenges and protect water resources in Kenya. These include enacting of water policies to protect water catchment areas, reduce pollution and enhance access to clean water.
ABSTRACT The purpose of this paper is to illustrate the importance of applying open-source techno... more ABSTRACT The purpose of this paper is to illustrate the importance of applying open-source technologies for mobile-based data collection for real-time tracking of seed yam (Dioscorea rotundata and Dioscorea alata) production. In the past, seed yam data in Nigeria have been predominantly collected using field notebooks, which were subsequently entered into a Microsoft Excel spreadsheet or Access database for analysis and reposition. Relevant areas of weakness within the current data systems include time delay in providing feedback and non-availability of data upon demand. As a result, this has hampered direct tracking of seeds at various stages of crop production and management. The study provided data collectors with a pre-installed yam seed tracking app for use on an Android device for data collection and management. The system architecture is based on the Open Data Kit (ODK) framework and a custom design based on requirements and lessons learned from literature. The ODK (Aggregate) made data easily accessible in minimum time possible from the point of data collection. The yam seed tracking application was developed as a result, which was field tested. The results indicated that this method improved efficiency, speed, and convenience in data collection and visualization, showing that this type of system can be used in crop management and research. The ODK was helpful to farmers in making their management decisions and ultimately boosting crop productivity. Stakeholders were able to visualize trends in yam production, which helps with marketing decisions.
Rose cut flower is one of the widely grown cut flowers in Kenya. However, most roses have a chall... more Rose cut flower is one of the widely grown cut flowers in Kenya. However, most roses have a challenge of short vase life. This study aimed at determining the efficacy of plant extracts from thyme and stevia in preservation of rose cut-flowers. Two rose cut-flower cultivars; ‘radiance and ‘high & sparkling’ were subjected to stevia and thyme extracts each at three levels (0.2, 0.4, and 0.6gL-1). Thyme extracts at a concentration of 0.2 gL-1 significantly (p≤001) extended the vase life of rose cut flower by 3.5 days and floral absorption rates by 10.4% compared to the commercial preservative (chrysal) at the same concentration rates. Application of higher doses (0.4gL-1 and 0.6gL-1) of plant extracts led to shorter vase life (6 days) of rose cut flower and maximum bent neck records at day 8. The response of rose cut flower to the treatments did not vary between cultivars. The results from this study indicate that thyme extracts offer an attractive alternative to the use of chemical fl...
Biological control agents are useful components in the enhancement of plant disease resistance an... more Biological control agents are useful components in the enhancement of plant disease resistance and improvement of soil properties. Effect of biological control agents (BCAs) as a disease control method in plants is hampered by their vulnerability to environmental and edaphic conditions. This study entailed the use of chitosan-silica nanocomposites for delivery of BCAs. Effect of BCAs-nanocomposite complexes (bionanocomposites) on resistance of tomato plants to bacterial wilt, mycorrhizal root colonization and rhizosphere soil properties were investigated. Replacement of mesoporous silica nanoparticles (MSN) in the nanocomposite with nano synthesized clay was also assessed on disease resistance. Tomato seeds and seedlings were pre-treated using bionanocomposites and then inoculated by Ralstonia solanacearum isolated from infected tomato plants in a greenhouse. Bionanocomposites treatment of tomato plants caused a significant increase (P≤0.05) in the level of pathogenesis-related bioc...
We reported a simple colorimetric probe based on gold nanoparticles (AuNPs) for detecting Ralston... more We reported a simple colorimetric probe based on gold nanoparticles (AuNPs) for detecting Ralstonia solanacearum. The AuNPs were synthesized through reduction with citrate ion and characterized by ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The freshly synthesized AuNPs were brick red due to an intense surface plasmon absorption band at 520 nm. Upon interaction with synthetic gibberellic acid (GA3), a bathochromic shift occurred in the surface plasmon resonance (SPR) peak of AuNPs to higher wavelengths. The 'eye-ball' limit of detection was 0.2 ppm. This shift was accompanied by a change in the color of the AuNPs from brick red to purple. Soil samples were collected from the rhizosphere of tomato plants, exhibiting bacterial wilt symptoms and pure cultures of Ralstonia solanacearum isolated using a modified Kelman’s TZC medium. Gibberellins (GA) were extracted from the culture of R. solanacearum u...
Finger millet blast disease, caused by Pyricularia oryzae, is a serious constrain of finger mille... more Finger millet blast disease, caused by Pyricularia oryzae, is a serious constrain of finger millet production which is threatening global food security especially to the resource poor smallholder farmers in arid and semi-arid regions. The disease adversely affects finger millet production and consumption due to its wide distribution and destruction in all finger millet growing areas of southern Asia and eastern Africa. Here, we present a study that investigated the occurrence, impact, risk factors and farmers’ knowledge and perceptions of finger millet blast in Kenya. We surveyed blast disease occurrence and interviewed farmers in Bungoma and Kisii Counties of Kenya during March–April 2019. Data were analysed using SPSS statistical program. Descriptive analysis was done by calculating means, percentages, frequencies, and standard errors. Comparative statistics, chi-square and t-tests, were used to evaluate differences existing among the farm characteristics and socio-demographics an...
Finger millet blast caused by Pyricularia oryzae is the most globally important disease of finger... more Finger millet blast caused by Pyricularia oryzae is the most globally important disease of finger millet. The disease ravages cultivated finger millet, posing a threat to one of the world’s most important, climate-resilient, and nutrient-rich cereal crops, which serves as an important source of food security. Both pathogenic and mutualistic fungi colonize plant tissues and compete for the same niche, subsequently influencing the disease pathogenesis. We analyzed the natural dynamics of the fungal community associated with finger millet blast. Fungal culture was performed on blast-diseased finger millet tissues collected from different agro-ecological regions in Kenya. Fifty-five isolates were obtained from finger, leaf and neck tissues with blast symptoms and characterized based on morphology and DNA sequencing of the internal transcribed spacer (ITS) and 28S rDNA regions. The identified fungal genera corresponded to Exserohilum, Sarocladium, Fusarium, Epicoccum, Cochliobolus, Curvularia, Bipolaris, Penicillium, Setosphaeria, Phoma, and Alternaria, in addition to two unnamed fungal species. Many fungal pathogens of other crops that are not inherently expected to be present on finger millet were encountered, including Penicillium citrinum. Multi-gene phylogenetic studies using concatenated sequences for the ITS and 28SrDNA regions were analyzed using IQ-tree on maximum likelihood basis and aligned using MAFFT to generate a tree with two distinct groups, which were further segregated into several subgroups. The outcome of this study provides useful information on the type of fungal community associated with finger millet blast, which may open avenues for understanding and protecting against finger millet blast disease in Kenya.
The United Nations classifies Kenya as a water-scarce country since it has less than 1000 m 3 per... more The United Nations classifies Kenya as a water-scarce country since it has less than 1000 m 3 per capita of renewable freshwater supplies. Numerous factors including global warming, contamination of drinking water, and a lack of investment in water resources have aggravated the water crisis in Kenya. Estimates indicate that only about 56% of its population has access to safe water supply. Like many developing countries, Kenya recognizes the crucial role of water in realizing its development goals. Its economic performance and poverty reduction are critically dependent on clean water availability for agriculture, industrialization, energy production and tourism among others. Similar to most developing countries, Kenya suffers from lack of human, monetary and institutional capabilities to efficiently provide clean and sufficient water to its citizens. The water shortage in the major cities is acute and chronic and has continued to worsen with increasing urbanization, water pollution and encroachment of water catchment areas by humans and invasive plant species. Despite the water challenges facing the urban populations, Kenya possesses sufficient water resources to meet demand if the available resources are properly managed. Several initiatives are being put in place in Kenya to mitigate the water challenges and protect water resources in Kenya. These include enacting of water policies to protect water catchment areas, reduce pollution and enhance access to clean water.
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Papers by Agnes Kavoo