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Articles 271 - 300 of 1443

Full-Text Articles in Life Sciences

Metabolites From Trypanosome-Infected Cattle As Sensitive Biomarkers For Animal Trypanosomosis, Merid N. Getahun, John Ngiela, John Mark O. Makwatta, Peter Ahuya, Tawich K. Simon, Samuel K. Kamau, Baldwyn Torto, Daniel Masiga Jul 2022

Metabolites From Trypanosome-Infected Cattle As Sensitive Biomarkers For Animal Trypanosomosis, Merid N. Getahun, John Ngiela, John Mark O. Makwatta, Peter Ahuya, Tawich K. Simon, Samuel K. Kamau, Baldwyn Torto, Daniel Masiga

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Trypanosomes are important global livestock and human pathogens of public health importance. Elucidating the chemical mechanisms of trypanosome-relevant host interactions can enhance the design and development of a novel, next-generation trypanosomosis diagnostics. However, it is unknown how trypanosome infection affects livestock volatile odors. Here, we show that Trypanosoma congolense and Trypanosoma vivax infections induced dihydro-β- ionone and junenol, while abundance of dihydro-α-ionone, phenolics, p-cresol, and 3-propylphenol significantly elevated in cow urine. These biomarkers of trypanosome infection are conserved in cow breath and the urine metabolites of naturally infected cows, regardless of population, diet, or environment differences. Furthermore, treating trypanosome-infected cows …

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Synergies Of Integrated Pest And Pollinator Management In Avocado Farming In East Africa: An Ex-Ante Economic Analysis, Charity Wangithi, Beatrice W. Muriithi, Gracious Diiro, Thomas Dubois, Samira Mohamed, Michael G. Lattorff, Benignus V. Ngowi, Elfatih M. Abdel-Rahman, Mariam Adan, Menale Kassie Jul 2022

Synergies Of Integrated Pest And Pollinator Management In Avocado Farming In East Africa: An Ex-Ante Economic Analysis, Charity Wangithi, Beatrice W. Muriithi, Gracious Diiro, Thomas Dubois, Samira Mohamed, Michael G. Lattorff, Benignus V. Ngowi, Elfatih M. Abdel-Rahman, Mariam Adan, Menale Kassie

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Using synthetic pesticides to manage pests can threaten pollination services, affecting the productivity of pollination-dependent crops such as avocado. The need to mitigate this negative externality has led to the emergence of the concept of integrated pest and pollinator management (IPPM) to achieve both pest and pollinator management, leading to complementary or synergistic benefits for yield and quality of the harvest. This paper aims to evaluate the potential economic and welfare impact of IPPM in avocado production systems in Kenya and Tanzania. We utilize both primary and secondary data and employed the economic surplus model. On average the potential economic …

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Genetic Diversity Of Diaphorina Citri (Hemiptera: Liviidae) Unravels Phylogeographic Structure And Invasion History Of Eastern African Populations, Inusa Jacob Ajene, Fathiya Mbarak Khamis, Barbara Van Asch, Gerhard Pietersen, Nurhussen Seid, Anne Wambui Wairimu, Fidelis Levi Ombura, Komivi Senyo Akutse, Mamoudou Sétamou, Sevgan Subramanian, Samira Mohammed, Sunday Ekesi Jul 2022

Genetic Diversity Of Diaphorina Citri (Hemiptera: Liviidae) Unravels Phylogeographic Structure And Invasion History Of Eastern African Populations, Inusa Jacob Ajene, Fathiya Mbarak Khamis, Barbara Van Asch, Gerhard Pietersen, Nurhussen Seid, Anne Wambui Wairimu, Fidelis Levi Ombura, Komivi Senyo Akutse, Mamoudou Sétamou, Sevgan Subramanian, Samira Mohammed, Sunday Ekesi

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The Asian citrus psyllid (Diaphorina citri Kuwayama) is a key pest of Citrus sp. worldwide, as it acts as a vector for Candidatus Liberibacter asiaticus, the bacterial pathogen that causes citrus Huanglongbing. Diaphorina citri has been reported in Kenya, Tanzania, and more recently in Ethiopia. This study assessed the genetic diversity and phylogeographic structure of the pest to gain insights into the potential sources of its introduction into Africa. Population structure and differentiation of D. citri populations from China, Ethiopia, Kenya, Tanzania, and the USA were assessed using 10 microsatellite loci. Additionally, five new complete mitogenomes of D. citri collected …

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Observing The Distribution Of Mosquito Bites On Humans To Inform Personal Protection Measures Against Malaria And Dengue Vectors, Winifrida P. Mponzi, Johnson K. Swai, Emmanuel W. Kaindoa, Khamis Kifungo, Alvaro E. Eiras, Elis P.A. Batista, Nancy S. Matowo, Peter O. Sangoro, Marceline F. Finda, Arnold S. Mmbando, Tegemeo Gavana, Halfan S. Ngowo, Fredros O. Okumu Jul 2022

Observing The Distribution Of Mosquito Bites On Humans To Inform Personal Protection Measures Against Malaria And Dengue Vectors, Winifrida P. Mponzi, Johnson K. Swai, Emmanuel W. Kaindoa, Khamis Kifungo, Alvaro E. Eiras, Elis P.A. Batista, Nancy S. Matowo, Peter O. Sangoro, Marceline F. Finda, Arnold S. Mmbando, Tegemeo Gavana, Halfan S. Ngowo, Fredros O. Okumu

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Background Understanding mosquito biting behaviours is important for designing and evaluating protection methods against nuisance biting and mosquito-borne diseases (e.g. dengue, malaria and zika). We investigated the preferred biting sites by Aedes aegypti and Anopheles arabiensis on adult volunteers in standing or sleeping positions; and estimated the theoretical protection limits affordable from protective clothing or repellent-treated footwear. Methods Adult volunteers dressed in shorts and t-shirts were exposed to infection-free laboratory-reared mosquitoes inside screened chambers from 6am to noon (for day-biting Ae. aegypti) or 6pm to midnight (night-biting An. arabiensis). Attempted bites on different body parts were recorded. Comparative observations were …

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Microhabitat And Patch Selection Detection From Gps Tracking Collars Of Semi-Free Ranging Mashona Cattle Within A Semi-Arid Environment, C. Gwatirisa, B. T. Mudereri, T. Chitata, C. Mukanga, M. M. Ngwenya, J. V. Muzvondiwa, R. Mugandani, M. Sungirai Jul 2022

Microhabitat And Patch Selection Detection From Gps Tracking Collars Of Semi-Free Ranging Mashona Cattle Within A Semi-Arid Environment, C. Gwatirisa, B. T. Mudereri, T. Chitata, C. Mukanga, M. M. Ngwenya, J. V. Muzvondiwa, R. Mugandani, M. Sungirai

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Over the last 30 years, the global positioning system (GPS) tracking collars have significantly enhanced livestock grazing behavior studies. Practices designed to understand and improve livestock grazing distribution can now be accurately and cost-effectively monitored with GPS tracking. The behavior and spatiotemporal microhabitat selection of Mashona cattle relative to the season in a semi-free-range grazing system was evaluated using a low‐cost GPS herd activity monitoring (GPSHAM) collar. The GPSHAM automatically logged the position of the lead cow at 20-second intervals over a 7–hour daily grazing period. Additionally, the GPS data was complemented by visually observing the lead cow during daylight …

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Sustainable Intensification Of Wheat Production Under Smallholder Farming Systems In Burera, Musanze And Nyamagabe Districts Of Rwanda, Athanase Rusanganwa Cyamweshi, Nsharwasi Léon Nabahungu, Jackson Cirhuza Mirali, Job Kihara, George Oduor, Harrison Rware, Gudeta Weldesemayat Sileshi Jun 2022

Sustainable Intensification Of Wheat Production Under Smallholder Farming Systems In Burera, Musanze And Nyamagabe Districts Of Rwanda, Athanase Rusanganwa Cyamweshi, Nsharwasi Léon Nabahungu, Jackson Cirhuza Mirali, Job Kihara, George Oduor, Harrison Rware, Gudeta Weldesemayat Sileshi

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The productivity of wheat is low on smallholder farms in Rwanda. Although mineral fertiliser use is being promoted as a sustainable intensification (SI) pathway, little is known about the nutrient use efficiency and profitability of various fertiliser inputs in Burera, Musanze and Nyamagabe districts of Rwanda. The objective of this study was to assess the use of combinations of nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), zinc (Zn) and boron (B) in wheat production in terms of nutrients management specifically, crop yield, production risk, input use efficiency and economic returns on smallholder farms. The study was conducted in three …

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Lepidopterans Of Economic Importance In Cameroon: A Systematic Review, José Ouaba, Timoléon Tchuinkam, Alida Waïmane, Henlay Juma Otieno Magara, Saliou Niassy, Félix Meutchieye Jun 2022

Lepidopterans Of Economic Importance In Cameroon: A Systematic Review, José Ouaba, Timoléon Tchuinkam, Alida Waïmane, Henlay Juma Otieno Magara, Saliou Niassy, Félix Meutchieye

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Lepidoptera represents one of the most abundant and diverse insect groups globally, with more than 178,159 species described in more than 4000 genera. This paper discusses the economic importance of these insects in Cameroon. The work was built on a comprehensive review of 60 relevant published articles from 1955 to 2021. Results show a great diversity of insects of economic importance belonging to the order Lepidoptera, of which 51 are known at the species level, eleven at the genus level, and many others not yet identified. Their economic importance is somehow conflicting, with a mix of harmful and beneficial species. …

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Plant Growth And Defense Traits In Sorghum Bicolor’S Response To Chilo Partellus In The Tropics, Adekunle W. Adesanya, Maria Isabel Gomez, Kimberly Morrell, Charles Midega, Zeyaur Khan, André Kessler, Katja Poveda Jun 2022

Plant Growth And Defense Traits In Sorghum Bicolor’S Response To Chilo Partellus In The Tropics, Adekunle W. Adesanya, Maria Isabel Gomez, Kimberly Morrell, Charles Midega, Zeyaur Khan, André Kessler, Katja Poveda

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In order to meet the increasing demands from an exploding human population, sustainable agriculture relies on the availability of crop varieties with high yields and optimal defenses to pests. However, ample work has suggested that domesticated plants could have reduced defenses at the expense of increased biomass or yield, and these potential trade-offs can vary among plant species and genotypes. Herbivory coping mechanisms such as tolerance and resistance can be expressed differently among plant genotypes, with variable relationships and inherent fitness costs. Knowledge of the connection between growth and defense mechanisms in cultivated plants is still limited, especially in tropical …

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Influence Of The Type Of Pollen Diet On The Survival, Body Weight, And Immune Response In The African Honeybee, Michael N.K. Muturi, Joel L. Bargul, H. Michael G. Lattorff Jun 2022

Influence Of The Type Of Pollen Diet On The Survival, Body Weight, And Immune Response In The African Honeybee, Michael N.K. Muturi, Joel L. Bargul, H. Michael G. Lattorff

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Pollen nutrition is critical for the development and well-being of the honeybee. Previous studies have compared the effect of pollen and carbohydrate-only diet on honeybee physiology. The effect of a monofloral versus polyfloral diet on the African honeybee (Apis mellifera scutellata) is poorly understood. This knowledge is critical as diversity-rich habitats are being altered to less diverse environments through increased urbanization and intensified agricultural activities, particularly in sub-Saharan Africa. Here, we report how lowly diverse (LD) and highly diverse (HD) pollen diets influence honeybee life-history traits and physiology. To achieve this, we fed caged bees with the two pollen diets …

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Impact Of Invasive Insects On Native Insect Communities, Taiadjana M. Fortuna, Philippe Le Gall, Samir Mezdour, Paul André Calatayud Jun 2022

Impact Of Invasive Insects On Native Insect Communities, Taiadjana M. Fortuna, Philippe Le Gall, Samir Mezdour, Paul André Calatayud

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Several biophysical factors are leading to the loss of biodiversity, among them the dominance of exotic invasive species on native communities is important. Their dominance can lead to changes in the structure of insect communities, by competing and displacing native species to other crops or habitats. These changes can impact the herbivore's natural enemies in invaded areas by diverging them from suitable herbivores and altering their biological control process. The development of edible insects and derived products at an industrial scale can also have an impact on the local fauna by the risks of spillover and accidental release in nature. …

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Harnessing Data Science To Improve Integrated Management Of Invasive Pest Species Across Africa: An Application To Fall Armyworm (Spodoptera Frugiperda) (J.E. Smith) (Lepidoptera: Noctuidae), Ritter A. Guimapi, Saliou Niassy, Bester Tawona Mudereri, Elfatih M. Abdel-Rahman, Ghislain T. Tepa-Yotto, Sevgan Subramanian, Samira A. Mohamed, Karl H. Thunes, Emily Kimathi, Komi Mensah Agboka, Manuele Tamò, Jean Claude Rwaburindi, Buyung Hadi, Maged Elkahky, May Guri Sæthre, Yeneneh Belayneh, Sunday Ekesi, Segenet Kelemu, Henri E.Z. Tonnang Jun 2022

Harnessing Data Science To Improve Integrated Management Of Invasive Pest Species Across Africa: An Application To Fall Armyworm (Spodoptera Frugiperda) (J.E. Smith) (Lepidoptera: Noctuidae), Ritter A. Guimapi, Saliou Niassy, Bester Tawona Mudereri, Elfatih M. Abdel-Rahman, Ghislain T. Tepa-Yotto, Sevgan Subramanian, Samira A. Mohamed, Karl H. Thunes, Emily Kimathi, Komi Mensah Agboka, Manuele Tamò, Jean Claude Rwaburindi, Buyung Hadi, Maged Elkahky, May Guri Sæthre, Yeneneh Belayneh, Sunday Ekesi, Segenet Kelemu, Henri E.Z. Tonnang

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After five years of its first report on the African continent, Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) is considered a major threat to maize, sorghum, and millet production in sub-Saharan Africa. Despite the rigorous work already conducted to reduce FAW prevalence, the dynamics and invasion mechanisms of FAW in Africa are still poorly understood. This study applied interdisciplinary tools, analytics, and algorithms on a FAW dataset with a spatial lens to provide insights and project the intensity of FAW infestation across Africa. The data collected between January 2018 and December 2020 in selected locations were matched with the monthly …

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Progress In Research On Site-Specific Nutrient Management For Smallholder Farmers In Sub-Saharan Africa, P. Chivenge, S. Zingore, K. S. Ezui, S. Njoroge, M. A. Bunquin, A. Dobermann, K. Saito May 2022

Progress In Research On Site-Specific Nutrient Management For Smallholder Farmers In Sub-Saharan Africa, P. Chivenge, S. Zingore, K. S. Ezui, S. Njoroge, M. A. Bunquin, A. Dobermann, K. Saito

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Increasing fertilizer access and use is an essential component for improving crop production and food security in sub-Saharan Africa (SSA). However, given the heterogeneous nature of smallholder farms, fertilizer application needs to be tailored to specific farming conditions to increase yield, profitability, and nutrient use efficiency. The site-specific nutrient management (SSNM) approach initially developed in the 1990 s for generating field-specific fertilizer recommendations for rice in Asia, has also been introduced to rice, maize and cassava cropping systems in SSA. The SSNM approach has been shown to increase yield, profitability, and nutrient use efficiency. Yield gains of rice and maize …

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Lintul-Cassava-Npk: A Simulation Model For Nutrient-Limited Cassava Growth, J. G. Adiele, A. G.T. Schut, K. S. Ezui, K. E. Giller May 2022

Lintul-Cassava-Npk: A Simulation Model For Nutrient-Limited Cassava Growth, J. G. Adiele, A. G.T. Schut, K. S. Ezui, K. E. Giller

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A solid understanding of the dynamics of plant nutrient requirements and uptake from the soil is needed to provide robust fertilizer recommendations, timing of applications and nutrient use efficiency. Our objective was to develop and test the ability of the crop model LINTUL-Cassava-NPK to simulate biomass growth and yield of cassava under nutrient-limited conditions. We used experimental data from six fields located in three different agro-ecologies in Nigeria: Rainforest Zone– Ogoja and Ikom (Cross River), Rainforest Transition Zone – Ekpoma (Edo) and Guinea Savanna Zone – Otukpo (Benue) over two consecutive growing seasons from 2016 to 2018. Nutrient stress in …

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Wrap-And-Plant Technology To Manage Sustainably Potato Cyst Nematodes In East Africa, Juliet Ochola, Laura Cortada, Onesmus Mwaura, Meklit Tariku, Shawn A. Christensen, Margaret Ng’Ang’A, Ahmed Hassanali, Tahira Pirzada, Saad Khan, Lokendra Pal, Reny Mathew, Dick Guenther, Eric Davis, Tim Sit, Danny Coyne, Charles Opperman, Baldwyn Torto May 2022

Wrap-And-Plant Technology To Manage Sustainably Potato Cyst Nematodes In East Africa, Juliet Ochola, Laura Cortada, Onesmus Mwaura, Meklit Tariku, Shawn A. Christensen, Margaret Ng’Ang’A, Ahmed Hassanali, Tahira Pirzada, Saad Khan, Lokendra Pal, Reny Mathew, Dick Guenther, Eric Davis, Tim Sit, Danny Coyne, Charles Opperman, Baldwyn Torto

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Renewable eco-friendly options for crop protection are fundamental in achieving sustainable agriculture. Here, we demonstrate the use of a biodegradable lignocellulosic banana-paper matrix as a seed wrap for the protection of potato plants against potato cyst nematode (PCN), Globodera rostochiensis. Potato cyst nematodes are devastating quarantine pests of potato globally. In East Africa, G. rostochiensis has recently emerged as a serious threat to potato production. Wrapping seed potatoes within the lignocellulose banana-paper matrix substantially reduced G. rostochiensis field inoculum and increased potato yields by up to fivefold in Kenya, relative to farmer practice, whether or not impregnated with ultra-low doses …

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Bioactive Volatiles From Push-Pull Companion Crops Repel Fall Armyworm And Attract Its Parasitoids, Islam S. Sobhy, Amanuel Tamiru, Xavier Chiriboga Morales, Dickens Nyagol, Duncan Cheruiyot, Frank Chidawanyika, Sevgan Subramanian, Charles A.O. Midega, Toby J.A. Bruce, Zeyaur R. Khan Apr 2022

Bioactive Volatiles From Push-Pull Companion Crops Repel Fall Armyworm And Attract Its Parasitoids, Islam S. Sobhy, Amanuel Tamiru, Xavier Chiriboga Morales, Dickens Nyagol, Duncan Cheruiyot, Frank Chidawanyika, Sevgan Subramanian, Charles A.O. Midega, Toby J.A. Bruce, Zeyaur R. Khan

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Fall armyworm, Spodoptera frugiperda, is a serious invasive pest in Africa but “Push-Pull” companion cropping can substantially reduce infestation. Here, we elucidate the underpinning chemical ecology mechanisms. We hypothesized that companion crop volatiles repel herbivores (push) while attracting natural enemies (pull). Headspace volatiles collected from companion plants (Desmodium intortum, Desmodium uncinatum, Brachiaria Mulato II) were used in bioassays and electrophysiological recordings with S. frugiperda and parasitoid wasps. Insect populations, plant damage and herbivore parasitism were assessed in field plots. Coupled GC-electroantennogram (GC-EAG) recordings showed robust responses to certain aromatic and terpenoid volatile compounds. In wind tunnel bioassays, maize volatiles mixed …

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The Endophyte Trichoderma Asperellum M2rt4 Induces The Systemic Release Of Methyl Salicylate And (Z)-Jasmone In Tomato Plant Affecting Host Location And Herbivory Of Tuta Absoluta, Ayaovi Agbessenou, Komivi S. Akutse, Abdullahi A. Yusuf, Fathiya M. Khamis Apr 2022

The Endophyte Trichoderma Asperellum M2rt4 Induces The Systemic Release Of Methyl Salicylate And (Z)-Jasmone In Tomato Plant Affecting Host Location And Herbivory Of Tuta Absoluta, Ayaovi Agbessenou, Komivi S. Akutse, Abdullahi A. Yusuf, Fathiya M. Khamis

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The use of endophytic fungi has dramatically increased plant performance through the enhancement of plant protection against abiotic and biotic stressors. We previously demonstrated that the endophytic fungus Trichoderma asperellum M2RT4 improves tomato defenses against the tomato leafminer Tuta absoluta through the reduction of oviposition, leafmining, pupation, and adult emergence. However, the underlying mechanism by which the presence of this endophytic fungus within tomato host plant affects T. absoluta host selection and life-history traits is unknown. We tested the behavioral responses of T. absoluta in Y-tube olfactometer bioassays and found that females preferred non-inoculated tomato plants against those inoculated by …

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Measuring And Modelling Crop Yield Losses Due To Invasive Insect Pests Under Climate Change, Henri Ez Tonnang, Bonoukpoè M. Sokame, Elfatih M. Abdel-Rahman, Thomas Dubois Apr 2022

Measuring And Modelling Crop Yield Losses Due To Invasive Insect Pests Under Climate Change, Henri Ez Tonnang, Bonoukpoè M. Sokame, Elfatih M. Abdel-Rahman, Thomas Dubois

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Climate change and agriculture are strongly correlated, and the fast pace of climate change will have impacts on agroecosystems and crop productivity. This review summarizes potential impacts of rising temperatures and atmospheric CO2 concentrations on insect pest-crop interactions and provides two-way approaches for integrating these impacts into crop models for sustainable pest management strategies designing. Rising temperatures and CO2 levels affect insect physiology, accelerate their metabolism and increase their consumption, ultimately increasing population densities, which result in greater crop injury and damage, and yield loss. Whereas these direct effects are empirically demonstrated for temperature rises, they are less straightforward for …

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Impact Of Net Houses On The Natural Regulation Of The Populations Of Trialeurodes Vaporariorum (Homoptera: Aleyrodidae) And Tuta Absoluta (Lepidoptera: Gelechiidae), Two Major Tomato Pests In Kenya, Anaïs Chailleux, Junitor Chepkemoi, Julien M. Haran, Laure Benoit, Robert Copeland, Emilie Deletre Apr 2022

Impact Of Net Houses On The Natural Regulation Of The Populations Of Trialeurodes Vaporariorum (Homoptera: Aleyrodidae) And Tuta Absoluta (Lepidoptera: Gelechiidae), Two Major Tomato Pests In Kenya, Anaïs Chailleux, Junitor Chepkemoi, Julien M. Haran, Laure Benoit, Robert Copeland, Emilie Deletre

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The abandonment of insecticide treatments to achieve sustainable crop production calls for a combination of methods to obtain satisfactory pest control. To this end, net houses and biological control are two promising methods, though we suspected that most natural enemies are blocked outside the net houses. In Kenya, tomato crops are particularly threatened by Trialeurodes vaporariorum (Westwood 1856) and Tuta absoluta (Meyrick, 1917) that are targets of most insecticide treatments in this country. We investigated in an on-farm experiment (i) the abundances of T. vaporariorum and T. absoluta in open fields and in net houses, (ii) the diversity of arthropod …

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Organic Maize And Bean Farming Enhances Free-Living Nematode Dynamics In Sub-Saharan Africa, Janet G. Atandi, Noah Adamtey, Agnes W. Kiriga, Edward N. Karanja, Martha W. Musyoka, Felix M. Matheri, Chrysantus M. Tanga, Danny L. Coyne, Komi K.M. Fiaboe, David Bautze, Solveig Haukeland Apr 2022

Organic Maize And Bean Farming Enhances Free-Living Nematode Dynamics In Sub-Saharan Africa, Janet G. Atandi, Noah Adamtey, Agnes W. Kiriga, Edward N. Karanja, Martha W. Musyoka, Felix M. Matheri, Chrysantus M. Tanga, Danny L. Coyne, Komi K.M. Fiaboe, David Bautze, Solveig Haukeland

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Despite their important ecological roles for soil health and soil fertility, free-living nematodes (FLN) have received relatively limited research attention. The present study evaluated the community structure and diversity of FLN in a field setting. The experiments were conducted in on-farm and on-station field plots sown to maize (Zea mays) and beans (Phaseolus vulgaris) under four cropping practices. These farming systems included organic (compost and biopesticide use), conventional (synthetic fertilizer and pesticide applications), farmer practice (organic and synthetic amendments) and a control (non-amended plots). Nineteen genera of free living nematodes, belonging to bacterivores, fungivores, omnivores and predators were recorded. Among …

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Genetic Connectivity Of Trypanosomes Between Tsetse-Infested And Tsetse-Free Areas Of Kenya, Naomi N. Kimenyi, Kelvin M. Kimenyi, Nelson O. Amugune, Merid N. Getahun Mar 2022

Genetic Connectivity Of Trypanosomes Between Tsetse-Infested And Tsetse-Free Areas Of Kenya, Naomi N. Kimenyi, Kelvin M. Kimenyi, Nelson O. Amugune, Merid N. Getahun

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The prevalence rates of trypanosomes, including those that require cyclical transmission by tsetse flies, are widely distributed in Africa. Trypanosoma brucei and Trypanosoma congolense are actively maintained in regions where there are no tsetse flies although at low frequencies. Whether this could be due to an independent evolutionary origin or multiple introduction of trypanosomes due to continuous movement of livestock between tsetse-free and -infested areas is not known. Thus, the aim of the study was to carry out microsatellite genotyping to explore intra-specific genetic diversity between T. (Trypanozoon), T. congolense and Trypanosoma vivax from the two regions: tsetse infested and …

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Genetic Diversity, Distribution, And Genomic Characterization Of Antibiotic Resistance And Virulence Of Clinical Pseudomonas Aeruginosa Strains In Kenya, Shahiid Kiyaga, Cecilia Kyany'a, Angela W. Muraya, Hunter J. Smith, Emma G. Mills, Caleb Kibet, Gerald Mboowa, Lillian Musila Mar 2022

Genetic Diversity, Distribution, And Genomic Characterization Of Antibiotic Resistance And Virulence Of Clinical Pseudomonas Aeruginosa Strains In Kenya, Shahiid Kiyaga, Cecilia Kyany'a, Angela W. Muraya, Hunter J. Smith, Emma G. Mills, Caleb Kibet, Gerald Mboowa, Lillian Musila

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Pseudomonas aeruginosa is a leading cause of nosocomial infections worldwide. It can produce a range of debilitating infections, have a propensity for developing antimicrobial resistance, and present with a variety of potent virulence factors. This study investigated the sequence types (ST), phenotypic antimicrobial susceptibility profiles, and resistance and virulence genes among clinical isolates from urinary tract and skin and soft tissue infections. Fifty-six P. aeruginosa clinical isolates were obtained from six medical centers across five counties in Kenya between 2015 and 2020. Whole-genome sequencing (WGS) was performed to conduct genomic characterization, sequence typing, and phylogenetic analysis of the isolates. Results …

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Host Plant-Based Artificial Diets Enhance Development, Survival And Fecundity Of The Edible Long-Horned Grasshopper Ruspolia Differens (Orthoptera: Tettigoniidae), Alfonce Leonard, James P. Egonyu, Chrysantus M. Tanga, Samuel Kyamanywa, Sunday Ekesi, Fathiya M. Khamis, Sevgan Subramanian Mar 2022

Host Plant-Based Artificial Diets Enhance Development, Survival And Fecundity Of The Edible Long-Horned Grasshopper Ruspolia Differens (Orthoptera: Tettigoniidae), Alfonce Leonard, James P. Egonyu, Chrysantus M. Tanga, Samuel Kyamanywa, Sunday Ekesi, Fathiya M. Khamis, Sevgan Subramanian

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Wild swarms of the long-horned grasshoppers Ruspolia differens (Serville) which are widely harvested for consumption and sale in Africa are seasonal and unsustainable, hence the need for innovative ways of artificially producing the insects. We investigated the development, survival, and reproduction of R. differens in the laboratory on diets mixed with host plants [Digitaria gayana Kunth, Cynodon dactylon (L.) and Megathyrsus maximus Jacq (Poales: Poaceae); Ageratum conyzoides L. (Asterales: Asteraceae)] identified from guts of their wild conspecifics with a view to developing a suitable diet for artificial mass rearing of the edible insect. A standard diet comprising ground black soldier …

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Insight On Fruit Fly Ipm Technology Uptake And Barriers To Scaling In Africa, Saliou Niassy, Beatrice Murithii, Evanson R. Omuse, Emily Kimathi, Henri Tonnang, Shepard Ndlela, Samira Mohamed, Sunday Ekesi Mar 2022

Insight On Fruit Fly Ipm Technology Uptake And Barriers To Scaling In Africa, Saliou Niassy, Beatrice Murithii, Evanson R. Omuse, Emily Kimathi, Henri Tonnang, Shepard Ndlela, Samira Mohamed, Sunday Ekesi

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Tephritid fruit flies are considered one of the world’s most notorious pests of horticultural crops, causing extensive direct and indirect damage. Over the past two decades, a comprehensive, integrated pest management (IPM) package for the management of a plethora of fruit fly pests, includ-ing Bactrocera dorsalis, B. latifrons, B. zonata, Ceratitis cosyra, C. rosa, C. fasciventris, C. quilici, C. capitata, Dacus spp. and Zeugodacus cucurbitae, has been developed, disseminated and promoted among horticultural growers in Africa. To estimate the numbers of beneficiaries reached by the fruit fly IPM technology and the barriers to technology uptake, we interviewed 290 experts in …

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Unravelling Causes Of Poor Crop Response To Applied N And P Fertilizers On African Soils, Gudeta W. Sileshi, Job Kihara, Lulseged Tamene, Bernard Vanlauwe, Elijah Phiri, Bashir Jama Feb 2022

Unravelling Causes Of Poor Crop Response To Applied N And P Fertilizers On African Soils, Gudeta W. Sileshi, Job Kihara, Lulseged Tamene, Bernard Vanlauwe, Elijah Phiri, Bashir Jama

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A number of studies across sub-Saharan Africa have recently reported poor crop responses and low agronomic use efficiencies of applied nitrogen (AEN), phosphorus (AEP) and potassium (AEK). However, the conditions under which non-responsiveness occurs, its underlying causes and its probability of occurrence on different soil types are not well understood. Using data from 542 sites and 14 soil types in 23 African countries, we provide novel insights into the linkage between lack of response to applied N, P and K, the mineralogy of soils and their resilience to erosion. We estimated mean responses as well as the probabilities (φ) of …

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Understanding Factors Influencing Wheat Productivity In Ethiopian Highlands, J. Kihara, B. Gurmessa, L. Tamene, T. Amede, R. Sommer Feb 2022

Understanding Factors Influencing Wheat Productivity In Ethiopian Highlands, J. Kihara, B. Gurmessa, L. Tamene, T. Amede, R. Sommer

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Increasing yields in farmer fields is a priority to address increasing food demands. The study was conducted within four wheat-growing areas in Ethiopia: Debre Birhan, Hosaina, Sinana and Maychew. The objectives were to identify (1) best-bet soil fertility management options based on agronomic performance and economic evaluation and (2) key yield-reducing factors in farmer fields based on an agronomic survey among 55 participating farmers. Two types of on-farm experiments were conducted: researcher-managed trials that tested combinations of nutrients, including micronutrients, organic resources or both over two cropping seasons and farmer-managed trials comparing 'improved practice' against 'farmer's practice'. Fertilizer treatment affected …

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Repellency Of Wild Oregano Plant Volatiles, Plectranthus Amboinicus, And Their Essential Oils To The Silverleaf Whitefly, Bemisia Tabaci, On Tomato, Cyrane Pouët, Emilie Deletre, Béatrice Rhino Feb 2022

Repellency Of Wild Oregano Plant Volatiles, Plectranthus Amboinicus, And Their Essential Oils To The Silverleaf Whitefly, Bemisia Tabaci, On Tomato, Cyrane Pouët, Emilie Deletre, Béatrice Rhino

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The Bemisia tabaci (Gennadius) whitefly is a major economically damaging pest of many crops such as tomato (Solanum lycopersicum L.). Pesticides are widely used to control B. tabaci while the use of aromatic plants is an alternative control method. The aim of this study was to assess the B.tabaci repellent effect of wild oregano, Plectranthus amboinicus (Lour.) Spreng, a widespread aromatic plant in the West Indies. We tested three origins of wild oregano, including northern, central, and southern Martinique (French West Indies). Our results showed that all essential oils of wild oregano had either masking properties or were true repellents—the …

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Understanding Changes In Cassava Root Dry Matter Yield By Different Planting Dates, Crop Ages At Harvest, Fertilizer Application And Varieties, Rebecca Oiza Enesi, Stefan Hauser, Pieter Pypers, Christine Kreye, Meklit Tariku, Johan Six Feb 2022

Understanding Changes In Cassava Root Dry Matter Yield By Different Planting Dates, Crop Ages At Harvest, Fertilizer Application And Varieties, Rebecca Oiza Enesi, Stefan Hauser, Pieter Pypers, Christine Kreye, Meklit Tariku, Johan Six

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Cassava is a perennial crop that can adapt to periods of drought at different times in a growing season, which permits scheduling planting and harvest to develop production systems supplying roots continuously. However, farmers plant and harvest cassava at the onset of rains which creates glut and results in unattractive root prices. Thus, farmers need to understand how cassava varieties respond to different planting dates and crop ages at harvest to be able to use opportunities in income generation that may arise from flexible planting and harvest dates resulting from price and dry matter (DM) variabilities. Thus, this study was …

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The Period Of Insect Research In The Tropics: A Bibliometric Analysis, M. C. Moshobane, T. T. Khoza, S. Niassy Feb 2022

The Period Of Insect Research In The Tropics: A Bibliometric Analysis, M. C. Moshobane, T. T. Khoza, S. Niassy

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The International Journal of Tropical Insect Science (Int J Trop Insect Sci) is a peer-reviewed journal established in 1980 to promote insect science mainly in the tropics. This study aimed to provide a Bibliometric overview of Int J Trop Insect Sci publications and citations between 2012 and 2020, ending September 2020. A sample of 488 documents extracted from the Web of Science (WoS) was analysed using widely used bioclimatic indicators. The articles were written by 1726 authors. During this period, the most productive authors comprised S Roy, followed by S Ekesi, S Subramanian and M Tamo. The dominant keyword was …

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Modeling Symbiotic Biological Nitrogen Fixation In Grain Legumes Globally With Lpj-Guess (V4.0, R10285), Jianyong Ma, Stefan Olin, Peter Anthoni, Sam S. Rabin, Anita D. Bayer, Sylvia S. Nyawira, Almut Arneth Jan 2022

Modeling Symbiotic Biological Nitrogen Fixation In Grain Legumes Globally With Lpj-Guess (V4.0, R10285), Jianyong Ma, Stefan Olin, Peter Anthoni, Sam S. Rabin, Anita D. Bayer, Sylvia S. Nyawira, Almut Arneth

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Biological nitrogen fixation (BNF) from grain legumes is of significant importance in global agricultural ecosystems. Crops with BNF capability are expected to support the need to increase food production while reducing nitrogen (N) fertilizer input for agricultural sustainability, but quantification of N fixing rates and BNF crop yields remains inadequate on a global scale. Here we incorporate two legume crops (soybean and faba bean) with BNF into a dynamic vegetation model LPJ-GUESS (Lund–Potsdam–Jena General Ecosystem Simulator). The performance of this new implementation is evaluated against observations from a range of water and N management trials. LPJ-GUESS generally captures the observed …

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Survival Rate, Blood Feeding Habits And Sibling Species Composition Of Aedes Simpsoni Complex: Implications For Arbovirus Transmission Risk In East Africa, Winnie W. Kamau, Rosemary Sang, Edwin O. Ogola, Gilbert Rotich, Caroline Getugi, Sheila B. Agha, Nelson Menza, Baldwyn Torto, David P. Tchouassi Jan 2022

Survival Rate, Blood Feeding Habits And Sibling Species Composition Of Aedes Simpsoni Complex: Implications For Arbovirus Transmission Risk In East Africa, Winnie W. Kamau, Rosemary Sang, Edwin O. Ogola, Gilbert Rotich, Caroline Getugi, Sheila B. Agha, Nelson Menza, Baldwyn Torto, David P. Tchouassi

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Aedes simpsoni complex has a wide distribution in Africa and comprises at least three described sub-species including the yellow fever virus (YFV) vector Ae. bromeliae. To date, the distribution and relative contributions of the sub-species and/or subpopulations including bionomic characteristics in relation to YF transmission dynamics remain poorly studied. In this study conducted in two areas with divergent ecosystems: peri-urban (coastal Rabai) and rural (Rift Valley Kerio Valley) in Kenya, survival rate was estimated by parity in Ae. simpsoni s.l. mosquitoes sampled using CO2-baited BG Sentinel traps. We then applied PCR targeting the nuclear internal transcribed spacer 2 (ITS2), region …

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