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International Centre of Insect Physiology and Ecology

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Articles 271 - 300 of 443

Full-Text Articles in Agricultural Science

Impact Assessment Of Integrated Pest Management (Ipm) Strategy For Suppression Of Mango-Infesting Fruit Flies In Kenya, Beatrice W. Muriithi, Hippolyte D. Affognon, Gracious M. Diiro, Sarah W. Kingori, Chrysantus M. Tanga, Peterson W. Nderitu, Samira A. Mohamed, Sunday Ekesi Mar 2016

Impact Assessment Of Integrated Pest Management (Ipm) Strategy For Suppression Of Mango-Infesting Fruit Flies In Kenya, Beatrice W. Muriithi, Hippolyte D. Affognon, Gracious M. Diiro, Sarah W. Kingori, Chrysantus M. Tanga, Peterson W. Nderitu, Samira A. Mohamed, Sunday Ekesi

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We utilized two waves of data collected from a sample of mango farmers in Meru County in Kenya to evaluate the impact of Integrated Pest Management (IPM) strategy for controlling fruit flies in mango-production. We specifically explored the effect of five IPM practices including parasitoids (p) and Metarhizium anisopliae-based biopesticides (biop), orchard sanitation (os), spot spray of food bait (fb) and male annihilation technique (mat) on three outcome indicators: farmer pesticide expenditure, farm-level mango fruit yield losses and profit. We fitted difference-in-difference and household fixed effects regression models that account for unobserved heterogeneity across households. Our estimates differentiated the impact …

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Influence Of Temperature On Intra- And Interspecific Resource Utilization Within A Community Of Lepidopteran Maize Stemborers, Eric Siaw Ntiri, Paul Andre Calatayud, Johnnie Van Den Berg, Fritz Schulthess, Bruno Pierre Le Ru Feb 2016

Influence Of Temperature On Intra- And Interspecific Resource Utilization Within A Community Of Lepidopteran Maize Stemborers, Eric Siaw Ntiri, Paul Andre Calatayud, Johnnie Van Den Berg, Fritz Schulthess, Bruno Pierre Le Ru

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Competition or facilitation characterises intra- And interspecific interactions within communities of species that utilize the same resources. Temperature is an important factor influencing those interactions and eventual outcomes. The noctuid stemborers, Busseola fusca and Sesamia calamistis and the crambid Chilo partellus attack maize in sub-Saharan Africa. They often occur as a community of interacting species in the same field and plant at all elevations. The influence of temperature on the intra- And interspecific interactions among larvae of these species, was studied using potted maize plants exposed to varying temperatures in a greenhouse and artificial stems kept at different constant temperatures …

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Developing And Deploying Insect Resistant Maize Varieties To Reduce Pre-And Post-Harvest Food Losses In Africa, Tadele Tefera, Stephen Mugo, Yoseph Beyene Feb 2016

Developing And Deploying Insect Resistant Maize Varieties To Reduce Pre-And Post-Harvest Food Losses In Africa, Tadele Tefera, Stephen Mugo, Yoseph Beyene

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Maize grain yield in Africa is low, 1.5 t ha−1 compared to the global average of 4.9 t ha−1. Maize production in Africa is constrained by various abiotic (drought, soil fertility) and biotic factors (insect pests, weeds and diseases). Stem borers and postharvest insect pests play considerable roles in reducing maize yield through damaging the leaves, stems, ears, and kernels. Stem borers can cause 10–15 % yield losses while the postharvest insect pests, particularly, the larger grain borer and maize weevil, can cause 14–36 % grain losses. The use of chemical insecticides has been recommended; however, in addition to health …

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Maize Landraces Are Less Affected By Striga Hermonthica Relative To Hybrids In Western Kenya, Charles A.O. Midega, John Pickett, Antony Hooper, Jimmy Pittchar, Zeyaur R. Khan Jan 2016

Maize Landraces Are Less Affected By Striga Hermonthica Relative To Hybrids In Western Kenya, Charles A.O. Midega, John Pickett, Antony Hooper, Jimmy Pittchar, Zeyaur R. Khan

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Production of maize in western Kenya is severely constrained by the parasitic weed striga. Although productivity of maize can be improved through adoption of improved varieties, adoption of such varieties remains low in the region, as the majority of smallholder farmers still grow unimproved open-pollinated varieties (landraces). The performance of two improved hybrid varieties was evaluated against six landraces in striga-infested soils in western Kenya. The varieties were planted in plots under natural striga infestation and were supplemented with pot experiments under artificial infestation. Striga emergence was lower in landraces than in the hybrid varieties in both field and pot …

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Spatial Separation Of Semiochemical Lurem-Tr And Entomopathogenic Fungi To Enhance Their Compatibility And Infectivity In An Autoinoculation System For Thrips Management, David K. Mfuti, Sevgan Subramanian, Rob Whm Van Tol, Gerrie L. Wiegers, Willem J. De Kogel, Saliou Niassy, Hannalene Du Plessis, Sunday Ekesi, Nguya K. Maniania Jan 2016

Spatial Separation Of Semiochemical Lurem-Tr And Entomopathogenic Fungi To Enhance Their Compatibility And Infectivity In An Autoinoculation System For Thrips Management, David K. Mfuti, Sevgan Subramanian, Rob Whm Van Tol, Gerrie L. Wiegers, Willem J. De Kogel, Saliou Niassy, Hannalene Du Plessis, Sunday Ekesi, Nguya K. Maniania

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BACKGROUND: The effect of spatial separation of the semiochemical Lurem-TR, which has been found to inhibit conidia of entomopathogenic fungi when put together, on the persistence of conidia of Metarhizium brunneum and M. anisopliae was evaluated in the greenhouse and field in order to develop an autodissemination strategy for the management of Megalurothrips sjostedti on cowpea crop. Influence of spatial separation of the semiochemical on thrips attraction and conidial acquisition by thrips from the autoinoculation device was also investigated in the field. RESULTS: Persistence of conidia of M. brunneum and M. anisopliae increased with distance of separation of Lurem-TR. Direct …

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Impact Of Reduced Tillage And Crop Residue Management On Soil Properties And Crop Yields In A Long-Term Trial In Western Kenya, Jeremiah M. Okeyo, Jay Norton, Saidou Koala, Boaz Waswa, Job Kihara, Andre Bationo Jan 2016

Impact Of Reduced Tillage And Crop Residue Management On Soil Properties And Crop Yields In A Long-Term Trial In Western Kenya, Jeremiah M. Okeyo, Jay Norton, Saidou Koala, Boaz Waswa, Job Kihara, Andre Bationo

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Sustainable farming practices are required to address the persistent problems of land degradation and declining crop productivity in Sub-Saharan Africa. Approaches such as reducing tillage and retaining crop residues as mulch are potential entry points for smallholder farmers to move towards sustainability. In this study, we assessed the impact of reduced tillage (RT) compared with conventional tillage (CT), each combined with crop residue reapplication, on soil quality indicators and crop yields under an 8-year trial in western Kenya. Our results indicate that RT combined with crop residue reapplication enhanced soil physical quality through increased macroaggregate (>2000μm) proportions and mean …

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Mitochondrial Coding Genome Analysis Of Tropical Root-Knot Nematodes (Meloidogyne) Supports Haplotype Based Diagnostics And Reveals Evidence Of Recent Reticulate Evolution, Toon Janssen, Gerrit Karssen, Myrtle Verhaeven, Danny Coyne, Wim Bert Jan 2016

Mitochondrial Coding Genome Analysis Of Tropical Root-Knot Nematodes (Meloidogyne) Supports Haplotype Based Diagnostics And Reveals Evidence Of Recent Reticulate Evolution, Toon Janssen, Gerrit Karssen, Myrtle Verhaeven, Danny Coyne, Wim Bert

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The polyphagous parthenogenetic root-knot nematodes of the genus Meloidogyne are considered to be the most significant nematode pest in sub-tropical and tropical agriculture. Despite the crucial need for correct diagnosis, identification of these pathogens remains problematic. The traditionally used diagnostic strategies, including morphometrics, host-range tests, biochemical and molecular techniques, now appear to be unreliable due to the recently-suggested hybrid origin of root-knot nematodes. In order to determine a suitable barcode region for these pathogens nine quickly-evolving mitochondrial coding genes were screened. Resulting haplotype networks revealed closely related lineages indicating a recent speciation, an anthropogenic-aided distribution through agricultural practices, and evidence …

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Active Aggregation Among Sexes In Bean Flower Thrips (Megalurothrips Sjostedti) On Cowpea (Vigna Unguiculata), Saliou Niassy, Sunday Ekesi, Nguya K. Maniania, Benedict Orindi, Gerald B. Moritz, Willem J. De Kogel, Sevgan Subramanian Jan 2016

Active Aggregation Among Sexes In Bean Flower Thrips (Megalurothrips Sjostedti) On Cowpea (Vigna Unguiculata), Saliou Niassy, Sunday Ekesi, Nguya K. Maniania, Benedict Orindi, Gerald B. Moritz, Willem J. De Kogel, Sevgan Subramanian

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Male sexual aggregations are a common territorial, mating-related or resource-based, behaviour observed in diverse organisms, including insects such as thrips. The influence of factors such as plant substrate, time of day, and geographic location on aggregation of thrips is uncertain, therefore we monitored the dispersion of male and female bean flower thrips (BFT), Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), on cowpea, Vigna unguiculata (L.) Walp. (Fabaceae), over three cowpea growth stages and across three cowpea-growing areas of Kenya. Our results indicated that for all the crop growth stages, the density of BFTs varied over the time of day, with higher densities …

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Eco-Friendly Nets To Improve Vegetable Production And Quality In Sub-Saharan Africa, T. Martin, S. Simon, L. Parrot, F. Assogba Komlan, F. Vidogbena, A. Adegbidi, V. Baird, M. Saidi, M. Kasina, L. A. Wasilwa, S. Subramanian, M. Ngouajio Dec 2015

Eco-Friendly Nets To Improve Vegetable Production And Quality In Sub-Saharan Africa, T. Martin, S. Simon, L. Parrot, F. Assogba Komlan, F. Vidogbena, A. Adegbidi, V. Baird, M. Saidi, M. Kasina, L. A. Wasilwa, S. Subramanian, M. Ngouajio

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Continuous coverage of vegetables with nets under different climate conditions in Benin and Kenya proved effective in protecting vegetable nurseries and main fields against key lepidopteran and dipteran pests. However, netting did not effectively protect the vegetables against small insects such as aphids and whiteflies, although a visual barrier could delay outbreaks. Hence, opening the nets during the day could be an alternative option to conserve the natural enemies for small insects. Moreover, the efficacy of the visual barrier may be complemented by a repellent compound impregnated in the net. The small-holder growers adopting the nets in Benin and Kenya …

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Cost: Benefit Analysis Of Insect Net Use In Cabbage In Real Farming Conditions Among Smallholder Farmers In Benin, Faustin Vidogbéna, Anselme Adégbidi, Françoise Assogba-Komlan, Thibaud Martin, Mathieu Ngouajio, Serge Simon, Rigobert Tossou, Laurent Parrot Dec 2015

Cost: Benefit Analysis Of Insect Net Use In Cabbage In Real Farming Conditions Among Smallholder Farmers In Benin, Faustin Vidogbéna, Anselme Adégbidi, Françoise Assogba-Komlan, Thibaud Martin, Mathieu Ngouajio, Serge Simon, Rigobert Tossou, Laurent Parrot

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Insect net use provides a physical exclusion of pests as well as a microclimate change, thus increasing soil humidity, vegetable quality and yields in tropical conditions. This paper presents the findings of a cost:benefit analysis of this technology in real farming conditions compared to current insecticide practices. The surveys were conducted in Benin for cabbage production (. Brassica oleracea L.) during two production cycles. There were almost no significant differences in costs between unnetted and netted cabbage for the two production cycles. The only factors that varied were farm gate prices, the number of cabbages marketed and their size. Improved …

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Characteristics Of Soils In Selected Maize Growing Sites Along Altitudinal Gradients In East African Highlands, Elijah Njuguna, Mary Gathara, Stanley Nadir, Sizah Mwalusepo, David Williamson, Pierre Etienne Mathé, Jackson Kimani, Tobias Landmann, Gerald Juma, George Ong'amo, Erastus Gatebe, Bruno Le Ru, Paul André Calatayud Dec 2015

Characteristics Of Soils In Selected Maize Growing Sites Along Altitudinal Gradients In East African Highlands, Elijah Njuguna, Mary Gathara, Stanley Nadir, Sizah Mwalusepo, David Williamson, Pierre Etienne Mathé, Jackson Kimani, Tobias Landmann, Gerald Juma, George Ong'amo, Erastus Gatebe, Bruno Le Ru, Paul André Calatayud

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Maize is the main staple crop in the East African Mountains. Understanding how the edaphic characteristics change along altitudinal gradients is important for maximizing maize production in East African Highlands, which are the key maize production areas in the region. This study evaluated and compared the levels of some macro and micro-elements (Al, Ca, Fe, K, Mg, Mn, Na and P) and other soil parameters (pH, organic carbon content, soil texture [i.e. % Sand, % Clay and % Silt], cation exchange capacity [CEC], electric conductivity [EC], and water holding capacity [HC]). Soil samples were taken from maize plots along three …

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Effects Of Agroforestry On Pest, Disease And Weed Control: A Meta-Analysis, Lorena Pumariño, Gudeta Weldesemayat Sileshi, Sofia Gripenberg, Riikka Kaartinen, Edmundo Barrios, Mary Nyawira Muchane, Charles Midega, Mattias Jonsson Nov 2015

Effects Of Agroforestry On Pest, Disease And Weed Control: A Meta-Analysis, Lorena Pumariño, Gudeta Weldesemayat Sileshi, Sofia Gripenberg, Riikka Kaartinen, Edmundo Barrios, Mary Nyawira Muchane, Charles Midega, Mattias Jonsson

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Agroforestry practices may influence pest incidence and abundance both through increased top-down regulation by natural enemies and via bottom-up factors such as moderation of microclimate, soil nutrients and water content. We conducted a meta-analysis of the effects of agroforestry on the abundance of invertebrate pests, weeds, natural enemies and plant damage due to pests and diseases. We also tested whether effects of agroforestry were dependent on crop type (annual or perennial), type of pest association (above or belowground) and weed type (parasitic Striga weeds or non-parasitic weeds).Agroforestry practices resulted in lower abundances of both parasitic and non-parasitic weeds, and in …

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The Biosynthesis Of Allelopathic Di-C-Glycosylflavones From The Roots Of Desmodium Incanum (G. Mey.) Dc, Bing Hao, John C. Caulfield, Mary L. Hamilton, John A. Pickett, Charles A.O. Midega, Zeyaur R. Khan, Junru R. Wang, Antony M. Hooper Oct 2015

The Biosynthesis Of Allelopathic Di-C-Glycosylflavones From The Roots Of Desmodium Incanum (G. Mey.) Dc, Bing Hao, John C. Caulfield, Mary L. Hamilton, John A. Pickett, Charles A.O. Midega, Zeyaur R. Khan, Junru R. Wang, Antony M. Hooper

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The allelopathic root exudate of the drought-tolerant subsistence cereal intercrop D. incanum, protecting against the parasitic weed Striga hermonthica, comprises a number of di-C-glycosylflavones specifically containing C-glucosyl, C-galactosyl and C-arabinosyl moieties. Here we demonstrate that the biosynthesis of all compounds containing a C-glucose involves C-glucosylation of 2-hydroxynaringenin with subsequent C-galactosylation, C-glucosylation or C-arabinosylation. In addition, the crude soluble enzyme extract converts two fluorinated 2-hydroxyflavanone analogues to corresponding mono- and di-C-glycosylflavones demonstrating that some differences in C-ring substitution can be tolerated by the plant enzymes. Elucidating the biosynthesis of these C-glycosylflavones (CGFs) has the potential to open up opportunities for transferring …

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Farmers' Control Practices Against The Invasive Red Spider Mite, Tetranychus Evansi Baker & Pritchard In Benin, Ginette Y. Azandémè-Hounmalon, Hippolyte D. Affognon, Françoise Assogba Komlan, Manuele Tamò, Komi K.M. Fiaboe, Serge Kreiter, Thibaud Martin Oct 2015

Farmers' Control Practices Against The Invasive Red Spider Mite, Tetranychus Evansi Baker & Pritchard In Benin, Ginette Y. Azandémè-Hounmalon, Hippolyte D. Affognon, Françoise Assogba Komlan, Manuele Tamò, Komi K.M. Fiaboe, Serge Kreiter, Thibaud Martin

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In 2008, the invasive tomato red spider mite Tetranychus evansi (Acari: Tetranychidae), a pest of solanaceous crops, was identified for the first time as the cause of serious damage on tomato (. Solanum lycopersicum L.; Solanaceae) crops in Benin. Since then, frequent outbreaks have been observed on Solanaceae and other leafy vegetables such as purple amaranth (. Amaranthus cruentus L.; Amaranthaceae) and bitter leaf (. Vernonia amygdalina D.; Asteraceae) in all growing areas in southern Benin. The objective of this study was to evaluate the intensity of damage by this invasive pest and the impact of farmers' control practices on …

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Evaluating The Sequential Masking Classification Approach For Improving Crop Discrimination In The Sudanian Savanna Of West Africa, Gerald Forkuor, Christopher Conrad, Michael Thiel, Tobias Landmann, Boubacar Barry Oct 2015

Evaluating The Sequential Masking Classification Approach For Improving Crop Discrimination In The Sudanian Savanna Of West Africa, Gerald Forkuor, Christopher Conrad, Michael Thiel, Tobias Landmann, Boubacar Barry

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Classification of remotely sensed data to reveal the spatial distribution of crop types has high potential for improving crop area estimates and supporting decision making. However, remotely sensed crop maps still demand improvements as e.g. variations in farm management practices (e.g. planting and harvesting dates), soil and other environmental factors cause overlaps in features available for classification and thus confusion in error matrices. In this study, a variant of the sequential masking classification technique was applied to multi-temporal optical and microwave remote sensing data (RapidEye, Landsat, TerraSAR-X) to improve the accuracy of crop discrimination in West Africa. This approach employs …

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Distribution Of Indigenous Strains Of Atoxigenic And Toxigenic Aspergillus Flavus And Aspergillus Parasiticus In Maize And Peanuts Agro-Ecological Zones Of Kenya, Daniel O. Okun, Fathiya M. Khamis, Geoffrey M. Muluvi, Joseph J. Ngeranwa, Fidelis O. Ombura, Moses O. Yongo, Eucharia U. Kenya Sep 2015

Distribution Of Indigenous Strains Of Atoxigenic And Toxigenic Aspergillus Flavus And Aspergillus Parasiticus In Maize And Peanuts Agro-Ecological Zones Of Kenya, Daniel O. Okun, Fathiya M. Khamis, Geoffrey M. Muluvi, Joseph J. Ngeranwa, Fidelis O. Ombura, Moses O. Yongo, Eucharia U. Kenya

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Background: Grains of important food and export crops in Africa are susceptible to contamination by toxin-producing moulds. Aflatoxins are mycotoxins associated with liver damage and cancer in humans and animals. These toxic substances are produced by fungi (such as Aspergillus flavus and Aspergillus parasiticus) in food and feed exposed to poor conditions during crop cultivation, storage or processing of harvest. The presence of aflatoxins in especially maize and peanuts in Kenya is of great concern. Recent developments in the application of atoxigenic strains of these fungi as biological control agents against toxigenic strains could be a solution to the problem. …

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Sternal Gland Structures In Males Of Bean Flower Thrips, Megalurothrips Sjostedti, And Poinsettia Thrips, Echinothrips Americanus, In Comparison With Those Of Western Flower Thrips, Frankliniella Occidentalis (Thysanoptera: Thripidae), Stephanie Krueger, Sevgan Subramanian, Saliou Niassy, Gerald B. Moritz Sep 2015

Sternal Gland Structures In Males Of Bean Flower Thrips, Megalurothrips Sjostedti, And Poinsettia Thrips, Echinothrips Americanus, In Comparison With Those Of Western Flower Thrips, Frankliniella Occidentalis (Thysanoptera: Thripidae), Stephanie Krueger, Sevgan Subramanian, Saliou Niassy, Gerald B. Moritz

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Sternal pores are important features for identification of male thrips, especially within the subfamily Thripinae. They vary in shape, size and distribution even between species of one genus. Their functional role is speculated to be that of sex- and/or aggregation pheromone production. Yet, sexual aggregations are not reported in Echinothrips americanus, known to have sternal pores, while we observed aggregations in Megalurothrips sjostedti, previously reported to lack them. We examined the sternal glands and pores of the thripine species E. americanus and M. sjostedti males, in comparison with those of Frankliniella occidentalis using light microscopy, as well as scanning and …

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Isolation And Identification Of Desmodium Root Exudates From Drought Tolerant Species Used As Intercrops Against Striga Hermonthica, A. M. Hooper, J. C. Caulfield, B. Hao, J. A. Pickett, C. A.O. Midega, Z. R. Khan Jul 2015

Isolation And Identification Of Desmodium Root Exudates From Drought Tolerant Species Used As Intercrops Against Striga Hermonthica, A. M. Hooper, J. C. Caulfield, B. Hao, J. A. Pickett, C. A.O. Midega, Z. R. Khan

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Abstract Plants from the genus Desmodium, in particular D. uncinatum, are used on sub-Saharan small-holder farms as intercrops to inhibit parasitism of cereal crops by Striga hermonthica and Striga asiatica via an allelopathic mechanism. The search for Desmodium species which are adapted to more arid conditions, and which show resilience to increased drought stress, previously identified D. intortum, D. incanum and D. ramosissimum as potential drought tolerant intercrops. Their potential as intercrops was assessed for resource poor areas of rain-fed cereal production where drought conditions can persist through normal meteorological activity, or where drought may have increasing impact through climate …

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Grower Adoption Of An Integrated Pest Management Package For Management Of Mango-Infesting Fruit Flies (Diptera: Tephritidae) In Embu, Kenya, J. K. Korir, H. D. Affognon, C. N. Ritho, W. S. Kingori, P. Irungu, S. A. Mohamed, S. Ekesi Jun 2015

Grower Adoption Of An Integrated Pest Management Package For Management Of Mango-Infesting Fruit Flies (Diptera: Tephritidae) In Embu, Kenya, J. K. Korir, H. D. Affognon, C. N. Ritho, W. S. Kingori, P. Irungu, S. A. Mohamed, S. Ekesi

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Mango (Mangifera indica L.) is a well-recognized fruit of economic and nutritional importance to smallholder farmers across Africa. Production and marketing of this fruit is, however, severely hampered by fruit fly infestation that is responsible for enormous fruit losses. In Kenya, control of this pest is primarily dependent on the use of chemical pesticides, a strategy that has been shown to be ineffective. Although the recently introduced fruit fly integrated pest management (IPM) package developed by the International Centre of Insect Physiology and Ecology (icipe) has proved to be effective against this pest, there is little demonstrable investigation on its …

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Predicting The Impact Of Temperature Change On The Future Distribution Of Maize Stem Borers And Their Natural Enemies Along East African Mountain Gradients Using Phenology Models, Sizah Mwalusepo, Henri E.Z. Tonnang, Estomih S. Massawe, Gerphas O. Okuku, Nancy Khadioli, Tino Johansson, Paul André Calatayud, Bruno Pierre Le Ru Jun 2015

Predicting The Impact Of Temperature Change On The Future Distribution Of Maize Stem Borers And Their Natural Enemies Along East African Mountain Gradients Using Phenology Models, Sizah Mwalusepo, Henri E.Z. Tonnang, Estomih S. Massawe, Gerphas O. Okuku, Nancy Khadioli, Tino Johansson, Paul André Calatayud, Bruno Pierre Le Ru

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Lepidopteran stem borers are among the most important pests of maize in East Africa. The objective of the present study was to predict the impact of temperature change on the distribution and abundance of the crambid Chilo partellus, the noctuid Busseola fusca, and their larval parasitoids Cotesia flavipes and Cotesia sesamiae at local scale along Kilimanjaro and Taita Hills gradients in Tanzania and Kenya, respectively. Temperature-dependent phenology models of pests and parasitoids were used in a geographic information system for mapping. The three risk indices namely establishment, generation, and activity indices were computed using current temperature data record from local …

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Determinants Of Adoption Of Climate-Smart Push-Pull Technology For Enhanced Food Security Through Integrated Pest Management In Eastern Africa, A. W. Murage, C. A.O. Midega, J. O. Pittchar, J. A. Pickett, Z. R. Khan Jun 2015

Determinants Of Adoption Of Climate-Smart Push-Pull Technology For Enhanced Food Security Through Integrated Pest Management In Eastern Africa, A. W. Murage, C. A.O. Midega, J. O. Pittchar, J. A. Pickett, Z. R. Khan

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Food security attainment in Africa has been hindered by poor yields of cereals that serve both as staple and cash crops for the majority of smallholder farmers. Among the various constraints responsible for lower yields are the parasitic weed Striga, and Stemborer pests whose control has remained a challenge. The International Centre of Insect Physiology and Ecology (icipe) with partners developed a novel conservation agricultural technology termed ‘push-pull’, based on companion cropping that effectively controls both constraints simultaneously. However, the effects of climate change threatened its expansion into drier areas where Striga is rapidly spreading. Further adaptation of the conventional …

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Napier Grass Stunt Disease In East Africa: Farmers' Perspectives On Disease Management, George O. Asudi, Johnnie Van Den Berg, Charles A.O. Midega, Jimmy Pittchar, John A. Pickett, Zeyaur R. Khan May 2015

Napier Grass Stunt Disease In East Africa: Farmers' Perspectives On Disease Management, George O. Asudi, Johnnie Van Den Berg, Charles A.O. Midega, Jimmy Pittchar, John A. Pickett, Zeyaur R. Khan

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Napier or Elephant grass (. Pennisetum purpureum), the most important livestock fodder crop in East Africa, is under threat from Napier grass stunt (NGS) disease. This disease is caused by a phytoplasma, which is transmitted by the leafhopper, Maiestas banda (Hemiptera: Cicadellidae). After inoculation, the disease rapidly infects the whole plant causing extensive damage to Napier grass plants. There is therefore a need to develop an integrated management approach for the disease. A survey was conducted in three East African countries (Kenya, Uganda and Tanzania) during which 198 farmers were interviewed using semi-structured questionnaires. The questionnaire addressed the prevalence of …

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Agronomic Survey To Assess Crop Yield, Controlling Factors And Management Implications: A Case-Study Of Babati In Northern Tanzania, J. Kihara, L. D. Tamene, P. Massawe, M. Bekunda May 2015

Agronomic Survey To Assess Crop Yield, Controlling Factors And Management Implications: A Case-Study Of Babati In Northern Tanzania, J. Kihara, L. D. Tamene, P. Massawe, M. Bekunda

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Improved agronomic management is important to reduce yield gaps and enhance food security in sub-Saharan Africa. This study was undertaken to understand contributing factors to observed yield gaps for maize in farmer fields and to demonstrate appropriate agronomic survey methods. The study aimed to (1) demonstrate an approach for farm-level agronomic survey, (2) identify key crop production constraints and (3) define the nutrient input and output balances of different fields. Agronomic survey was conducted in 117 farmer fields randomly distributed in a 10 km by 10 km block in Babati, northern Tanzania. A semi-structured questionnaire and production measurements were used …

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Responses Of Parasitoids To Volatiles Induced By Chilo Partellus Oviposition On Teosinte, A Wild Ancestor Of Maize, Daniel M. Mutyambai, Toby J.A. Bruce, Charles A.O. Midega, Christine M. Woodcock, John C. Caulfield, Johnnie Van Den Berg, John A. Pickett, Zeyaur R. Khan Apr 2015

Responses Of Parasitoids To Volatiles Induced By Chilo Partellus Oviposition On Teosinte, A Wild Ancestor Of Maize, Daniel M. Mutyambai, Toby J.A. Bruce, Charles A.O. Midega, Christine M. Woodcock, John C. Caulfield, Johnnie Van Den Berg, John A. Pickett, Zeyaur R. Khan

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Maize, a genetically diverse crop, is the domesticated descendent of its wild ancestor, teosinte. Recently, we have shown that certain maize landraces possess a valuable indirect defense trait not present in commercial hybrids. Plants of these landraces release herbivore-induced plant volatiles (HIPVs) that attract both egg [Trichogramma bournieri Pintureau & Babault (Hymenoptera: Trichogrammatidae)] and larval [Cotesia sesamiae Cameron (Hymenoptera: Braconidae)] parasitoids in response to stemborer egg deposition. In this study, we tested whether this trait also exists in the germplasm of wild Zea species. Headspace samples were collected from plants exposed to egg deposition by Chilo partellus Swinhoe (Lepidoptera: Crambidae) …

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Pathogenicity And Performance Of Two Candidate Isolates Of Metarhizium Anisopliae And Beauveria Bassiana (Hypocreales: Clavicipitaceae) In Four Liquid Culture Media For The Management Of The Legume Pod Borer Maruca Vitrata (Lepidoptera: Crambidae), V. Tumuhaise, S. Ekesi, S. A. Mohamed, P. N. Ndegwa, L. W. Irungu, R. Srinivasan, N. K. Maniania Mar 2015

Pathogenicity And Performance Of Two Candidate Isolates Of Metarhizium Anisopliae And Beauveria Bassiana (Hypocreales: Clavicipitaceae) In Four Liquid Culture Media For The Management Of The Legume Pod Borer Maruca Vitrata (Lepidoptera: Crambidae), V. Tumuhaise, S. Ekesi, S. A. Mohamed, P. N. Ndegwa, L. W. Irungu, R. Srinivasan, N. K. Maniania

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The aim of this study was to identify and develop entomopathogenic fungi as biopesticides for management of Maruca vitrata (Fabricius). Fourteen isolates of Metarhizium anisopliae (Metchnikoff) Sorokin and six of Beauveria bassiana (Bals.-Criv.) Vuill. were screened against first instar larvae of M. vitrata. The two most virulent isolates were selected and further tested for production in four liquid media. Different formulations of one isolate were evaluated against different developmental stages. Metarhizium anisopliae ICIPE 18 and ICIPE 69 caused highest larval mortality of 91 and 81%, with lethal time to 50% mortality (LT50) values of 1.8 and 1.7 days and LC50 …

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Optimizing Western Flower Thrips Management On French Beans By Combined Use Of Beneficials And Imidacloprid, Johnson O. Nyasani, Sevgan Subramanian, Hans Michael Poehling, Nguya K. Maniania, Sunday Ekesi, Rainer Meyhöfer Mar 2015

Optimizing Western Flower Thrips Management On French Beans By Combined Use Of Beneficials And Imidacloprid, Johnson O. Nyasani, Sevgan Subramanian, Hans Michael Poehling, Nguya K. Maniania, Sunday Ekesi, Rainer Meyhöfer

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Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is an important pest of vegetable crops worldwide and has developed resistance to many insecticides. The predatory mites Neoseiulus (=Amblyseius) cucumeris (Oudemans), the entomopathogenic fungus Metarhizium anisopliae (Metsch.), and an insecticide (imidacloprid) were tested for their efficacy to reduce WFT population density and damage to French bean (Phaseolus vulgaris L.) pods under field conditions in two planting periods. Metarhizium anisopliae was applied as a foliar spray weekly at a rate of one litre spray volume per plot while imidacloprid was applied as a soil drench every two weeks at a rate of two …

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Control Of Vegetable Pests In Benin - Farmers' Preferences For Eco-Friendly Nets As An Alternative To Insecticides, Faustin Vidogbéna, Anselme Adégbidi, Rigobert Tossou, Françoise Assogba-Komlan, Mathieu Ngouajio, Thibaut Martin, Serge Simon, Laurent Parrot, Kerstin K. Zander Jan 2015

Control Of Vegetable Pests In Benin - Farmers' Preferences For Eco-Friendly Nets As An Alternative To Insecticides, Faustin Vidogbéna, Anselme Adégbidi, Rigobert Tossou, Françoise Assogba-Komlan, Mathieu Ngouajio, Thibaut Martin, Serge Simon, Laurent Parrot, Kerstin K. Zander

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We investigated if eco-friendly nets (EFNs) are a viable and acceptable alternative to extremely high levels of insecticide use in vegetable production. Using a choice experiment, we found that vegetable producing farmers in Benin preferred all of the characteristics of EFNs except the higher labor requirements. The nets had been distributed in a trial phase for free but in the long run farmers would need to purchase the EFNs. The break-even point for investing in nets was found to vary with the lifespan of EFNs, their purchase price and potential health benefits from avoiding large quantities of insecticides. To break …

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Do Nerica Rice Cultivars Express Resistance To Striga Hermonthica (Del.) Benth. And Striga Asiatica (L.) Kuntze Under Field Conditions?, Jonne Rodenburg, Mamadou Cissoko, Juma Kayeke, Ibnou Dieng, Zeyaur R. Khan, Charles A.O. Midega, Enos A. Onyuka, Julie D. Scholes Jan 2015

Do Nerica Rice Cultivars Express Resistance To Striga Hermonthica (Del.) Benth. And Striga Asiatica (L.) Kuntze Under Field Conditions?, Jonne Rodenburg, Mamadou Cissoko, Juma Kayeke, Ibnou Dieng, Zeyaur R. Khan, Charles A.O. Midega, Enos A. Onyuka, Julie D. Scholes

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The parasitic weeds Striga asiatica and Striga hermonthica cause high yield losses in rain-fed upland rice in Africa. Two resistance classes (pre- and post-attachment) and several resistant genotypes have been identified among NERICA (New Rice for Africa) cultivars under laboratory conditions (in vitro) previously. However, little is known about expression of this resistance under field conditions. Here we investigated (1) whether resistance exhibited under controlled conditions would express under representative Striga-infested field conditions, and (2) whether NERICA cultivars would achieve relatively good grain yields under Striga-infested conditions. Twenty-five rice cultivars, including all 18 upland NERICA cultivars, were screened in S. …

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Effect Of Temperature On The Phenology Of Chilo Partellus (Swinhoe) (Lepidoptera, Crambidae); Simulation And Visualization Of The Potential Future Distribution Of C. Partellus In Africa Under Warmer Temperatures Through The Development Of Life-Table Parameters, N. Khadioli, Z. E.H. Tonnang, E. Muchugu, G. Ong'amo, T. Achia, I. Kipchirchir, J. Kroschel, B. Le Ru Dec 2014

Effect Of Temperature On The Phenology Of Chilo Partellus (Swinhoe) (Lepidoptera, Crambidae); Simulation And Visualization Of The Potential Future Distribution Of C. Partellus In Africa Under Warmer Temperatures Through The Development Of Life-Table Parameters, N. Khadioli, Z. E.H. Tonnang, E. Muchugu, G. Ong'amo, T. Achia, I. Kipchirchir, J. Kroschel, B. Le Ru

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Maize (Zea mays) is a major staple food in Africa. However, maize production is severely reduced by damage caused by feeding lepidopteran pests. In East and Southern Africa, Chilo partellus is one of the most damaging cereal stem borers mainly found in the warmer lowland areas. In this study, it was hypothesized that the future distribution and abundance of C. partellus may be affected greatly by the current global warming. The temperature-dependent population growth potential of C. partellus was studied on artificial diet under laboratory conditions at six constant temperatures (15, 18, 20, 25, 28, 30, 32 and 35 °C), …

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Molecular Mapping Of Qtls For Domestication-Related Traits In Cowpea (V. Unguiculata (L.) Walp.), Mebeaselassie Andargie, Remy S. Pasquet, Bhavani S. Gowda, Geoffrey M. Muluvi, Michael P. Timko Dec 2014

Molecular Mapping Of Qtls For Domestication-Related Traits In Cowpea (V. Unguiculata (L.) Walp.), Mebeaselassie Andargie, Remy S. Pasquet, Bhavani S. Gowda, Geoffrey M. Muluvi, Michael P. Timko

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Understanding the genetic basis underlying domestication-related traits (DRTs) of cowpea (Vigna unguiculata (L.) Walp.) is important since the genome has experienced divergent domestication and in addition it is also useful to utilize the wild germplasm efficiently for improving different traits of the cultivated cowpea. Quantitative trait loci (QTLs) for DRTs were identified in a population of 159 F7 recombinant inbred lines derived from a cross between a domesticated cowpea (V. unguiculata (L.) Walp.) variety, 524B, and a wild accession, 219. Using the constructed linkage map, QTLs for 10 DRTs were analysed and mapped. QTLs for seed, pod and flower related …

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