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International Centre of Insect Physiology and Ecology

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Articles 331 - 360 of 443

Full-Text Articles in Agricultural Science

Duration Analysis Of Technology Adoption Effects Of Dissemination Pathways: A Case Of 'Push-Pull' Technology For Control Of Striga Weeds And Stemborers In Western Kenya, A. W. Murage, G. Obare, J. Chianu, D. M. Amudavi, J. Pickett, Z. R. Khan May 2011

Duration Analysis Of Technology Adoption Effects Of Dissemination Pathways: A Case Of 'Push-Pull' Technology For Control Of Striga Weeds And Stemborers In Western Kenya, A. W. Murage, G. Obare, J. Chianu, D. M. Amudavi, J. Pickett, Z. R. Khan

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Since its introduction, the 'push-pull' technology (PPT) has been promoted as an innovative approach for addressing yield losses caused by Striga weeds and stemborer infestations on farmers' maize fields in western Kenya. The technology has been disseminated through different pathways each of which might have different uptake enhancement capabilities. This study was concerned with how different dissemination pathways impacted on farmers' time to adoption while controlling the effects of selected socio-economic and regional factors. This assessment was necessary in order to recommend which dissemination pathway or combination of pathways that could provide an effective dissemination strategy that speed up adoption, …

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Construction Of A Ssr-Based Genetic Map And Identification Of Qtl For Domestication Traits Using Recombinant Inbred Lines From A Cross Between Wild And Cultivated Cowpea (V. Unguiculata (L.) Walp.), Mebeaselassie Andargie, Remy S. Pasquet, Bhavani S. Gowda, Geoffrey M. Muluvi, Michael P. Timko Jan 2011

Construction Of A Ssr-Based Genetic Map And Identification Of Qtl For Domestication Traits Using Recombinant Inbred Lines From A Cross Between Wild And Cultivated Cowpea (V. Unguiculata (L.) Walp.), Mebeaselassie Andargie, Remy S. Pasquet, Bhavani S. Gowda, Geoffrey M. Muluvi, Michael P. Timko

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Cowpea (Vigna unguiculata (L.) Walp.) is a grain legume commonly grown and consumed in many parts of the tropics and subtropics. A genetic linkage map was constructed using simple sequence repeat (SSR) markers and a recombinant inbred (RI) population of159 individuals derived from a cross between the breeding line 524B, a California Blackeye, and 219-01, a perennial wild cowpea from Kenya. Out of 912 primer combinations predicted to amplify SSRs in cowpea, 639 reliably produced amplification products in PCR assays and 202 (31.6%) were polymorphic between the two parents. These polymorphic SSRs were used to construct a genetic map consisting …

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Spider Cognition, Robert R. Jackson, Fiona R. Cross Jan 2011

Spider Cognition, Robert R. Jackson, Fiona R. Cross

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Spiders, having minute brains, were once considered simple, instinct-driven automatons, but research on spider biology is revealing increasing evidence of their cognitive abilities. In this review, we discuss the complex, flexible behaviour of spiders, especially salticids, and highlight how sometimes the cognitive character of spider behaviour closely parallels that of much bigger animals. This includes the use of selective attention (both visual and olfactory) and the use of planned detours. The implications of these findings, and how they relate to bigger issues traditionally associated with big-brain animals, such as 'representation' and 'mind', are discussed. Also discussed are issues relating to …

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Isolation, Phylogeny And Evolution Of The Symrk Gene In The Legume Genus Lupinus L., Frédéric Mahé, Dragomira Markova, Rémy Pasquet, Marie Thérèse Misset, Abdelkader Aïnouche Jan 2011

Isolation, Phylogeny And Evolution Of The Symrk Gene In The Legume Genus Lupinus L., Frédéric Mahé, Dragomira Markova, Rémy Pasquet, Marie Thérèse Misset, Abdelkader Aïnouche

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SymRK is one of the key genes involved in initial steps of legume symbiotic association with fungi (mycorrhization) and nitrogen-fixing bacteria (nodulation). A large portion of the sequence encoding the extracellular domain of SYMRK was obtained for 38 lupine accessions and 2 outgroups in order to characterize this region, to evaluate its phylogenetic utility, and to examine whether its molecular evolutionary pattern is correlated with rhizobial diversity and specificity in Lupinus. The data suggested that, in Lupinus, SymRK is a single copy gene that shows good phylogenetic potential. Accordingly, SymRK provided additional support to previous molecular phylogenies, and shed additional …

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Control Of Invasive Liriomyza Leafminer Species And Compliance With Food Safety Standards By Small Scale Snow Pea Farmers In Kenya, Zachary Maina Gitonga, Adenirin Chabi-Olaye, Dagmar Mithöfer, Julius Juma Okello, Cecilia Nyawira Ritho Dec 2010

Control Of Invasive Liriomyza Leafminer Species And Compliance With Food Safety Standards By Small Scale Snow Pea Farmers In Kenya, Zachary Maina Gitonga, Adenirin Chabi-Olaye, Dagmar Mithöfer, Julius Juma Okello, Cecilia Nyawira Ritho

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The Kenyan horticultural industry faces a new challenge following invasion by the quarantine Liriomyza leafminer species Liriomyza huidobrensis, Liriomyza sativae and Liriomyza trifolii which have recently become pests of economic importance. Controlling Liriomyza leafminers poses serious difficulties due to their biology and quarantine status. This paper examines farmers' awareness of the pests and difficulties faced in controlling them. (1) A questionnaire survey showed that snow pea farmers in Kenya rely mainly on pesticides for control of invasive Liriomyza leafminers; (2) Sixty five percent of respondents perceived pesticides to be ineffective; (3) As a result, 74% of respondents increased the frequency …

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Anopheles Larval Abundance And Diversity In Three Rice Agro-Village Complexes Mwea Irrigation Scheme, Central Kenya, Joseph M. Mwangangi, Josephat Shililu, Ephantus J. Muturi, Simon Muriu, Benjamin Jacob, Ephantus W. Kabiru, Charles M. Mbogo, John Githure, Robert J. Novak Aug 2010

Anopheles Larval Abundance And Diversity In Three Rice Agro-Village Complexes Mwea Irrigation Scheme, Central Kenya, Joseph M. Mwangangi, Josephat Shililu, Ephantus J. Muturi, Simon Muriu, Benjamin Jacob, Ephantus W. Kabiru, Charles M. Mbogo, John Githure, Robert J. Novak

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Background. The diversity and abundance of Anopheles larvae has significant influence on the resulting adult mosquito population and hence the dynamics of malaria transmission. Studies were conducted to examine larval habitat dynamics and ecological factors affecting survivorship of aquatic stages of malaria vectors in three agro-ecological settings in Mwea, Kenya. Methods. Three villages were selected based on rice husbandry and water management practices. Aquatic habitats in the 3 villages representing planned rice cultivation (Mbui Njeru), unplanned rice cultivation (Kiamachiri) and non-irrigated (Murinduko) agro-ecosystems were sampled every 2 weeks to generate stage-specific estimates of mosquito larval densities, relative abundance and diversity. …

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Geographic Distribution, Host Range And Perennation Of Cotesia Sesamiae And Cotesia Flavipes Cameron In Cultivated And Natural Habitats In Kenya, Duna Madu Mailafiya, Bruno Pierre Le Ru, Eunice Waitherero Kairu, Paul André Calatayud, Stéphane Dupas Jul 2010

Geographic Distribution, Host Range And Perennation Of Cotesia Sesamiae And Cotesia Flavipes Cameron In Cultivated And Natural Habitats In Kenya, Duna Madu Mailafiya, Bruno Pierre Le Ru, Eunice Waitherero Kairu, Paul André Calatayud, Stéphane Dupas

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Field surveys were carried out in four agroecological zones to assess the geographic distribution, host range and perennation of Cotesia sesamiae and Cotesia flavipes in cultivated and natural habitats in Kenya. The distribution of the two Cotesia species in different ecological regions was most affected by the suitability of the local stem borer species for parasitoid development, and temperature, as both species were found in localities dominated by their suitable host(s) where temperature favoured their occurrence. Fourteen years after its release, C. flavipes has maintained a high level of specificity to its target host Chilo partellus on maize and sorghum …

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Isoschaftoside, A C-Glycosylflavonoid From Desmodium Uncinatum Root Exudate, Is An Allelochemical Against The Development Of Striga, Antony M. Hooper, Muniru K. Tsanuo, Keith Chamberlain, Kay Tittcomb, Julie Scholes, Ahmed Hassanali, Zeyaur R. Khan, John A. Pickett Jun 2010

Isoschaftoside, A C-Glycosylflavonoid From Desmodium Uncinatum Root Exudate, Is An Allelochemical Against The Development Of Striga, Antony M. Hooper, Muniru K. Tsanuo, Keith Chamberlain, Kay Tittcomb, Julie Scholes, Ahmed Hassanali, Zeyaur R. Khan, John A. Pickett

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In East African small-holder farming of maize, the cattle forage legume, Desmodium uncinatum is used as an intercrop due to its allelopathic inhibition of parasitism by Striga hermonthica, an obligate parasitic weed that can devastate the maize crop. Bioassay-guided fractionation of the root extract of D. uncinatum revealed isoschaftoside to be the main compound in the most potent fraction inhibiting growth of germinated S. hermonthica radicles. Bioassays repeated with isoschaftoside isolated from a different plant source, Passiflora incarnata, proved it to be a biologically active component. Analysis of the root exudates produced by hydroponically grown D. uncinatum showed isoschaftoside to …

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Participatory Evaluation Of Integrated Pest And Soil Fertility Management Options Using Ordered Categorical Data Analysis, Hugo De Groote, Esther Rutto, George Odhiambo, Fred Kanampiu, Zeyaur Khan, Richard Coe, Bernard Vanlauwe Jun 2010

Participatory Evaluation Of Integrated Pest And Soil Fertility Management Options Using Ordered Categorical Data Analysis, Hugo De Groote, Esther Rutto, George Odhiambo, Fred Kanampiu, Zeyaur Khan, Richard Coe, Bernard Vanlauwe

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Maize is becoming the major food crop around Lake Victoria. Major constraints to its production are Striga, stem borer, and declining soil fertility. Innovative integrated technologies have been developed: the 'push-pull' system (intercropping with Desmodium and surrounded by Napier grass), soybean and Crotalaria rotations, and imidazolinone-resistant (IR) maize seed. In 12 demonstration trials in four villages in Siaya and Vihiga districts (Kenya) and two villages in Busia (Uganda) in 2003 and 2004, 504 farmers evaluated all cropping systems and a mono-cropped continuous maize, each cropped with IR or local maize, and supplemented or not with fertilizer, totaling 16 treatments. Farmers …

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Effect Of African Nightshade Species (Solanaceae) On Developmental Time And Life Table Parameters Of Tetranychus Evansi (Acari: Tetranychidae), Lucy Kananu Murungi, Aggrey Nyende, John Wesonga, Peter Masinde, Markus Knapp Mar 2010

Effect Of African Nightshade Species (Solanaceae) On Developmental Time And Life Table Parameters Of Tetranychus Evansi (Acari: Tetranychidae), Lucy Kananu Murungi, Aggrey Nyende, John Wesonga, Peter Masinde, Markus Knapp

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The effect of five African nightshade (Solanum sp.) species on the biological and demographic parameters of the tomato spider mite, Tetranychus evansi Baker and Pritchard, was examined in the laboratory at 25 ± 1°C, 70-80% RH and 12L:12D photoperiod. Duration of each development stage, reproduction rate, longevity, intrinsic rate of natural increase (rm), and doubling time (DT) of the tomato spider mite on the five nightshade species were calculated. The results indicated that S. villosum, S. scabrum, S. tarderemotum and S. americanum are more suitable for T. evansi due to a shorter developmental period, longer adult longevity, higher reproduction and …

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Proximity To A Forest Leads To Higher Honey Yield: Another Reason To Conserve, Susan O. Sande, Robin M. Crewe, Suresh K. Raina, Susan W. Nicolson, Ian Gordon Nov 2009

Proximity To A Forest Leads To Higher Honey Yield: Another Reason To Conserve, Susan O. Sande, Robin M. Crewe, Suresh K. Raina, Susan W. Nicolson, Ian Gordon

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Although tropical forest conservation is a top priority for human and environmental health, deforestation persists, mainly because of food and economic needs. No community will totally give up economic activities for the sake of ecological integrity, unless it is given alternative economic activities from which to draw its livelihood. Beekeeping in the forest buffer zone instead of traditional destructive honey-harvesting from forest trees is one such option at Arabuko Sokoke Forest (ASF) in Kenya. ASF is a dry coastal forest which is home to endangered and threatened fauna and is a hotspot considered a priority for conservation. In order to …

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Integration Of Edible Beans (Phaseolus Vulgaris L.) Into The Push-Pull Technology Developed For Stemborer And Striga Control In Maize-Based Cropping Systems, Zeyaur R. Khan, Charles A.O. Midega, Japhether M. Wanyama, David M. Amudavi, Ahmed Hassanali, Jimmy Pittchar, John A. Pickett Nov 2009

Integration Of Edible Beans (Phaseolus Vulgaris L.) Into The Push-Pull Technology Developed For Stemborer And Striga Control In Maize-Based Cropping Systems, Zeyaur R. Khan, Charles A.O. Midega, Japhether M. Wanyama, David M. Amudavi, Ahmed Hassanali, Jimmy Pittchar, John A. Pickett

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Smallholder farming systems in eastern Africa are characterized by cereal/edible legume intercrops in fields severely constrained by parasitic weed, Striga hermonthica, cereal stemborers and declining soil fertility. The push-pull technology concurrently addresses these constraints. It involves intercropping maize with stemborer repellent fodder legume, Desmodium spp. (push), with an attractant crop, Napier grass, Pennisetum purpureum (pull), planted around this intercrop, thus making it difficult to interplant edible legumes. We assessed farmers' practice and perceptions on intercropping and willingness to integrate beans in their push-pull plots from a sample of 300 farmers in six districts in western Kenya. All the respondents traditionally …

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White Lupin Leads To Increased Maize Yield Through A Soil Fertility-Independent Mechanism: A New Candidate For Fighting Striga Hermonthica Infestation?, Laure Weisskopf, Pollycarp Akello, Roxane Milleret, Zeyaur R. Khan, Fritz Schulthess, Jean Michel Gobat, Renée Claire Le Bayon Jun 2009

White Lupin Leads To Increased Maize Yield Through A Soil Fertility-Independent Mechanism: A New Candidate For Fighting Striga Hermonthica Infestation?, Laure Weisskopf, Pollycarp Akello, Roxane Milleret, Zeyaur R. Khan, Fritz Schulthess, Jean Michel Gobat, Renée Claire Le Bayon

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Nitrogen (N)-deficiency and lack of phosphorus (P) availability are major constraints to maize yields in Western Kenya. In a two-season field study in the lake Victoria basin, we tested the capacity of white lupin (Lupinus albus (L.), cv. Ultra), as a nitrogen-fixing crop with a highly efficient P-acquisition capacity, to increase maize yields when used as a companion or cover crop, or as a source of organic matter. Each experiment was performed on three different fields (Vertisols) differing in N/P availability, previous cropping history and in levels of infestation by the parasitic weed Striga hermonthica (Del.) Benth. Our results show …

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Diversity, Distribution And Role Of Wild Crucifers In Major Cabbage And Kale Growing Areas Of Kenya, R. Kahuthia-Gathu, B. Löhr, H. M. Poehling, P. K. Mbugua Jun 2009

Diversity, Distribution And Role Of Wild Crucifers In Major Cabbage And Kale Growing Areas Of Kenya, R. Kahuthia-Gathu, B. Löhr, H. M. Poehling, P. K. Mbugua

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An investigation of the diversity and distribution of wild crucifer species and their importance for cultivated crucifers was conducted during 2005 and 2006 in the highland and mid-altitude semi-arid areas of Kenya. Thirteen species of wild crucifers in nine genera were recorded: Raphanus raphanistrum, Erucastrum arabicum, Sisymbrium officinale, Crambe kilimandscharica, Capsella bursa-pastoris, Rorippa nudiuscula, Ro. micrantha, Ro. microphylla, Lepidium bonariense, Coronopus didymus, Brassica rapa, B. juncea and an unidentified Brassica species. Highland areas had significantly higher species diversity and species richness than mid-altitude semi-arid areas. Species richness, diversity and evenness varied with season and location. Raphanus raphanistrum was the dominant …

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Bed Net Use And Associated Factors In A Rice Farming Community In Central Kenya, Peter N. Ng'ang'a, Gayathri Jayasinghe, Violet Kimani, Josephat Shililu, Charity Kabutha, Lucy Kabuage, John Githure, Clifford Mutero May 2009

Bed Net Use And Associated Factors In A Rice Farming Community In Central Kenya, Peter N. Ng'ang'a, Gayathri Jayasinghe, Violet Kimani, Josephat Shililu, Charity Kabutha, Lucy Kabuage, John Githure, Clifford Mutero

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Background. Use of insecticide-treated nets (ITNs) continues to offer potential strategy for malaria prevention in endemic areas. However their effectiveness, sustainability and massive scale up remain a factor of socio-economic and cultural variables of the local community which are indispensable during design and implementation stages. Methods. An ethnographic household survey was conducted in four study villages which were purposefully selected to represent socio-economic and geographical diversity. In total, 400 households were randomly selected from the four study villages. Quantitative and qualitative information of the respondents were collected by use of semi-structured questionnaires and focus group discussions. Results. Malaria was reported …

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Spatiotemporal Dynamics Of Immature Culicines (Subfamily Culicinae) And Their Larval Habitats In Mwea Rice Scheme, Kenya, Ephantus J. Muturi, Joseph M. Mwangangi, Benjamin G. Jacob, Josephat I. Shililu, Charles M. Mbogo, John I. Githure, Robert J. Novak Mar 2009

Spatiotemporal Dynamics Of Immature Culicines (Subfamily Culicinae) And Their Larval Habitats In Mwea Rice Scheme, Kenya, Ephantus J. Muturi, Joseph M. Mwangangi, Benjamin G. Jacob, Josephat I. Shililu, Charles M. Mbogo, John I. Githure, Robert J. Novak

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An ecological study was conducted at three study sites in Mwea Rice Scheme, Kenya to identify the diverse aquatic habitats in which culicine mosquitoes thrived and to explore the best strategies for mosquito control in the area. During the 11-month study period, ten habitat categories and 11 culicine species mainly dominated by Culex quinquefasciatus (72.0%) and Culex annulioris (17.9%) were identified from pupae and late instars larval samples. Two of the 11 culicine species, Ficalbia (Mimomyia) plumosa and Uranotaenia spp., have not been reported previously in the study area. Rurumi had more habitat types than either of the other study …

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Evaluation Of Farmers' Field Days As A Dissemination Tool For Push-Pull Technology In Western Kenya, David M. Amudavi, Zeyaur R. Khan, Japhether M. Wanyama, Charles A.O. Midega, Jimmy Pittchar, Ahmed Hassanali, John A. Pickett Mar 2009

Evaluation Of Farmers' Field Days As A Dissemination Tool For Push-Pull Technology In Western Kenya, David M. Amudavi, Zeyaur R. Khan, Japhether M. Wanyama, Charles A.O. Midega, Jimmy Pittchar, Ahmed Hassanali, John A. Pickett

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Our earlier study on farmers' adoption of 'Push-pull' technology (PPT) for management of cereal stemborers and Striga weed showed that field days (FDs) could be effective in technology dissemination. Hence, in an effort to utilize effective and economical dissemination strategies, we undertook a detailed study in 2007 to assess their effectiveness in PPT dissemination by interviewing 1492 participants randomly selected during participation in FDs. A majority (80%) of the respondents learnt about the biology and damage caused by stemborers and Striga, how PPT works, how to implement PPT and utilize its products, among others. Consequently, over 70% of them favoured …

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Field Release Of A Non-Toxigenic Aspergillus Flavus L Strain In Central Benin, A. M. Klueken, C. Borgemeister, B. Hau Jan 2009

Field Release Of A Non-Toxigenic Aspergillus Flavus L Strain In Central Benin, A. M. Klueken, C. Borgemeister, B. Hau

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Non-toxigenic strains of Aspergillus flavus (Link) can be used as biological control agents to reduce the contamination of grains such as maize with carcinogenic and immunotoxic aflatoxins. Based on its sclerotial morphology, A. flavus is commonly divided into two types: L strains and S strains. In this study, we applied the non-toxigenic A. flavus L strain BN030D to the soil of five maize fields in Djidja, central Benin, to investigate its effects on the composition of the prevailing fungal communities, on the ratio of A. flavus L strains and S strains, and on the vegetative compatibility of L strains with …

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Economic Performance Of The 'Push-Pull' Technology For Stemborer And Striga Control In Smallholder Farming Systems In Western Kenya, Zeyaur R. Khan, Charles A.O. Midega, Esther M. Njuguna, David M. Amudavi, Japhether M. Wanyama, John A. Pickett Jul 2008

Economic Performance Of The 'Push-Pull' Technology For Stemborer And Striga Control In Smallholder Farming Systems In Western Kenya, Zeyaur R. Khan, Charles A.O. Midega, Esther M. Njuguna, David M. Amudavi, Japhether M. Wanyama, John A. Pickett

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The 'push-pull' technology (PPT), developed in Africa, offers effective control of cereal stemborers and Striga weed in maize-based cropping systems. It involves intercropping maize with desmodium, Desmodium uncinatum, with Napier grass, Pennisetum purpureum, planted as border around this intercrop. Desmodium repels the stemborer moths (push) that are subsequently attracted to the Napier grass (pull). Desmodium also suppresses and eliminates Striga. We assessed economic performance of this technology compared to the conventional maize mono- and maize-bean intercropping systems in six districts in western Kenya over 4-7 years. Ten farmers were randomly recruited in each district and each planted three plots representing …

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Potential Of Improved Fallows To Increase Household And Regional Fuelwood Supply: Evidence From Western Kenya, B. A. Jama, J. K. Mutegi, A. N. Njui Jun 2008

Potential Of Improved Fallows To Increase Household And Regional Fuelwood Supply: Evidence From Western Kenya, B. A. Jama, J. K. Mutegi, A. N. Njui

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Fuelwood is the main energy source for households in rural Africa, but its supply is rapidly declining especially in the densely populated areas. Short duration planted tree fallows, an agroforestry technology widely promoted in sub-Sahara Africa for soil fertility improvement may offer some remedy. Our objective was to determine the fuelwood production potential of 6, 12 and 18 months (the common fallow rotation periods) old Crotalaria grahamiana, Crotalaria paulina, Tephrosia vogelli and Tephrosia candida fallows under farmer-managed conditions in western Kenya. Based on plot-level yields, we estimated the extent to which these tree fallows would meet household and sub-national fuelwood …

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Farmers' Perceptions Of A 'Push-Pull' Technology For Control Of Cereal Stemborers And Striga Weed In Western Kenya, Zeyaur R. Khan, David M. Amudavi, Charles A.O. Midega, Japhether M. Wanyama, John A. Pickett Jun 2008

Farmers' Perceptions Of A 'Push-Pull' Technology For Control Of Cereal Stemborers And Striga Weed In Western Kenya, Zeyaur R. Khan, David M. Amudavi, Charles A.O. Midega, Japhether M. Wanyama, John A. Pickett

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Striga and cereal stemborers are major constraints to cereal production in sub-Saharan Africa causing serious food security concerns. The International Centre of Insect Physiology and Ecology (ICIPE) and partners have developed a novel integrated management system called the 'push-pull' technology (PPT) in mitigation. This involves inter-cropping maize with a stemborer moth-repellent forage legume, silverleaf desmodium (push), and planting an attractive trap crop, Napier grass (pull), around the intercrop. Additionally, chemicals produced from desmodium roots inhibit Striga. We evaluated farmers' perceptions of the pests, PPT attributes and factors influencing the likelihood of its adoption in 15 districts in western Kenya. A …

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Integrated Management Of Striga Hermonthica, Stemborers, And Declining Soil Fertility In Western Kenya, B. Vanlauwe, F. Kanampiu, G. D. Odhiambo, H. De Groote, L. J. Wadhams, Z. R. Khan May 2008

Integrated Management Of Striga Hermonthica, Stemborers, And Declining Soil Fertility In Western Kenya, B. Vanlauwe, F. Kanampiu, G. D. Odhiambo, H. De Groote, L. J. Wadhams, Z. R. Khan

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Striga hermonthica (Delile) Benth., stemborers, and declining soil fertility are serious threats to sustainable food production in the Lake Victoria zone of Kenya. To address these constraints, promising integrated crop management technologies were evaluated, using a multi-locational design in four sub-locations in Siaya and Vihiga district (western Kenya) for six cropping seasons. Technologies evaluated consisted of the traditional maize (Zea mays L.) - bean (Phaseolus vulgaris L.) intercrop, maize - Desmodium (Desmodium uncinatum (Jacq.) DC.) push-pull intercrop, Crotalaria (Crotalaria ochroleuca G. Don) - maize rotation, and soybean (Glycine max (L.) Merr) - maize rotation. Within each of these systems, imazapyr-coated …

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Blood-Feeding Patterns Of Culex Quinquefasciatus And Other Culicines And Implications For Disease Transmission In Mwea Rice Scheme, Kenya, Ephantus J. Muturi, Simon Muriu, Josephat Shililu, Joseph M. Mwangangi, Benjamin G. Jacob, Charles Mbogo, John Githure, Robert J. Novak May 2008

Blood-Feeding Patterns Of Culex Quinquefasciatus And Other Culicines And Implications For Disease Transmission In Mwea Rice Scheme, Kenya, Ephantus J. Muturi, Simon Muriu, Josephat Shililu, Joseph M. Mwangangi, Benjamin G. Jacob, Charles Mbogo, John Githure, Robert J. Novak

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Studies were conducted in Mwea Rice Scheme, Kenya during the period April 2005 and January 2007 to determine the host-feeding pattern of culicine mosquitoes. Mosquitoes were collected indoors and outdoors and tested for human, bovine, goat, and donkey blood meals by an Enzyme-Linked Immunosorbent Assay. A total of 1,714 blood-engorged samples comprising Culex quinquefasciatus Say (96.1%), Culex annulioris Theobald (1.8%), Culex poicilipes Theobald (0.9%), Aedes cuminsi Theobald (1.0%), Aedes taylori Edwards (0.1%), and Mansonia africana Theobald (0.1%) were tested. Except for A. taylori, in which the single blood meal tested was of bovine origin, the other species fed mostly on …

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Location, Acceptance And Suitability Of Lepidopteran Stemborers Feeding On A Cultivated And Wild Host-Plant To The Endoparasitoid Cotesia Flavipes Cameron (Hymenoptera: Braconidae), Meshack Obonyo, Fritz Schulthess, Juma Gerald, Onesmus Wanyama, Bruno Le Rü, Paul André Calatayud Apr 2008

Location, Acceptance And Suitability Of Lepidopteran Stemborers Feeding On A Cultivated And Wild Host-Plant To The Endoparasitoid Cotesia Flavipes Cameron (Hymenoptera: Braconidae), Meshack Obonyo, Fritz Schulthess, Juma Gerald, Onesmus Wanyama, Bruno Le Rü, Paul André Calatayud

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Maize fields in Africa are usually surrounded by land occupied by wild plants many of which harbor lepidopteran stemborer species not found on crops. It is not known if the exotic braconid parasitoid Cotesia flavipes, which was released in Kenya in 1993 against the invasive crambid Chilo partellus, searches for and attacks these borers in their natural habitats and whether they are suitable for parasitoid development. The objective of this study was to assess the relationship between acceptance and suitability of six stemborer species attacking cultivated sorghum (C. partellus, Busseola fusca, Sesamia calamistis, and S. nonagrioides) or Napier grass (Busseola …

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On-Farm Evaluation Of The 'Push-Pull' Technology For The Control Of Stemborers And Striga Weed On Maize In Western Kenya, Zeyaur R. Khan, Charles A.O. Midega, David M. Amudavi, Ahmed Hassanali, John A. Pickett Mar 2008

On-Farm Evaluation Of The 'Push-Pull' Technology For The Control Of Stemborers And Striga Weed On Maize In Western Kenya, Zeyaur R. Khan, Charles A.O. Midega, David M. Amudavi, Ahmed Hassanali, John A. Pickett

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The 'push-pull' technology is a novel pest management strategy developed for control of stemborers and striga weed, Striga hermonthica, in maize-based farming systems in eastern Africa, where maize is intercropped with desmodium, a forage legume, and Napier grass is planted as a border crop. Desmodium repels stemborer moths while Napier grass attracts them. Desmodium also suppresses the parasitic striga weed through a series of mechanisms ranging from shading to allelopathy through the root system. The technology is currently being disseminated among smallholder farmers in eastern Africa and adoption rates are rising. Our on-station studies have reported efficacy of this technology …

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Release And Establishment Of Cotesia Flavipes For Biological Control Of Maize Stemborers In Zimbabwe, P. Chinwada, F. Schulthess, W. A. Overholt, P. Jowah, C. O. Omwega Mar 2008

Release And Establishment Of Cotesia Flavipes For Biological Control Of Maize Stemborers In Zimbabwe, P. Chinwada, F. Schulthess, W. A. Overholt, P. Jowah, C. O. Omwega

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Five populations of the crambid stemborer Chilo partellus (Swinhoe) and one of the noctuid borer Busseola fusca (Fuller) from Zimbabwe were evaluated for their suitability for immature development of the exotic braconid larval parasitoid Cotesia flavipes Cameron. Successful parasitoid development occurred only on C. partellus but parasitism as well as egg-to-adult development time did not vary among the five populations. Smallest parasitoid broods, and sex ratios as the proportion of female offspring, however, were produced with C. partellus from the Muzarabani area of Zimbabwe. Co. flavipes became successfully established in five out of eight locations, where it had been released …

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Potential Of Sequential Cropping In The Management Of Root-Knot Nematodes In Okra, A. N. Mweke, J. W. Kimenju, A. A. Seif, E. W. Mutitu, G. K. Mutua Jan 2008

Potential Of Sequential Cropping In The Management Of Root-Knot Nematodes In Okra, A. N. Mweke, J. W. Kimenju, A. A. Seif, E. W. Mutitu, G. K. Mutua

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The response of different crops to a mixed population of root-knot nematodes, Meloidogyne javanica and M. incognita and their potential as suppressants in sequential cropping systems was evaluated in greenhouse and field experiments. Crops rated as resistant were five maize cultivars, four sorghum cultivars, two millet varieties, guwar and two pigeonpea cultivars which had galling indices ranging between 1.4-3.6. cowpea cv. K80 was rated as moderately resistant with a galling index of 4 while greengram and cowpea cv. KKI were rated as susceptible with galling indices ranging from 5.6 to 7.4. Four crops namely sweetcorn, babycorn, maize cv. Pioneer (Ph3253) …

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Differential Expression Of The Crv1 Haemocyte Inactivation-Associated Polydnavirus Gene In The African Maize Stem Borer Busseola Fusca (Fuller) Parasitized By Two Biotypes Of The Endoparasitoid Cotesia Sesamiae (Cameron), C. W. Gitau, D. Gundersen-Rindal, M. Pedroni, P. J. Mbugi, S. Dupas Jul 2007

Differential Expression Of The Crv1 Haemocyte Inactivation-Associated Polydnavirus Gene In The African Maize Stem Borer Busseola Fusca (Fuller) Parasitized By Two Biotypes Of The Endoparasitoid Cotesia Sesamiae (Cameron), C. W. Gitau, D. Gundersen-Rindal, M. Pedroni, P. J. Mbugi, S. Dupas

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Polydnaviruses are rarely studied for their natural variation in immune suppressive abilities. The polydnavirus harboring braconid Cotesia sesamiae, a widespread endoparasitoid of Busseola fusca and Sesamia calamistis in sub-Saharan Africa exists as two biotypes. In Kenya, the western biotype completes development in B. fusca larvae. However, eggs of the coastal C. sesamiae are encapsulated in this host and ultimately, no parasitoids emerge from parasitized B. fusca larvae. Both biotypes develop successfully in S. calamistis larvae. Encapsulation activity by B. fusca larvae towards eggs of the avirulent C. sesamiae was detectable six hours post-parasitization. The differences in encapsulation of virulent and …

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Cross-Modality Effects During Male-Male Interactions Of Jumping Spiders, Fiona R. Cross, Robert R. Jackson, Simon D. Pollard, Mark W. Walker Jul 2007

Cross-Modality Effects During Male-Male Interactions Of Jumping Spiders, Fiona R. Cross, Robert R. Jackson, Simon D. Pollard, Mark W. Walker

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An important prediction from game theory is that the value of a resource influences the level to which male-male conflict escalates. Earlier experimental studies have shown that the seven salticid species we study here (Bavia aericeps, Euryattus sp., Hypoblemum albovittatum, Jacksonoides queenslandicus, Marpissa marina, Portia africana and Simaetha paetula) determine by sight whether a female is a conspecific or a heterospecific and then escalate the intensity with which they interact (i.e., they adopt behaviour that is likely to put them at greater risk of injury after detecting the presence of a conspecific female). Here the earlier studies are extended by …

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Livestock Farmers' Perception And Epidemiology Of Bovine Trypanosomosis In Kwale District, Kenya, S. O. Ohaga, E. D. Kokwaro, I. O. Ndiege, A. Hassanali, R. K. Saini Jun 2007

Livestock Farmers' Perception And Epidemiology Of Bovine Trypanosomosis In Kwale District, Kenya, S. O. Ohaga, E. D. Kokwaro, I. O. Ndiege, A. Hassanali, R. K. Saini

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We did cross-sectional surveys in Kwale District, Kenya to determine the epidemiology of bovine trypanosomosis and livestock owners' perceptions of the disease. The surveys involved relative importance of trypanosomosis, examination of the current disease constraints, current control practices and drug-use patterns. Informal meetings were held with farmers and cattle census undertaken. Tsetse-fly densities and trypanosomosis prevalences in cattle were determined. A total of 132 farmers were interviewed. Trypanosomosis, anaplasmosis, East Coast fever, foot-and-mouth diseases were reported to be the major constraints to livestock production. Trypanosomosis was the most important compared to other diseases. Chemotherapy was the most widely used method …

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