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Articles 211 - 240 of 429

Full-Text Articles in Agricultural Science

Identification Of Kairomones Of Second Instar Nymphs Of The Variegated Coffee Bug Antestiopsis Thunbergii (Heteroptera: Pentatomidae), Teresiah N. Njihia, Baldwyn Torto, Lucy K. Murungi, Janet Irungu, Dickson M. Mwenda, Régis Babin Dec 2017

Identification Of Kairomones Of Second Instar Nymphs Of The Variegated Coffee Bug Antestiopsis Thunbergii (Heteroptera: Pentatomidae), Teresiah N. Njihia, Baldwyn Torto, Lucy K. Murungi, Janet Irungu, Dickson M. Mwenda, Régis Babin

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The variegated coffee bug Antestiopsis thunbergii Gmelin is a key pest of Coffea arabica in East Africa. Although the bug feeds on various parts of the coffee plant, it has a strong preference for mature green berries which are essential for the bug to complete its life cycle, reproduce and enhance its longevity. To locate mature green coffee berries, we hypothesized that second instar nymphs, which are the most mobile and active feeding immature stage of the bug, must rely on key volatile compounds emitted by the host for recognition. We tested this hypothesis using behavioral and electrophysiological assays and …

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Strong Spatial-Temporal Patterns In Maize Yield Response To Nutrient Additions In African Smallholder Farms, Samuel Njoroge, Antonius G.T. Schut, Ken E. Giller, Shamie Zingore Dec 2017

Strong Spatial-Temporal Patterns In Maize Yield Response To Nutrient Additions In African Smallholder Farms, Samuel Njoroge, Antonius G.T. Schut, Ken E. Giller, Shamie Zingore

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Large variability in crop responses to macronutrient application at various spatial scales present challenges for developing effective fertilizer recommendations for crop production in smallholder farming systems of sub-Saharan Africa. We assessed maize yield responses to nitrogen (N), phosphorus (P) and potassium (K) application and evaluated relationships between crop responses to N, P and K application and soil analysis data. Nutrient omission trials were conducted on 23 farms located in Sidindi, Western Kenya, selected to be representative of the main soil and management factors in maize based systems in Siaya County. Treatments included a control and PK, NK, NP and NPK …

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The Cotesia Sesamiae Story: Insight Into Host-Range Evolution In A Hymenoptera Parasitoid And Implication For Its Use In Biological Control Programs, L. Kaiser, S. Dupas, A. Branca, E. A. Herniou, C. W. Clarke, C. Capdevielle Dulac, J. Obonyo, R. Benoist, J. Gauthier, P. A. Calatayud, J. F. Silvain, B. P. Le Ru Dec 2017

The Cotesia Sesamiae Story: Insight Into Host-Range Evolution In A Hymenoptera Parasitoid And Implication For Its Use In Biological Control Programs, L. Kaiser, S. Dupas, A. Branca, E. A. Herniou, C. W. Clarke, C. Capdevielle Dulac, J. Obonyo, R. Benoist, J. Gauthier, P. A. Calatayud, J. F. Silvain, B. P. Le Ru

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This review covers nearly 20 years of studies on the ecology, physiology and genetics of the Hymenoptera Cotesia sesamiae, an African parasitoid of Lepidoptera that reduces populations of common maize borers in East and South Africa. The first part of the review presents studies based on sampling of C. sesamiae from maize crops in Kenya. From this agrosystem including one host plant and three main host borer species, studies revealed two genetically differentiated populations of C. sesamiae species adapted to their local host community, and showed that their differentiation involved the joint evolution of virulence genes and sensory mechanisms of …

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Predicting Minimum Tillage Adoption Among Smallholder Farmers Using Micro-Level And Policy Variables, Paswel P. Marenya, Menale Kassie, Moti Jaleta, Dil Bahadur Rahut, Olaf Erenstein Dec 2017

Predicting Minimum Tillage Adoption Among Smallholder Farmers Using Micro-Level And Policy Variables, Paswel P. Marenya, Menale Kassie, Moti Jaleta, Dil Bahadur Rahut, Olaf Erenstein

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Minimum tillage combined with mulching (MTM) is critical to conservation agriculture, yet its use by smallholder farmers raises challenging questions regarding adoption, diffusion and scaling at farm level. In this paper, we used probit regression and post-estimation simulations to identify the key micro (farm specific) and macro (country specific) factors as predictors of MTM adoption in four countries spanning a north-south gradient in eastern and southern Africa (ESA): Ethiopia, Kenya, Tanzania and Malawi. We found that farmers’ access to markets and social capital empirically predicted MTM adoption. Policies that increased fertilizer subsidies and extension-staff-to-farmer ratios had similar effects, even if …

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Parasitic Nematode Meloidogyne Incognita Interactions With Different Capsicum Annum Cultivars Reveal The Chemical Constituents Modulating Root Herbivory, Ruth Kihika, Lucy K. Murungi, Danny Coyne, Margaret Ng'ang'a, Ahmed Hassanali, Peter E.A. Teal, Baldwyn Torto Dec 2017

Parasitic Nematode Meloidogyne Incognita Interactions With Different Capsicum Annum Cultivars Reveal The Chemical Constituents Modulating Root Herbivory, Ruth Kihika, Lucy K. Murungi, Danny Coyne, Margaret Ng'ang'a, Ahmed Hassanali, Peter E.A. Teal, Baldwyn Torto

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Plant volatile signatures are often used as cues by herbivores to locate their preferred hosts. Here, we report on the volatile organic compounds used by the subterranean root-knot nematode (RKN) Meloidogyne incognita for host location. We compared responses of infective second stage juveniles (J2s) to root volatiles of three cultivars and one accession of the solanaceous plant, Capsicum annum against moist sand in dual choice assays. J2s were more attracted to the three cultivars than to the accession, relative to controls. GC/MS analysis of the volatiles identified common constituents in each plant, five of which were identified as α-pinene, limonene, …

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Profitability Of Diammonium Phosphate Use In Bush And Climbing Bean-Maize Rotations In Smallholder Farms Of Central Burundi, Marie Chantal Niyuhire, Pieter Pypers, Bernard Vanlauwe, Generose Nziguheba, Dries Roobroeck, Roel Merckx Oct 2017

Profitability Of Diammonium Phosphate Use In Bush And Climbing Bean-Maize Rotations In Smallholder Farms Of Central Burundi, Marie Chantal Niyuhire, Pieter Pypers, Bernard Vanlauwe, Generose Nziguheba, Dries Roobroeck, Roel Merckx

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Soil fertility decline is a major constraint to bean (Phaseolus vulgaris L.) and maize (Zea mays) production in the Central Highlands of Burundi. Nutrient sources, specifically fertilizers, are paramount to increasing the production in the regions. Hence, improving fertilizer use efficiency is considered as a key factor towards sustainable intensification. The use of grain legumes with low harvest indices, such as climbing beans, are assumed to improve soil fertility and fertilizer use efficiency. This study compares the rotational effects of bush and climbing bean varieties on maize and evaluates the profitability of diammonium phosphate (DAP, 18–46-0) fertilizer in the bean-maize …

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Organic Farming Provides Improved Management Of Plant Parasitic Nematodes In Maize And Bean Cropping Systems, Janet G. Atandi, Solveig Haukeland, George M. Kariuki, Danny L. Coyne, Edward N. Karanja, Martha W. Musyoka, Komi K.M. Fiaboe, David Bautze, Noah Adamtey Sep 2017

Organic Farming Provides Improved Management Of Plant Parasitic Nematodes In Maize And Bean Cropping Systems, Janet G. Atandi, Solveig Haukeland, George M. Kariuki, Danny L. Coyne, Edward N. Karanja, Martha W. Musyoka, Komi K.M. Fiaboe, David Bautze, Noah Adamtey

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Intensification of agriculture, combined with poor agronomic practices have increased the incidence of plant parasitic nematodes (PPN) and other soil pathogens in East Africa, which consequently affects crop productivity in small holder farms. The objective of the study was to assess the effectiveness of farming systems in management of PPN and to recommend the best practice to farmers. Therefore, two field trials were established, one in farmer fields and one on-station, using maize (Zea mays L.), intercropped with beans (Phaseolus vulgaris L.) and in rotation with beans as a sole crop. Organic farming (that received compost, Tithonia diversifolia and neem …

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Mapping Leaf Nitrogen And Carbon Concentrations Of Intact And Fragmented Indigenous Forest Ecosystems Using Empirical Modeling Techniques And Worldview-2 Data, Galal Omer, Onisimo Mutanga, Elfatih M. Abdel-Rahman, Kabir Peerbhay, Elhadi Adam Sep 2017

Mapping Leaf Nitrogen And Carbon Concentrations Of Intact And Fragmented Indigenous Forest Ecosystems Using Empirical Modeling Techniques And Worldview-2 Data, Galal Omer, Onisimo Mutanga, Elfatih M. Abdel-Rahman, Kabir Peerbhay, Elhadi Adam

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Forest nitrogen (N) and carbon (C) are among the most important biochemical components of tree organic matter, and the estimation of their concentrations can help to monitor the nutrient uptake processes and health of forest trees. Traditionally, these tree biochemical components are estimated using costly, labour intensive, time-consuming and subjective analytical protocols. The use of very high spatial resolution multispectral data and advanced machine learning regression algorithms such as support vector machines (SVM) and artificial neural networks (ANN) provide an opportunity to accurately estimate foliar N and C concentrations over intact and fragmented forest ecosystems. In the present study, the …

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An Assessment Of The Magnitudes And Factors Associated With Postharvest Losses In Off-Farm Grain Stores In Kenya, Joseph K. Mwangi, Christopher M. Mutungi, Soul Kifouly G. Midingoyi, Abdul K. Faraj, Hippolyte D. Affognon Sep 2017

An Assessment Of The Magnitudes And Factors Associated With Postharvest Losses In Off-Farm Grain Stores In Kenya, Joseph K. Mwangi, Christopher M. Mutungi, Soul Kifouly G. Midingoyi, Abdul K. Faraj, Hippolyte D. Affognon

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Off-farm grain storage is an important postharvest undertaking by government, traders and processors in Kenya. A survey was conducted in 2014/2015 to assess the kinds and magnitudes of perceived losses experienced in off-farm stores, and the factors associated with them. Store supervisors or key personnel charged with grain storage in 39 public and 74 private stores, spread across the six maize growing agro-ecological zones, were interviewed using a structured questionnaire. Total perceived losses averaged 17.6± 2.3%, and were attributed to insects (7.2± 1.0%), molds (5.7± 2.1%), moisture loss (3.4± 0.5%), rodents (2.0± 0.5%), spillage (0.50 ± 0.0%) and birds (0.10± …

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Quality Of Charcoal Produced Using Micro Gasification And How The New Cook Stove Works In Rural Kenya, Mary Njenga, Yahia Mahmoud, Ruth Mendum, Miyuki Iiyama, Ramni Jamnadass, Kristina Roing De Nowina, Cecilia Sundberg Aug 2017

Quality Of Charcoal Produced Using Micro Gasification And How The New Cook Stove Works In Rural Kenya, Mary Njenga, Yahia Mahmoud, Ruth Mendum, Miyuki Iiyama, Ramni Jamnadass, Kristina Roing De Nowina, Cecilia Sundberg

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Wood based energy is the main source of cooking and heating fuel in Sub-Saharan Africa. Its use rises as the population increases. Inefficient cook stoves result in fuel wastage and health issues associated with smoke in the kitchen. As users are poor women, they tend not to be consulted on cook stove development, hence the need for participatory development of efficient woodfuel cooking systems. This paper presents the findings of a study carried out in Embu, Kenya to assess energy use efficiency and concentrations of carbon monoxide and fine particulate matter from charcoal produced using gasifier cook stoves, compared to …

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Application Of Secondary Nutrients And Micronutrients Increases Crop Yields In Sub-Saharan Africa, Job Kihara, Gudeta Weldesemayat Sileshi, Generose Nziguheba, Michael Kinyua, Shamie Zingore, Rolf Sommer Aug 2017

Application Of Secondary Nutrients And Micronutrients Increases Crop Yields In Sub-Saharan Africa, Job Kihara, Gudeta Weldesemayat Sileshi, Generose Nziguheba, Michael Kinyua, Shamie Zingore, Rolf Sommer

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Secondary and micronutrients are important in enhancing crop productivity; yet, they are hardly studied in sub-Sahara Africa. In this region, the main focus has been on macronutrients but there is emerging though scattered evidence of crop productivity limitations by the secondary and micronutrients. Elsewhere, widespread deficiencies of these nutrients are associated with stagnation of yields. Here, we undertake a meta-analysis using 40 articles reporting crop response to secondary and micronutrients to (1) determine the productivity increase of crops and nutrient use efficiency associated with these nutrients, and (2) provide synthesis of responses to secondary nutrients and micronutrients in sub-Sahara Africa. …

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Why Organic Resources And Current Fertilizer Formulations In Southern Africa Cannot Sustain Maize Productivity: Evidence From A Long-Term Experiment In Zimbabwe, Tongai J. Mtangadura, Florence Mtambanengwe, Hatirarami Nezomba, Jairos Rurinda, Paul Mapfumo Aug 2017

Why Organic Resources And Current Fertilizer Formulations In Southern Africa Cannot Sustain Maize Productivity: Evidence From A Long-Term Experiment In Zimbabwe, Tongai J. Mtangadura, Florence Mtambanengwe, Hatirarami Nezomba, Jairos Rurinda, Paul Mapfumo

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Sustainability of maize-based cropping systems is a major challenge for southern Africa, yet the demand for maize as staple food and animal feed in the region continues to increase. A study was conducted on a sandy clay loam (220 g clay kg-1 soil) at Domboshawa in Zimbabwe to investigate the long-term effects of organic resource quality and application rate, and nitrogen (N) fertilization on soil chemical properties and maize (Zea mays L.) productivity. Crotalaria juncea (high quality), Calliandra calothyrsus (medium quality), cattle manure (variable quality), maize stover and Pinus patula sawdust (both low quality) were incorporated into soil at 4.0 …

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Drought-Tolerant Desmodium Species Effectively Suppress Parasitic Striga Weed And Improve Cereal Grain Yields In Western Kenya, Charles A.O. Midega, Charles J. Wasonga, Antony M. Hooper, John A. Pickett, Zeyaur R. Khan Aug 2017

Drought-Tolerant Desmodium Species Effectively Suppress Parasitic Striga Weed And Improve Cereal Grain Yields In Western Kenya, Charles A.O. Midega, Charles J. Wasonga, Antony M. Hooper, John A. Pickett, Zeyaur R. Khan

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The parasitic weed Striga hermonthica Benth. (Orobanchaceae), commonly known as striga, is an increasingly important constraint to cereal production in sub-Saharan Africa (SSA), often resulting in total yield losses in maize (Zea mays L.) and substantial losses in sorghum (Sorghum bicolor (L.) Moench). This is further aggravated by soil degradation and drought conditions that are gradually becoming widespread in SSA. Forage legumes in the genus Desmodium (Fabaceae), mainly D. uncinatum and D. intortum, effectively control striga and improve crop productivity in SSA. However, negative effects of climate change such as drought stress is affecting the functioning of these systems. There …

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Screening Napier Grass Accessions For Resistance To Napier Grass Stunt Disease Using The Loop-Mediated Isothermal Amplification Of Dna (Lamp), N. I.E. Wamalwa, C. A.O. Midega, S. Ajanga, N. E. Omukunda, F. N. Muyekho, G. O. Asudi, M. Mulaa, R. K. Zeyaur Aug 2017

Screening Napier Grass Accessions For Resistance To Napier Grass Stunt Disease Using The Loop-Mediated Isothermal Amplification Of Dna (Lamp), N. I.E. Wamalwa, C. A.O. Midega, S. Ajanga, N. E. Omukunda, F. N. Muyekho, G. O. Asudi, M. Mulaa, R. K. Zeyaur

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Napier grass stunt (NGS) disease is a major threat to Napier grass cultivation and the smallholder dairy industry in East and Central Africa. The disease is caused by a phytoplasma, which is transmitted by the leafhopper Maiestas banda (Kramer) (Hemiptera: Cicadellidae). The current study was conducted to identify among 65 Napier grass accessions that could be resistant to NGS disease using the loop-mediated isothermal amplification of DNA (LAMP). The accessions were caged with NGS phytoplasma-infected Napier grass as inoculum source and M. banda as the vector. All Napier grass accessions were subjected to phytoplasma testing thereafter 18 phytoplasma negative and …

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The Yield Gap: Closing The Gap By Widening The Approach, Katherine A. Snyder, Sriyanie Miththapala, Rolf Sommer, Juliet Braslow Jul 2017

The Yield Gap: Closing The Gap By Widening The Approach, Katherine A. Snyder, Sriyanie Miththapala, Rolf Sommer, Juliet Braslow

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The yield gap has arisen again as a focus for agricultural research to ensure food security and economic growth for farmers around the world. To examine this renewed interest, we carried out a review of key literature in the field of yield gap analysis to identify important gaps in research and analysis. In so doing, both the complexities in yield gap studies emerged along with some significant omissions. Much of the literature and research on the yield gap has been framed by larger concerns and initiatives to raise agricultural productivity. This focus has led to an emphasis on technical solutions …

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Advances In Crop Insect Modelling Methods—Towards A Whole System Approach, Henri E.Z. Tonnang, Bisseleua D.B. Hervé, Lisa Biber-Freudenberger, Daisy Salifu, Sevgan Subramanian, Valentine B. Ngowi, Ritter Y.A. Guimapi, Bruce Anani, Francois M.M. Kakmeni, Hippolyte Affognon, Saliou Niassy, Tobias Landmann, Frank T. Ndjomatchoua, Sansao A. Pedro, Tino Johansson, Chrysantus M. Tanga, Paulin Nana, Komi M. Fiaboe, Samira F. Mohamed, Nguya K. Maniania, Sunday Ekesi, Christian Borgemeister Jun 2017

Advances In Crop Insect Modelling Methods—Towards A Whole System Approach, Henri E.Z. Tonnang, Bisseleua D.B. Hervé, Lisa Biber-Freudenberger, Daisy Salifu, Sevgan Subramanian, Valentine B. Ngowi, Ritter Y.A. Guimapi, Bruce Anani, Francois M.M. Kakmeni, Hippolyte Affognon, Saliou Niassy, Tobias Landmann, Frank T. Ndjomatchoua, Sansao A. Pedro, Tino Johansson, Chrysantus M. Tanga, Paulin Nana, Komi M. Fiaboe, Samira F. Mohamed, Nguya K. Maniania, Sunday Ekesi, Christian Borgemeister

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A wide range of insects affect crop production and cause considerable yield losses. Difficulties reside on the development and adaptation of adequate strategies to predict insect pests for their timely management to ensure enhanced agricultural production. Several conceptual modelling frameworks have been proposed, and the choice of an approach depends largely on the objective of the model and the availability of data. This paper presents a summary of decades of advances in insect population dynamics, phenology models, distribution and risk mapping. Existing challenges on the modelling of insects are listed; followed by innovations in the field. New approaches include artificial …

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Returns To Research And Outreach For Integrated Pest Management Of Western Flower Thrips Infesting French Bean And Tomato In Kenya, E. A. Mujuka, H. Affognon, B. W. Muriithi, S. Subramanian, P. Irungu, J. Mburu Jun 2017

Returns To Research And Outreach For Integrated Pest Management Of Western Flower Thrips Infesting French Bean And Tomato In Kenya, E. A. Mujuka, H. Affognon, B. W. Muriithi, S. Subramanian, P. Irungu, J. Mburu

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Thrips, Frankliniella occidentalis (Pergande), is a major invasive pest that causes extensive yield losses in French bean and tomato in Kenya. Thrips management is based on the application of pesticides. In addition to increased environmental risks associated with pesticides, frequent use of these chemicals increases production costs and pesticide resistance. Furthermore, exports are restricted due to non-compliance to maximum residue levels in important consumer export markets, especially the European Union (EU). This study was conducted to estimate the potential benefits of the effectiveness of the icipe-developed strategy for control of western flower thrips before dissemination of the technology in Kenya, …

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Genetic Structure And Diversity Of Western Flower Thrips, Frankliniella Occidentalis In A French Bean Agroecosystem Of Kenya, P. Hondelmann, J. O. Nyasani, S. Subramanian, R. Meyhöfer Jun 2017

Genetic Structure And Diversity Of Western Flower Thrips, Frankliniella Occidentalis In A French Bean Agroecosystem Of Kenya, P. Hondelmann, J. O. Nyasani, S. Subramanian, R. Meyhöfer

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Western flower thrips (WFT) (Frankliniella occidentalis) is an introduced pest that harms French bean production in Kenya and other countries. Since new WFT management approaches are being developed, a closer look at the genetic makeup of WFT populations can give new insights into source habitats, crop colonization patterns or host plant preferences, which are prerequisites for integrated pest management (IPM) strategies. For this purpose, we used six microsatellite loci to analyse the genetic structure, diversity and gene flow of WFT sampled on French beans, intercrops and weeds in Kenyan French bean production areas. The results of this preliminary study indicate …

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Evaluation Of Onion (Allium Cepa) Germplasm Entries For Resistance To Onion Thrips, Thrips Tabaci (Lindeman) In Tanzania, Gabriel Michael Njau, Agnes M.S. Nyomora, Fekadu Fufa Dinssa, Jian Cheng Chang, P. Malini, S. Subramanian, R. Srinivasan Jun 2017

Evaluation Of Onion (Allium Cepa) Germplasm Entries For Resistance To Onion Thrips, Thrips Tabaci (Lindeman) In Tanzania, Gabriel Michael Njau, Agnes M.S. Nyomora, Fekadu Fufa Dinssa, Jian Cheng Chang, P. Malini, S. Subramanian, R. Srinivasan

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Onion thrips, Thrips tabaci (Lindeman), is a prominent species infesting onion and tomato in the northern highlands of Tanzania. It causes considerable leaf damage by direct feeding and also transmits the Iris yellow spot virus (IYSV). Hence, one of the objectives of this study was to identify the most resistant onion entries against T. tabaci. One highly resistant (VI038552) and two resistant onion entries (VI038512 and AVON 1067) were identified against T. tabaci. Besides thrips resistance, the bulb size of VI038512 was also equivalent to one of the commercial varieties, Texas. The highly resistant VI038552 recorded the highest yield, followed …

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Deinbollia Mosaic Virus: A Novel Begomovirus Infecting The Sapindaceous Weed Deinbollia Borbonica In Kenya And Tanzania, Martina Kyallo, Peter Sseruwagi, Robert A. Skilton, Mildred Ochwo-Ssemakula, Peter Wasswa, Joseph Ndunguru May 2017

Deinbollia Mosaic Virus: A Novel Begomovirus Infecting The Sapindaceous Weed Deinbollia Borbonica In Kenya And Tanzania, Martina Kyallo, Peter Sseruwagi, Robert A. Skilton, Mildred Ochwo-Ssemakula, Peter Wasswa, Joseph Ndunguru

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Four isolates of a bipartite begomovirus from naturally infected Deinbollia borbonica plants exhibiting yellow mosaic symptoms in Kenya and Tanzania were molecularly characterised. The DNA-A was most closely related to that of tomato leaf curl Mayotte virus (AM701764; 82%), while the DNA-B shared the highest nucleotide sequence identity with that of East African cassava mosaic virus (AJ704953) at 65%. Based on the current ICTV species demarcation criterion for the genus Begomovirus (≥91% sequence identity for the complete DNA-A), we report the full-length genome sequence of this novel bipartite begomovirus. The results reveal additional diversity and reservoir hosts of begomoviruses in …

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Predicting Stem Borer Density In Maize Using Rapideye Data And Generalized Linear Models, Elfatih M. Abdel-Rahman, Tobias Landmann, Richard Kyalo, George Ong'amo, Sizah Mwalusepo, Saad Sulieman, Bruno Le Ru May 2017

Predicting Stem Borer Density In Maize Using Rapideye Data And Generalized Linear Models, Elfatih M. Abdel-Rahman, Tobias Landmann, Richard Kyalo, George Ong'amo, Sizah Mwalusepo, Saad Sulieman, Bruno Le Ru

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Average maize yield in eastern Africa is 2.03 t ha−1 as compared to global average of 6.06 t ha−1 due to biotic and abiotic constraints. Amongst the biotic production constraints in Africa, stem borers are the most injurious. In eastern Africa, maize yield losses due to stem borers are currently estimated between 12% and 21% of the total production. The objective of the present study was to explore the possibility of RapidEye spectral data to assess stem borer larva densities in maize fields in two study sites in Kenya. RapidEye images were acquired for the Bomet (western Kenya) test site …

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Effect Of Organic And Conventional Farming Systems On Nitrogen Use Efficiency Of Potato, Maize And Vegetables In The Central Highlands Of Kenya, Martha W. Musyoka, Noah Adamtey, Anne W. Muriuki, Georg Cadisch May 2017

Effect Of Organic And Conventional Farming Systems On Nitrogen Use Efficiency Of Potato, Maize And Vegetables In The Central Highlands Of Kenya, Martha W. Musyoka, Noah Adamtey, Anne W. Muriuki, Georg Cadisch

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Increased per capita food production in the tropics is closely tied to soil organic matter and water management, timely nitrogen (N) supply and crop N use efficiency (NUE) which are influenced by farming systems. However, there is lack of data on the effect of organic farming systems on NUE and how this compares to conventional farming systems under tropical conditions. Therefore, the objectives of this study were to determine the effect of conventional and organic farming systems at low and high management intensities on N uptake and N use efficiency of potato (Solanum tuberosum L.), maize (Zea mays L.), cabbage …

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Farm Production, Market Access And Dietary Diversity In Malawi, Stefan Koppmair, Menale Kassie, Matin Qaim Feb 2017

Farm Production, Market Access And Dietary Diversity In Malawi, Stefan Koppmair, Menale Kassie, Matin Qaim

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Objective The association between farm production diversity and dietary diversity in rural smallholder households was recently analysed. Most existing studies build on household-level dietary diversity indicators calculated from 7d food consumption recalls. Herein, this association is revisited with individual-level 24 h recall data. The robustness of the results is tested by comparing household- and individual-level estimates. The role of other factors that may influence dietary diversity, such as market access and agricultural technology, is also analysed. Design A survey of smallholder farm households was carried out in Malawi in 2014. Dietary diversity scores are calculated from 24 h recall data. …

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A Survey Of Root Knot Nematodes And Resistance To Meloidogyne Incognita In Sweet Potato Varieties From Kenyan Fields, Hannah W. Karuri, Daniel Olago, Roy Neilson, Enock Mararo, Jandouwe Villinger Feb 2017

A Survey Of Root Knot Nematodes And Resistance To Meloidogyne Incognita In Sweet Potato Varieties From Kenyan Fields, Hannah W. Karuri, Daniel Olago, Roy Neilson, Enock Mararo, Jandouwe Villinger

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The root knot nematode, Meloidogyne is one of the most economically damaging plant parasitic nematode groups, and are widely distributed in Kenyan agro-ecosystems. The aim of this study was to determine the diversity of Meloidogyne species in Kenyan sweet potato fields and identify sweet potato varieties that exhibit resistance to M. incognita. Meloidogyne species were collected from Nyanza, Western, Eastern and Central Provinces of Kenya. Mitochondrial DNA was used to differentiate Meloidogyne species. The most common species in all sampled regions was M. incognita. Meloidogyne hapla was recorded for the first time in Kenyan sweet potato growing areas (Mosocho, Matayos, …

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Diversity Of Lepidopteran Stemborers And Their Parasitoids On Maize And Wild Host Plants In The Rain Forest Of Kisangani, Dr Congo, Onésime Mubenga Kankonda, Benjamin Dudu Akaibe, George Otieno Ong’Amo, Bruno Pierre Le Ru Feb 2017

Diversity Of Lepidopteran Stemborers And Their Parasitoids On Maize And Wild Host Plants In The Rain Forest Of Kisangani, Dr Congo, Onésime Mubenga Kankonda, Benjamin Dudu Akaibe, George Otieno Ong’Amo, Bruno Pierre Le Ru

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Lepidopteran stemborers are considered as the most important insect pests of cereal crops in Sub-Saharan Africa. However, limited information exists on stemborers and their parasitoids in the rain forest of the DR Congo. In order to enhance the understanding of the pest ecology, sampling in both cultivated and wild habitats has been recommended as a bottom line to any action aiming at the design of pest management measures. Following this recommendation, a survey was carried out in the rain forest of the DR Congo on maize and wild host plants. We collected eighteen stemborer and one earborer species belonging to …

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Impact Of Push-Pull Technology On The Nutritional Status Of Farmers' Children In Western Kenya, Nicholas O. Ogot, J. O. Pittchar, C. A.O. Midega, Z. R. Khan Jan 2017

Impact Of Push-Pull Technology On The Nutritional Status Of Farmers' Children In Western Kenya, Nicholas O. Ogot, J. O. Pittchar, C. A.O. Midega, Z. R. Khan

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This study examined the impact of push-pull technology (PPT) on the nutritional status of children aged 1-12 years. Non-push-pull (NPPT) farmers were used as a control group to establish a comparative model for this study. It determined household production, consumption, and surpluses, comparing the PPT adopters to the nonadopters; found out the incomes and food expenditures from farm products; found out the household dietary diversity scores; and finally found the nutritional status of the two household groups. A six faceted household-level metrics was employed. A sample of 216 households that registered 326 children was derived. This study was conducted in …

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Determinants Of Integrated Soil Fertility Management Technologies Adoption By Smallholder Farmers In The Chinyanja Triangle Of Southern Africa, Powell Mponela, Lulseged Tamene, Gift Ndengu, Ruth Magreta, Job Kihara, Nelson Mango Dec 2016

Determinants Of Integrated Soil Fertility Management Technologies Adoption By Smallholder Farmers In The Chinyanja Triangle Of Southern Africa, Powell Mponela, Lulseged Tamene, Gift Ndengu, Ruth Magreta, Job Kihara, Nelson Mango

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Integrated Soil Fertility Management (ISFM) technologies have proven to be viable options for improving land productivity and increasing yield. However, adoption of the set of complementary technologies that are required in ISFM is quite variable and studies tend to focus on single technologies. In this study we used cluster analysis to group technologies and ordered probit to determine the probability of multiple technology adoption. The result show that usage of ISFM in the Chinyanja Triangle (Southern Africa) is grouped into 3 technological sets based on complementarities. The set of nutrient dense technologies of inorganic fertiliser, compost and animal manure (ISFMset3) …

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Exploring Factors That Shape Small-Scale Farmers’ Opinions On The Adoption Of Eco-Friendly Nets For Vegetable Production, F. Vidogbéna, A. Adégbidi, R. Tossou, F. Assogba-Komlan, T. Martin, M. Ngouajio, S. Simon, L. Parrot, S. T. Garnett, K. K. Zander Dec 2016

Exploring Factors That Shape Small-Scale Farmers’ Opinions On The Adoption Of Eco-Friendly Nets For Vegetable Production, F. Vidogbéna, A. Adégbidi, R. Tossou, F. Assogba-Komlan, T. Martin, M. Ngouajio, S. Simon, L. Parrot, S. T. Garnett, K. K. Zander

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If agro-ecological systems are to realize their potential as sustainable alternatives to conventional agricultural systems, innovation diffusion needs to be enhanced. We conducted surveys among 214 small-scale vegetable farmers in Benin, a food-deficit country in West Africa, on how they perceived the different attributes of eco-friendly nets (EFNs). The nets act as physical barriers against insects in vegetable production and so reduce pesticide use. Understanding farmer perceptions about new technologies helps reveal farmers’ propensity to adopt them. Intensity of attitude was measured on a Likert scale, and an ordered probit model was used to determine which characteristics of nets were …

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Managing Storage Pests Of Maize: Farmers' Knowledge, Perceptions And Practices In Western Kenya, Charles A.O. Midega, Alice W. Murage, Jimmy O. Pittchar, Zeyaur R. Khan Dec 2016

Managing Storage Pests Of Maize: Farmers' Knowledge, Perceptions And Practices In Western Kenya, Charles A.O. Midega, Alice W. Murage, Jimmy O. Pittchar, Zeyaur R. Khan

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Insect pests are a key constraint to effective utilization of cereal crops in sub-Saharan Africa (SSA), with damage caused by these pests in the stores of particular concern. Although a number of approaches have been advanced for control of storage pests of maize, uptake remains a challenge, with effectiveness of some approaches being questionable. We conducted a survey in western Kenya among 330 respondents using face to face interviews and focus group discussions to evaluate farmers' practices, knowledge and perceptions of storage pests of maize, and their current practices in managing such pests as a basis for development of efficient …

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On-Farm Maize Storage Systems And Rodent Postharvest Losses In Six Maize Growing Agro-Ecological Zones Of Kenya, Kukom Edoh Ognakossan, Hippolyte D. Affognon, Christopher M. Mutungi, Daniel N. Sila, Soul Kifouly G. Midingoyi, Willis O. Owino Dec 2016

On-Farm Maize Storage Systems And Rodent Postharvest Losses In Six Maize Growing Agro-Ecological Zones Of Kenya, Kukom Edoh Ognakossan, Hippolyte D. Affognon, Christopher M. Mutungi, Daniel N. Sila, Soul Kifouly G. Midingoyi, Willis O. Owino

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Rodents are one of the major postharvest pests that affect food security by impacting on both food availability and safety. However, knowledge of the impact of rodents in on-farm maize storage systems in Kenya is limited. A survey was conducted in 2014 to assess magnitudes of postharvest losses in on-farm maize storage systems in Kenya, and the contribution of rodents to the losses. A total of 630 farmers spread across six maize growing agro-ecological zones (AEZs) were interviewed. Insects, rodents and moulds were the main storage problems reported by farmers. Storage losses were highest in the moist transitional and moist …

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