Time filter

Source Type

Murage A.W.,Kenya Agricultural and Livestock Research Organization KALRO
Crop Protection | Year: 2016

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 integrated pest management (IPM) approaches for the pests. Majority of the respondents stored maize in traditional granaries, with less than 10% of them using modern improved facilities, mainly due to inability to afford these. Majority of the respondents also cited attack of their stored grains by a number of insect pests, causing about 40% grain losses. The larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), sawtoothed grain beetle, Oryzaephilus surinamensis (L) (Coleoptera: Silvanidae), and maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), were perceived as the most common and damaging pests. Farmers' perceptions of pests were positively and significantly influenced by level of education and farming experience, indicating that education and experience build farmers' understanding of storage pests. Storing maize in unshelled form seemed to result in less pest attack, although majority of the respondents stored their maize in shelled form. Moreover, local maize varieties were perceived to be resistant to pests. The farmers applied various control methods, with sun-drying being the most popular practice. Usage of pesticides was minimal, mainly due to high costs, lack of information, and unavailability of appropriate and effective products. There were also other cultural methods applied, such as use of smoke and insecticidal plants. The respondents decried lack of training and extension services on storage pests and their management, underscoring the need to develop extension services. The underlying mechanisms of the perceived pest resistance in local varieties of maize and cultural pest management methods need to be established for exploitation in development of effective IPM approaches. There is also need to address the challenges hindering uptake of modern storage and control approaches. © 2016 The Authors


PubMed | International Institute Of Tropical Agriculture, International Plant Nutrition Institute, Institute dEconomie Rurale, Kenya Agricultural and Livestock Research Organization KALRO and 3 more.
Type: | Journal: Agriculture, ecosystems & environment | Year: 2016

Improved understanding of soil fertility factors limiting crop productivity is important to develop appropriate soil and nutrient management recommendations in sub-Saharan Africa. Diagnostic trials were implemented in Kenya, Malawi, Mali, Nigeria and Tanzania, as part of the African Soils Information Service (AfSIS) project, to identify soil fertility constraints to crop production across various cropping systems and soil fertility conditions. In each country, one to three sites of 10km10km were included with each site having 12-31 field trials. The treatments tested included a control, an NPK treatment, three treatments in which the N, P and K nutrients were omitted one at a time from the NPK treatment, and three treatments in which secondary and micronutrients (Ca, Mg, S, Zn and B) simply referred here as multi-nutrients, manure and lime were added to the NPK. The field trials were conducted for 1-2 seasons; the test crop was maize except in Mali where sorghum was used. Nitrogen was limiting in all sites and generally the most limiting nutrient except in Sidindi (Kenya) and Kontela (Mali) where P was the most limiting. The general pattern in Kiberashi (Tanzania) shows none of the nutrients were limiting. K is mainly limiting in only one site (Mbinga) although incidences of K limitation were seen in almost all sites. Addition of multi-nutrients and manure further improved the yields of NPK in most sites. Cluster analyses revealed that maize crop in 11% of fields were highly responsive to nitrogen application, 25% (i.e., 21% poor and 4% fertile) non-responsive to any nutrient or soil amendment, 28% being low responsive and 36% of intermediate response. This study indicates that constraints to crop production vary considerably even within a site, and that addressing limitations in secondary and micronutrients, and increasing soil carbon can improve response to fertilizers. For sustainable crop production intensification in smallholder farming systems in SSA, there is need to develop management strategies to improve efficiency of fertilizer use and of other inputs, recognizing the site-specific nutrient response patterns at various spatial scales.


Bajgain P.,Purdue University | Bajgain P.,University of Minnesota | Rouse M.N.,U.S. Department of Agriculture | Rouse M.N.,University of Minnesota | And 8 more authors.
BMC Plant Biology | Year: 2015

Background: The recently identified Puccinia graminis f. sp. tritici (Pgt) race TTKSK (Ug99) poses a severe threat to global wheat production because of its broad virulence on several widely deployed resistance genes. Additional virulences have been detected in the Ug99 group of races, and the spread of this race group has been documented across wheat growing regions in Africa, the Middle East (Yemen), and West Asia (Iran). Other broadly virulent Pgt races, such as TRTTF and TKTTF, present further difficulties in maintaining abundant genetic resistance for their effective use in wheat breeding against this destructive fungal disease of wheat. In an effort to identify loci conferring resistance to these races, a genome-wide association study was carried out on a panel of 250 spring wheat breeding lines from the International Maize and Wheat Improvement Center (CIMMYT), six wheat breeding programs in the United States and three wheat breeding programs in Canada. Results: The lines included in this study were grouped into two major clusters, based on the results of principal component analysis using 23,976 SNP markers. Upon screening for adult plant resistance (APR) to Ug99 during 2013 and 2014 in artificial stem rust screening nurseries at Njoro, Kenya and at Debre Zeit, Ethiopia, several wheat lines were found to exhibit APR. The lines were also screened for resistance at the seedling stage against races TTKSK, TRTTF, and TKTTF at USDA-ARS Cereal Disease Laboratory in St. Paul, Minnesota; and only 9 of the 250 lines displayed seedling resistance to all the races. Using a mixed linear model, 27 SNP markers associated with APR against Ug99 were detected, including markers linked with the known APR gene Sr2. Using the same model, 23, 86, and 111 SNP markers associated with seedling resistance against races TTKSK, TRTTF, and TKTTF were identified, respectively. These included markers linked to the genes Sr8a and Sr11 providing seedling resistance to races TRTTF and TKTTF, respectively. We also identified putatively novel Sr resistance genes on chromosomes 3B, 4D, 5A, 5B, 6A, 7A, and 7B. Conclusion: Our results demonstrate that the North American wheat breeding lines have several resistance loci that provide APR and seedling resistance to highly virulent Pgt races. Using the resistant lines and the SNP markers identified in this study, marker-assisted resistance breeding can assist in development of varieties with elevated levels of resistance to virulent stem rust races including TTKSK. © 2015 Bajgain et al.


PubMed | University of Minnesota, Purdue University, Kenya Agricultural and Livestock Research Organization KALRO, Ethiopian Institute of Agricultural Research EIAR and 3 more.
Type: | Journal: BMC plant biology | Year: 2015

The recently identified Puccinia graminis f. sp. tritici (Pgt) race TTKSK (Ug99) poses a severe threat to global wheat production because of its broad virulence on several widely deployed resistance genes. Additional virulences have been detected in the Ug99 group of races, and the spread of this race group has been documented across wheat growing regions in Africa, the Middle East (Yemen), and West Asia (Iran). Other broadly virulent Pgt races, such as TRTTF and TKTTF, present further difficulties in maintaining abundant genetic resistance for their effective use in wheat breeding against this destructive fungal disease of wheat. In an effort to identify loci conferring resistance to these races, a genome-wide association study was carried out on a panel of 250 spring wheat breeding lines from the International Maize and Wheat Improvement Center (CIMMYT), six wheat breeding programs in the United States and three wheat breeding programs in Canada.The lines included in this study were grouped into two major clusters, based on the results of principal component analysis using 23,976 SNP markers. Upon screening for adult plant resistance (APR) to Ug99 during 2013 and 2014 in artificial stem rust screening nurseries at Njoro, Kenya and at Debre Zeit, Ethiopia, several wheat lines were found to exhibit APR. The lines were also screened for resistance at the seedling stage against races TTKSK, TRTTF, and TKTTF at USDA-ARS Cereal Disease Laboratory in St. Paul, Minnesota; and only 9 of the 250 lines displayed seedling resistance to all the races. Using a mixed linear model, 27 SNP markers associated with APR against Ug99 were detected, including markers linked with the known APR gene Sr2. Using the same model, 23, 86, and 111 SNP markers associated with seedling resistance against races TTKSK, TRTTF, and TKTTF were identified, respectively. These included markers linked to the genes Sr8a and Sr11 providing seedling resistance to races TRTTF and TKTTF, respectively. We also identified putatively novel Sr resistance genes on chromosomes 3B, 4D, 5A, 5B, 6A, 7A, and 7B.Our results demonstrate that the North American wheat breeding lines have several resistance loci that provide APR and seedling resistance to highly virulent Pgt races. Using the resistant lines and the SNP markers identified in this study, marker-assisted resistance breeding can assist in development of varieties with elevated levels of resistance to virulent stem rust races including TTKSK.


PubMed | University of Minnesota, Agricultural Research Council Small Grain Institute, Purdue University, Kenya Agricultural and Livestock Research Organization KALRO and 2 more.
Type: Journal Article | Journal: PloS one | Year: 2016

We combined the recently developed genotyping by sequencing (GBS) method with joint mapping (also known as nested association mapping) to dissect and understand the genetic architecture controlling stem rust resistance in wheat (Triticum aestivum). Ten stem rust resistant wheat varieties were crossed to the susceptible line LMPG-6 to generate F6 recombinant inbred lines. The recombinant inbred line populations were phenotyped in Kenya, South Africa, and St. Paul, Minnesota, USA. By joint mapping of the 10 populations, we identified 59 minor and medium-effect QTL (explained phenotypic variance range of 1% - 20%) on 20 chromosomes that contributed towards adult plant resistance to North American Pgt races as well as the highly virulent Ug99 race group. Fifteen of the 59 QTL were detected in multiple environments. No epistatic relationship was detected among the QTL. While these numerous small- to medium-effect QTL are shared among the families, the founder parents were found to have different allelic effects for the QTL. Fourteen QTL identified by joint mapping were also detected in single-population mapping. As these QTL were mapped using SNP markers with known locations on the physical chromosomes, the genomic regions identified with QTL could be explored more in depth to discover candidate genes for stem rust resistance. The use of GBS-derived de novo SNPs in mapping resistance to stem rust shown in this study could be used as a model to conduct similar marker-trait association studies in other plant species.


Waruru B.K.,Kenya Agricultural and Livestock Research Organization KALRO | Shepherd K.D.,World Agroforestry Center | Ndegwa G.M.,Jomo Kenyatta University of Agriculture and Technology | Sila A.,World Agroforestry Center | Kamoni P.T.,Kenya Agricultural and Livestock Research Organization KALRO
Soils and Foundations | Year: 2015

Methods for rapid and accurate soil tests are needed for the index properties of material attributes commonly applied in civil engineering. We tested the application of mid-infrared (MIR) spectroscopy for the rapid characterization of selected key stability-related soil properties. Two sample sets, representing different soils from across Lake Victoria basin in Kenya, were used for the study: A model calibration set (n=135) was obtained following a conditioned Latin hypercube sampling, and a validation set (n=120) was obtained from independent sites using a spatially stratified random sampling strategy. Air-dried ground (<0.5 mm) soil was scanned using a high-throughput screening accessory for diffuse reflectance attached to a Fourier transform infrared spectrometer. The soil properties were calibrated to smoothed first derivative MIR spectra using partial least-square regression (PLS), and screening tests were developed for various limitation classes applicable in civil works using the soft independent modeling of class analogy (SIMCA). The hold-out full cross-validation coefficient of determination (r2)≥0.8 was obtained for the liquid limit (LL), linear shrinkage (LS), coefficient of linear extensibility (COLE), air-dried moisture content, (W) and cation exchange capacity (CEC). Further independent validation gave r2≥0.73 and the ratio of prediction deviation (RPD) 4.4-2.1 for LL, LS, COLE, W, CEC, plastic limit (PL), plasticity index (PI), and volumetric shrinkage (VS). The independent validation likelihood ratios for the diagnostic screening tests were: LL>55%, 4.2; PI>30%, 2.7; LS>12%, 2.4; exchangeable sodium (eNa)>2 cmol (+) kg-1, 2.3; exchangeable sodium percent (ESP)>10%, 1.8; W>8.3%, 1.6, and Activity number (A)>1.25 units, 1.5. MIR can provide the rapid assessment of several soil properties that yield stability indices in material testing for engineering land use. Further studies should test the ability of MIR PLS for establishing broader calibrations across more diverse soil types and the direct correlation of MIR to material functional attributes. © 2015 Japanese Geotechnical Society.


Nyongesa D.,Kenya Agricultural and Livestock Research Organization KALRO | Mwirigi M.K.,Institute of Biotechnology | Yongo D.,Ministry of Agriculture | Makokha S.,Institute of Biotechnology
International Journal of Agricultural Resources, Governance and Ecology | Year: 2016

Smallholder dairy farming is a key economic activity for improving rural livelihoods. This paper reports a study on six smallholder dairy groups that evaluated the importance of gender-concerns in the dairy value-chain towards improved livelihoods. Longitudinal study design was applied for two years from April 2012. Purposive and multistage sampling techniques were used. Data collection was through focus group discussions and evaluations. Data analyses encompassed descriptive statistics, value-scale ranking and gender-analyses. Men dominated decision-making and resource-control, indicating gender-inequality. Women performed all the nine activities in the three counties, over 70% while men and youths shared about 30%. Percentage change in milk handled and incomes generated ranged from 15.3 to 100 and 13.3 to 102 respectively after intervention (especially training on gender issues) within the groups. Hence, gender-concerns indeed mattered. Copyright © 2016 Inderscience Enterprises Ltd.


Muthoni J.,University of KwaZulu - Natal | Muthoni J.,Kenya Agricultural and Livestock Research Organization KALRO | Shimelis H.,University of KwaZulu - Natal | Melis R.,University of KwaZulu - Natal
Australian Journal of Crop Science | Year: 2015

In potatoes (Solanum tuberosum L. 2n=4x=48) both the general combining ability (GCA) effects of parents and specific combining ability (SCA) effects of crosses are important in conditioning traits of economic importance. The objective of this study was to determine the combining abilities for tuber yield, its components and bacterial wilt resistance on selected potato varieties and clones. Fourteen parents [eight male varieties that are commonly grown in Kenya and six female clones with moderate tolerance to bacterial wilt from the International Potato Center (CIP)] were crossed using the North Carolina II mating design. The resultant 48 families were evaluated for yield and yield components and bacterial wilt resistance in inoculated fields at Kenya Agricultural Research Institute, National Agricultural Research Laboratories (KARI-NARL) and at a farmer's field at Kinale using a 6 × 8 alpha lattice experimental design with three replications. Generally, crosses tested at Kinale took a longer time to start wilting, had lower values for the area under the disease progress curve (AUDPC), percentage of symptomatic tubers based on tuber numbers (PSTTN) and percentage of symptomatic tubers based on weight (PSTTW) than at KARI-NARL. Significant (P≤0.001) GCA effects were observed for males for total tuber weight (TTW) and days to maturity (DTM) while the GCA effects for females were significant (P≤0.001) for TTW and total tuber numbers ha-1(TTN)(P<0.01) at KARI-NARL.


Mutoko M.C.,Kenya Agricultural and Livestock Research Organization KALRO | Mutoko M.C.,Wageningen University | Hein L.,Wageningen University | Shisanya C.A.,Kenyatta University
Ecosystem Services | Year: 2015

Ecosystem services provided by tropical forests are becoming scarcer due to continued deforestation as demand for forest benefits increases with the growing population. There is need for comprehensive valuation of key ecosystem services in order to inform policy and implement better management systems to enhance the supply of ecosystem services. This study estimates local economic value of key ecosystem services provided by Kakamega rainforest and examines how the information can support sustainable forest management in Kenya. This is the only rainforest in Kenya and it has exceptional biodiversity value including several unique species not found anywhere else in the country. Kakamega rainforest also provides a classic case of conflict between conservation and exploitation goals given the dense population around it. We carried out elaborate household and visitors surveys to collect data used to estimate the economic value of three main ecosystem services. We estimated the total economic value of key ecosystem services (excluding biodiversity value) at about US$ 7.4 million per year or US$ 415ha-1yr-1. The local economic benefits are considerably less than forgone returns from agricultural activities if the forest were to be converted to the best agricultural uses. Arguably, continued protection of this forest is justified on the basis of the unknown value of its rich biodiversity and capacity to sequester CO2. Empirical findings show that the existing forest management system was less effective due to resource constraints and institutional weaknesses. Our study provides insights for the need to manage this forest for multiple uses. We recommend an integrated management strategy that balances local resource needs with biodiversity conservation. We suggest that improved stakeholder collaboration can facilitate sustainable management of this forest resource. Besides, carefully crafted payment for ecosystem services mechanisms and broad environmental education programs can support sustainable forest conservation for this and other similar forest ecosystems in Africa. © 2015 Elsevier B.V.


Mutoko M.C.,Kenya Agricultural and Livestock Research Organization KALRO | Mutoko M.C.,Wageningen University | Hein L.,Wageningen University | Shisanya C.A.,Kenyatta University
Journal of Rural Studies | Year: 2014

Sub-Saharan Africa (SSA) faces further population growth in the coming decades and it is essential to increase food production in rural areas. However, development programs to enhance agricultural productivity have achieved mixed results. This study investigates farm household responses to a changing agro-environment in one of the most densely populated rural districts in SSA and examines practical implications for the promotion of sustainable land management (SLM) practices. The specific objective is to analyze farm diversity and resource use efficiency and their implications for promoting SLM in the highlands of Western Kenya. We carried out an elaborate survey of 236 households, and applied multivariate analysis to analyze farm efficiency and livelihood strategies. We found major differences in responses to a changing agro-environment between five farm types in terms of resource endowment, income strategies and farm practices. Across farm types, efficiency was low indicating poor land productivity. Our study shows that there has been a lack of intensification in land use and that households are increasingly depending on off-farm income. Our findings have a number of implications to programs aiming to promote sustainable land management in SSA. We propose that successful implementation of such programs requires targeting areas highly reliant on agriculture and within these areas focus on households mostly dependent on farming to sustain their welfare. © 2014 Elsevier Ltd.

Loading Kenya Agricultural and Livestock Research Organization KALRO collaborators
Loading Kenya Agricultural and Livestock Research Organization KALRO collaborators