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Gichuki, S.T.

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Gichuki
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S.T.
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Gichuki, S.T.

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2005 - 200912010 - 20114
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Author: Mugo, S.N. × Region: Eastern Africa ×

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Now showing 1 - 5 of 5
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    Testing public Bt maize events for control of stem borers in the first confined field trials in Kenya
    (Academic Journals, 2011) Mugo, S.N.; Mwimali, M.; Taracha, C.; Songa, J.M.; Gichuki, S.T.; Tende, R.; Karaya, H.; Bergvinson, D.J.; Pellegrineschi, A.; Hoisington, D.A.
    Transgenic maize (Zea mays L), developed using modified genes from the bacterium Bacillus thuringiensis (Bt), controls stem borers without observable negative effects to humans, livestock or the environment, and is now sown on 134 million hectares globally. Bt maize could contribute to increasing maize production in Kenya. Nine public Bt maize events of cry1Ab and cry1Ba genes were tested in confined field trials site (CFTs) to assess the control of four major Kenyan stem borer species. Leaf damage rating, number of exit holes and tunnel length were scored in the field evaluations. Leaf area consumed and mortality rates among stem borers were scored in the leaf bioassays in a Biosafety Level II laboratory, located at the Kenya Agricultural Research Institute (KARI), National Agricultural Research Laboratories (NARL). Field evaluations showed that Bt maize controlled Chilo partellus with mean damage scores of 1.2 against 2.7 for the non-Bt CML216 control. Laboratory bioassays showed high control for Eldana saccharina and Sesamia calamistis, with mean larval mortality of 64 and 92%, respectively. However, substantial control was not observed for Busseola fusca. These results showed that Bt maize could control three of the four major stem borers in Kenya with mortality records of 52.7% for B. fusca, 62.3% for E. saccharina and 85.8% for S. calamistis. Additional Bt genes need to be sought and tested for effective stem borer control in all maize growing ecologies in Kenya.
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    Control of Busseola fusca and Chilo partellus stem borers by Bacillus thuringiensis (Bt)-δ-endotoxins from Cry1Ab gene Event MON810 in greenhouse containment trials
    (Academic Journals, 2011) Mugo, S.N.; Murenga, M.G.; Karaya, H.; Tende, R.; Taracha, C.; Gichuki, S.T.; Ininda, J.; M'bijjewe, K.; Chavangi, A.
    Previous testing of several public Bacillus thuringiensis (Bt)-maize events did not show control of the African stem borer (Busseola fusca Fuller), an important stem borer species, without which stewardship would be compromised by the possibility of rapid development of resistance to Bt delta-endotoxins. This study was carried out to test Bt-maize Event MON810 as an option to control all major stem borer species in Kenya. Two Bt-maize hybrids, DKC8073YG and DKC8053YG, both containing Bt Event MON810 of Cry1Ab gene were imported to carry out greenhouse containment trials. The hybrids together with the controls were grown in 10 replications upto the V6 and V8 stages. Infestations on whole plants were carried out at two stages of growth using 5 neonates of the spotted stem borer (Chilo partellus Swinhoe) and B. fusca. Bt-maize Event MON810 hybrids showed resistance to both stem borer species with low leaf damage scores and few surviving larvae recovered from the whole plant. The public Bt-maize Event 223 did not control B. fusca. Deploying Bt-maize Event MON810 may, therefore, be used to control the two species of stem borers. However, the efficacy of Bt-maize Event MON810 will, need to be evaluated under field environments.
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    Experiences with the biosafety regulatory system in Kenya during the introduction, testing and development of Bt maize
    (Academic Journals, 2011) Mugo, S.N.; Gichuki, S.T.; Mwimali, M.; Taracha, C.; Macharia, H.
    The introduction of genetically modified (GM) crops in Kenya is governed by a biotechnology policy, a biosafety law, and a biotechnology awareness strategy to enable research and development of GM crops. In addition, Kenya has the National Biosafety Authority (NBA) that regulates plant biosafety through technical institutions including the Kenya Plant Health Inspectorate Services (KEPHIS). Bacillus thuringiensis (Bt) maize for stem borer pest control was imported and tested under this regulatory system. The Insect Resistant Maize for Africa (IRMA) project aimed at developing and deploying transgenic Bt maize for stem borer control in Kenya. The IRMA project developed and implemented an internal biosafety strategy. To comply with and implement the biosafety regulations, IRMA set-up biosafety facilities to develop, maintain and test the Bt maize. These included a biosafety level 2 laboratory, a biosafety level 2 greenhouse containment and a confined field trial site, which also provided valuable models to national and international interests. IRMA also developed protocols for the use and disposal of transgenic plant materials, and also generated data for guidance on post-harvest monitoring at Bt-maize trial sites. IRMA also trained Kenyan administrators, scientists, technicians and regulators on conducting and handling GM trials. Training included informal courses, seminars, scientists? visits to established institutes, and support to research for degree related training. The project, therefore, provided major inputs in the development and advancement of biotechnology framework in Kenya. This paper reports on the achievements realized, challenges encountered by IRMA, and lessons learnt in research and development of GM crops in Kenya
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    Experiences in effective communication on transgenic technology in Africa - the case of the insect resistant maize for Africa (IRMA) project
    (Academic Journals, 2011) Wangalachi, A.; Poland, D.; Mugo, S.N.; Gichuki, S.T.; Ouya, D.; Kimani, G.; Rabar, J.
    The Insect Resistant Maize for Africa (IRMA) Project, aimed to improve food security through developing and deploying locally adapted stem borer resistant maize varieties using both conventional and biotechnology mediated methods, especially Bt technology. This technology uses a gene from the soil bacterium Bacillus thuringiensis (Bt) to create transgenic maize varieties. Transgenic technologies have been a controversial and emotive topic in recent years, and the IRMA project was launched against this backdrop. To ensure widespread acceptance of the IRMA project and its Bt technology, the project carefully planned and implemented its communication and public awareness strategy. Following its public launch in March 2000, the project promoted an open communication environment and continuously engaged with stakeholders to update them on progress. The project achieved this through targeted and diverse communications products such as media articles and broadcast news pieces, newsletters, websites, videos and reports. To complement these, the project conducted annual stakeholders' meetings, and specialized training for frontline project staff and collaborators, especially extension agents. This paper reviews the IRMA Project's public awareness and communication strategy and analyzes its effectiveness.
    Publication
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    Developing Bt maize for resource-poor farmers - Recent advances in the IRMA project
    (Academic Journals, 2005) Mugo, S.N.; De Groote, H.; Bergvinson, D.J.; Mulaa, M.; Songa, J.M.; Gichuki, S.T.
    This paper presents an overview of the advances in the IRMA project, which develops insect resistant maize varieties for resource-poor farmers, using both conventional breeding and genetic engineering. The project started in 1999 and is active in product development, impact assessment, and communication, all within the Kenya regulatory framework. So far, four application for introduction of tissue or commencement of field research were made to and approved by the National Biosafety Committee (NBC), and Bt maize leaves or seeds genes imported for testing against different stem borer species in bioassays on cut leaves in a biosafety laboratory, in potted plants in a Biosafety Greenhouse, and as whole plants in confined field trials in the Open Quarantine Station (OQS) at KARI Kiboko. All these biosafety facilities were specially built by the project for these evaluations. So far, good control has been realized against four of the five major stem borer species: Chilo partellus, Chilo orichalcociliellus, Eldana saccharina and Sesamia calamistis. Economic impact assessment demonstrated that stem borers are major constraints and cause substantial losses. Resistant maize varieties are likely to be adopted and to provide major returns to the investment if resistance against the economically most important species, Busseola fusca, can be found. Otherwise, returns would still be positive but small. Environmental impact research indicate that build-up of resistance against the Bt genes has not developed after that sufficient natural refugia exist in most areas, but suitable strategies acceptable to farmers need to be developed for some. Surveys, stakeholders meetings and other communications indicate that farmers, consumers and other stakeholders are cautiously optimistic about technology. Frequent interaction with the stakeholders and regulatory agencies assures a participative decision-making process and compliance with the strictest scientific and regulatory standards.
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