Posts Tagged ‘Kenya’

Resistance of Bt-maize (MON810) against the stem borers Busseola fusca (Fuller) and Chilo partellus (Swinhoe) and its yield performance in Kenya

Posted by gabrielamartinez on , in Journal Articles

A study was conducted to assess the performance of maize hybrids with Bt event MON810 (Bt-hybrids) against the maize stem borer Busseola fusca (Fuller) in a biosafety greenhouse (BGH) and against the spotted stem borer Chilo partellus (Swinhoe) under confined field trials (CFT) in Kenya for three seasons during 2013e2014. The study comprised 14 non-commercialized hybrids (seven pairs of near-isogenic Bt and non-Bt hybrids) and four non-Bt commercial hybrids. Each plant was artificially infested twice with 10 first instar larvae. In CFT, plants were infested with C. partellus 14 and 24 days after planting; in BGH, plants were infested with B. fusca 21 and 31 days after planting. In CFT, the seven Bt hybrids significantly differed from their non-Bt counterparts for leaf damage, number of exit holes, percent tunnel length, and grain yield. When averaged over three seasons, Bt-hybrids gave the highest grain yield (9.7 t ha1), followed by non-Bt hybrids (6.9 t ha1) and commercial checks (6 t ha1). Bt-hybrids had the least number of exit holes and percent tunnel length in all the seasons as compared to the non-Bt hybrids and commercial checks. In BGH trials, Bt-hybrids consistently suffered less leaf damage than their non-Bt near isolines. The study demonstrated that MON810 was effective in controlling B. fusca and
C. partellus. Bt-maize, therefore, has great potential to reduce the risk of maize grain losses in Africa due to stem borers, and will enable the smallholder farmers to produce high-quality grain with increased
yield, reduced insecticide inputs, and improved food security.

Source: Resistance of Bt-maize (MON810) against the stem borers Busseola fusca (Fuller) and Chilo partellus (Swinhoe) and its yield performance in Kenya

Determination of resistance against to Cereal cyst nematode, Heterodera avenae (Wollenweber, 1924) in some wheat germplasm

Posted by Carelia Juarez on , in Journal Articles

Published in Turkiye Entomoloji Dergisi – Turkish Journal Of Entomology 37 (2) : 229-238, 2013

Imren, M.; Toktay, H.; Bozbuga, R.; Dababat, A.A.; Ozkan, H.; Elekcioglu, I.H.

The cereal cyst nematode, Heterodera avenae is one of the most important pests of wheat in many countries in the world with different climatic types. Heterodera. avenae is commonly distributed in the Eastern Mediterranean region of Turkey and all populations investigated belong to the Ha1 group, Ha21 pathotype. This study was aimed to found resistance sources from the national wheat varieties, wheat wild genotypes and international wheat genotypes against H. avenae Karlık?Adana population (Ha21 pathotype). Results showed that four national wheat varieties, seventeen wheat wild genotypes and twenty three international wheat genotypes were found to be moderately resistant against to Eastern Mediterranean Region of Turkey H. avenae population. Among these genotypes, the national bread wheat variety, Adana 99 (PFAU/SERI82//BOG”S”), some wild genotypes and international genotypes can be used in national wheat breeding programmes. However, Cre1 was not showed completely resistant against H. avenae. Additionally resistance sources in of Turkish national wheat and wild genotypes needs to be determined.

What determines gender inequality in household food security in Kenya? Application of exogenous switching treatment regression

Posted by Carelia Juarez on , in Journal Articles

Published in World Development 56 : 153-171, 2013

Berresaw Menale Kassie; Ndiritu, S.W.; Stage, J.

This paper explores the link between the gender of a household head and food security in rural Kenya. The results show that the food security gap between male-headed households (MHHs) and female-headed households (FHHs) is explained by their differences in observable and unobservable characteristics. FHHs’ food security status would have been higher than it is now if the returns (coefficients) on their observed characteristics had been the same as the returns on the MHHs’ characteristics. Even if that had been the case, however, results indicate that FHHs would still have been less food-secure than the MHHs due to unobservable characteristics.

Tradeoffs in crop residue utilization in mixed crop-livestock systems and implications for conservation agriculture

Posted by Carelia Juarez on , in Journal Articles

Published in Agricultural Systems 121 : 96-105, 2013

Moti Jaleta, Menale Kassieb and Bekele Shiferaw

Crop residue use for soil mulch and animal feed are the two major competing purposes and the basic source of fundamental challenge in conservation agriculture (CA) where residue retention on farm plots is one of the three CA principles. Using survey data from Kenya and applying bivariate ordered Probit and bivariate Tobit models, this paper analyzes the tradeoffs in maize residue use as soil mulch and livestock feed in mixed farming systems. Results show that both the proportion and quantity of maize residue used for soil mulch and livestock feed are strongly affected by livestock holding. More livestock holding decreases the proportion of maize residue retained as soil mulch and increases the proportion used as feed. Farmer knowledge about alternative use of crop residues and farmer perception of soil erosion risk (proxied through plot steepness) positively affect the amount of residue farmers retain on maize plots. Results imply that crop residue use assoil mulch in conservation agriculture is challenged in mixed crop–livestock systems and particularly by smallholder farmers owning cross-bred and exotic dairy animals. In general, reducing the use of crop residues as livestock feed through the introduction of alternative feed sources, better extension services on the use of crop residue as soil mulch and designing context specific strategies and interventions could facilitate the adoption and expansion of CA-based practices in mixed crop–livestock systems.

Striga hermonthica parasitism in maize in response to N and P fertilisers

Posted by Carelia Juarez on , in Journal Articles

Published in Field Crops Research 134 (12): 1-10, 2012

M. Jamil, F.K. Kanampiu, H. Karaya, T. Charnikhova, H.J. Bouwmeester

Parasitism by the parasitic weed, Striga hermonthica (Striga), constitutes a major biological constraint to maize production in sub-Sahara Africa. Nutrient deficiency is known to aggravate Striga infestation and in a number of plant species it was recently shown that this may be due to increased secretion of Strigagermination stimulants into the soil. The present study was designed to observe the connection between soil fertility, secretion of germination stimulants and Striga infection in maize under greenhouse and field conditions. The experiments were conducted during two successive cropping seasons (2008 and 2009). The greenhouse study showed that maize secretes a number of so far unidentified strigolactones that induceStriga seed germination and the amount of these strigolactones increases upon N and P deficiency. The increased secretion of germination stimulants under N and P deficiency resulted in increased Striga infection in pot experiments. The on-station and on-farm field trials in Western Kenya also showed reduction in Strigainfestation with the application of mineral nutrients but the results were less consistent than in the greenhouse. Increasing levels of N showed a fair reduction of Striga in the field especially during the first year, whereas P application did not have much effect in contrast to the greenhouse study where both N and P clearly reduced Striga infection. The likely explanation for this discrepancy is that availability of mineral nutrients under field conditions is less predictable than under greenhouse conditions, due to a number of factors such as soil texture and structure, pH, salinity, drought, leaching and runoff. Hence, further studies are needed on the importance of these factors before a fertiliser application strategy can be formulated to improve control of Striga in maize in the field.

Experiences with the biosafety regulatory system in Kenya during the introduction, testing and development of Bt maize

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Published in African Journal of Biotechnology 10(23); 4682-4693, 2011

Experiences with the biosafety regulatory system in Kenya during the introduction, testing and development of Bt maize

Stephen Mugo, Simon Gichuki, Murenga Mwimali, CatherineTaracha, and Harrison Macharia

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.


Estimating consumer willingness to pay for food quality with experimental auctions: the case of yellow versus fortified maize meal in Kenya

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Published in Agricultural Economics 42(1): 2011

Estimating consumer willingness to pay for food quality with experimental auctions: the case of yellow versus fortified maize meal in Kenya

Hugo De Groote; Simon Chege Kimenju; Ulrich B. Morawetz

Biofortification of maize with provitamin A carotenoids is a new approach to the alleviation of vitamin A deficiencies in Africa. Unfortunately these varieties are yellow or orange, while consumers generally prefer white. Consumer willingness to pay for yellow and fortified maize was compared in experimental auctions in three regions in Kenya. The premium that consumers are willing pay for fortified maize (24%) was higher than the discount they require to buy yellow maize (11%), and in one zone consumers prefer yellow. Yellow color is, therefore, not an impossible obstacle for biofortified maize, although it would clearly be easier to introduce this maize first in regions where yellow maize is currently grown.