Prof. Chemining'wa's biography

I am an agricultural scientist specialized in agronomy with special focus on

integrated crop management. I am currently an Associate Professor and Chairman of the

Department of Plant Science and Crop Protection, University of  Nairobi. I hold a

PhD in Plant Science (University of Manitoba, Canada), M.Sc. Agronomy (University of

Nairobi), B.Sc. Agriculture at First Class Honours (University of Nairobi) and

Postgraduate Diploma in Integrated Agricultural Research for Development (ICRA, The



Kudra, A1, and 1 C’wa SGN2 KP, 1 SKP.  2014.  2014-Striga asiatica growth and seed production in response to organic and inorganic P - fertilizers(3). ACCESS INTERNATIONAL JUORNAL OF AGRIC SCIE. Vol. 2(1), pp.6-12, March 2014(Vol. 2(1), pp.6-12, March 2014):Vol.2(1),pp.6-12,March2014.2014-striga_asiatica_growth_and_seed_production_in_response_to_organic_and_inorganic_p_-_fertilizers3.pdf


Mwangi1, PW, Chemining’wa2 GN, Mburu3 MWK, Mureithi1 JG.  2013.  International Decomposition and nutrient release rates of selected legume residues in a cold semiarid environment of Kenya. International Journal of Agronomy and Agricultural Research (IJAAR). Vol. 3(No. 2):p.1-13,2013.
Chemining’wa1, GN, Mwangi2 PW, MMWK, George N. Chemining’wa1*, Peter W. Mwangi2 MM3 JM2WKG.  2013.  Nitrogen fixation potential and residual effects of selected. International Journal of Agronomy and Agricultural Research (IJAAR). Vol. 3(No. 2):14-20,2013.2013-nitrogen_fixation_potential_and_residual_effects_of_selected4.pdf
Kahiu Ngugi*, Jerono Cheserek, Muchira C, Dept GC’wa.  2013.  Anthesis to Silking Interval Usefulness in Developing Drought Tolerant Maize. Journal of Renewable Agriculture. 1(5):84-88.anthesis_to_silking_interval_usefulness_in_developing_drought_tolerant_maize.pdf
Mwangi, PW, Chemining'wa GN, Mburu MWK, Mureithi JG.  2013.  Decomposition and nutrient release rates of selected legume residues in a cold semiarid environment of Kenya.. International Journal of Agronomy and agricultural Research. 3(2):1-13.decomposition_and_nutrient_release_rates_of_selected_legume.pdf
Chemining’wa, GN, Mwangi PW, Mburu MWK, Mureithi JG.  2013.  Nitrogen fixation potential and residual effects of selected grain legumes in a Kenyan soil. International Journal of Agronomy and Agricultural Research . 3(2):14-20.nitrogen_fixation_potential_and_residual_effects_of_selected.pdf
Kitonyo, OM, Chemining'wa GN, Muthomi JW.  2013.  Productivity of farmer-preferred maize varieties intercropped with beans in semi-arid Kenya. International Journal of Agronomy and agricultural Research. 3(1):6-16.productivity_of_farmer_preferred_maize_varieties.


Muthomi J., Mureithi B., C’wa GMGJE.  2012.  Aspergillus species and Aflatoxin b1 in soil, maize grain and flour samples from semi-arid and humid regions of Kenya. International Journal of AgriScience . 2(1):22-34. Abstractaspergilllus_species_and_aflatoxin_b1.

Recurrent outbreaks of Aflatoxin (AF) poisoning in maize continue to exacerbate the food security crisis in Sub-Saharan Africa. This study determined the distribution and contamination levels of Aspergillus spp. and Aflatoxin B1 (AFB1) in soil, maize and maize-based products. Maize grain samples (n=256), semi-processed grain (n=56), flour (n=52), hammer mill dust (n=11), and soil (n=117) were collected during the 2008 and 2009 growing seasons. Aspergillus spp. was isolated and AFB1 was determined by Enzyme-Linked Immunosorbent Assay (ELISA). Aspergillus flavus was frequently isolated in maize samples from the semi-arid regions. The frequency of A. flavus was higher in semi-processed grain than in whole grain and packed flour samples. AFB1 was not detected in samples from the humid regions. AFB1 was detected at levels exceeding the Kenyan legal limit of 10 μg/kg in 20% of the samples, at maximum of 136 μg/kg for semi-processed maize,77 μg/kg for whole grain and 41 μg/kg for flour sold in open bags. The high temperature and periodic drought prevalent in the semi-arid regions could explain the higher levels of A. flavus and AFB1 contamination in that climate. In addition, unfavourable drying and storage practices may aggravate the problem. Therefore, it is recommended that the careful monitoring of AF be continued.

and C. Lung’aho, G. Chemining’wa, SHSM.  2012.  Dynamics of on-farm management of potato (Solanum tuberosum) cultivars in Central Kenya.. African Journal of Agricultural Research . 7(17):2701-2712.Dynamics_of_on-farm_management_of_potato


C., L’aho, G. C’wa, Y. F, M. H, G. P.  2011.  Genetic diversity of Kenyan potato germplasm revealed by simple sequence repeat markers. American Journal of Potato Research. 88:424-434.genetic_diversity_of_kenyan_potato_germplasm_revealed.
Lungaho C., Chemining’w G. Shibairo S., HMMM.  2011.  Cost effective slow growth in vitro conservation of potato (Solanum tuberosum L.) using table sugar as an alternative carbon source. African Journal of Biotechnology. 11(5):1092-1099.cost_effective_slow_growth_invitro.


E., G, S. S, J. K, Demo P..  2009.  Effects of light intensity on quality of potato seed tubers.. African Journal of Agricultural Research . 3(10):732-739.effects_of_light_intensity_on_quality_of_potato_seed_tubers.pdf


Lung’aho, C, Lung’aho, C. C’wa SHGSM, G. C’wa, Shibairo S, M. H.  2008.  Reaction of potato cultivars to natural infestation of late blight caused by Phytopthora infestans in Kenya. East Africa Agriculture and Forestry Journal . 74(3):195-200.reaction_of_potato_cultivars_to_natural_infestation_of_late_blight_caused_by_phytopthora_infestans_in_kenya.pdf



and Chemining’wa G.N., Njarui M.D.G., MGMJGJNS.  2006.  Response of green manure legumes to phosphorous application and rhizobial inoculation. Enhancing Agricultural Productivity in East Africa; Development and Up-scaling of Greed Manure Legume Technologies in Kenya. , Nairobi: Kenya Agricultural Research Institute.


Mustafa, KN;, Chemining'wa GN;, Nyabundi JO.  2005.  Effect of rhizobium inoculation of beans on growth and yield of maize and beans under different Intercropping patterns. Abstract

The same row and this also out-yielded sole Rhizobium inoculation of beans (Phaseolus vulgaris L.) and intercropping patterns of maize and beans were evaluated for two seasons in a field study. Plant population of each crop in all planting patterns was 53,333 plants ha-1. Beans were either uninoculated or inoculated with Rhizobium. Planting patterns consisted of maize and beans intercropped in the same hill, maize and beans intercropped as. alternating plants in the same row, maize and beans intercropped in alternate rows, sole maize and sole beans. Increasing intimacy between the intercrop species and inoculation significantly increased biomass and leaf area indices of both maize and beans, and also the number of nodules per bean plant. Inoculation significantly increased yield of maize in all intercropping treatments. In the inoculated treatments, intercropping maize and beans in the same hill had significantly higher maize grain yield than intercropping in alternate hills in the same row and this, in turn, out-yielded sole maize cropping and intercropping in alternate rows whose yields were not significantly different. When beans were inoculated, similar results were obtained but in the second season no difference was observed between intercropping in the same hill and intercropping in alternate hills in the same row. Sole maize was also significantly superior to maize intercropped with beans in alternate rows. Beans intercropped with maize in the same hill out-yielded beans intercropped with maize in alternate hills in the same row and this also out-yielded sole beans. Beans intercropped with maize in alternate rows had the lowest yield. These results demonstrate the superiority of intercropping maize and beans in close proximity and Rhizobium inoculation both of which promoted nodulation by the bean plants. There is need to establish why beans intercropped with maize in the same hill out¬yielded sole beans.

Gathumbi, J. K.; Muthomi, N'u C'waJW; JK.  2005.  Fusarium and mycotoxin contamination in freshly harvested wheat grain in Kenya. Abstract

A survey was carried out during the 2004 wheat-cropping season in 6 agro-ecclogical zones to determine fusarium contamination of freshly harvested wheat grain. This was done by plating in culture media. Contaminations with mycotoxins t!cnxynivalcnol, zenralenonc and aflatoxin B I were determined by competitive EUSA. Farmers indicated presence ol'hcnd blight 111 wheat fields and occurrence of wet weather during flowering. Wheat residue was mainly directly grazed to animals in the field or ploughed in. Most popular rotation was wheal-maize followed by continuous wheat cropping. Fusarium contaminated 85 % of the wheat samples, but kernel infection rate was 15%. Fusarium species most isolated were F.poae. F. chlumvdospnrum and F. grammC:Ul1lfll. Other fungi isolated were Alternaria. Epicoccum. Aspergigiilus anti Penicillium. Mycotoxins deoxynivalenol, zearalenone and aflatoxin B1. There is need for regular screening for Fusarium mycotoxins in wheat grain.


Ndiema, G.  2002.  The abundance, efficacy, and diversity of Rhizobium leguminosarum bv. viciae populations in southern Manitoba soils. AbstractWebsite

Innoculation of field pea is necessary in the absence of compatible rhizobial strains, when the rhizobial populations are low or symbiotically ineffective. The prevalence and efficacy of Rhizobium leguminosarum bv. viciae (the pea microsymbiont) in southern Manitoba soils is not known. Field experiments were conducted from 1998 to 2000 in multiple sites in southern Manitoba to characterize the abundance, efficacy, and diversity of indigenous R. leguminosarum bv. viciae. Uninoculated and inoculated (with and without N fertilizer) treatments of pea (Pisum sativum L.) were arranged in a randomized complete block design with four replicates in five sites (1999/2000). Pea was established in 21 sites in 1998 to trap indigenous rhizobia. Uninoculated and inoculated plants were evaluated for relative nodulation and growth. Pea and Lathyrus sp. isolates and commercial strains of R. leguminosarum bv. viciae were characterized by plasmid profile and polymerase chain reaction-restriction fragment length polymorphism of 16S-23S rDNA intergenic space analyses. Uninoculated plants were were nodulated in cultivated soils, but not in virgin soils. Inoculation had no effect on nodulation in all sites but one. Inoculated plants accumulated significantly more biomass than uninoculated plants in 1998 and in four of five sites in 2000. Out of 230 strains of R. leguminosarum bv. viciae typed, 77 distinct plasmid profiles were established. Plasmid profile diversity index (number of distinct profiles/number of isolates typed) varied from 0.2 to 0.83 in sites with 10 or more isolates. Few pea isolates from previously inoculated sites had profiles that matches those of the inoculants. Each site shared at least one profile with 3 to 18 other sites, but the number of profiles shared was independent of proximity... This research has shown that R. leguminosarum bv. viciae populations in southern Manitoba are abundant, diverse and competitive in nodulation, but may be less effective nitrogen fixers than commercial strains.


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