Prof. Joseph P Onyango Gweyi

Position: Associate professor of Systems Agronomy/Plant Nutrition and Chairman of Department Agricultural Science and Technology
Department: Agricultural Science and Technology
Contact Address:P.O. Box 43844 Nairobi 00100
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Area of Specialization: Plant nutrition/systems agronomy
Google Scholar: Joseph Gweyi-Onyango
ORCID ID: 0000-0002-3019-6353
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Research Interests:

Modelling, artificial intelligence, precision nutrient management, nitrogen flows and budgeting, phosphorus uptake kinetics, mycorrhizae in degraded soils, and biofertilizers, agroecology and biodiversity management, outreach and community service

Research Publications

Refereed Journal Papers

Ngugi MM, Gitari H I Muui C Wand Gweyi-Onyango J P (2022). Growth tolerance, concentration, and uptake of heavy metals as ameliorated by silicon application in vegetables. International Journal of Phytoremediation. : org/10.1080/15226514.2022.2045251
Ntinyari W, Giweta M, Gweyi-Onyango J , Mochoge B , Mutegi J , Nziguheba G and Cargele Masso C (2022). Assessment of the 2006 Abuja Fertilizer Declaration With Emphasis on Nitrogen Use Efficiency to Reduce Yield Gaps in Maize Production. Sustain. Food Syst. 5:758724. doi: 10.3389/fsufs.2021.758724
Ntinyari W, Gweyi-Onyango, Giweta M , Mochoge B , Mutegi J, Nziguheba G and Masso C (2022). Nitrogen use efficiency trends for sustainable crop productivity in Lake Victoria basin: smallholder farmers’ perspectives on nitrogen cycling. Res. Commun. 4 (2022) 015004.
Gweyi-Onyango J P, Ntinyari W, Ogolla E A, Mose R, Njinju S, Giweta M, Masso C. (2021). Differences in seasons and rice varieties provide opportunities for improving nitrogen use efficiency and management in irrigated rice in Kenya. Journal of Environmental Research Letters. 16 (07) -5003. doi.org/10.1088/1748-9326/ac03dd
Moses M. Ngugi, Harun I. Gitari, Catherine Muii and Gweyi-Onyango J P (2021): Cadmium mobility, uptake, and accumulation in spinach, kale, and amaranths vegetables as influenced by silicon fertilization, Bioremediation Journal, DOI: 10.1080/10889868.2021.1924111
Ochieng’ I O, Gitari H I , Benson Mochoge B, Esmaeil Rezaei-Chiyaneh E R and Gweyi-Onyango J P (2021). Optimizing Maize Yield, Nitrogen Efficacy and Grain Protein Content under Different N Forms and Rate. Journal of Soil Science and Plant Nutrition https://doi.org/10.1007/s42729-021-00486-0
Mwangi SM, Korir N K, Mose R , Osei-Kwarteng M , Akuja E T and Gweyi-Onyango J P (2021). African Journal of Horticultural Science 18 (2): 21-3
Kaaria K G , Gweyi-Onyango J P and Muui C W (2021). African Journal of Horticultural Science 18 (2): 1-20
Catherine Mathenge C, Thuita, M Cargele Masso C, Gweyi-Onyango J and Vanlauwe B (2019). Variability of soybean response to rhizobia inoculant, vermicompost, and a legume-specific fertilizer blend in Siaya County of Kenya. Soil & Tillage Research 194 (2019) 104290. doi.org/10.1016/j.still.2019.06.007
EL Chimoita, CM Onyango, JP Gweyi-Onyango and JW Kimenju (2019) Socio-economic and Institutional Factors Influencing Uptake of Improved Sorghum Technologies in Embu, Kenya. East African Agricultural and Forestry Journal 83 (2): 69–79
Munyasi T and Gweyi-Onyango JP (2019). Growth and Nutritional Status of Sweet Pepper (Capsicum Annum L.) are Co-Influenced by Nitrogen Application and Meloidogyne Spp. Infection. African Journal Horticultural Science. 16:55 - 70
M.Wambua, N. Korir, S.M.Ngene and J. Gweyi-Onyango (2018). Heavy metal concentration in amaranthus, cowpea, black nightshade and kale in response to wastewater irrigation in Kitui County, Kenya. African Journal of Rural Development: 3(4): 1025-1033
Sakha M A, Jefwa J and Gweyi-Onyango J P (2019). Effects of Arbuscular Mycorrhizal Fungal Inoculation on Growth and Yield of Two Sweet Potato Varieties. Journal of Agriculture and Ecology Research International 18(3): 1-8
Wahome N Mbatha, Nicholas K Korir and Joseph P Gweyi-Onyango (2019). Influence of SIRI fertilizer practice on yield components and grain yield of hybrid rice varieties in Kenya. Asian Plant Research Journal. 2(2): 1-7
Alice Ngetich, Nicholas Korir and Joseph P Gweyi-Onyango (2018). Influence of Nitrogen Levels and Planting Architecture on Grain Amaranth in Kenya. London Journal of Research in Science: Natural and Formal. 18(3):43-49
Ntinyari Winnie and Joseph P. Gweyi-Onyango (2018). Impact of Nitrogen Forms and Levels on Yield and Quality of Rice in Kirinyaga and Kisumu Counties Kenya. Asian Journal of Soil Science and Plant Nutrition. 3(4): 1-7.
Joseph P. Gweyi-Onyango (2018). Effects of Nitrogen Levels on Yield and Nitrogen Utilization Efficiencies of Two Rice Varieties in Kirinyaga County, Kenya. African Journal of Horticultural Science. 14:23-34
Etabo E. Mathew, Wekha N. Wafula, Nicholas K. Korir and J. P. Gweyi-Onyango (2018). Effect of Phosphorus Levels on Soil Properties and Plant Tissues of Two Nerica Varieties. Asian Soil Research Journal. 1(3): 1-9.
Winnie Ntinyari and Joseph Gweyi-Onyango (2018). Biofertilizers as an Alternative to Inorganic Fertilizers in Sub-Saharan African: Is the Adoption the Missing Link? Elexir Agriculture. 114:49564-49551
Wekha N Wafula, Nicholas K Korir, Henry F Ojulong, Moses Siambi and Joseph P Gweyi-Onyango (2018). Protein, Calcium, Zinc and Iron contents of Finger Millet Grain Response to Varietal Differences and Phosphorus Application in Kenya. Agronomy-MDPI. 8(24):1-9. doi:10.3390/agronomy8020024.
Symon M. Njinju, Hiroaki Samejima, Keisuke Katsura, Mayumi Kikuta, Joseph P. Gweyi-Onyango, John M. Kimani, Akira Yamauchi and Daigo Makihara (2018). Grain yield responses of lowland rice varieties to increased amount of nitrogen fertilizer under tropical highland conditions in central Kenya. Plant Production Science. 109:1-12 doi.org/10.1080/1343943X.2018.1436000
Kariithi Tabitha, Thagana Wilson and P. Gweyi-Onyango Joseph (2018). Influence of Organic and Inorganic Manures on Macro-Nutrients, Micro-Nutrients and Anti-Nutrients in two Amaranth spp in Kiambu Couny, Kenya. Asian Journal of Research in Crop Science. 1: (1) 1-17.
Mwirigi Peter, Joseph Gweyi-Onyango and Maina Mwangi (2018). Flowering and Fruiting of Yellow Passion Fruit (Passiflora Edulis,Var F. Flavicarpa. Deg) as Influenced by Different Fertilizer Applications in Kiambu and Embu Counties, Kenya. The International Journal of Science & Technoledge. 6(4): 28-31
Ikiba L. Kalawa, Wekha N. Wafula, Nicholas K. Korir and Joseph Gweyi-Onyango (2018). Interaction Effect of Growth Regulators and Irrigation Schedules on Growth and Yield of French Beans in Kiambu County, Kenya. Asian Journal of Research in Crop Science. 1(1): 1-8.
Mutuerandu C. Miriko, Nicholas K. Korir and Joseph P. Gweyi-Onyango (2018). Benefits of Rhizobial Inoculation and Phosphorus Application on Growth of Lucerne (Medicago sativa) in Kenya. International Journal of Plant & Soil Science. 21(6): 1-7
Okello P. Odhiambo, Joseph P. Gweyi-Onyango and Mildred P Nawiri (2017). Effects of Water stress on Phenolics Content and Antioxidant Activity of African Nightshades. Biofarmasi Journal of Natural Product Biochemistry. 15(2) 79-95.
Evans L. Chimoita, Cecillia M. Onyango, John W. Kimenju, Joseph P. Gweyi-Onyango (2017). The Agricultural Extension Agents Influence on the Uptake of Improved Sorghum Technologies in Embu County, Kenya (2017). Universal Journal of Agricultural Research 5(4): 219-225. DOI: 10.13189/ujar.2017.050403.
Rozy Munene, Evans Changamu, Nicholas Korir and Joseph P Gweyi-Onyango (2017). Differential Impact of Nitrogen Forms on Selected Phytochemicals and Oxalate Contents in Three Vegetable Amaranth Varieties in Kenya. Annals, Food Science and Technology 18(2) 238-256.
Ocharo N. Edgar Joseph P. Gweyi-Onyango and Nicholas K. Korir (2017). Green Pepper Growth and Yield Response to the Integration of Mulching Materials and Row Plant Spacing. Journal of Agriculture and Crops. 3(9) 72-77.
Alice Ngetich Rotich, Joseph P. Gweyi-Onyango and Nicholas K. Korir (2017). Diagonal Offset Arrangement and Spacing Architecture Effect on Growth and Yield Components of Grain Amaranth in Kenya. Asian Research Journal of Agriculture. 6(1): 1-8
Odhiambo Peter Okello, Mildred P. Nawiri, Winfred Musila and Joseph P. Gweyi-Onyango (2017). Water Stress Effect on Total Antioxiant Activity and Total Phenolic Content of Solanum scabrum Mill and Solanum scabrum in Kiambu, Kenya. International Journal of Biochemistry Research & Review.17(1): 1-9.
Ocharo N. Edgar Joseph P. Gweyi-Onyango and Nicholas K. Korir (2017). Plant Row Spacing Effect on Growth and Yield of Green Pepper (Capsicum annuum) in Western Kenya. Archives of Current Research International. 7(3): 1-9.
Grace J. Chirchir, Maina Mwangi, Desterio O. Nyamongo and Joseph P. Gweyi-Onyango (2017). Effects of genotype and agro-ecological conditions on storability of soybean [Glycine max (L.) Merr.] seed. Tropical Plant research: An Agricultural Journal 4(1): 126–133. DOI: 10.22271/tpr.2017.v4.i1.019.
Ogembo Oyaro Joel, P. Nawiri, W. Musila and Joseph P. Gweyi-Onyango (2017). Effect of Phosphorus Deficiency on Phenolics and Antioxidants Content of Two African Nightshade Varieties Grown in Kenya. International Journal of Plant & Soil Science 15(3): 1-11.
Mildred Osei-Kwarteng, Joseph Patrick Gweyi-Onyango and Gustav Komla Mahunu (2017). Commodity Systems Assessment Methodology of Postharvest Losses in Vegetable Amaranths: The Case of Tamale, Ghana. International Journal of Agronomy. 2017: 1-7. doi.org/10.1155/2017/1747869.
Rozy Munene, Evans Changamu, Nicholas Korir and Gweyi-Onyango Joseph (2017). Effects of different nitrogen forms on growth, phenolics, flavonoids and antioxidant activity in amaranth species. Tropical Plant research: An Agricultural Journal 4(1):81-89 DOI: 10.22271/tpr.2017.v4.i1.012
Munene Rozy, Changamu Evans, Korir Nicholas and P. Gweyi-Onyango Joseph (2017). Comparison of Cationic and Anionic Forms of Nitrogen Fertilization on Growth and Calcium, Zinc and Iron Content in Shoots of Two Varieties of Vegetable Amaranth. Journal of Agriculture and Ecology Research International.11(1): 1-
Wekha N. Wafula, Moses Siambi, Henry Ojulong, Nicholas Korir and Joseph Gweyi-Onyango (2017). Finger Millet (Eleusine coracana L) Fodder Yield Potential and Nutritive Value under Different Levels of Phosphorus in Rainfed Conditions. Journal of Agriculture and Ecology Research International 10(4): 1-10; ISSN: 2394-1073.
Ocharo N. Edgar, Joseph P. Gweyi-Onyango and Nicholas Kibet Korir (2017). Transparent, Black and Organic Mulches Effect on Weed Suppression in Green Pepper (Capsicum annuum L) in Western Kenya. Journal of Agricultural Studies: 1(5):67-76:ISSN 2166-0379
Wafula Nelson Wekha, Nicholas Kibet Korir, Moses Siambi, Henry F. Ojulong and Joseph P. Gweyi-Onyango (2017). Agromorphological Performance and Character Association of Finger Millet under Varying Phosphorus Regimes. Journal of Agricultural Studies: 1(5):90-102:ISSN 2166-0379.
Peter Mwirigi, Maina Mwangi, and Joseph Gweyi-Onyango, (2016). Agronomic Management of Yellow Passion Fruit Among Farmers in Mbeere Sub-County, Kenya. African Journal of Horticultural Sciences 10: 1 – 13.
Wekha N. Wafula, Nicholas K. Korir, Henry F. Ojulong, Moses Siambi and Joseph P. Gweyi-Onyango (2016). Nitrogen and Phosphorus Uptake and Partitioning in Finger Millet as Influenced by Phosphorus Fertilization. Journal of Experimental Agriculture International 14(4): 1-11.
Grace Jepleting Chirchir, Maina Mwangi, Desterio Ondieki Nyamongo and Joseph P Gweyi-Onyango (2016). Soybean: An Assessment of Varieties Grown, Seed Sources and Farm-saved Seed Management Practices in Meru South Sub-County, Kenya. Elixir Agriculture 98: 42471-42475
Wekha N. Wafula, Korir K. Nicholas, Ojulong F. Henry, Moses Siambi and Joseph P. Gweyi-Onyango (2016). Finger millet (Eleusine coracana) grain yield and yield components as influenced by phosphorus application and variety in Western Kenya. Tropical Plant research: An Agricultural Journal. 3 (3): 673-680. DOI: 10.22271/tpr.2016.v3.i3.088
Lydia Nduku Mutua, S. Omuterema and O. Gweyi (2016). Evaluation of the Nature of Drought Experienced in Makueni County, Kenya. Research on Humanities and Social Sciences. 6(16):92-102. ISSN (Paper)2224-5766 ISSN (Online)2225-0484 (Online)
Ocharo N. Edgar, Joseph P. Gweyi-Onyango and Nicholas K. Korir (2016). Influence of Mulching Materials on the Growth and Yield Components of Green Pepper at Busia County in Kenya. Asian Research Journal of Agriculture 2(2): 1-10: Article no.ARJA.29909
Wekha N. Wafula, Nicholas K. Korir, Henry F. Ojulong and Joseph P. Gweyi-Onyango (2016). Effect of Phosphate Levels on Soil Rhizosphere Nutrient Balances and Finger Millet Yield. Asian Research Journal of Agriculture 2(1): 1-8, 2016, Article no.ARJA.29606
Lydia Nduku Mutua, Stanely. Omuterema and Joseph P.Gweyi –Onyango (2016). Evaluation of the of Mitigation and Response Strategies used for Drought Management in Makueni County, Kenya. Elixir Fin. Mgmt. 98 (2016) 42563-42566
Munene Rozy, Changamu Evans, Korir Nicholas and P. Gweyi-Onyango Joseph (2016). Characterization and Documentation of Factors Contributing to Production and Consumption of African Leafy Vegetables (ALVs) in Kiambu and Kirinyaga Counties in Kenya. Asian Research Journal of Agriculture 1(3): 1-9, 2016, Article no.ARJA.28734
Wekha N. Wafula, Nicholas K. Korir, Henry F. Ojulong, Moses Siambi and Joseph P. Gweyi-Onyango (2016). Phosphorus Influence on Plant Tissue Nitrogen Contents and Yield Attributes of Finger Millet Varieties in Semi-arid Region of Kenya. International Journal of Plant & Soil Science 13(3): 1-9, 2016; Article no.IJPSS.29901 ISSN: 2320-7035
Wekha N Wafula, Nicholas K Korir, Henry F Ojulong and Joseph P Gweyi-Onyango (2016). Flowering and maturation periods of Finger Millet as influenced by phosphorus and variety in different agro-ecologies in Kenya. Elixir Agriculture. 101: 43458-43462
Wekha N Wafula, Nicholas N Korir, Henry F Ojulong and Joseph P Gweyi-Onyango (2016). Effect of phosphate levels on soil rhizosphere nutrient balances and filler millet yields. Asian Research Journal of Agriculture. 2(1): 1-8
Ocharo N Edgar, Joseph P Gweyi-Onyango and Nicholas Korir (2016). Influence of mulching materials on growth and yield components of green pepper in Busia county in Kenya. Asian Research Journal of Agriculture. 2(2): 1-10
Kennedy Ouko Alai, Stanley Omuterema and Joseph Gweyi (2016). Fire Disaster Risk Plans on Preparedness: A Case Study of Informal Settlements in Nairobi County. Elixir project management journal. 95: 40833-40837. ISSN:2229-71X
Grace J. Chirchir, Maina Mwangi, Desterio O. Nyamongo, Joseph P. Gweyi-Onyango (2016). Soybean farm-saved seed viability and vigor as Influenced by agroecological conditions of Meru South Sub-county, Kenya. Journal of Applied Biosciences. 101: 9634-1942.ISSN 1997–5902
Rosally A Onyango, Wilson M Thagana, Laura Karanja and Joseph Onyango-Gweyi (2016). Assessment of Sweet Potato propagules for Re-infection by various viruses in East Kamagak Location-Homa Bay County- Kenya. American Journal of Experimental Agriculture. 11(1):1-9. ISSN:2231-0606. Doi:10.9734/AJAEA/2016/21868
Onyango Rosally, Thagana Wilson, Gweyi Joseph and Karanja Laura (2015). Yield and Nutritive Attributes Are Not Considered by Farmers in Choice of Sweet Potato Varieties Grown in East Kamagak Location –Homabay County-Kenya. The international Journal of Technoledge 3(9):69-73 (ISSN 2321-919X)
Evans L. Chimoita, Gatahi D. Maina, Dennis O. Olila, Joseph P.Gweyi Onyango (2015). The Role of Farmer Field Schools Approach in Improving Tea Production among Smallholding in Kenya. Universal Journal of Agricultural Research 3(1): 4-10. DOI: 10.13189/ujar.2015.030102.
Chimoita E L, Embeywa HE and Gweyi-Onyango J P (2014). Secondary School Teachers’ Understanding of Energy Flow in Ecosystems: Carbon Sink and Sequestration perspectives. Journal of Human Ecology. 48(3): 461-467
Filbert L. Ahmat; Jayne N. Mugwe; Stephen K. Kimani, and Joseph P. Gweyi-Onyango (2014). Maize response to Tithonia diversifolia and rock phosphate application under two maize cropping systems in Kenya. Journal of Applied Biosciences 79:6983 – 6991. ISSN 1997–5902
Chimoita Evans, Babu Mary, Gweyi-onyango Joseph, Machacha Kennedy; Omufwoko J (2014). Secondary School Students’ Understanding of Energy Flow in Ecosystems. Asian Academic Research Journal of Social Science and Humanities. 1(28) 231-244. ISSN 2278-859X
Waswa F, Gweyi-Onyango J P, Mucharo M (2012). Contract sugarcane farming and farmers’ incomes in the Lake Victoria basin, Kenya. Journal of Applied Biosciences. 52:3685-3695. ISSN 1997-5902
Joseph P Gweyi-Onyango and Mildred Osei-Kwarteng (2011). Safe Vegetable Production with Wastewater in Developing Countries: Demystifying Negative notions: African Journal of Horticultural Science. 5:70-83
Gweyi-Onyango J P, Tesfamariam T and Günter N (2011). Contrasting Responses to Phosphorus status by Arachis pintoi (Krapov and W.C Gregory): A Lesson for Selecting Vegetables for Cultivation in Kenyan Ecozones. Asian Journal of Agricultural Research. 5(1): 45-55.Doi:10.3923/ajar.2011.
Joseph P Gweyi-Onyango, Peter Akwee, Christine Onyango and Tesfamaria Tsehaye (2011). Genotypic responses of Cowpea (Vigna anguiculata) to Sub-Optical Phosphorus Supply in Alfisols of Western Kenya: A Comparative Analysis of Legumes. Journal of Agricultural Sciences. Vol 1(2): 1-8.
Makau Mulei, Sagaffu S Masito and Joseph P Gweyi-Onyango (2011). A Rapid Hydroponic Screening of Field and Horticultural and Crops for Aluminium Tolerance. African Journal of Horticultural Sciences. 4:48-59.
Gweyi-Onyango J P, Günter N and V Römheld (2010). Differential benefits of rock phosphate (RP) by tomato (Lycopersicon esculentum Mill.) plant as affected by nitrogen forms and soil types. African Journal of Food Agriculture Nutrition and Development, 4(10): 2460-2477.
Akwee P.E, Palapala V A and Gweyi-Onyango J P (2010). A Comparative study of plant species composition grassland in Saiwa Swamp National part and Kakamega Forest, Kenya. Journal of Biodiversity: 1(2):77-83.
Gweyi-Onyango J P, Neumann G and Roemheld V (2009). Effects of Different Forms of Nitrogen on Relative Growth Rate and Growth Components of Tomato (Lycopersicon esculentum Mill.). African Journal of Horticultural Science (2):43-55.
Gweyi-Onyango J.P, G. Neumann, V. Römheld (2006). Role of nitrogen forms in solubilization and Utilization of rock phosphate by Tomato (Lycopersicon esculentum L.) plants (2006). African Crop Science Journal: 7(3) 1029-1032.
Gweyi-Onyango, J. P; Römheld, V.; Neumann, G (2006). Rock phosphate alleviates detrimental effects of aluminium in tomato production on acid soils. Proceedings of 3rd International Symposium on Phosphorus Dynamics in the Soil-Plant Continuum, Uberlandia, Minas Gerais, Brazil, May14-19 2006; pp165-166, (eds). Vera M. C. Alves et al. Sete Lagoas: Embrapa Milho e Sorgo.
Gweyi, Onyango J P (2006) - Utilization of rock phosphate by tomato (Lycopersicon esculentum Mill.) as affected by nitrogen forms and soil types: Mechanisms, prospects and limitations. Verlag Grauer. Beuren (Publishers). Stuttgart. 2006. ISBN 3-86186-516-5
Claasen, N. Castaneda-Ortiz, G.Neumann, J.P Gweyi-Onyango and I.M. Rao (2005). Root exudation of Organic acids and/or acid phosphatase cannot explain phosphorus mobilization by Arachis Pintoi. 460-461. In. Li C.J; Zang, FS; Dobermann,A; Lambers, H; Li XL, Maschner, P; McGrath, S; Oenema O; peng, S B; Rengel Z; Shen QR; Welch R, von Wiren N; Yan XL; Zhu YG (eds). Plant nutrition for food security, human health and environmental protection. Tsingua University Press.

Other Publications

University level scholarly book

Joseph Onyango Gweyi 2018. A handbook of postharvest of perishable produce- Kenyatta University press – (in Press)
Patented Invention or Innovation

Book chapter in a university level scholarly book

Gweyi-Onyango J P and Ntinyari W (2022). Optimizing Nitrogen Management for Improved Productivity, Nitrogen Use Efficiency, and Food and Nutrition Security: African Context Perspectives. Springer Nature Switzerland AG 2022. A. Kumar et al. (eds.), Agriculture, Livestock Production and Aquaculture, https://doi.org/10.1007/978-3-030-93262-6_4 - pp 45-48
Ntinyari W, Giweta M, Mutegi J, Masso C, and Gweyi-Onyango J P (2022). Managing Agricultural Nitrogen Losses in Crop Production and Mitigation of Climate Change Effects. Springer Nature Switzerland AG 2022. A. Kumar et al. (eds.), Agriculture, Livestock Production and Aquaculture, https://doi.org/10.1007/978-3-030-93258-9_2: -pp 21-40
Sakha M A, Jefwa J, and Gweyi-Onyango J P (2022). Critical Analysis and Evaluation of Groundnut Value Chain for Revamping Its Production for Global Food Security. Springer Nature Switzerland AG 2022. A. Kumar et al. (eds.), Agriculture, Livestock Production and Aquaculture, https://doi.org/10.1007/978-3-030-93258-9: pp 43-58
Manzi K. H and Gweyi-Onyango J P (2002). Geoinformation for Land Suitability Modelling for Climate-Smart Farming in Africa. Springer Nature Switzerland AG 2022. A. Kumar et al. (eds.), Agriculture, Livestock Production and Aquaculture, https://doi.org/10.1007/978-3-030-93258-9_9: pp 155-165
Njinju S M, Gweyi-Onyango J and Mayoli R (2022). Drought-Resilient Climate Smart Sorghum Varieties for Food and Industrial Use in Marginal Frontier Areas of Kenya. Springer Nature Switzerland AG 2022. A. Kumar et al. (eds.), Agriculture, Livestock Production and Aquaculture, https://doi.org/10.1007/978-3-030-93262-6_3: 33-44
Otieno E O Gweyi-Onyango J and Oduor N O (2022). Revolutionizing Crops and Soil Resources’ Resilience to Climate Change: A Case for Best-Fit Agronomic Practices in Low and High Input Systems. Springer Nature Switzerland AG 2022. A. Kumar et al. (eds.), Agriculture, Livestock Production and Aquaculture, https://doi.org/10.1007/978-3-030-93262-6_2: PP 15-31
Ntinyari W and Gweyi-Onyango J P (2021). Greenhouse Gases Emissions in Agricultural Systems and Climate Change Effects in Sub-Saharan Africa. Springer Nature Switzerland AG. In W. Leal Filho et al. (eds.), African Handbook of Climate Change Adaptation, https://doi.org/10.1007/978-3-030-42091-8_43-
Gweyi-Onyango J.P., Sakha M.A., Jefwa J. (2021) Agricultural Interventions to Enhance Climate Change Adaptation of Underutilized Root and Tuber Crops. In: Leal Filho W., Oguge N., Ayal D., Adeleke L., da Silva I. (eds) African Handbook of Climate Change Adaptation. Springer, Cham. https://doi.org/10.1007/978-3-030-45106-6_40.
Sakha M A, Korir M J, Gweyi-Onyango J P and Jefwa J (2021). Good Agricultural Practices in Mushroom Cultivation Value Chain in Kenya: The Role of Agronomic Inputs, Chapter 2, pg 19-36. In Rawat et al (ed). AkiNik Publications. ISBN: 978-93-90846-45-0; https://doi.org/10.22271/ed.book.1182
Manzi H and Gweyi-Onyango J P (2020). Agro-ecological Lower Midland Zones IV and V in Kenya Using GIS and Remote Sensing for Climate-Smart Crop Management. . Springer Nature Switzerland AG. In W. Leal Filho et al. (eds.), African Handbook of Climate Change Adaptation, https://doi.org/10.1007/978-3-030-42091-8_43-
Osei-Kwarteng M, Gweyi-Onyango J P and Mahunu G K (2021). Harvesting, storage, postharvest management, and marketing of Hibiscus sabdariffa in: Roselle (Hibiscus sabdariffa) Chemistry, Production, Products, and Utilization. ed. Mariod, Tahir and Mahunu. Pp-15 Elsevier, Academic Press.
Gweyi-Onyango J P, Osei-Kwarteng M and Mahunu G K (2021). Measurement and maintenance of Hibiscus sabdariffa quality in: Roselle (Hibiscus sabdariffa) Chemistry, Production, Products, and Utilization. ed. Mariod, Tahir and Mahunu. Pp-47 Elsevier, Academic Press.
Osei-Kwarteng M, Gweyi-Onyango J P, Mahunu G K, Tahir H E and Apaliyaa M T (2021). Hibiscus sabdariffa: protein products, processing, and utilization in: Roselle (Hibiscus sabdariffa) Chemistry, Production, Products, and Utilization. ed. Mariod, Tahir and Mahunu. Pp-77 Elsevier, Academic Press.
Mahunu G K, Tahir H E, Osei-Kwarteng M, Mariod A A and Gweyi-Onyango J P (2021). Food use of whole and extracts of Hibiscus sabdariffa in: Roselle (Hibiscus sabdariffa) Chemistry, Production, Products, and Utilization. ed. Mariod, Tahir and Mahunu. Pp-123 Elsevier, Academic Press.
Römheld V, Jiménez-Becker S, Neumann G, Gweyi-Onyango J.P, Puelschen, L, Spreer W and Bangerth F. (2008): Non-nutritional fertigation effects as a challenge for improved production and quality in horticulture. In: Fertigation: Optimizing the utilisation of water and nutrients. International Potash Institute, Horgen, Switzerland., pp-103-115

Peer Reviewed conference papers

Michael Sakha, Joseph Gweyi-Onyango and Joyce Mnyanzi Jefwa (2019). Role of arbuscular mycorrhizal fungi inoculation on nutrients uptake of sweet potato varieties in Nairobi County, Kenya. First International Symposium inTropical African Mycology (FISTSM)- Exploring Tropcial Mycodiversity: Progress, Facilities and Challenges. 9^th to 13^th September 2019, University of Parakou, Parakou, Benin.
Sakha Michael, Joseph P Gweyi-Onyango (2019). Good agricultural practices in mushroom cultivation value chain in Kenya: Role of agronomic inputs. Kenyatta University Biennial Research and Innovation Conference. Research and Innovation for the achievement of SDGS and Kenya’s Big Agenda. 23^rd -25^th October 2019. Pg 79
Rosepiah Munene and Joseph P Gweyi-Onyango (2019). Impact of nitrogen fertilization on plant growth and selected secondary metabolite concentrations in three vegetable amaranth varieties in Kenya. : Role of agronomic inputs. Kenyatta University Biennial Research and Innovation Conference. Research and Innovation for the achievement of SDGS and Kenya’s Big Agenda. 23^rd -25^th October 2019. Pg 81
Rosepiah Munene and Joseph P Gweyi-Onyango (2017). Postharvest losses in fruits: Dissecting possible role and implications of pre-harvest NPK nutritional status of fruits. Page 28-29. The I^st ALL AFRICA POSTHARVEST CONGRESS AND EXHIBITON. Reducing postharvest losses and waste: Sustainable solution for Africa. Conference proceedings (peer-review extended abstract)-28th-31st March 2017. Safari Park Hotel, Nairobi, Kenya.
Nelson Wafula, Moses Siambi and Joseph P Gweyi-Onyango (2017). Smallholder Oriented Approach to postharvest management for groundnuts in Kenya: A review. Pg 104-105. The Ist ALL AFRICA POSTHARVEST CONGRESS AND EXHIBITON. Reducing postharvest losses and waste: Sustainable solution for Africa. Conference proceedings (peer-review extended abstract)-28th-31st March 2017. Safari Park Hotel, Nairobi, Kenya.
Winnie Ntinya and Joseph P Gweyi-Onyango (2017). Postharvest losses of Banana production value chain in Meru and Kisii counties of Kenya: The role of Socio-Cultural diversity. Pg 104-105. The Ist ALL AFRICA POSTHARVEST CONGRESS AND EXHIBITON. Reducing postharvest losses and waste: Sustainable solution for Africa. Conference proceedings (peer-review extended abstract)-28th-31st March 2017. Safari Park Hotel, Nairobi, Kenya.
Kimani M Maina and Joseph P Gweyi-Onyango (2017). Post-Harvest Loss Reduction in Fruits: Is Proper Identification Methods of Maturity Indices a Solution? Pg.168-169. The I^st ALL AFRICA POSTHARVEST CONGRESS AND EXHIBITON. Reducing postharvest losses and waste: Sustainable solution for Africa. Conference proceedings (peer-review extended abstract)-28th-31st March 2017. Safari Park Hotel, Nairobi, Kenya.
Mwangi M, Gweyi JO, and Mbaka J, 2016. Promotion of technologies to enhance passion fruit productivity under recurring drought events in semi arid eastern Kenya.
Kimani, M.M., Gweyi, J.O., Mbaka, J.N., Mwangi M, 2016. Towards passion fruit (Passiflora species) production in ASALs of Eastern Kenya: understanding plant responses to moisture stress.
Michoma J.M.,Korir, N, Gweyi, J.O., Mbaka, J.N., Mwangi M, 2016: Water stress management for profitable production of sweet yellow passion fruit.

Non reviewed conference paper

Wafula WN, Siambi M, Ojulong H, Korir N and Gweyi-Onyango J (2018). Finger Millet (Eleusine coracana) Fodder Yield Potential and Nutritive Value under Different Levels of Phosphorus in Rainfed Conditions. “Strengthening Theoretical Research Methods-Systems Analysis” 17th Workshop on Sustainable Horticultural Production in the Tropicas. Pwani University, Kilifi-Kenya 12th-16th February 2018. Pg 11.
Chimoita EL, Onyango CM and Gweyi-Onyango J (2018). Socio-economic and institutional factors influencing uptake of improved sorghum technologies in Embu, Kenya. “Strengthening Theoretical Research Methods-Systems Analysis” 17th Workshop on Sustainable Horticultural Production in the Tropicas. Pwani University, Kilifi-Kenya 12th-16th February 2018. Pg 12.
Mwirigi P, Gweyi-Onyango J and Mwangi M (2018). Flowering and fruiting of yellow passion fruit (Passiflora edulis var f. flavicarpa. deg) as influenced by different fertilizer applications in Kiambu and Embu county, Kenya “Strengthening Theoretical Research Methods-Systems Analysis” 17th Workshop on Sustainable Horticultural Production in the Tropicas. Pwani University, Kilifi-Kenya 12th-16th February 2018. Pg 21.
Munene R, Changamu E, Korir NK, and Gweyi-Onyango J (2018). Impact of nitrogen forms on biomass and biochemical accumulations in two vegetable amaranth varieties “Strengthening Theoretical Research Methods-Systems Analysis” 17th Workshop on Sustainable Horticultural Production in the Tropicas. Pwani University, Kilifi-Kenya 12th-16th February 2018. Pg 24
Ntinyari W and Gweyi-Onyango J (2018). Analysis of nitrogen losses in rice farming systems: A case of Sub-Saran Africa “Strengthening Theoretical Research Methods-Systems Analysis” 17th Workshop on Sustainable Horticultural Production in the Tropicas. Pwani University, Kilifi-Kenya 12th-16th February 2018. Pg 25
Maina MK, Gweyi-Onyango JP, Mwangi M and Mwirigi P. Dodder Cuscuta: an emerging threat to food security and environment. A review paper. Book of Abstracts page 5.
Kimani M Maina and Joseph P Gweyi-Onyango (2017). Post-Harvest Loss Reduction in Fruits: Is Proper Identification Methods of Maturity Indices a Solution? All 1st All African Postharvest Congress and Exhibition. Reducing food losses and wastes: Sustainable solutions for Africa. March 28th- 31st 2017. Safari Park Hotel, Nairobi, Kenya. pg 137.
Winnie Ntinyari and Joseph P Gweyi-Onyango (2017). Post-Harvest Losses in Banana Production Value Chain in Meru and Kisii Counties of Kenya: The Role of Socio-Cultural Diversity. All 1st All African Postharvest Congress and Exhibition. Reducing food losses and wastes: Sustainable solutions for Africa. March 28th- 31st 2017. Safari Park Hotel, Nairobi, Kenya. pg 144.
Nelson Wafula, Moses Siambi and Joseph P Gweyi-Onyango (2017). Smallholder Oriented Approach to Post-Harvest For Groundnuts In Kenya: A Review. All 1st All African Postharvest Congress and Exhibition. Reducing food losses and wastes: Sustainable solutions for Africa. March 28th- 31st 2017. Safari Park Hotel, Nairobi, Kenya. pg 165.
Rosepiah Munene, Joseph P Gweyi-Onyango (2017) Postharvest Losses in Fruits: Dissecting Possible Role and Implications of Pre-Harvest NPK Nutritional Status of Fruits. All 1st All African Postharvest Congress and Exhibition. Reducing food losses and wastes: Sustainable solutions for Africa. March 28th- 31st 2017. Safari Park Hotel, Nairobi, Kenya. pg 63.
Symon M Njinju, Hiroaki Samejima, Joseph P Gweyi-Onyango, Mayumi Kikuta, John M Kimani, Akira Yamauchi and Daigo Makihara (2016). Growth and Yield responses of Kenyan popular rice varieties to increased fertilizer in Mwea Irrigation Scheme, Kenya. Tailor-made rice breeding and cultivation technology development for sub-Sararan Africa. SATREPS international Symposium. 6th December, KALRO-Nairobi, pg 8.
Sammy Kagito, Hiroaki Samejima, Mayumi Kikuta and Joseph P Gweyi-Onyango, Esther Gikonyo, John M Kimani, Akira Yamauchi abd Daigo Makihara (2016).Tailor-made rice breeding and cultivation technology development for sub-Sararan Africa. SATREPS international Symposium. 6th December, KALRO-Nairobi, pg 18.
Nelson W. Wafula, Nicholas K Korir, Henry Ojulong and Joseph Gweyi-Onyango. Effects of phosphorus application on growth, Nitrogen uptake, yield and quality of finger millet in Kenya. Phase 1: 2012-2016 Review Meeting-Reflections on four years of research aimed to improve the lives of smallholder farmers. Patancheru, Hyderabad, India: 03-07 October, 2016.
Godfrey Nambafu, Enos Onyuka, Holger Bessler, Nicolai Hoeppner, Darius O. Andika, Joseph P Gweyi-Onyango, Samuel Mwonga, Christof Engels (2016). Strategies of African Indigenous Vegetables to Cope with Phosphorus Deficient Soils. International conference on research on food security, natural resource management and rural development, ‘Solidarity in a competing world – fair use of resources’. Tropentag 18th – 21st September, University of Natural Resources and life Sciences (BOKU), Vienna, Austria. Pg 72
Enos Onyuka, Godfrey Nambafu, Holger Bessler, Anna Adam, Darius O. Andika, Joseph Patrick Gweyi-Onyango, Samuel Mwonga, Christof Engels (2016). Plant Residue-Derived Organic Carbon Input into Soil in African Indigenous Vegetable Production Systems. International conference on research on food security, natural resource management and rural development, ‘Solidarity in a competing world – fair use of resources’. Tropentag 18th – 21st September, University of Natural Resources and life Sciences (BOKU), Vienna, Austria. Pg 47
Onyuka EA, Bessler H, Nambafu GN, Adam A, Gweyi-Onyango J P, Andika DO, Mwonga S and Engels C (2016). Species-specific carbon fluxes in AIV cropping systems. Diversifying food systems: Horticultural Innovation and Learning for Improved Nutrition and Livelihoods in East Africa (Hortinlea) Biennual workshop held at Egerton University, Kenya: ARC Hall, 1st -10th September 2016.
Enos Onyuka, Godfrey Nambafu, Svenja Holst, Holger Bessler, Darius Andika, Joseph P Gweyi-Onyango, Samuel Mwonga and Christof Engels (2016). Challenges for Soil fertility on AIV farms in Kenya: Socioeconomic and /or natural factors. Diversifying food systems: Horticultural Innovation and Learning for Improved Nutrition and Livelihoods in East Africa (Hortinlea) Biennual workshop held at Egerton University, Kenya: ARC Hall, 1st -10th September 2016.
Bessler H, Nambafu GN, Onyuka EA, Adam A, Andika D O, Gweyi-Onyango JP, Mwonga S, Engels C (2016). Mineral Nutrient fluxes in AIV production systems. Diversifying food systems: Horticultural Innovation and Learning for Improved Nutrition and Livelihoods in East Africa (Hortinlea) Biennual workshop held at Egerton University, Kenya: ARC Hall, 1st -10th September 2016.
Nambafu GN, Onyuka EA, Bessler H, Eckhard U, Gweyi-Onyango JP, Andika DO, Mwonga S and Engels C (2016). Nutritional value of Afican Indigenous Vegetables: Toxic and essential micronutrients. Diversifying food systems: Horticultural Innovation and Learning for Improved Nutrition and Livelihoods in East Africa (Hortinlea) Biennual workshop held at Egerton University, Kenya: ARC Hall, 1st -10th September 2016.
Wafula, N. K. Korir., H. F. Ojulong and Gweyi-Onyango J. P. (2016). Effects of phosphate rates on nitrogen uptake, yield and quality of finger millet Busia, Kakamega and Makueni Counties, Kenya. Poster and paper presented at the Regional planning meeting “Developing a framework for cooperation and integration to enable holistic research” held in Harare, Zimbabwe, 26-27 April 2016.
Chirchir J. G, Mwangi M, Nyamongo D, and Gweyi-Onyango P. J. (2016). Influence of Priming, Dressing and Agroecologies on Storage of Selected Soybean Genotypes. “Research and Networking: Laying the Foundation for the Sustainable Development Goals” Hombuldt “Kollege” 2016. Naivasha, Kenya, April 6th – 8th , 2016, pg 74
Mwirigi P, Mwangi M and Gweyi-Onyango J P (2015). Canopy growth of sweet yellow passion fruit in response to different levels of planting fertilizer under greenhouse management. “Strengthening the experimental research environment-Field Experimentation” The 15th workshop on sustainable horticultural production in the tropics. The workshop held at Kenya Agricultural Research and Livestock Organization (KALRO), Kandara center &Horticultural research institute (HRI), Muranga county 1at-4th December, pp 21
Odhiambo P O, Musila W, Nawiri M and Gweyi-Onyango J P (2015). Water stress effect on antioxidant activity and phenolic content of African nightshades in Kiambu county, Kenya. “Strengthening the experimental research environment-Field Experimentation” The 15th workshop on sustainable horticultural production in the tropics. The workshop held at Kenya Agricultural Research and Livestock Organization (KALRO), Kandara center &Horticultural research institute (HRI), Muranga county 1at-4th December, pp 23
Ogembo J O, Nawiri P, Musila W and Gweyi-Onyango J P (2015). Effect of phosphorus deficiency on phenolics and antioxidants of two African nightshade varieties in Kenya. “Strengthening the experimental research environment-Field Experimentation” The 15th workshop on sustainable horticultural production in the tropics. The workshop held at Kenya Agricultural Research and Livestock Organization (KALRO), Kandara center &Horticultural research institute (HRI), Muranga county 1at-4th December, pp 31
Mathege C, Thuita M, Gweyi-Onyango J P and Cargele M (2015). Rhizobal inoculation responses in Soybean (Glycine max) as affected influenced by soil nitrogen and carbon levels. “Strengthening the experimental research environment-Field Experimentation” The 15th workshop on sustainable horticultural production in the tropics. The workshop held at Kenya Agricultural Research and Livestock Organization (KALRO), Kandara center &Horticultural research institute (HRI), Muranga county 1at-4th December, pp 31-32
Chimoita E L, Mugivane FI, Onyango CM, Kimenju JW and Gweyi-Onyango J P (2015). Extension approaches influencing uptake of improved sorghum crop in Embu County, Kenya. “Strengthening the experimental research environment-Field Experimentation” The 15th workshop on sustainable horticultural production in the tropics. The workshop held at Kenya Agricultural Research and Livestock Organization (KALRO), Kandara center &Horticultural research institute (HRI), Muranga county 1at-4th December, pp 44.
Wafula N, Korir NK, Ojulong H, Siambi M and Gweyi-Onyango J P (2015). Effects of phosphorus rates on nitrogen and yield responses of finger millet varieties in Makueni county, Kenya. “Strengthening the experimental research environment-Field Experimentation” The 15th workshop on sustainable horticultural production in the tropics. The workshop held at Kenya Agricultural Research and Livestock Organization (KALRO), Kandara center &Horticultural research institute (HRI), Muranga county 1at-4th December, pp 45.
Kimutai W, Mathu S, Thuta M, Masso C and Gweyi-Onyango J P (2015). Effect of selected Bradyrhizobia on growth, biological nitrogen fixation and yield of cowpea in soils from Kilifi and Embu counties of Kenya. “Strengthening the experimental research environment-Field Experimentation” The 15th workshop on sustainable horticultural production in the tropics. The workshop held at Kenya Agricultural Research and Livestock Organization (KALRO), Kandara center &Horticultural research institute (HRI), Muranga county 1at-4th December, pp 46.
Joseph Gweyi-Onyango, Pauline Nawiri, Winfred Musila, paul Omolo, Joseph Ogembo and Peter Odhiambo (2015). Water and Phosphorus effects on Distribution of Nighshade Species in Siaya County, Kenya. International Conference on Economically Viable and Sustainable Agricultural Systems for Food Security in Africa. African Society of Agronomy, Crop, Soil and Environmental Science. Abuja, Nigeria, 2-3November 2015. pgs 5-12.
Ulrich Eckhardt, Julius Beer, Holger Bessler, Godfrey Nambafu, Enos Onyuka, Samuel Mwonga, Darius O Andika, Joseph P Gweyi-Onyango, Christof Engels (2015). Iron Concentrations in Roots and Edible Organs of African Indigenous Vegetable species. International conference on research on food security, natural resource management and rural development. Tropentag 16th -18th September. Humboldt-Universität zu Berlin. Pgs 601
Enos Onyuka, Wilhem Van Hausen, Godrey Nambafu, Holger Bessler, Darius O Andika, Joseph P Gweyi-Onyango, Samuel Mwonga, Christian Ulrichs, Christof Engels (2015). Cadmium Uptake and Distribution to Edible Organs in African Indigenous Vegetables. International conference on research on food security, natural resource management and rural development. Tropentag 16th -18th September, Humboldt-Universität zu Berlin. Pgs 602
Godrey Nambafu, Anna Adam, Enos Onyuka, Samuel Mwonga, Darius O Andika, Joseph P Gweyi-Onyango, Christof Engels (2015). Essential and Toxic Minerals in Leafy Vegetables from Open Air and Supermarkets in Nairobi. International conference on research on food security, natural resource management and rural development. Tropentag 16th -18th September, Humboldt-Universität zu Berlin. Pgs 611
Rosepiah Munene, Jacqueline C Kipkorir-Mwendah , Nicholas Korir Kibet Joseph P Gweyi-Onyango (2014). Effects of Nitrogen Forms on Growth, Yield and Quality of Amaranths Accessions in Nairobi and Kiambu Counties. BUILDING A NEW GENERATION OF AGRICULTURAL SCIENTISTS. “BRIDGING THE GAP BETWEEN SOCIETY, SCIENCE AND INDUSTRY” – Conference held at Kenyatta University, Nairobi, Kenya- 1st to 5th December 2014. pages 43-44.
Joas Tugizimana, Kennedy Mwetu and Joseph Gweyi-Onyango (2014). Influence of land slope on soil physico-chemical properties and bean yield in Birembo Catchment, Nyamasheke District-Rwanda. BUILDING A NEW GENERATION OF AGRICULTURAL SCIENTISTS. “BRIDGING THE GAP BETWEEN SOCIETY, SCIENCE AND INDUSTRY” – Conference held at Kenyatta University, Nairobi, Kenya- 1st to 5th December 2014- pg 56-57
Simon M Mwangi, Joseph P Gweyi-Onyango and Nicholas Kibet Korir (2014). Root Development Does Not Affect Regeneration of Double Node Cutting in Tea Propagation. BUILDING A NEW GENERATION OF AGRICULTURAL SCIENTISTS. “BRIDGING THE GAP BETWEEN SOCIETY, SCIENCE AND INDUSTRY” – Conference held at Kenyatta University, Nairobi, Kenya- 1st to 5th December 2014- pg 129-130.
Onyango, RA, W.M. THAGANA, J.O.GWEYI, L.KARANJA (2014). Assessment of Sweet Potato Propagules for Infection by Various Viruses in East Kamagak Location-Homabay County. BUILDING A NEW GENERATION OF AGRICULTURAL SCIENTISTS. “BRIDGING THE GAP BETWEEN SOCIETY, SCIENCE AND INDUSTRY” – Conference held at Kenyatta University, Nairobi, Kenya- 1st to 5th December 2014- pg 141-142.
Odhiambo Peter Okello, Joseph Gweyi Onyango, Mildred Nawiri and Winfred Musila (2014). Water Stress Effect on Distribution and Antioxidants Concentration of African Nightshades In Kisii and Siaya Counties of Kenya. BRIDGING THE GAP BETWEEN SOCIETY, SCIENCE AND INDUSTRY” – Conference held at Kenyatta University, Nairobi, Kenya- 1st to 5th December 2014- pg 155-156.
Ogembo Oyaro J., P. Nawiri, W. Musila and Joseph P.Gweyi-Onyango (2014).Effects of Phosphorus Deficiency on Secondary Metabolites and African Nightshade Distribution in Kisii, Siaya and Kakamega Counties, Kenya. BRIDGING THE GAP BETWEEN SOCIETY, SCIENCE AND INDUSTRY” – Conference held at Kenyatta University, Nairobi, Kenya- 1st to 5th December 2014- pg 145.
Grace Jepleting Chirchir, Joseph Gweyi Onyango, Maina Mwangi, Desterio Ondieki Nyamongo (2014). Assessment of Soybean Agronomic Systems, Seed Handling and Quality in Eastern Kenya. . BRIDGING THE GAP BETWEEN SOCIETY, SCIENCE AND INDUSTRY” – Conference held at Kenyatta University, Nairobi, Kenya- 1st to 5th December 2014- pg 160.
Gweyi-Onyango J P, Musila MM, Nawiri M P and Omolo P O (2014). African nightshade distribution in response to phosphorus and water status in three Kenyan agroecologies: Phenolics and related antioxidant profiling. Ruforum Biennial conference” July 19th to 25th –Maputo, Mozambique (on 24th at Maputo hall).
Ogembo-Oyaro J, Nawiri P, Musila W and Gweyi-Onyango J P (2014). Effects of phosphorus deficiency on secondary metabolites and African nightshade distributions in Kisii, Kisumu and Kakamega counties, Kenya. Ruforum Biennial conference” July 19th to 25th –Maputo, Mozambique- poster No. 72
Okello P O, Nawiri M, Musila W and Gweyi-Onyango J P (2014). Water stress effect on growth parameters and distribution of African nightshade in Kisii and Siaya counties of Kenya. Ruforum Biennial conference” July 19th to 25th –Maputo, Mozambique- poster No. 76
Mwangi SM, Gweyi-Onyango JP and Kibet Korir NK (2013). Influence of one and two node cuttings on performance of infilling tea seedlings. “Concepts to promoting Young Academics- Soft Skills” 13th Workshop on Sustainable Horticultural production in the Tropics. Meru University of Science and Technology (MUST), Meru, Kenya, 3rd to 6th December 2013, Pg 44.
Chimoita EL and Gweyi-Onyango JP (2013). The role of community in mitigation of climate change through conservation in Kenya. “Concepts to promoting Young Academics- Soft Skills” 13th Workshop on Sustainable Horticultural production in the Tropics. Meru University of Science and Technology (MUST), Meru, Kenya, 3rd to 6th December 2013, Pg 56-57.
Gweyi-Onyango J P, Neumann G and Roemheld V (2013). Adaptive responses of tomato to limiting phosphorus status. “Sowing innovations for sustainable food and nutrition in Africa” 11th African crop Science Society Conference. Imperial Botanical Beach Hotel, Entebbe-Uganda. 13th -17th October 2013, pg 5
Anyang R T, Thagana W and Gweyi-Onyango J P (2013). Effect of genotype, plant spacing and weeding regimes on weed density and yields of upland rice in Uganda. . “Sowing innovations for sustainable food and nutrition in Africa” 11th African crop Science Society Conference. Imperial Botanical Beach Hotel, Entebbe-Uganda. 13th -17th October 2013, pg 224
First international symposium on Ornamentals in Africa. Morendat Training and Conference Center, Naivasha-Kenya. 9th-13th September 2013.
Chimoita EL and Gweyi-Onyango J P (2012). Assessing knowledge versus adoption rate through farmer field school participation on tea productivity in East of Rift Valley, Kenya. Sustainable Horticultural production in the Tropics “How should we teach in Horticulture courses?” From frontal teaching to problem-based learning. Bondo University College (BUC), Bondo Kenya. 4th-7th December 2012, pg 27.
Onyango RA, Thagana WM, karanja L and Gweyi-Onyango J P (2012). Characterization of sweet potato [Ipomea batatas (L)] landrace using morphological and DNA markers in East Kamagak location of Rachuonyo district. Sustainable Horticultural production in the Tropics “How should we teach in Horticulture courses?” From frontal teaching to problem-based learning. Bondo University College (BUC), Bondo Kenya. 4th-7th December 2012, pg 35.
Gweyi-Onyango, J. P; Musila M M; Nawiri M and Omolo P O (2012). African Nightshade distribution in Kenya agroecologies in response to phosphorus and water status: phenolics and related antioxidant profiling. Third Regional Universities Forum for Capacity Building in Agriculture Biennial Conference- Partnerships & Networking for Strengthening Agricultural Innovation and Higher Education in Africa; Imperial Resort Beach Hotel and Imperial Botanical Beach Hotel, Entebbe, Uganda: 24-28 September, 2012;
Ogembo J and Gweyi-Onyango J P (2012). Influence of monomeric aluminium on morphological characteristic and shelf life of selected amaranth species. Sustainable Horticultural production in the Tropics “How should we teach in Horticulture courses?” From frontal teaching to problem-based learning. Bondo University College (BUC), Bondo Kenya. 4th-7th December 2012, pg 36.
Gweyi-Onyango J P (2012). Role of Pre-Harvest Mineral Nutrition on Postharvest Handling and Quality of Selected Amaranth spp. International Workshop on Maintenance of the Quality within the value added chain with special focus on postharvest treatment, GaFooN pg 5; 16-22 September 2012, Yogyakarta, Indonesia.
Osei-Kwarteng M, Gweyi-Onyango J P and Mahunu G K (2012) Commodity Systems Assessment Methodology (CSAM) and Postharvest losses in Amaranthus: the case of Tamale, Northern Region of Ghana. International Workshop on Maintenance of the Quality within the value added chain with special focus on postharvest treatment, GaFooN pg 11; 16-22 September 2012; Yogyakarta, Indonesia.
Elizabeth Kabura Nyaga, Anthony Gikandi Muriithi and Joseph Patrick Gweyi-Onyango. A Mechanism to Discover Hidden Markets and to Improve Information Flow Towards Food Producers: A Case of Kiambu District, Kenya. "Resilience of agricultural systems against crises" Tropentag, September 19 - 21, 2012 in Göttingen. tropentag.de/abstract.php?code=cRuzJLs3
Chimoita E L and Gweyi-Onyango J P. (2011). The effects of good agricultural practices in increasing green leaf production per tea bush: Ngere tea factory small holding farms. 11th workshop on Sustainable Horticultural production in the Tropics. Pwani University College. Kenya. 7th – 10th December 2011.
Joseph P Gweyi-Onyango and Hartmut Stuetzel (2011): Nitrate does not alleviate aluminium toxicity in two commercial aluminium amaranth (Amaranthus hybridus) genotypes. 10th African Conference held in Maputo Mozambique; October 10th -13th. 2011: Pp 71.
Makau Festo, Saggafu and Gweyi Onyango J P (2010). A Rapid Hydroponics Characterization of One Monocotyledonous and Three Dicotyledonous Crops for Aluminium Tolerance. Sustainable Horticultural production in Tropics, Value Chains of Flowers for Local markets, export and processing pg 40- ICAD 30th November-3rd Dec 2010.
Gweyi-Onyango J P, V Römheld, G Neumann (2009). Effects of N Form Supply on Growth and Morphogenesis of Tomato (Lycopersicon Esculentum) var Moneymaker. International Conference on Plant Abiotic Stress Tolerance, Vienna, Austria; 8-11 February 2009; pp125.
Gweyi-Onyango J P, Akwee P, Onyango C, Agevi H and Pakia A (2009). Differential Genotypic Yield Responses of Cowpea (Vigna anguiculata) to suboptimal Phosphorus Supply in Acid Alfisols of Western Kenya. In. Sustainable Horticultural production in Tropics, Value Chains of Vegetables for Local markets, export and processing P22; Arusha, Tanzania -2nd -5th December 2009.
Gweyi-Onyango J P, Neumann G and Roemheld V (2008). Effects of Different Forms of Nitrogen on Relative Growth Rate and Growth Components of Tomato (Lycopersicon esculentum). Value chain of fruits for local market, export and processing. 8th International workshop on Sustainable Horticultural Production in the Tropics, Masinde Muliro University of Science and Technology (MMUST)-Kakamega, Kenya 8th-11th 2008; pp 17.
Ekwee P.E and Gweyi-Onyango J P (2008). Environmental and Socio-Economic Aspects on Utilization of Wild Fruits in Arid and Semi-Arid of Kenya. Value chain of fruits for local market, export and processing. 8th International workshop on Sustainable Horticultural Production in the Tropics, Masinde Muliro University of Science and Technology (MMUST)-Kakamega, Kenya 8th-11th 2008; pp 13.
Gweyi-Onyango J P, G Neumann and V Römheld (2007). Utilization of rock phosphate (PR) by tomato plant as affected by N-forms and soil types. 24^th Conference of the Soil Science Society of East Africa. Improved Livelihoods through Applied Soil Science and Land Management. Izaak Walton Hotel, Embu Kenya. 26^th-30^th November 2007, pp 28.
Gweyi-Onyango J P, G Neumann and V Roemheld (2006). Rock-Phosphate Alleviates Detrimental Effects of Aluminium in Tomato (Lycopersicon esculentum L) Production in Acid Soils. “Prosperity and Poverty in a Globalized World-Challenges for Agricultural Research. Universitaet Bonn, Bonn, Germany- 11th -13th October 2006. www.tropentag.de/2006/abstracts/links/neumann_mUd2hxyd.pdf
Gweyi-Onyango J P, V Römheld, G Neumann (2006). Differential expression of adaptations for acquisition of sparingly soluble P sources in two genotypes of tomato. “Plant Nutrition Meets Plant Breeding” – First Joint conference of The German Society for Plant Nutrition – DGP (Annual Meeting) and The Research Centre Biotechnology & Plant Breeding – Universitaet Hohenheim; FSP (21st Colloquium), University of Hohenheim, Stuttgart, Germany. September 26-28, 2006.
Mulwa, R., E.-A. Nuppenau and J. P. Gweyi-Onyango (2006). Incorporating Environmental Bads in Total Factor Productivity Estimation. A Paper presented in 1st Halle Efficiency and Productivity Analysis Workshop (HEPAW), Halle, Germany, June, 2006.
Gweyi-Onyango, J. P; Römheld, V.; Neumann, G (2006). Rock phosphate alleviates detrimental effects of aluminium in tomato production on acid soils. Proceedings of 3rd International Symposium on Phosphorus Dynamics in the Soil-Plant Continuum, Uberlandia, Minas Gerais, Brazil, May14-19 2006; pp165-166, (eds). Vera M. C. Alves et al. Sete Lagoas: Embrapa Milho e Sorgo.

Prof. Joseph P Onyango Gweyi

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