Prof. Samuel K. Offei

Prof. Samuel K. Offei

Founding Director, soffei@ug.edu.gh

contact info

offei@ug.edu.gh

About

The Founding Director of the Biotechnology Centre is a renowned Professor of Plant Virology who has distinguished himself through his scholarly works towards food security in Ghana and in Africa at large. He has held many academic and research leadership positions in the University of Ghana and Nationally. He has raised millions of dollars in grants and funding for research and development projects at the University of Ghana and has published 128 peer-reviewed scientific articles in journals of international repute, 4 books, many book chapters, and has supervised hundreds of students, and has won many scholarly awards and prizes through his dedication to his work and humanity. He continues to lead impactful research on crop virology and disease resistance for food and nutrition security.

Prof. S. Kwame Offei was appointed the Pro Vice-Chancellor for Academic and Student Affairs in August 2014. He is a Professor of Biotechnology and holds a BSc in Agriculture from the University of Ghana a MPhil in Plant Virology and a PhD in Molecular Virology from the Imperial College of Science, Technology and Medicine, University   of London. Prof. Offei started his working life in the then Faculty of Agriculture, University of Ghana, as a Teaching Assistant. In 1987, he was appointed a Lecturer in the Department of Crop Science. In 1996 he was promoted to the rank of Senior Lecturer then Associate Professor in 2004, and Professor in 2006. His research areas have focused on analysis of plant responses to biotic and abiotic stresses, development of molecular diagnostic probes for plant microbes, and integration of biological and social science in the implementation of research.  He has demonstrated a sustained high level of professional excellence and contribution to knowledge in his field of expertise through innovative research.

In his work history at the University of Ghana, Prof. Offei has held key administrative positions. From 2005 to 2006, he was the Head of the Biotechnology Centre and then between 2006 and 2011, he served as the Dean of School of Agriculture and as Provost for the College of Agriculture and Consumer Sciences from 2011-2014. He was appointed as interim Provost for College of Basic and Applied Sciences in 2013 to oversee the establishment of the new College under the University of Ghana Collegiate system. On international platforms, he has engaged with many international organizations as a resource person in the development and dissemination of biological technologies. He has consulted extensively for a number of international organizations including; the Food and Agriculture Organization (FAO), International Institute of Tropical Agriculture (IITA), United States Aid for International Development (USAID), Department for International Development (DFID), the United Nations University, Technical Centre for Agricultural and Rural Cooperation ACP-EU (CTA), and the West and Central African Council for Agricultural Research and Development (CORAF/WECARD), among others.

 

Education

Institution

Date

Programme

Degree

Imperial College of Science and Technology University of London

1991-1994

Molecular Plant Biology

Ph.D

Royal University of Veterinary and 

Agricultural Science, Denmark

1990

Seed Pathology

Diploma

University of London

1985-1987

Plant Virology

M. Phil 

University of Ghana- Legon

1979-1981

Agriculture, Crop Science 

B.Sc (Hons) Agriculture 

 

Research Areas

  • Molecular diversity in the genetic resources of crop plants, and microbes
  • Molecular analysis of plant responses to biotic and abiotic stresses 
  • Development of crop plants resistant to biotic and abiotic stresses
  • Developing of molecular diagnostic probes for plant microbes
  • Integration of biological and social science in implementation of research 

Publications

 

  • Aghogho, C. I., Kayondo, S. I., Maziya-Dixon, B., Eleblu, S. J. Y., Asante, I., Offei, S. K., Parkes, E., Ikpan Smith, A., Adesokan, M., Abioye, R., Chijioke, U., Ogunpaimo, K., Kulakow, P., Egesi, C., Dufour, D., & Rabbi, I. Y. (2023). Exploring genetic variability, heritability, and trait correlations in gari and eba quality from diverse cassava varieties in Nigeria. Journal of the Science of Food and Agriculture. https://doi.org/10.1002/jsfa.12889
  • Aliyu, A., Ishiyaku, M. F., Offei, S. K., Asante, I. K., Eleblu, J. S. Y., & Aliyu, R. E. (2023). Enhancing cowpea production through breeding efforts for aphid (aphis crassivora koch) resistance: a review. Euphytica, 219(1). https://doi.org/10.1007/s10681-022-03140-7 
  • Diatta, C., Tovignan, T., Sine, B., Ifie, B., Faye, J., Diatta-Holgate, E., Sylla, F., Bodian, S., Aidara, O., Danquah, E., Offei, S., & Cisse, N. (2023). Farmers’ Production Constraints, Preferred Varietal Traits and Perceptions on Sorghum Grain Mold in Senegal. https://doi.org/10.2139/ssrn.4441354 
  • Gelaw, Y. M., Eleblu, J. S. Y., Ofori, K., Fenta, B. A., Mukankusi, C., Emam, E. A., & Offei, S. (2023). High-density DArTSeq SNP markers revealed wide genetic diversity and structured population in common bean (Phaseolus vulgaris L.) germplasm in Ethiopia. Molecular Biology Reports, 50(8), 6739–6751. https://doi.org/10.1007/s11033-023-08498-y
  • Gelaw, Y. M., Eleblu, J. S. Y., Ofori, K., Fenta, B. A., Mukankusi, C., & Offei, S. (2023). Genome-wide association study of grain iron and zinc concentration in common bean (Phaseolus vulgaris). Plant Breeding, 142(3), 357–371. https://doi.org/10.1111/pbr.13090
  • Kayondo, S. I., Pino, D., Del Carpio, D., Lozano, R., Ozimati, A., Wolfe, M., Baguma, Y., Gracen, V., Offei, S., Ferguson, M., Kawuki, R., & Jannink, J.-L. (2023). Genome-wide association mapping and genomic prediction for CBSD resistance in Manihot esculenta OPEN.
  • Omiat, E. G., Asante, M. D., Traoré, V. S. E., Oppong, A., Ifie, B. E., Ofosu, K. A., Aribi, J., Pinel-Galzi, A., Comte, A., Fargette, D., Hébrard, E., Traoré, O., Offei, S. K., Danquah, E. Y., & Poulicard, N. (2023). Genetic diversity and epidemic histories of rice yellow mottle virus in Ghana. Virus Research, 329. https://doi.org/10.1016/j.virusres.2023.199106
  • Aghogho, C. I., Eleblu, S. J. Y., Bakare, M. A., Kayondo, I. S., Asante, I., Parkes, E. Y., Kulakow, P., Offei, S. K., & Rabbi, I. (2022). Genetic variability and genotype by environment interaction of two major cassava processed products in multi-environments. Frontiers in Plant Science, 13. https://doi.org/10.3389/fpls.2022.974795
  • Diatta, C., Tovignan, T. K., Akata, E. A., Ifie, B. E., Sarr, M. P., Bassene, C., Aidara, O., Ndione, P. A., Gackou, M., Manga, A. G. B., Danquah, E. Y., Offei, S. K., & Cisse, N. (2022). Heterosis and combining ability for yield and resistance to grain mold in tannin-free photoperiod-insensitive sorghum [Sorghum bicolor (L) Moench] in Senegal. Journal of Crop Science and Biotechnology, 25(2), 149–160. https://doi.org/10.1007/s12892-021-00119-z
  • Sadessa, K., Beyene, Y., Ifie, B. E., Suresh, L. M., Olsen, M. S., Ogugo, V., Wegary, D., Tongoona, P., Danquah, E., Offei, S. K., Prasanna, B. M., & Gowda, M. (2022). Identification of Genomic Regions Associated with Agronomic and Disease Resistance Traits in a Large Set of Multiple DH Populations. Genes, 13(2). https://doi.org/10.3390/genes13020351
  • Uchendu, K., Njoku, D. N., Ikeogu, U. N., Dzidzienyo, D., Tongoona, P., Offei, S., & Egesi, C. (2022). Genotype-by-environment interaction and stability of root mealiness and other organoleptic properties of boiled cassava roots. Scientific Reports, 12(1). https://doi.org/10.1038/s41598-022-25172-8 
  • Abebrese, S. O., Amoah, N. K. A., Dartey, P. K. A., Bimpong, I. K., Akromah, R., Gracen, V. E., Offei S. K. and Danquah, E. Y. (2021). Mapping chromosomal regions associated with anther indehiscence with exerted stigmas in CRI-48 and Jasmine 85 cross of rice (Oryza sativa L). Heliyon, 7(3), e06483.
  • Abu, P., Badu-Apraku, B., Ifie, B. E., Tongoona, P., Melomey, L. D., Offei, S. K. (2021). Genetic diversity and inter-trait relationship of tropical extra-early maturing quality protein maize inbred lines under low soil nitrogen stress. Plos One, 16(6), e0252506. https://doi.org/10.1371/journal. pone.0252506
  • Abu, P., Badu-Apraku, B., Ifie, B. E., Tongoona, P., Ribeiro, P. F., Obeng-Bio, E., & Offei, S. K. (2021). Genetics of extra-early-maturing yellow and orange quality protein maize inbreds and derived hybrids under low soil nitrogen and Striga infestation. Crop Science, 61(2), 1052–1072. https://doi.org/10.1002/csc2.20384
  • Diatta, C., Sarr, M. P., Tovignan, T. K., Aidara, O., Dzidzienyo, D. K., Diatta-Holgate, E., Faye, J. M., Danquah, E. Y., Offei, S. K., & Cisse, N. (2021). Multienvironment Evaluation of Tannin-Free Photoperiod-Insensitive Sorghum (Sorghum bicolor (L) Moench) for Yield and Resistance to Grain Mold in Senegal. International Journal of Agronomy, 2021. https://doi.org/10.1155/2021/5534314
  • Diatta, C., Sarr, M. P., Tovignan, T. K., Aidara, O., Dzidzienyo, D. K., Diatta-Holgate, E., Faye, M. J., Danquah, E. Y., Offei, S. K., and Cisse, N. (2021). Multienvironment Evaluation of Tannin-Free Photoperiod-Insensitive Sorghum (Sorghum bicolor (L) Moench) for Yield and Resistance to Grain Mold in Senegal. International Journal of Agronomy, 2021, 1–12. https://doi.org/10.1155/2021/5534314
  • Kosgei, A; Kimurto, P; Gaur, P; Yeboah, M; Offei, S & Danquah, E. (2021). Farmers’ Perception on Production Constraints, Trait Preference and Variety Selection of Chickpea (Cicer arietinum L.) in Kenya. Journal of African Interdisciplinary Studies, 5(9), 18–40. https://kenyasocialscienceforum.files.wordpress.com/2021/09/pdf-kosgei-et-al-farmers-perception-on-production-constraints.pdf 
  • Torkpo, S. K., Amponsah, E., Arhin, C. D., & Offei, S. K. (2021). Occurrence of cassava mosaic begomovirus-associated satellites on cassava in Ghana. Cogent Food and Agriculture, 7(1). https://doi.org/10.1080/23311932.2021.1963929
  • Uchendu, K., Njoku, D. N., Paterne, A., Rabbi, I. Y., Dzidzienyo, D., Tongoona, P., Offei, S., & Egesi, C. (2021). Genome-Wide Association Study of Root Mealiness and Other Texture-Associated Traits in Cassava. Frontiers in Plant Science, 12. https://doi.org/10.3389/fpls.2021.770434
  • Abu, P., Badu-Apraku, B., Ifie, B.E., Tongoona, P., Ribeiro, P.F., Obeng-Bio, E., and Offei, S. K., (2020). Genetics of extra-early maturing yellow and orange quality-protein maize (QPM) inbreds and derived hybrids under low soil nitrogen and Striga-infestation. Crop Science, 61(2), 1052 – 1072. https://doi.org/10.1002/csc2.20384.
  • Addy, S. N. T. T., Cichy, K. A., Adu-Dapaah, H., Asante, I. K., Emmanuel, A., and Offei, S. K. (2020). Genetic Studies on the Inheritance of Storage-Induced Cooking Time in Cowpeas [Vigna unguiculata (L.) Walp]. Frontiers in Plant Science, 11(May), 444.  https://doi.org/10.3389/fpls.2020.00444
  • Adjebeng-Danquah, J., Asante, I. K., Manu-Aduening, J., Agyare, R. Y., Gracen, V. E., and Offei, S. K. (2020). Genotypic variability in some morpho-physiological traits in different environments and their relationship with cassava (Manihot esculenta Crantz) Root Yield. International Journal of Agronomy, 2020, 1-19 https://doi.org/10.1155/2020/5871351
  • Adjebeng-Danquah, J., Martey, E., Manu-Aduening, J., Gracen, V., Kwadwo, I., and Offei, S. K., (2020). Farmers’ perception on drought constraints and mitigation strategies in cassava cultivation in northern Ghana : Implications for cassava breeding. Sustainable Futures, 2(June), 100041. https://doi.org/10.1016/j.sftr.2020.100041
  • Adjebeng-Danquah, J., Manu-Aduening, J., Asante, I. K., Agyare, R. Y., Gracen, V., and Offei, S. K. (2020). Genetic diversity and population structure analysis of Ghanaian and exotic cassava accessions using simple sequence repeat (SSR) markers. Heliyon, 6(1), e03154. https://doi.org/10.1016/j.heliyon.2019.e03154
  • Akaogu, I. C., Badu-Apraku, B., Gracen, V., Tongoona, P., Gedil, M., Unachukwu, N., Offei, S. K., Dzidzienyo D. K., Hearne S., and Garcia-Oliveira, A. L. (2020). Genetic diversity and inter-trait relationships among maize inbreds containing genes from zea diploperennis and Hybrid Performance under Contrasting Environments. Agronomy, 10(10), 1–25. https://doi.org/10.3390/agronomy10101478
  • Banla, M. E., Dzidzienyo, D. K., Diangar, M. M., Melomay, D. L., Offei, S. K., Tongoona, P., and Desmae, H. (2020). Molecular and phenotypic diversity of groundnut (Arachis hypogaea L.) cultivars in Togo. Physiology and Molecular Biology of Plants, 26(7), 1489–1504.
  • Naa, R., Prempeh, A., Manu-aduening, J. A., Quain, M. D., Asante, I. K., Offei, S. K., and Danquah, E. Y. (2020). Assessment of genetic diversity among cassava landraces using single nucleotide polymorphic markers. African Journal of Biotechnology, 19(6),  383–391. https://doi.org/10.5897/AJB2018.16420
  • Nisah, S. A., Tokpor, S. K., Owusu, S., Owusu, B. O., Amponsah, E., Arhin, C. D., and Offei, S. K. (2020). First record of the occurrence of cassava mosaic virus begomovirus-associated satellite on cassava in Ghana. Retrieved from: http://ugspace.ug.edu.gh/handle/123456789/35080
  • Oppong, A., Appiah-Kubi, D., Ife, E. B., Abrokwah, A. L., Ofori, K., Offei, K. S., Adu-Dappah H., Mochiah, B. M., and Warburton, L. M. (2020). Analyzing combining abilities and heterotic groups among Ghanaian maize landraces for yield and resistance/tolerance to Maize Streak Virus Disease. Maydica Electronic Publication, 64(3), 1-10.
  • Soutonnoma, Z. S., Sanou, J., Ouedraogo, B., Gracen, V., Tongoona, P., and Offei, S. K. (2020). Genetic diversity of sorghum (Sorghum bicolor (L) Moench) accessions from thirteen regions of Burkina Faso. International Journal of Biological and Chemical Sciences, 14(5), 1547-1557. doi: 10.4314/ijbcs.v14i5.5s
  • Abebrese SO, Yeboah A, Dogbe W, Dartey PKA, Akromah R, Gracen VE, Offei SK, Danquah EY (2019). Evaluation of Yield, Reaction to Diseases, and Grain Physical Attributes of Some Introduced Rice Hybrids in Ghana. International Journal of Agronomy, pp. 1-8.https://doi.org/10.1155/2019/3926765.
  • bebrese, S. O., Martey, E., Dartey, P. K. A., Akromah, R., Gracen, V. E., Offei, S. K., and Danquah, E. Y. (2019). Farmer preferred traits and potential for adoption of hybrid rice in Ghana. Journal of Agriculture and Food Technology, 7(6), 1-11. https://doi.org/10.5539/sar.v8n3p38
  • Afuape, S. O., Tongoona, P. B., Asante, I. K., Egesi, C. N., Nwaigwe, G. and Offei, S. K., (2019). Breeding new sweet potato genotypes combining elevated content of two antagonistic traits of high dry matter and beta-carotene content in a high root yield background. Euphytica, 215(11), 211. 
  • Akaogu, I. C., Badu‐Apraku, B., Tongoona, P., Ceballos, H., Gracen, V., Offei, S. K., and Dzidzienyo, D. (2019). Inheritance of Striga hermonthica adaptive traits in an early‐maturing white maize inbred line containing resistance genes from Zea diploperennis. Plant Breeding, 138, 546–552.
  • Bediako, K. A., Dzidzienyo, D., Ofori, K., Offei, S. K., Asibuo, J. Y., Amoah, R. A., and Obeng, J. (2019). Prevalence of fungi and aflatoxin contamination in stored groundnut in Ghana. Food Control, 104, 152-156.
  • Bediako, K. A., Ofori, K., Offei, S. K., Dzidzienyo, D., Asibuo, J. Y., and Amoah, R. A. (2019). Aflatoxin contamination of groundnut (Arachis hypogaea L.): Predisposing factors and management interventions. Food Control, 98, 61-67.
  • Melomey, L. D., Danquah, A., Offei, S. K., Ofori, K., Danquah, E., and Osei, M. (2019). Review on Tomato (Solanum lycopersicum L.) Improvement Programmes in Ghana. Recent Advances in Tomato Breeding and Production, 1, 49-69. DOI:10.5772/intechopen.75843
  • Sanogo, O., Tongoona, P. B., Ofori, K., Offei, S. K., and Desmae, H. (2019). Evaluation of yield and yield components of some groundnut genotypes under rainfed condition in Mali using biplot analysis. African Journal of Agricultural Research, 14(34), 1904-1912.  DOI: 10.5897/AJAR2018.13776
  • Sanogo, O., Tongoona, P. B., Ofori, K., Offei, S. K., and Desmae, H. (2019). Parent-offspring regression, correlation and genetic advance of drought and yield traits at early generation in groundnut (Arachis hypogaea L.). African Journal of Agricultural Research, 14(31), 1349-1358.
  • Sobda, G., Atemkeng, F. M., Boukar, O., Fatokun, C., Tongoona, P. B., Ayertey, J., & Offei, S. K. (2018). Generation Mean Analysis in Cowpea [Vigna unguiculata (L.) Walp.] under Flower Thrips Infestation. Journal of Agricultural Science, 10(4), 86.
  • Banla, E. M., Dzidzienyo, D. K., Beatrice, I. E., Offei, S. K., Tongoona, P., & Desmae, H. (2018). Groundnut production constraints and farmers’ trait preferences: a pre-breeding study in Togo. Journal of ethnobiology and ethnomedicine, 14(1), 75.
  • Bediako, K. A., Ofori, K., Offei, S. K., Dzidzienyo, D., Asibuo, J. Y., & Amoah, R. A. (2018). Aflatoxin contamination of groundnut (Arachis hypogaea L.): Predisposing factors and management interventions. Food Control. 98:61–67. doi: 10.1016/j.foodcont.2018.11.020.
  • Andres, C., Hoerler, R., Home, R., Joerin, J., Dzahini-Obiatey H. K, Ameyaw G.A, Domfeh O, Blaser W.J, Gattinger A, S. K. Offei, & Six J. (2018). Social network to inform and prevent the spread of cocoa swollen shoot virus disease in Ghana. Agronomy for Sustainable Development, 38(5), 53.
  • Abebrese, S. O., Dartey, P. K. A., Akromah, R., Gracen, V. E., Offei, S. K., & Danquah, E. Y. (2018). Genetics of anther indehiscence with exerted stigmas and its application in hybrid rice breeding. Journal of Crop Improvement, 32(4), 552-565.
  • Kanfany, G., Zoclanclounon, Y. A. B., Tongoona, P., Danquah, A., Offei, S. K., Fofana, A., Thiawa, C., Danquah, E. Y., & Cisse, N. (2018). Evidence of pathogenic variation in Sclerospora graminicola populations from pearl millet growing regions in Senegal. Journal of Plant Pathology, 1-6.
  • S.O Abebrese, P. K A. Dartey, R. Akromah, V. E Gracen, S. K. Offei & E. Y. Danquah (2018) Identification of CMS maintainers and restorers for hybrid rice development in Ghana. Journal of Crop Improvement, 32 (5), 690-704. 
  • G. Kanfany, A. Fofana, P. Tongoona, A. Danquah, S. Offei, E. Danquah, & N. Cisse (2018). Estimates of Combining Ability and Heterosis for Yield and Its Related Traits in Pearl Millet Inbred Lines under Downy Mildew Prevalent Areas of Senegal. International Journal of Agronomy, 2018.
  • G. Kanfany, A. Fofana, P. Tongoona, A. Danquah, S. Offei, E. Danquah, & N. Cisse (2018). Identification of new sources of resistance for pearl millet downy mildew disease under field conditions. Plant Genetic Resources, 1-4.
  • S. I. Kayondo, D. P Del Carpio, R. Lozano, A. Ozimati, M. Wolfe, Y. Baguma, V. Gracen, S. Offei, M. Ferguson, R. Kawuki & J. L Jannink (2018). Genome-wide association mapping and genomic prediction for CBSD resistance in Manihot esculenta. Scientific Reports, 8(1), 1549.
  • C. Andres, W. J. Blaser, H. K. Dzahini-Obiatey, G. A. Ameyaw, O. K. Domfeh, M. A. Awiagah, A. Gattingera, M. Schneidera, S. K. Offei & J. Six (2018). Agroforestry systems can mitigate the severity of cocoa swollen shoot virus disease. Agriculture, Ecosystems & Environment, 252, 83-92.
  • Kosgei, A.J., Kimurto, P.K., Gaur, P.M., Yeboah, M.A., Offei, S.K. & Danquah, E.Y. 2022. Introgression of drought tolerance root traits into Kenyan commercial chickpea varieties using marker assisted backcrossing. African Crop Science Journal, 30, 31–50. https://www.ajol.info/index.php/acsj/article/view/223426 
  • G. Sobda, O. Boukar, P. B. Tongoona, J. Ayertey, & S. K. Offei (2017). Quantitative trait loci (QTL) for cowpea resistance to flower bud thrips (Megalurothrips sjostedti Trybom). International Journal of Plant Breeding and Genetics, 4(6), 292-299.
  • M. Salifou, J. B. L. S. Tignegre, P. Tongoona, S. Offei, K. Ofori, & E. Danquah (2017). Differential responses of 15 cowpea genotypes to three Striga hot spots in Niger. International Journal of Biological and Chemical Sciences, 11(4), 1413-1423.
  • S. K. Torkpo, Y. Gafni, E. Y. Danquah, & S. K. Offei (2017). Farmers’ Perception of Cassava Mosaic Disease and Cassava Cultivar Attributes Preferences in Ghana. Innovative Techniques in Agriculture, 2(1), 2575-5196.
  • R. Prempeh, J. A Manu-Aduening, B. O. Asante, I. K. Asante, S. K. Offei & Danquah, E. Y. (2017). Farmers’ knowledge and perception of postharvest physiological deterioration in cassava storage roots in Ghana. Agriculture & Food Security, 6(1), 27.
  • C. Andres, A. Gattinger, H. K Dzahini-Obiatey, W. J. Blaser, S. K. Offei & J. Six (2017). Combatting cocoa swollen shoot virus disease: what do we know? Crop protection, 98, 76-84.
  • A. S. Appiah, F. L. Sossah, R. S. Tegg, S. K. Offei & C. R. Wilson (2017). Assessing sequence diversity of Groundnut rosette disease agents and the distribution of Groundnut rosette assistor virus in major groundnut-producing regions of Ghana. Tropical plant pathology, 42(2), 109-120.
  • J. Adjebeng-Danquah, J. Manu-Aduening, V. E. Gracen, I. K. Asante & S. K. Offei (2017). AMMI stability analysis and estimation of genetic parameters for growth and yield components in cassava in the forest and Guinea Savannah ecologies of Ghana. International Journal of Agronomy, 2017 1-12.
  • Appiah A, Tegg R, Offei S, Wilson C (2016) Studies on Groundnut rosette disease and implications of the newly reported Groundnut ringspot virus for groundnut production in Ghana. Phytopathology 106 (12), 43-43.
  • Adjebeng-Danquah J, Gracen VE, Offei SK, Asante IK, Manu-Aduening J (2016). Genetic variability in storage root bulking of cassava genotypes under irrigation and no irrigation. Agriculture & Food Security 5 (1), 
  • Appiah AS, Tegg RS, Offei SK, Wilson, CR (2016). Impact of groundnut rosette disease on nutritive value and elemental composition of four varieties of peanut (Arachis hypogaea) Annals of Applied Biology 168 (3), 400-408.
  • Appiah AS, Offei SK, Tegg RS, Wilson CR (2016). Varietal Response to Groundnut Rosette Disease and the First Report of Groundnut ringspot virus in Ghana. Plant Disease 100 (5), 946-952.
  • Adjebeng-Danquah J., Gracen V. E, Offei S. K., Asante I. K., Manu-Aduening J. (2016). Agronomic performance and genotypic diversity for morphological traits among cassava genotypes in the guinea savannah ecology of Ghana. Journal of Crop Science and Biotechnology 19 (1), 99-108.    
  • Honger J.O., Offei S.K., Oduro K.A., Odamtten G.T., Nyaku S.T. (2016). Identification and molecular characterisation of Colletotrichum species from avocado, citrus and pawpaw in Ghana. South African Journal of Plant and Soil, 1-9.           
  • Honger J.O., Offei S.K., Oduro K.A., Odamtten G.T., Nyaku S.T. (2016). Phenotypic and molecular characterisation of the causal agent of mango anthracnose disease in Ghana. Ghana Journal of Science 54, 71-82.           
  • J. Adjebeng-Danquah, J. Manu-Aduening, V. E. Gracen, S. K. Offei & I. K. Asante (2016). Genotypic variation in abscisic acid content, carbon isotope ratio and their relationship with cassava growth and yield under moisture stress and irrigation. Journal of Crop Science and Biotechnology, 19(4), 263-273.
  • Traore V. S. E., Asante M. D., Gracen V. E., Offei S. K., Traore O. (2015). Screening of Rice Accessions For Resistance to Rice Yellow Mottle Virus. American Journal of Experimental Agriculture 9(4): 1-12, 2015.
  • Traoré S. E., Néya B. J., Camara M., Gracen V., Offei S. K., Traoré O. (2015). Farmers’ Perception and Impact of Rice Yellow Mottle Disease on Rice Yields in Burkina Faso. Agricultural Sciences, 2015, 6, 943-952.
  • Egbadzor, K. F., Offei, S. K., Danquah, E. Y., Kotey, D. A., Gamedoagbao, D. K., Dadoza, M., Ofori, K. (2015). Farmer participation in selection within segregating populations of cowpea in Volta Region, Ghana. Agriculture & Food Security, 4(1), 17. 
  • Oppong, A., Offei, S. K., Ofori, K., Adu-Dapaah, H., Lamptey, J. N., Kurenbach, B., ...&Varsani, A. (2015). Mapping the distribution of maize streak virus genotypes across the forest and transition zones of Ghana. Archives of virology, 160(2), 483-492.
  • Njoku, D. N., Gracen, V. E., Offei, S. K., Asante, I. K., Egesi, C. N., Kulakow, P., & Ceballos, H. (2015). Parent-offspring regression analysis for total carotenoids and some agronomic traits in cassava. Euphytica, 206(3), 657-666.
  • Usman, A., Ofori, K., Danquah, E. Y., Offei, S. K., & Ado, S. G. (2015). Genetic analysis of groundnut rosette virus disease in groundnut (Archis hypogaea L.). African Journal of Plant Science, 9(3), 115-123.
  • Egbadzor, K. F., Ofori, K., Yeboah, M., Aboagye, L. M., Opoku-Agyeman, M. O., Danquah, E. Y., &Offei, S. K. (2014). Diversity in 113 cowpea [Vigna unguiculata (L) Walp] accessions assessed with 458 SNP markers. Springer Plus, 3(1), 541.
  • Egbadzor, K.F., Danquah, E.Y., Ofori, K., Yeboah, M. and Offei, S.K. (2014). Diversity in 118 cowpea accessions assessed with 16 morphological traits. International Journal of Plant Breeding and Genetics 8 (1): 13-24.
  • Njoku, D. N., Gracen, V. E., Offei, S. K., Asante, I. K., Danquah, E. Y., Egesi, C. N., & Okogbenin, E. (2014). Molecular marker analysis of F1 progenies and their parents for carotenoids inheritance in African cassava (Manihot esculenta Crantz). African Journal of Biotechnology, 13(40).
  • Oppong, A., Bedoya, C. A., Ewool, M. B., Asante, M. D., Thomson, R. N., Adu-Dapaah, H., Offei, SK ... & Warburton, M. L. (2014). Bulk genetic characterization of Ghanaian maize landraces using microsatellite markers. Maydica, 59(1), 01-08.
  • Honger, J. O., Offei, S. K., Oduro, K. A., Odamtten, G. T., & Nyaku, S. T. (2014). Identification and species status of the mango biotype of Colletotrichum gloeosporioides in Ghana. European Journal of Plant Pathology, 140(3), 455-467.
  • Egbadzor, K.F., Yeboah, M, Gamedoagbao, D.K., Offei, S.K., Danquah, E.Y and Ofori, K. (2014). Inheritance of Seed Coat Colour in Cowpea [Vigna unguiculata (L) Walp]. International Journal of Plant Breeding and Genetics 8 (1): 35-43.
  • Njoku, D.N., Egesi, C.N., Gracen, V.E., Offei, S.K., Asante, I.K., &Danquah, E.Y. (2014). Identification of pro-vitamin A cassava (Manihot esculenta Crantz) varieties for adaptation and adoption through participatory research. Journal of Crop Improvement 28 (3): 361-376.
  • Oppong A., Ofori K., Adu-Dapaah H., Asante B.O., Nsiah-Frimpong B, Appiah-Kubi Z., Abrokwa L.A., Marfo E.A. and Offei SK. (2014). Farmers Perceptions on Maize streak virus disease, Production constraint and Preferred maize varieties in the forest and transition zones of Ghana. Projournal of Agricultural Science Research 2(4), pp. 1-13. 
  • Njoku, D. N., Egesi, C. N., Okogbenin, E., Gracen, E. V., Asante, I., & Offei, S. (2013). Assessment of genetic diversity in cassava based on SSR markers and morphological characters. Journal of Sustainable Agriculture and the Environment, 14(1/2), 1-16.
  • Asante, M. D., Asante, B. O., Acheampong, G. K., Wiredu, A. N., Offei, S. K., Gracen, V., ... & Danquah, E. Y. (2013). Grain quality and determinants of farmers preference for rice varietal traits in three districts of Ghana: implications for research and policy. Journal of Development and Agricultural Economics, 5(7), 284-294.
  • Egbadzor, K. F., Dadoza, M., Danquah, E. Y., Yeboah, M., Offei S. K., &Ofori, K. (2013). Genetic Control of Seed Size in Cowpea (Vigna unguiculata (L.) Walp). International Journal of Agriculture Sciences 5 (2): 367 – 371.
  • Asante, M. D., Asante, B. O., Acheampong, G. K., Offei, S. K., Gracen, V., Adu-Dapaah, H., & Danquah, E. Y. (2013). Farmer and consumer preferences for rice in the Ashanti region of Ghana: Implications for rice breeding in West Africa. Journal of Plant Breeding and Crop Science, 5(12), 229-238.
  • Asante, M. D., Offei, S. K., Gracen, V., Adu‐Dapaah, H., Danquah, E. Y., Bryant, R., & McClung, A. (2013). Starch physicochemical properties of rice accessions and their association with molecular markers. Starch‐Stärke, 65(11-12), 1022-1028.
  • A.M. Dadzie, D.S. Livingstone III, S.Y. Opoku, J. Takrama, F. Padi, S.K. Offei, E.Y. Danquah, J.C. Motamayor, R.J. Schnell & D.N. Kuhn (2013) Conversion of Microsatellite Markers to Single Nucleotide Polymorphism (SNP) Markers for Genetic Fingerprinting of Theobroma cacao L. Journal of Crop Improvement, 27, (2), 215-241.
  • K.F. Egbadzor, M. Yeboah, E.Y. Danquah, K. Ofori and S.K. Offei, 2013. Identification of SNP Markers Associated with Seed Size in Cowpea [Vigna unguiculata (L) Walp]. International Journal of Plant Breeding and Genetics, 7, 115-123. DOI:10.3923/ijpbg.2013.115.123. https://scialert.net/abstract/?doi=ijpbg.2013.115.123
  • K. F. Egbadzor, M. Yeboah, S. K. Offei, K. Ofori and E. Y. Danquah (2013) Farmers’ key production constraints and traits desired in cowpea in Ghana Journal of Agricultural Extension and Rural Development Vol. 5(1), 14-20.
  • Oteng-Frimpong, R., Levy, Y., Torkpo, S. K., Danquah, E. Y., Offei, S. K., & Gafni, Y. (2012). Complete genome sequencing of two causative viruses of cassava mosaic disease in Ghana. Acta Virol, 56(4), 305-314.
  • F.C. Brentu, K.A. Oduro, S.K. Offei, G.T. Odamtten, A.Vicent,  N.A. Peres& L.W. Timmer. (2012). Crop loss, aetiology, and epidemiology of citrus black spot in Ghana. European Journal of Plant Pathology, 133, (3),657-670, (DOI: 10.1007/s10658-012-9944-1).
  • F.C. Brentu, K.A. Oduro, S.K. Offei, G.T. Odamtten, & L.W. Timmer (2012). Evaluation of fungicides for control of citrus black spot on ‘Valencia’ sweet orange in Ghana, 2006-2008. Plant Disease Management Reports 6. (on-line) V156. DOI:10,1094/PDMR6. The American Phytopathological Society, St Paul MN.
  • K.F. Egbadzor, M. Yeboah, S.K. Offei, K. Ofori & E.Y. Danquah (2012). Farmers’ key production constraints and traits desired in cowpea in Ghana. Journal of Agricultural Extension and Rural Development 5(1), 14-20.
  • A. Dayaram, A. Opong, A. Jäschke, J. Hadfield, M. Baschiera, R.C.J. Dobson, S.K. Offei. D.N. Shepherd, D. P.Martin &A.Varsani(2012) Molecular characterisation of a novel cassava associated circular ssDNA virus. Virus Research166, (1–2), 130–135.
  • K.F. Egbadzor, I. Amoako-Attah, E.Y. Danquah, S.K. Offei, K. Ofori & M.O. Opoku-Agyeman (2012). Relationship between flower, immature pod pigmentation and seed testa of cowpea. International Journal of Biodiversity and Conservation Vol. 4(12), 411-415.
  • E. Sapey, S.K.Offei, E.Y Danquah & I.K. Asante (2012). Assessment of genetic diversity among 60 sorghum accessions in Ghana using Microsatellites. Elixir Bio Tech. 44, 7171-7177.
  • D.N. Njoku, G. Vernon, C.N. Egesi, I. Asante, S.K. Offei, E. Okogbenin, P. Kulakow, O.N. Eke-Okoro& H. Ceballos (2011). Breeding for enhanced B-carotene content in cassava: Constraints and Accomplishments. Journal of Crop Improvement, 25: pp 560-571.
  • D.N. Njoku, C.N. Egesi, S.K. Offei, I. Asante, G. Vernon, C. Amadi, O.N. Eke-Okoro & I.I.Chimaobi (2011). Genotyping variation in fresh root colour, harvest period and dry matter content of improved cassava genotypes. Niger. Agric. J. 42: pp138-144.
  • Njoku, D.N, C.N. Egesi, S.K. Offei, I. Asante, G.E. Vernon, E. Okogbenin, K.C. Ekwe, T.O. Ezulike, O.N. Eke-okoro & K.I. Nwosu (2011). Prospects for biofortification of farmers’ preferred cassava varieties in Nigeria. In: Root and Tuber crops research for food security and empowerment. Amadi C.O, Ekwek.C, Chukwu G.O, Olojede A.O .and Egesi C.N. (ed) NRCRI Umudike. pp 163 – 175.
  • K.F. Egbadzor, S.K. Offei, E. Danquah &I.D.K. Atople (2010). Variability in thirty-six accessions of sorghum assessed with eight groups of qualitative traits. International Journal of Agriculture 2, 86-92.
  • Offei, S. K., Almekinders, C., Crane, T. A., Hughes, S. G., Mokuwa, A., Nuijten, E., ... & Richards, P. (2009). Making better seeds for African food security-a new approach to scientist-farmer partnerships. Aspects of applied biology, (96), 141-148.
  • P. Richards, M. De Bruin-Hoekzema, S.G. Hughes, C. Kudadjie-Freeman, S. K.  Offei, P. C. Struik, and A. Zannou (2009). Seed systems for African food security: linking molecular genetic analysis and cultural knowledge in West Africa, International Journal of    Technology Management 45, 196-214.
  • Y. Lokko, A.G.O. Dixon, S.K. Offei and E.Y. Danquah (2009). Genetic relationships among improved cassava accessions and landraces for resistance to the cassava mosaic disease. Journal of Food, Agriculture & Environment.7 (1):156-162. 
  • I.K. Asante, G.C. Carson, R. Addey & S.K. Offei (2009). Correlation and path –coefficient analysis of components of agronomic characters in Lima bean (Phaseolus lunatus L). Ghana Journal of Science, 49, 61-66.
  • Oppong, A., Lamptey, J. N. L., Ofori, F. A., Anno-Nyako, F. O., Offei, S. K., & Dzomeku, B. M. (2007). Serological detection of Dioscorea alata potyvirus on white yams (Dioscorea rotundata) in Ghana. J. Plant Sci, 2, 630-634.
  • C. Kudadjie, P.C. Struik, P. Richards, S.K. Offei & P. Atengdem (2007) “Understanding variation in sorghum through with-farmer experimentation”, International Journal of Agricultural Sustainability, 5 (2&3), 124-139.
  • J.O. Honger, K.A. Oduro, S.K. Offei & K.G. Ofosu-Budu (2007). Canker-like disease caused by Xanthomonas spp in a citrus nursery in Ghana. Ghana Journal of Horticulture, 6, 95-101.
  • I.K. Asante, S.K. Offei, R. Addey & G.C. Carson (2007). Phenotypic and Seed Analysis in 31 accessions of Lima bean (Phaseolus lunatus L,) in Ghana. West African Journal of Applied Ecology, 12, 129-138.
  • J. Ofosu-Anim, S.K. Offei & S. Yamaki (2006). Pistil receptivity, pollen tube growth and gene expression during early fruit development in sweet pepper (Capsicum annuum). International Journal of Agriculture & Biology, 8, 1-5.
  • A. Danquah, S.K. Offei, E. T. Blay, E. Asare & E.Y. Danquah (2006). Characterization of a mutant population of cocoyam (Xanthosoma sagittifolium L. Schott). International Journal of Botany, 2, (2), 128-132.
  • S.K. Torkpo, E.Y. Danquah, S.K. Offei & E.T. Blay (2006). Esterase, total protein and seed storage protein diversity in okra (Abelmoschus esculentus L. Moench). West African Journal of Ecology, 177-183.
  • Y. Lokko., E. Danquah, S.K. Offei, A.G.O Dixon & M. Fregene (2006). Assessment of genetic diversity among African cassava Manihot esculenta Grantz accessions resistant to the cassava mosaic virus disease using Genetic Resources and Crop Evolution, 53(7), 1441-1453. 
  • Y. Lokko, A.G.O. Dixon, S.K. Offei & E.Y. Danquah (2006) Combining Ability Analysis of Resistance to Mosaic Virus Disease in Cassava. African Journal of Crop Science, 14, (3), 221-230.
  • Y. Lokko, A.G.O. Dixon, S.K. Offei & E.Y. Danquah (2006). Gene complementarity of resistance to the cassava mosaic disease among African cassava accessions. African Journal of Crop Science, 14(3):207-220.
  • J. Ofosu-Anim, S.K. Offei & I.O. Bimpeh (2005). Identification of endogenous sources of gibberellic acid for horticultural crops. Ghana Journal of Horticulture3, 87-91.
  • Y. Lokko, E.Y. Danquah, S.K. Offei, A.G.O. Dixon& M.A. Gedil(2005). Molecular markers associated with a new source of resistance to the cassava mosaic disease. African Journal of Biotechnology 4, 873-881.
  • F. Aboagye-Nuama, S.K. Offei, E. W. Cornelius & R.D. Bancroft (2005). Severity of spoilage rots of white yam (Dioscorea rotundata). Annals of Applied Biology, 147, 183-190.
  • S.K. Offei, J. Ofosu-Anim, E.V. Teiko& S. Yamaki (2005) Induction of multiple tuberisation in yam using growth regulators. International Journal of Agriculture and Boiology 8 (1), 73-75. 
  • S.K. Offei & S.E. Albrechtsen (2005). Effect of a cowpea mild isolate on growth and yield of bambara groundnut Vigna subterranea (L). Ghana Journal of Agricultural Science (1) 63-69.
  • S.K. Offei, N. Arciniegas, G. Müller M. Guzmán, L.F. Salazar, & R.H.A. Coutts (2004). Molecular variation of Potato yellow mosaic virus isolates. Archives of Virology, 149 (4), 821-827.
  • J.O. Fening, A Sessitsch, S.K. Offei and S.K. Danso (2004) Genomic heterogeneity within cowpea Bradyrhizobia isolated from Ghana. West Africa Journal of Applied Ecology, 6, 20-29.
  • C.Y. Kudadjie, P.C. Struik, P. Richards &S.K. Offei (2004) Assessing production constraints, management and use of sorghum diversity in north-east Ghana: a diagnostic study. Netherlands Journal of Agricultural Science, 52, 371-391.
  • N.G. Roling, H.D. Hounkonnou, S.K. Offei, R. Touddou & V. Huis (2004). Linking science and farmers innovative capacity: diagnostic studies from Ghana and Benin. Netherlands Journal of Agricultural Science, 52, 211-235.
  • B. Omondi-Aman, D. Obeng-Ofori, E.Y. Danquah &S.K. Offei (2004). Genetic diversity and oviposition host preference of Bemisiatabaci (Gennadius) (Homoptera: Alerodidae) infesting four crops in Ghana. Journal of the Ghana Science Association, 6, (1) 105-116.
  • I.K. Asante &S.K. Offei (2003). RAPD-based genetic diversity study of fifty cassava (Manihot esculenta Crantz) genotypes. Euphytica, 131, 113-119.
  • S.K. Offei, I.K. Asante & E.Y. Danquah (2003). Variation in size, protein, cyanide and tannin contents of lima bean (Phaseolus lunatus). Tropical Science, 43, 132-134.
  • E.Y. Danquah, S.K. Offei, E.T. Blay& I.K. Asante (2003). Genetic polymorphism among accessions of cocoyams (Xanthosoma sagittifolium L. Schott) from Eastern and Volta regions of Ghana. Ghana Journal of Horticulture, 1, 1-10.
  • S.K. Offei, I.K. Asante & E.Y. Danquah (2003). Genetic structure of seventy cocoyam (Xanthosoma sagittifolium, Linn, Schott) accessions based on RAPD. Hereditas, 140, 123-8.
  • E.W. Cornelius, S.K. Offei & K.A. Oduro (2003). The impact of Tuber rots on the post- harvest exploitation of white yam (Dioscorea rotundata) by retailers and exporters in Ghana. Ghana Journal of Horticulture, 2, 106-112.
  • I.K. Asante, E. Laing, E.Y. Danquah & S.K.Offei (2003). Genetic structure at the isocitrate dehydrogenase and malate dehydrogenase enzyme gene loci in cowpea (Vigna unguiculata (L) Walp) accessions Ghana Journal of Agricultural Science, 36, 53-63.
  • Offei, S.K., Cornelius E.W., Ofosu-Budu G.K., Kpesese V.K. (2002). Reaction of citrus rootstocks to Lasiodiplodia theobromae (Pat.) Griffon and Maub.: causal agent of citrus gummosis disease in Ghana.  Journal of Applied Science and Technology, 7,44-50.
  • Offei, S., Danquah, E., E.T., B., & Aboagye-Nuamah, F. (2002). Isozyme and total protein polymorphism among 52 accessions of cocoyam (Xanthosoma sagitifolium). Ghana Journal of Horticulture, 1, 1–8.
  • Offei, S.K., Ofori-Atta, C., Amoatey, H., Fening, J.O., Thottappilly, G. (2001) Symptomatology of banana streak disease and distribution of banana streak virus in naturally infected plantain (Musa AAB) cultivars.  Journal of the Ghana Science Association, 3(1), 42-50.
  • Danquah, E., E.T., B., Offei, S., Fosu-Nyarko, J., & Amiteye, S. (2001). Genetic diversity in cocoyam as revealed by random amplified polymorphic DNA. African Journal of Root and Tuber Crops, 4, 41–46.
  • Ofosu-Anim, J., Budu, K. G., Blay, E. T., & Offei, S. K. (2000). Effect of transplanting seedlings in compost on yield, fruit quality and incidence of wilt diseases in tomato (Lycopersicon esculentum Mill.). Advances in Horticultural Science, 14(3), 143–146. http://www.jstor.org/stable/42882088 
  • Offei, S. K., Owuna-Kwakye, M., & Thottappilly, G. (1999). First Report of East African Cassava Mosaic Begomovirus in Ghana. Plant disease, 83(9), 877. https://doi.org/10.1094/PDIS.1999.83.9.877C
  • Blay, E.T., Danquah, E.Y., Offei, S.K. and Kudadjie, C. (1999). Morphologic and agronomic characterisation of some tomato (Lycopersicon esculentum) germplasm in Ghana. Ghana Journal of Agricultural Science, 32: 169-175.
  • Offei, S. K., and Coutts R. H. A. 1996. Location of the 5′ termini of tobacco necrosis virus strain D subgenomic mRNAs. Journal of Phytopathology. 144(1), 13-17.
  • Drouzas, A. D., Offei, S. K., & Coutts, R. H. A. (1996). Subcellular location and expression of tobacco Necrosis necrovirus p7a protein. Journal of Phytopathology, 144(6), 297-299. https://doi.org/10.1111/j.1439-0434.1996.tb01532.x 
  • Offei, S. K., & Oduro, K. A. (1996). Plant pathology in Ghana: Past, present and future. Ghana Journal of Science, 36(1). Volume 31-36, 1991-1996. https://doi.org/10.4314/gjs.v36i1.47992
  • Offei, S. K., Coffin, R. S., & Coutts, R. H. (1995). The tobacco necrosis virus p7a protein is a nucleic acid-binding protein. The Journal of general virology, 76 (Pt 6), 1493–1496. https://doi.org/10.1099/0022-1317-76-6-1493.
  • Offei, S.K., Ibidapo, O., Brunt, A.A., & Coutts, R.H. (1995). Further evidence for the recognition of ullucus mild mottle virus as a distinct tobamovirus. Journal of Phytopathology, 143, 543-545.
  • Thottappilly, G., Hamilton, R. I., Huguenot, C., Rossel, H. W., Furneaux, M. T., Gumedzoe, M. Y., ... & Offei, S. K. (1993). Identification of cowpea viruses and their strains in tropical Africa-an international pilot project. FAO Plant Protection Bulletin, 41(2), 65-71.
  • Bailiss, K.W., & Offei, S.K. (1990). Alfalfa mosaic virus in lucerne seed during seed maturation and storage, and in seedlings. Plant Pathology, 39, 539-547

 

Books
  • S.K. Offei, O. Sakyi-Dawson & E. Cornelius. (2009) A Hand Book of Plant Disease and their Control in Ghana. Smartline Ltd 104pp.
  • Danquah, E.Y., Obeng-Ofori, D, Offei, S.K., Ofosu-Anim, J and Cornelius E. (2005) Agricultural Science for Junior Secondary Schools Book 1, 2 & 3.Smartline Ltd., Ghana.
  • Danquah, E.Y., Obeng-Ofori, D, Offei, S.K., Ofosu-Anim, J and Cornelius E. (2005) Agricultural Science for Junior Secondary Schools, Teachers’Book 1, 2 &3.Smartline Ltd., Ghana.
  • Hughes, S. Offei& B. Ronellenfitch (2004) Plant Viruses in Sub-Saharan Africa. Practical Laboratory Manual. International Institute of Tropical Agriculture 

 

Edited Proceedings
  • S.K. Offei, C. Almekinders, T.A. Crane, S.G. Hughes, A. Mokuwa, E. Nuijten, F. Okry, P.C. Struik, B. Teekenand P. Richards (2010). Making better seeds for African food security - a new approach to scientist-farmer partnershipsAspects of Applied Biology 96, Africa’s “Engine for Growth” Plant Science & Biotechnology hold the key pp 141-148.
  • Y. Lokko, A. Dixon, S.K.Offei,&E.Y. Danquah (2004). Genetic analysis of   resistance to the cassava mosaic virus disease. New Directions for a diverse plant. In: Proceedings of the 4th   International Crop Science Congress, Brisbane, Australia, 26,September - 1 October, 2004.
  • Y. Lokko, M. Gedil, A. Dixon, S.K.Offei&E.Y. Danquah (2004). Identification of molecular markers associated with a new source of resistance to the cassava mosaic disease. Pages 482-486. In The small processor and development of local food industries for market economy, edited by M.O. Akorada, Proceedings of the 8th Symposium of the International Society for Root and Tuber Crops-Africa Branch (ISTC-AB), 12-16 November 2001, IITA, Ibadan, Nigeria
  • S.K. Offei, E.Y. Danquah, E. Okai, H.D. Mihnouna&A.D.O. Dixon (2004). Genetic diversity in 91 accessions of cassava as revealed by random amplified polymorphic DNAs (RAPDs). Pages 476-481. In: The small processor and development of local food industries for the market economy, edited by M.O. Akorada, Proceedings of the 8th Symposium of the International Society for Root and Tuber Crops-Africa Branch (ISTC-AB), 12-16 November 2001, IITA, Ibadan, Nigeria.
  • E.T. Blay, S.K.Offei, E.Y. Danquah,H.A. Amoatey& E. Asare(2004). Improvement of cocoyam (Xanthosomasagittifolium) using gamma irradiation and tissue culture. IAEA-TECDOC-1426: 128-130. 
  • S.K. Offei (2001) Virus and viral diseases of yams in sub-Saharan Africa: Analysis of responses to questionnaires by scientists in sub-Saharan Africa. In Plant Virology in Sub- Saharan Africa Proceedings of a conference organized by IITA 4-8 June, 2001, pp 128-136. (eds  J. d’A Hughes and B.O.Odu) IITA, Ibadan Nigeria.
  • Y. Lokko, A.G.O. Dixon, & S.K. Offei (1998). Combining ability and resistance to the cassava mosaic virus disease. In Proceedings of the 7th Triennial conference ofInternational Society for Tuber and Root Crops, Africa Branch, 11-17 Oct, 1998 Cotonou pp 438-442, (eds  M. O. Akorada and J.M Ngeve) IITA, Ibadan Nigeria.
  • S.K Offei, A. Tymon& P. Jones (1995). Note on screening of insects as putative vectors of Cape St Paul wilt disease of coconut in Ghana. Proceedings of an International Workshop on Lethal Yellowing-Like Diseases of Coconut, Elimina, Ghana 5-10 November, 1995, 219-220.