Mr Guei, of Ivorian nationality, holds a General Agronomy Diploma and a Agricultural Engineering Diploma from the National School of Agronomy (ENSA), in Abidjan, Ivory Coast; a Master's and Doctorate Degree (PhD) in Genetics and Plant Breeding from Kansas State University, USA.
 
Mr Guei began his career in 1988 as a Corn Research Assistant in the Department of Agriculture at Kansas State University. From 1991 to 1994, at the West African Rice Development Association (WARDA) in Sierra Leone, he served as a genetic researcher, mangrove rice breeder, and then responsible for germplasm issues and seeds. From 1994 to 2005 he is Coordinator of the International Network of Genetic Evaluation of Rice (INGER-Africa) in Bouaké, Ivory Coast and Head of Program of Plant Genetic Resources of Rice (WARDA) in Bouaké, Côte d'Ivoire from 2002 to 2005. He joined FAO in 2005 as Agricultural Officer (seed production) in the Plant Production and Protection Division (AGP) and in 2011 he was appointed Senior Technical Officer / Secretary of the Committee on Agriculture (COAG), Department of Agriculture and Consumer Protection (GA), in Rome, Italy.