99 The Korean Society of Crop Science J. Crop Sci. Biotech. 2016 (March) 19 (1) : 99 ~ 108 RESEARCH ARTICLE DOI NO. 10.1007/s12892-015-0095-8a Agronomic performance and genotypic diversity for mor- phological traits among cassava genotypes in the Guinea Savannah Ecology of Ghana J. Adjebeng-Danquah* 1,3 , V. E. Gracen 2,3 , S. K. Offei 3 , I. K. Asante 3 , J. Manu-Aduening 4 1 CSIR-Savanna Agricultural Research Institute 2 Cornell University, Ithaca, USA 3 WACCI/University of Ghana, Legon 4 CSIR-Crops Research Institute, Kumasi Received: September 15. 2015 / Revised: November 18. 2015 / Accepted: December 19. 2015 Ⓒ Korean Society of Crop Science and Springer 2016 Abstract We evaluated the agronomic performance and diversity for morphological traits among a collection of local and exotic cas- sava genotypes in the Guinea Savannah agroecology of Ghana. One hundred and fifty cassava genotypes were assessed using 28 agro-morphological (18 qualitative and 10 quantitative) traits recorded from three months after planting until harvesting at 12 months after planting. There was significant genetic variability among the genotypes for most of the traits evaluated. High broad sense heritability was observed for most of the traits. Principal component analyses of the traits indicated that the first three principal component axes which accounted for more than 55% of the variation for 10 quantitative traits included storage root yield, number of leaves, harvest index, height at first branching, and plant height as the most important traits. A greater proportion of the phenotypic variances of plant height, height at branching, and harvest index were accounted for by genetic variances indicating that progress could made with selection. Pearson correlation analysis indicated that a number of traits were related to growth and yield of cassava in the Guinea Savanna ecology, making indirect selection for root yield possible. The study revealed ample genotypic variation in these morphological and agronomic traits to support selection for improved varieties. Key words : agro-morphological traits, broad sense heritability, genotypic diversity, genotypic variance, principal component axes, quantitative traits Cassava (Manihot esculenta Crantz) is the third most important source of calories in the tropics after rice and maize with millions of people depending on it in Africa, Asia, and Latin America (FAO 2014). It can be cultivated under marginal ecologies characterised by poor, erratic rain- fall and extended periods of drought where most crops will fail (El-Sharkawy 2004; Hillocks 2002). However the per- formance of the crop vary among different genotypes in dif- ferent environments thereby affecting selection efficiency (Aina et al. 2007; Egesi et al. 2007a; Okogbenin et al. 2003). Aina et al. (2009) indicated that progress in cassava yield could be made by utilizing the vast genotypic variability present in different cassava genotypes for different traits under varying environmental conditions like drought. For this reason genotypes are evaluated in the targeted environ- ment for desirable traits that contribute to high root yield is such specific environments for the genetic improvement of the crop (Haldavankar et al. 2009; Ntawuruhunga and Dixon 2010). Genetic improvement of crops depends on the existence of Introduction J. Adjebeng-Danquah ( ) Email : bachus2003@yahoo.com