Abstract

Forty-three cassava genotypes were evaluated to assess genetic variability for root yield and its components at three locations (Ibadan, Mokwa and Onne) in Nigeria, during 2004 - 2005 cropping season. Data were collected for cassava mosaic disease (CMD), cassava bacterial blight (CBB), sprouting, plant height, root number, root weight, shoot weight and root dry matter. Genotype x location interaction was significant for all the characters studied, indicating considerable influence of the environment on the expression of the traits. High heritability and genetic gain were observed in cassava mosaic disease (73.1%), root number (69.7%) and plant height (95.0%), suggesting that the traits are primarily under genetic control and that reliable selection with simple recurrent phenotypic selection would be rewarding. Though genotypes differed significantly at (p > 0.001) for all the traits studied, nine genotypes, namely 97/2205, 96/1632, 97/4763, 98/0581, 95/0289, 97/4779, 98/0505, 96/0603 and 98/0002 were found to constitute a pool of germplasm with adequate genetic variability from which selection will bring about significant progress in cassava improvement programs.

Key words: Cassava genotypes, genetic variability, root yield, agro ecology, correlation coefficients, heritability.