Abstract
Genotypic, phenotypic and environmental correlation coefficients were calculated for fourteen characters in twenty-three cassava accessions planted in Ibadan (7°30`N, 3°54`E) and Mokwa (9°30`N, 5°54`E), Nigeria in 2004. The aim of this study was to determine the contribution of plant characters to storage tuber yield. The field experiment was conducted in a randomized complete block design with three replicates. Genotypic correlation coefficients of six characters that exhibited significant association with tuber yield were partitioned into direct and indirect effects. Stem diameter, leaf chlorophyll concentration, tuber diameter, fresh weight of tubers per plant, number of tubers per plant and dry matter of fresh tuber were found to be positively and significantly correlated with dry tuber yield per plant. Leaf chlorophyll concentration, fresh weight of tubers per plant and dry matter of fresh tuber had positive direct effects on dry tuber yield per plant. It was concluded that knowledge of the relationship of characters that had significant association with tuber yield will aid the selection of genotypes that have high tuber yield. The results suggest that fresh weight of tubers per plant is the most reliable index of dry tuber yield per plant in the regions studied.
