Variation among cassava (Manihot esculenta Crantz) genotypes for storage root yield, yield components and response to cassava mosaic disease at advanced breeding stage

Abstract

Cassava is a crucial starchy root crop cultivated worldwide in tropical and subtropical areas. Its preferred traits are continually been improved to enhance food and nutritional security. However, adoption of new varieties of cassava can be influenced by its yield performance which can be affected by cassava mosaic disease (CMD). This study was therefore conducted to evaluate the performance of selected cassava genotypes at advanced breeding stage across two years. Using a randomized complete block design with two replications, 16 genotypes; a yellow root variety (TMS07/0593) and a white root (TMS30572) as checks were evaluated for yield, yield related traits and response to CMD. There were highly significant (P < 0.001) variations among the cassava genotypes for yield-related traits but no genetic variation was reported for fresh root yield and dry root yield. The effect of season and genotypes x season interaction on all traits was not significant except season for harvest index. Genotype UIC-17-2428 and the two national check varieties (TMS07/0593 and TMS30572) did not exhibit complete resistance to CMD. At harvest, genotype UIC-17-2031 had the highest fresh root yield (39.0 t/ha), dry root yield (10.5 t/ha), and harvest index (0.63). Genotype UIC-17-58 had the highest dry matter content (37.2%) at harvesting followed by UIC-17-46 (36.4%) while genotype UIC-17-583 had the lowest value (22.8%). The genotypes evaluated have promising premium agronomic traits. Genotypes with outstanding dry root yield need to be evaluated across multiple environments to assess their stability.