Genetic variation and determination the optimal crop age for harvest in cassava (Manihot esculenta Crantz) accessions based on accumulated storage root yield

Abstract

AbstractThe early optimal crop age for harvest is a desirable characteristic in cassava. Many cassava accessions have been disregarded due to their late maturity. In Ethiopia, there is a lack of data on cassava maturity studies, highlighting the need for further research. The study aimed to determine the optimal crop age for harvest in cassava using stored root yield over time. A total of 64 accessions were evaluated using a lattice design from 10 to 22 months after planting (MAP). Results of the analysis of variance showed a highly significant (p < 0.001) difference in the optimal crop ages for harvest in cassava. The fresh storage root yield (FSRY) ranged from 5.5 t ha-1 at 10 MAP to 72 t ha-1 at 18 MAP crop age. Clustering analysis categorized 64 accessions into three clusters with varied crop ages. The highest genetic coefficient of variation (35.2%) was at 10 MAP crop ages, while the lowest genetic coefficient of variation (21.8%) was at 18 MAP crop age. This indicates that the evaluated accessions had high genetic variability in the optimal FSRY over time. Furthermore, the FSRY had high broad-sense heritability and a genetic advance percent mean at all crop ages, indicating the presence of an additive gene effect. G30 at 10 MAP, G11, G17, G31, G55, and G56 at 12 MAP crop ages are selected as promising candidates for utilization. The study indicates that cassava cultivars can be developed below the national recommended crop age for harvest in the evaluated population.

Keywords

• Accessions
• cassava
• cluster
• crop age
• root yield
• variability