Effect of Cultural Practices on the Dry Matter, Ash, Total Sugars, and Reducing Sugars Contents of Two Varieties of Dioscorea cayenensis-rotundata ("Kangba" and "Kounougbé") During Post-Harvest Storage

Aims: To assess the influence of some cultural practices on biochemical composition of yam varieties "Kounougbé" and "Kangba" and their performance during post-harvest storage. Study Design: Analysis of Variance (ANOVA) was applied in this study. Place and Duration of Study: Laboratory of Biocatalysis and Bioprocesses, during the period from December 2023 to June 2024. Methodology: Tubers of Dioscorea cayenensis-rotundata varieties Kounougbé and Kangba, cultivated under different cultural practices, were stored for six (6) months after harvest in an aired storage. Some biochemical parameters were analyzed at 0, 2, 4, and 6 months of storage. Results: Dry matter, ash, and sugar contents significantly increased (p < 0.05) during storage, regardless of cultural practices. After six months, dry matter content ranged from 63.61 ± 0.05% to 73.42 ± 0.75%, compared to 35.58 ± 0.49% to 43.74 ± 0.42% in fresh tubers. Initially, chemically treated tubers exhibited lower dry matter content, but this trend reversed after two months. Chemical seed treatment and staking significantly influenced dry matter content (p < 0.05) at this stage. A similar trend was observed for ash. Chemical treatment significantly affected ash content initially, but differences became non-significant over time (p > 0.05). Chemical weeding resulted in higher ash content than manual weeding, particularly after two months. Cultural practices did not significantly affect sugar content (p > 0.05). Conclusion: This study provides a scientific basis for improving yam storage, utilization, and valorization of yam varieties "Kounougbé" and "Kangba".