Comparative analysis of hybrid underground pit storage structure for yam and sweet potato tubers

Storage of crop as post-harvest operation is very important, in order to reduce wastage during the season of the crop, maintain the quality of the crop, to meet up with demand in times of scarcity and reduce price cost. This can be achieved with the design and construction of a good storage structure. In order to improve one of the storage structures used for yam and sweet potato tuber crops, underground pit storage structure was modified by hybridizing the bottom and side wall lining using closed-cell foam and sawdust material at ratio 50:50 in terms of thickness. Twenty tubers of yam and sweet potato were stored in the hybrid underground pit structure. The lowest and highest temperatures of the underground pit were 20 and 23oC, while the lowest and highest temperatures of the ambient environment were 27.9 and 29.8oC. The lowest relative humidity in the hybrid underground pit and ambient environment were 70.6% and 57.3%, while the highest were 86 and 79.6% respectively. It was discovered that at the end of eight week of storage, the weight loss in the tubers of yam and sweet potato was 10.5 and 22.5%, while the sprouting rates were 15 and 20%, percentages of rottenness were 10.5 and 15% respectively. It can be concluded that the hybrid underground pit storage structure improved the storage period of yam and sweet potato but can prolong the storage and life span of yam tuber than sweet potato.