Performance evaluation of three yam storage structures in Fiaso in the Techiman Municipality, Ghana
The study was conducted in Fiaso, a yam farming community in the Techiman Municipality of the Brong Ahafo region of Ghana where two new yam barns were constructed. These structures differ by way of shape (rectangular and circular). The general objective of the study was to evaluate the performance of two yam varieties namely Pona and Denteh, stored in the newly constructed storage structures. A control treatment was included in the study by selecting an existing storage structure in the community. Storage conditions and parameters monitored included temperature, relative humidity, weight loss, sprouting and tuber rot. The study was done between February and June 2015. From the study, it was observed that ambient temperatures ranged from 15.4 oC to 46.3 oC. The rectangular storage structure recorded minimum and maximum internal temperatures of 18.2 oC and 38.4 oC respectively whilst the circular storage structure recorded 18.7 oC and 35.9 oC respectively. The existing local storage structure recorded minimum and maximum temperatures of 18.3 oC and 39.6 oC respectively. It was observed that the minimum relative humidity recorded for ambient, rectangular, circular and existing local storage structures were 11%, 17.3%, 18.5% and 16.7% respectively. Maximum relative humidity for the ambient, rectangular, circular and existing local storage structures were 99.5%, 89.2%, 89.9% and 90% respectively. Rectangular, circular and the existing local storage structures recorded 54.9%, 55.5% and 58.7% weight loss for the Pona respectively and 40.4%, 32.4 and 35.1% for Denteh respectively during the storage period of 17 weeks. Sprouting index for circular, rectangular and the existing local storage structures were observed to be 45.2%, 46.5% and 59.2% for Pona respectively as against 53.1%, 48.7% and 57.5% for Denteh respectively. During the study, rot in Pona was observed to be the lowest in the rectangular storage structure with 37.5% against 50% and 56.3% for the circular and the existing local storage structures respectively. For Denteh, there was no tuber rot observed in the circular storage structure. However, the rectangular and the existing local storage structures recorded 6.3% and 8.3% respectively for Denteh. The newly constructed storage structures performed well in almost all aspects of the parameters monitored and therefore can be recommended as an improved storage structures over the local method in the study area.
A thesis submitted to The Department of Agricultural Engineering, Kwame Nkrumah University of Science and Technology in partial fulfillment of the requirements for the award of degree in Master Of Philosophy (MPhil.) In Food and Postharvest Engineering, 2015