Abstract: The storage of sweet potato tuberous roots in tropical countries is a major challenge to farmers and retailers due to unfavourable climatic conditions. In this research the storage performance of sweet potato roots in an evaporative cooling barn was investigated with three different pre-storage treatments - ash, brine and Lantana camara extract to evaluate their effects on weight loss, shrinkage, weevil damage, sprouting and decay over 12 weeks duration. The control comprised roots with no pre-treatment. Weight loss increased linearly from the inception of storage whilst shrinkage became apparent only after 2 weeks and rose linearly. The roots were held against weevil damage until the 6th week. Sprouting was initiated after 4 weeks of storage. By the 12th week, the Lantana camara treatment yielded better results, recording overall root wholesomeness of 76%, followed by the control (56%), the ash treatment (50%) and the brine treatment (48%). The Lantana camara treatment also recorded the lowest weight loss of 28%, lowest shrinkage of 3.8%, lowest severity of decay and sustained less weevil damage at 47.5% compared with the other treatments. Sprouting was however, higher than the other treatments. The brine and ash treatments performed poorest with the performance indicators.