Response of Sweet Potato Storability with Different Pre-storage Treatments at Ambient Temperature
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 study, the storage performance of sweet potato roots in an ambient condition was investigated over a 12-week duration. The three different pre-storage treatments used were ash, alkaline solution (1.5 mol dm-3) and Siam weed (Chromolaena odorata) extract – to evaluate their effects on weight loss, shrinkage, weevil damage and sprouting. The control comprised tubers with no pre-treatment. It was observed that weight loss increased linearly from the inception of storage while shrinkage became apparent only after two (2) weeks. The percentage shrinkage of the tuber pre-treated with Siam weed increased at decreasing rate from 8 WAP. Treatment of tuber with Siam weed extract provided significantly higher protection against weevil damage (p > 0.05). After this, sprouting was initiated. By the 12th week, the Siam weed (Chromolaena odorata) extract treatment yielded better results. The Siam weed (Chromolaena odorata) treatment also recorded the lowest weight loss of 28% and lowest shrinkage of 2.8%. It also sustained less weevil damage at 33.5% compared with the other treatments. Sprouting was higher in the tuber without pre-storage treatment. The alkaline solution and ash treatments had varied degree of performance for all the indicators.
Keywords: Sweet potato storability, Ambient condition, Pre-storage treatment, Chromolaena odorata