Response of Sweet Potato Storability with Different Pre-storage Treatments at Ambient Temperature

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 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 12^th 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