Effectiveness of pruning and waxing in reducing postharvest physiological deterioration in Uganda local cassava varieties

Abstract

Cassava (Manihot esculenta Crantz) roots in the fresh form, are susceptible to postharvest physiological deterioration (PPD), thus reducing their economic value and farmer benefits. The objective of this study was to evaluate the effectiveness of pruning and waxing on fresh root storability among cassava varieties in Uganda. Sixteen cassava plants per variety (TME 14, NASE 14, Nyaraboke, Kirimumpale, and Bukalasa) were pruned seven days before harvest, leaving the rest as unpruned controls. After harvest, roots were divided into two portions and one portion was waxed using food grade wax. Pruning alone reduced PPD of stored roots by 23% at day 14 of storage; and by 19% at day 28 compared with the control. Pruning as a treatment resulted into increased sugar content, ranging 9-30%), and significant (P<0.05) losses in starch yield. Pruning combined with waxing, resulted in a reduction of up to 43% in PPD by day 14, and up to 67 at day 28. Reduction in carbohydrate (starch) was not significant (P>0.05) under the pruning and waxing treatment, which had minor effects on stored root composition. The results indicate that pruning is appropriate for the short-term storage of fresh cassava roots for up to 14 days. Waxing, combined with pruning, is suitable for longer term storage up to 28 days under Uganda conditions.

Key words: Carbohydrate, Manihot esculenta, starch, storage