Performance Evaluation of Organically Grown Sweetpotato Varieties, Nutritional and Cost-Benefit Analysis

This research investigates problems faced by sweetpotato producers as regards weed management, yield, nutrition and economic gains. Fourteen sweetpotato cultivars used were grown on the certified organic research farm of Tennessee State University in Nashville, TN. Three types of mulch – wheat straw, pine needle, and black plastic with control (no mulch) were evaluated using data collected during the 2015 and 2016 growing season. A randomized complete block design with four replicates was employed. Data was gathered dry weight of weeds recorded during the growing season and on the yield of the various cultivars. Some cultivars were further utilized in sensory evaluation, anticancer studies and economic analysis. Our results showed significantly higher total dry weight of weeds recorded in the control (no mulch) plots. Sweetpotato yields varied significantly among varieties. In the 2016 growing season, significantly higher yield was observed in the wheat straw mulch compared to other mulch treatments, though not significantly different from the control (Tukey’s post-hoc test, p\u3c0.05). Marketable yields in varieties ranged from 39719 kg·ha–1 in Beauregard to 4925 kg·ha –1 in O’ Henry. There was no significant interaction between variety and mulch treatment; therefore, their effects are additive. Sensory results favored consumer-preference towards non-traditional cultivars. Sweetpotato beverage was developed using the response surface model procedure and antioxidant content was not affected. When compared with 100% orange, apple and vegetable juices purchased commercially, Sweetpotato beverage exhibited the slowest glucose release pattern, as well as the lowest overall glucose concentration. Methanolic extracts from the Carolina ruby and All Purple sweetpotato stem and leaf extracts exhibited cytotoxic effect on the on breast (BT549) and lung (A549) cancer cell lines in a dose dependent manner. Sweetpotato yield and unit cost of production was discovered to be greater in conventional farming systems while the sweetpotato selling price was more in the organic production systems with a possibility of generating 100% more profit. Our findings suggest organic sweetpotato production is profitable even when compared to conventional production with a potential to expand and be adopted due to the numerous health benefits and anticancer potential of the crop