Sweet potato is a nutritious root crop, rich in fibers, beta-carotene and vitamin C, especially in highly pigmented varieties. The warm climate of Georgia provides ideal conditions for the cultivation of sweet potatoes. Maintaining postharvest quality during long-term storage remains a challenge for sweet potatoes packers and shippers. This study aimed to evaluate the effects of controlled atmosphere (CA) storage on the postharvest quality and shelf life of ‘Covington’ sweet potatoes. Roots from two farms in South Georgia, Herring Farms (HF) and Bland Farms (BF), were cured at 29 °C and 85–90% relative humidity (RH), for three weeks and one week, respectively. After curing, samples were stored at 13 °C and 85–90% RH for up to six months under different atmosphere compositions: (1) Air 21 kPa O2-Control, (2) 7 kPa O2, (3) 7 kPa O2 2 kPa CO2, and (4) 7 kPa O2 10 kPa CO2, using an Oxystat 200 control atmosphere system, which mixed and regulated O2 and CO2 gases under constant pressure, ensuring gas levels within ± 0.5% of the target concentrations. After cold storage, roots were transferred to ambient conditions (21 °C and 85–90% RH) to simulate market and consumer handling. Quality parameters, including firmness, color, weight loss, decay incidence, sprouting, and respiration rates, were assessed at six time points: one month, one month plus two weeks at ambient conditions (AC), three months, three months plus two weeks at AC, six months, and six months plus two weeks at AC. For each location, 1,260 roots were evaluated, with 315 roots assigned to each atmospheric composition (three replicates of 15 roots per evaluation time point). Results demonstrated that storage under low O2 and moderate CO2 levels (7 kPa O2 2 kPa CO2) reduced weight loss and decay while maintaining higher firmness compared to Control (storage in air). In contrast, higher CO2 levels (10 kPa) resulted in increased weight loss and surface decay. These findings suggest that controlled atmosphere storage with low O2 and moderate CO2 levels can improve postharvest quality and extend the shelf life of sweet potatoes, whereas higher CO2 levels negatively affect postharvest quality of Georgia-grown ‘Covington’ sweet potatoes.
