2017 ASHS Annual Conference

Sweetpotatoes (Ipomoea batatas) are nutritious, easily stored and well-adapted to fit large or small organic farming operations. This widely consumed root crop is propagated through use of cuttings, known as slips, which are grown primarily in the Southeastern United States. Consequently, growers in the Central U.S. have limited control of and access to local planting material. Production of organic slips in high tunnels could be a profitable enterprise for growers in the Central U.S. that would allow them to diversify their operation and encourage the use of crop rotations in high tunnels. Our study evaluates the yield and performance of slips grown in high tunnels as compared to the open-field. Similar trials were conducted in 2016 at two research stations in Northeast and South Central Kansas. We utilized a randomized complete block design for all trials, with at least 4 replications per treatment. Slip beds were established in high tunnels (HT) and open-field (OF) under identical cultural methods and planting schedule. At the Northeast trial we implemented a split plot design in which the sub-plot treatments consisted of three planting densities (45, 65 and 85 seed roots/m²) in both the HT and OF. We transplanted slips from both sites, HT and OF treatments, to field plots at our Northeast location to investigate the impact of slip origin (HT vs. OF) on root crop production. The marketable slip yields (slips/m²) were approximately 110% greater in HT plots compared to OF. Our research team also observed larger slip yield with increasing planting densities, however the benefit of higher density plateaued between 65 and 85 seed roots/m². Although individual plant samples grown in the HT were on average 36% less compact (measurement of slip dry weight mg/cm of slip length) than OF comparison, the marketable root yield produced per slip was similar for both treatments. More research is needed to evaluate the feasibility of sweetpotato slips grown in high tunnel systems and to determine recommendations for seed root planting densities. However, the results of this study suggest that organic sweetpotato slip production could add to diversity in high tunnel systems. Moreover, local slip production might further promote the adoption of an underutilized vegetable crop that can be grown throughout the region.