2019 ASHS Annual Conference

A market for ornamental edible transplants continues to increase for vegetables in the home landscape. As a result, a method for extending the salability of sweetpotato transplants in retail outlets is needed because containerized transplants, especially for root crops such as sweetpotato, can lead to root spiraling and deformation of tubers. Implementing techniques to ameliorate container-bound roots before planting in the landscape are not suitable. Altering phosphorus (P) fertility affects rooting and could be an easy method to slow sweetpotato rooting to limit root spiraling and tuber development. Sweetpotato cuttings were planted in 100% sand filled containers and fertilized at 0, 5, 10, 15, 20, and 31 mg L-1 using a modified Hoagland solution over a 6-week period. Each week, transplant shoots were measured for plant height, quality, and biomass while roots were analyzed for total root length, surface area, volume, average diameter, and biomass. All sweetpotato transplants regardless of P fertility increased in plant height, quality, and biomass for the first three to four weeks followed by declines in transplant quality. Rooting followed a similar pattern for all architectural parameters but continued to increase throughout the duration of the experiments with the exception of the control. In general, as P fertility decreased root growth was slowed. However, fertilizing transplants at the lowest P fertility of 5 ppm did not slow root growth sufficiently to extend the salable period of 4 weeks compared to transplants fertilized at higher P fertilities.