Master of Science (MS)


Plant, Environmental Management and Soil Sciences

Document Type



As the sweetpotato industry moves towards more processed products, there is a need to develop strategies in which to optimize total yield and reduce costs. Unlike the fresh market product, desirable processing roots are larger in size and overall tonnage is preferred over aesthetic appeal. Plant spacing and row width along with planting dates and harvest dates are believed to affect the size and tonnage of sweetpotato roots. The Beauregard and Evangeline varieties were planted at an early planting date (June 1) and a late planting date (July 1) on 38 and 42 inch row spacing. Harvests were at ~125 and ~140 days after planting. The delay in harvest increased yield of all grade categories except for U.S. No.1. The first planting date was also superior to the second planting date. Row width had a marginal effect. Only the canner grade was significantly higher for the 42 inch width in 2010 which caused the total yield category to be significantly higher. Plant spacing was less important and demonstrated that lower planting densities are possible. Furthermore, results demonstrated that a delayed harvest does not reduce the U.S. No.1 yield and only increases total yield. Storage root quality must be maintained all the while reducing costs. Consumers demand processed sweetpotato products that taste as good as the fresh market product. Many times roots for processing are not cured and therefore do not gain in sugar contents and visual appeal. Roots could possibly be left in the field after de-vining and before harvest in the hot, humid times of the year which is similar to the curing room environment. Beauregard and Evangeline varieties were de-vined in successive days from day 0 to day 4 early in the harvest season (~September 1) and late in the harvest season (~November 1). Raw and French fry roots were analyzed for sucrose, fructose, glucose, maltose, and total sugar content. As the de-vining period was extended, few treatments showed trends toward higher sugar contents. Significant differences did exist but they were not consistent enough to recommend a reliable field curing schedule that would increase sugar contents.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

LaBonte, Don