Differential Response of ‘Beauregard' Sweetpotato Storage Roots to Ethephon, 1-Methylcyclopropene and Water Submergence Treatments, Poster Board #022

Effects of short-duration submergence of ‘Beauregard’ storage roots in ethephon (2-chloroethyl phosphonic acid), 1-MCP (1-Methylcyclopropene), and water were examined. ‘Beauregard’ storage roots were cured for 1 week at 30 °C, 90% relative humidity (RH), and held at 15 °C and 85% RH until utilized. Submergence treatments were the following: 1 ppm 1-MCP, 2.6 mM ethephon and water. All submergence treatments included 0.1% Nu Film P® and were imposed for one hour. After one month, samples submerged in ethephon and water showed signs of localized tissue death (necrosis), as confirmed by trypan blue staining.  Necrotic tissue was observed on storage root surfaces and tips. The responses included pitting-type damage associated with chilling injury as well as necrotic tissue associated with tip rot- or end rot-like symptoms. The development of lenticel-like features was also observed on the surface of storage roots treated with ethephon.  Storage roots treated with 1-MCP failed to show evidence for localized tissue death even after three months of observation. The results suggest the involvement of ethylene in the development of pitting- and tip rot-like injury in ‘Beauregard’ sweetpotatoes.