Susceptibility to Pressure Flattening Correlates with Texture Analysis of Potato Tubers

The physiological disorder referred to as pressure flattening is a cause of significant economic losses in the storage of Irish potatoes (Solanum tuberosum L.) intended for use in the fresh market. As the flattened area on each tuber becomes larger in diameter or becomes more depressed the USDA quality grade, and therefore the market value of the potatoes is reduced. Experiments were conducted to identify at-harvest which potato lots within and among cultivars were likely to pressure flatten earlier or more severely. The use of an instrumented penetrometer or texture analyzer to measure peak load required for periderm deformation at harvest appears to anticipate correctly the majority of fields from which tubers are more likely to have severe pressure flattening at six months’ storage duration. At-harvest texture analysis appears to segregate varieties according to susceptibility to deformation based on cultivar specific factors that play a role in pressure flattening development during storage. The Pearson correlation coefficient (R²=0.5481) indicates that there is a correlation between tuber texture at harvest and pressure flattened area on the tuber following storage. Testing of tubers from different fields and cultivars as the potatoes are loaded into storage, may allow growers to identify and ship potatoes that are more susceptible before they develop significant pressure flattening.