Reconditioning and weather conditions affect black spot damage during storage of potato (Solanum tuberosumL.) tubers

Abstract

In potatoes (Solanum tuberosum L.), mechanical damage can cause the formation of black spots in the tuber flesh as the result of oxidation of phenolic compounds. This damage can result in substantial economic losses and degradation of quality. External factors contributing to the formation and the prevention of black spot damage (BSD) are not fully understood. The aim of this study was to determine the effect of weather conditions, using a hydrothermal coefficient, and of two potato tuber reconditioning methods on the formation of BSD. Five potato varieties were divided into high, moderate and low BSD susceptibility groups. The research was carried out over two growing seasons that differed greatly in precipitation and temperature. The black spot index was determined immediately after harvest and after 3 and 7months of storage. Two reconditioning methods, applied for 7days at 8°C and for 7days at 15 °C, were used for each variety. The incidence of BSD in susceptible varieties did not depend significantly on weather conditions, although statistically significant variation was observed. We found a correlation between the hydrothermal coefficient (dry conditions) and BSD in the Etiuda variety. There was no significant effect of storage time and temperature on BSD incidence in susceptible or moderately susceptible varieties. The reconditioning methods significantly reduced the formation of BSD in tubers after storage in all three groups. Regardless of the level of susceptibility of the variety, storage time and storage temperature, the most efficient treatment to limit BSD was reconditioning for 7days at 15 °C. Identification of the significant effects of weather, and strong reduction of BSD in tubers that had been reconditioned, allows examination of the underlying mechanisms. The described reconditioning method can lead to satisfactory reduction of BSD in potato tubers. Data from this research will be of interest to potato breeders, particularly if valuable alleles that affect this phenomeon can be isolated. © 2019 Society of Chemical Industry.