Effect of UV-C irradiation on sprouting of potatoes in storage

Postharvest UV-C irradiation has been shown to alter the postharvest quality of some horticulture crops. In these preliminary experiments, freshly harvested potatoes (Solanum tuberosum 'Innovator') were exposed to UV-C light at five different intensities (0.0, 3.4, 7.1, 10.5 and 13.6 kJ m-2). After treatment, potatoes were stored in the dark in air at 20°C and 80% RH for up to 40 days. During storage the potatoes were assessed for the number and length of each sprout at 10 day interval and at the end of 40 days storage, all sprouts were weighed individually. UV-C irradiation significantly affected the number of sprouts. In the first 20 days of storage, the number of sprouts in irradiated potatoes was significantly lower than untreated tubers, however, this effect diminished during storage. UV-C irradiation also affected the sprout length where irradiated potatoes had significantly shorter sprouts than untreated potatoes during storage of 20 days. Similarly this effect diminished over the storage time. The individual weight of the different sprouts was not significantly different between untreated and irradiated tubers. These results indicate promise for UV-C as a potential postharvest treatment to reduce the incidence of sprouting in potato tubers stored in air at 20°C.