Influence of different doses of fast electron beams and CIPC on the qualitative and quantitative changes of potato during storage.

Potato is an important economical vegetable crop in Iran. Post-harvest management of potato is a sever problem in Iran. The crops are harvested once a year , from September to November. Thus they have to be stored to ensure the supplies until the next harvest. Approximately 30% of the harvest is lost at few months of storage. The existing chemical methods (such as malic hydroxide, naphthalene acetic acid, methylester and isopropyl n-3 phenyl carbamate) for long term storage not only are not adequate to control the deterioration but also produce many undesirable side effects. In this regard a 3-year research project of radiation preservation of potato was carried out. Agria and Sante bulbs of potatoes were irradiated at a dose of 0.03 to 0.15 kGy or treated with 0.5 or 1 gr/kg CIPC and then Stored along with the unirradiated controls, at a technical store or traditional storage for a period of more than 8 months. Treating of samples were done 1 or 3-4 or 7-8 weeks after harvest. Each 6 weeks, some quality parameters including content of moisture, reduced sugar, vit.c, starch, nitrate, total acidity and sproutig and darkness of texture in peeled tubers were examined. According to the results In both cultivars (Agria & Sante) Irradiation at 0.09 or 0.12 kGy significantly (P less than or equal 0.05) decreased sugar accumulation , sporouting, weight losses and texture darkness of tubers more than the other treatments. Timing of the irradiation had a significant effect. For the best result, it must be done not later than 1 month after harvest. The effect of irradiation on nitrate content of tubers was not clear. Treatments of CIPC= 1gr/kg and 0.15 kGy showed the best and the worst retention effect on the vitamin C content of tubers respectively. By increasing the storage time, the content of moisture, starch, total acidity and vitamin C of tubers were decreased. None of the treatments was recommendable for treating on seed tubers. By using of this method, potato wastes decrease at least %5 which it's price will be 1500 billion Rials per year.