MINIMIZING POST HARVEST LOSSES IN POTATO TUBERS (SOLANUM TUBEROSUM L.) USING GAMMA IRRADIATION, MINT OIL, PACLOBUTRAZOLE AND THEIR RELATES UNDER UNREFRIGE- RATED STORAGE CONDITION

Abstract

This experiment was carried out on potato tubers at the Department of Natural Products, National Center for Radiation Research and Technology, Nasr City, Cairo, Egypt. The research aims to reduce losses resulting from the storage at room temperature and to reduce cooled storage costs of potato tubers using gamma radiation, mint oil and paclobutrazole treatments. Potato tubers cvs. Sponta and Diamont were treated with 100 Gy of gamma radiation, 5% of mint oil, 100 ppm of paclobutrazole during the two successive seasons of 2013/2014 and 2014/2015. Concerning Sponta tubers results showed that, tubers irradiated with 100 Gy and soaked in 100 ppm paclobutrazole scored the lowest values of weight loss, sprouting, shrinkage, decay and total weight loss, whereas, the highest values of weight loss were recorded to paclobutrazole + mint oil treatment. While mint oil treatment and mint oil + irradiation treatment scored the highest values of sprouting, shrinkage and decay. On the other hand, tubers irradiated with 100 Gy of gamma irradiation then soaked in 100 ppm of paclobutrazole had a higher content of starch and carbohydrates than other treatments. The highest values of protein were recorded with irradiation treatment and irradiation + paclobutrazole treatment. Irradiation + paclobutrazole treatment scored the highest value in specific gravity. GA and IAA hormones levels were higher after storage than before storage, whereas ABA showed opposite direction. The results of Diamont tubers showed that paclobutrazole treatment and radiation + paclobutrazole treatment scored the lowest value of weight loss. Paclobutrazole treatment, irradiation treatment and paclobutrazole + irradiation recorded the lowest values of sprouting and shrinkage with no decay. Irradiation treatment and paclobutrazole treatment recorded the highest percentage values of protein. Irradiation treatment and mint oil treatment scored the highest values of starch. Results of hormones can be summarized as general, the level for GA3 and IAA were higher after storage than before storage, whereas ABA showed opposite results. The lowest values of total loss in both cvs Sponta and Diamont tubers were recorded with irradiation treatment, paclobutrazole treatment and irradiation + paclobutrazole treatment.