INFLUENCE OF PLANTING AND HARVEST DATES ON THE PRODUCTIVITY AND STORAGE ABILITY OF TWO SWEET POTATO CULTIVARS TO FACE THE CLIMATE CHANGES. 2- STORABILITY AND STORAGE ROOT QUALITY

Sweet potato (Ipomoea batatas (L.) Lam.), one of the most substantial tuber crops in tropical and subtropical countries, was selected to study the influence of climate alteration, in the form of higher temperatures, on crop storage. Two sweet potato cultivars (Menofia and Mabrouka) were cultivated in two different dates [23 April (the current recommended planting date) and 29 July (climate change planting date scenario)] and harvested after 169 day from planting the stem cuttings.   Climate change, by changing planting date to hot months negatively affects root weight during storage, dry matter percentage and carotenoids, but showed a higher iron content and score of general appearance of storage roots than those produced at the recommended planting date. At the end of storage, ‘Munofia’ showed lower values of carbohydrates, Fe, Ca, K, P in the first planting date, and the lower value of zinc in the second planting date, while ‘Mabruka’ showed lower values of general appearance in the first planting date and zinc in the second planting date.Phosphorus and potassium, calcium, iron, carotenoids, carbohydrate contents, the score of general appearance of storage roots and zinc significantly declined, while Hue angle continuously increased with prolongation of the storage period.