INFLUENCE OF DRYING CONDITIONS AND STORAGE TEMPERATURE ON DESICCATION AND LOSS OF TUBERS DURING STORAGE AND SUBSEQUENT GROWTH OF ZANTEDESCHIA TUBERS

Abstract

After lifting Zantedeschia tubers in autumn severe losses of tubers occur during storage and the subsequent growing season caused by soft rot (Erwinia carotovora) and calcification of tubers. In this study the effects of post-harvest drying conditions and storage temperature were investigated. After lifting early November tubers were dried at 17°C without air circulation, with moderate air circulation and with strong air circulation. After one week tubers were placed at different temperatures (9, 13, 17, 20°C) for storage with moderate air circulation during the rest of the storage period until planting in April. No air circulation at 17°C during the first week after lifting caused losses of tubers by bacterial rot during that week and calcification during subsequent storage. Hardly any rot or calcification was observed after moderate and strong air circulation. The temperature during subsequent storage had a great influence on desiccation of the tubers. Remarkably, in the period from cleaning the tubers in December until planting in April, weight loss increased with decreasing temperature. The big loss of weight at 9°C resulted in calcification during storage or severe losses of tubers during the subsequent growing season. It is suggested that drying or storage at temperatures higher than 13°C are necessary to form a skin that prevents desiccation of the tuber.