STUDY ON THE FACTORS AFFECTING STORAGE OF EDIBLE AROIDS

The effects of temperature (15-degrees-C, 25-degrees-C, 30-degrees-C and 24 - 29-degrees-C), relative humidity (45%, 85% and 86 - 98%) and harvest maturity on the storag behaviour of cormels of the edible aroid species Colocasia esculenta and Xanthosoma sagittifolium were studied. The changes monitored were respiration rates, weight losses, incidence of decay and sprouting. Post-harvest losses that occurred during storage were influenced by the storage conditions, the state of maturity at harvest and the morphological characteristics of the cormels. When stored under high temperature and humidity more sprouting and decay occurred with C. esculenta cormels than with X. sagittifolium cormels. Less sprouting and decay occurred with Colocasia cormels at high temperature and low humidity than at high temperature and high humidity but higher weight losses were recorded. Wound pathogens were the major cause of post-harvest deterioration in Colocasia cormels and the causal pathogen of cormel decay was Sclerotium rolfsii. Under conditions of low temperature (15-degrees-C) and high humidity (85%), cormels of both C. esculenta and X. sagittifolium were successfully stored for periods of 5-6 weeks. Similar storage periods were also possible under tropical ambient conditions with the Xanthosoma cultivars used in these experiments. Under the same storage conditions up to 60% decay occurred in the Colocasia cormels indicating the need for post-harvest fungicide treatment.