Abstract:
Among the important pests of dried fruits are nitidulid beetles. Infestation starts in the field and unless control measures are employed, they and other pests continue to multiply and develop during storage. Methyl bromide has been used for fumigating dried fruits. However, because it is associated with the depletion of the atmospheric ozone, action has been taken to phase out its use in agriculture. This research was undertaken to develop a controlled atmosphere treatment that would remove insects from the dried fruit, prevent insect development and preserve fruit quality. Dates grown in Israel served as a model for development of the technology. A controlled atmosphere of 60-80% carbon dioxide was used within a 151 m3 plastic chamber partially filled with 30 tons of dates stacked in crates on pallets. At the initial purge phase the desired carbon dioxide concentration was obtained in the chamber within one hour by introducing the gas under high pressure. An intermittent maintenance phase was then applied for 4.5 months using approximately 0.8 kg carbon dioxide per day. At the end of storage, quality of the treated dates was compared to controls stored at -18 °C. No significant difference was found between the treated dates and controls. The insect population was effectively controlled. This technology is proposed for the treatment of stored dried figs to control pests and maintain quality.