The Survey of Postharvest Diseases and the Controlling Methods of Citrus and Some Other Fruits

Abstract

依據國外報告，柑桔貯藏病害以綠黴病、青黴病、炭疽病、黑色蒂腐病、褐色蒂腐病、果腐病、黑腐病、褐腐病、灰黴病及菌核病等為主；臺灣累積三年之調查結果，亦以綠黴病、青黴病、炭疽病、果腐病、黑腐病為主，而由Botryosphaeria sp.引起之蒂腐病亦相當普遍，至於灰黴病及菌核病則甚少發現。不同種之柑桔對貯藏病害之感病性有差異，其中以甜橙最為感病。田間栽培管理、採收及貯運方式明顯影響貯藏病害之發生，至於採收時若遇陰雨，則往往導致貯藏病害之大發生，乃因採收過程中造成之傷口為病原菌之主要侵入管道，而下雨造成之高濕度則為病勢進展之助力，因此改變採收及貯運方式以減少傷口，可降低貯藏病害之發生。而採收期間之藥劑處理以採收後浸果處理之效果最佳，但農藥殘留量亦高。貯藏空間之環境衛生、罹病果實及包裝材料之清理亦明顯影響貯藏病害之發生；因此於栽培期加強管理減少病害發生、採收時避免傷口產生、採收後適度藥劑處理，再配合貯藏前貯藏空間之廢棄物清理及消毒、貯藏期間定期清理病果及殺菌，當可減少貯藏病害之發生。 Ten kinds of postharvest diseases were occurred severe on the citrus cultivars when survey was done in the foreign country. They were green mold, blue mold, anthracnose, diplodia stem- end rot, phomopsis stem-end rot, fusarium rot, alternaria rot, brown rot, gray mold and cottony rot. Five kinds of postharvest diseases were occurred frequently in Taiwan, when surveyed continuously within recently three years. They are green mold, blue mold, anthracnose, fusarium rot and alternaria rot. The disease caused by Botryosphaeria sp. also occurred commonly. The gray mold and sclerotinia are found scarcely in Taiwan. The variety sweet orange( Citrus sinensis Osb.) was the most severe when different varieties were store and showed different degree of sensitivity to postharvest diseases. Both the cultural practice and methods of harvesting and transporting could influence the occurrence of postharvest diseases. The injury produced during the harvesting and handling period could induce the severity of postharvest diseases if the fruit were harvested in the raining days. The major reason is because of the high humidity for disease to development and the infection occurs commonly through injuries inflicted during harvesting and handling. The dipping method showed more effective than other methods when fungicides were used and high residue problem was remained. Another three factors could influence the occurrence of postharvest disease significantly. They were the sanitary of packinghouse, number of diseased fruits and cleaning of the packing material. The strategy for controlling postharvest disease followed step by step are good cultural practice, avoiding injury formation during harvesting, treatment of chemicals after postharvesting, and sanitary of packinghouse and packing material