Recovery of Orange Peel Essential Oil from ‘Sai-Namphaung’ Tangerine Fruit Drop Biomass and Its Potential Use as Citrus Fruit Postharvest Diseases Control

In this study, we assessed the quality of essential oil recovered from fruit drop biomass and assessed its usefulness in preventing postharvest diseases in the tangerine ‘Sai-Namphaung’. Greening was the primary cause of the fruit drop, based on the enduring symptoms and occurrence of the disease in the area. Limonene, together with the presence of β-pinene and linalool, was discovered to be prevalent in essential oils of tangerine fruit peel, particularly that of ‘Sai-Namphaung’. Through isolation of citrus postharvest fungi, we were able to identify four genera which were later DNA sequenced using Internal Transcribed Spacer: ITS and subjected to Basic Local Alignment Search Tool (BLAST), with a high possibility (>98% similarity) of being Penicillium digitatum, Colletotrichum gloeosporioides, Fusarium sarcochrum and Geotrichum candidum. Essential oil from ‘Sai-Namphaung’ and ‘Fremont’ peel biomass positively inhibited green mold rot and citrus anthracnose caused by P. digitatum, C. gloeosporiodes, but were less effective than the commercial citrus oil and Zanthoxylum myriacanthum oil. This is the first evidence of ‘Sai-Namphaung’ postharvest diseases caused by these two fungi and their controls using citrus essential oil.