Satsuma ‘Okitsu’ Rind Breakdown

Anatomical Description and Effect of Environmental Conditions and Postharvest Practices

Abstract

During postharvest of Satsuma ‘Okitsu’ mandarin it has been detected in Uruguay a rind breakdown, which some years causes important losses. In this work, we studied microscopic and macroscopic damage, its association to environmental preharvest conditions, and the effect of postharvest fruit degreening and waxing on its incidence and severity. After 15 days of storage, irregular brownish areas boarding oil glands started to appear in the peel. After 15 days of shelf life, in areas with severe symptoms, a depression and cell collapse could be detected at sub-epidermis, advancing to subjacent parenchyma and occasionally to the epidermis, but the cuticle was not affected. In the former two years, fruit rind breakdown incidence was respectively 17 % and 7 %, while no damaged fruits were detected in the following two years. The highest rind breakdown incidence was associated to higher maximum temperature, lower relative humidity, and less precipitation during the last 10 days before harvest. Fruit degreening did not affect rind breakdown incidence after 30 days of storage + 15 days of shelf life, while fruit waxing diminished it more than 50 %. Results suggest that preharvest environmental conditions that promote fruit dehydration and/or postharvest conditions that fail to prevent fruit water loss, promote this ‘Okitsu’ Satsuma mandarin rind breakdown.