Postharvest Treatments for Degreening of ‘Villa franca’ Lemons

Abstract

<jats:p>‘Villa franca’ is the main lemon (<jats:italic>Citrus limon</jats:italic>) variety in Israel, also cultivated in several other citrus-growing countries. In winter, the fruit turns yellow naturally, but during the summer and autumn, it remains green on the tree and requires postharvest ethylene treatment to stimulate color change from green to yellow. However, ‘Villa franca’ lemons are very sensitive to ethylene, which enhances development of reddish/brown peel blemishes known as red blotch. In the present study, we provide three different methods for postharvest degreening of ‘Villa franca’ lemons without causing red blotch. First is a slow process, involving natural degreening during 4–5 weeks of storage at 13 °C without ethylene exposure. Second is a moderate “under-degreening” process, involving a short 48-hour exposure to ethylene followed by 2 weeks of storage at 13 °C. Third is a fast process involving degreening with ethylene for up to 4 days at a constant high conditioning temperature of 30 °C or a combination of 24 hours of ethylene treatment at 30 °C followed by additional 72 hours of exposure to ethylene at 25 °C. Overall, ‘Villa franca’ lemon growers, packers, and exporters may now choose to use any of these proposed degreening procedures, according to commercial needs and market demands.</jats:p>