Reducing chilling injury and decay in stored sweet basil

Abstract

Storage of greenhouse-grown sweet basil (Ocimum basilicum L.) at temperatures below 12 °C results in chilling injury (CI), expressed as leaf browning, necrosis, and decay, followed by leaf abscission upon transfer to higher temperature. Storing basil at temperatures above 12 °C might result in soft rot caused by Botrytis cinerea and Erwinia carotovora, accompanied by increased leaf abscission. Ethylene is involved in the induction of leaf abscission. At a storage temperature of 12 °C, severe CI and decay may occur if the basil is harvested early in the morning, while these are markedly reduced if harvest is delayed to afternoon or evening. Postharvest hot-air treatment consisting of 38 °C for 8 h applied to afternoon- or evening-harvested basil markedly reduced its susceptibility to CI and decay, and enabled storage of some basil cultivars at 9 °C, a temperature which normally results in substantial injury. Harvesting of basil before noon should be delayed to at least 4 h after sunrise, and heat treatment...