Glycerol uptake preserves cut juvenile foliage of Eucalyptus cinerea

Abstract

This is the first report of experimentation aimed at developing a postharvest glycerol uptake treatment protocol for juvenile-form Eucalyptus cinerea foliage. Glycerol uptake and accumulation were monitored and the protocol was varied by adding the surfactant nonylphenolpolyglycol ether (Agral-600) to the preservation solution. Visual characteristics of preserved unhardened (soft or immature) and hardened (mature) foliage were assessed. Foliage respiration rate was monitored during treatment to establish when metabolic function ceased. Glycerol proved a suitable preservative for E. cinerea foliage, with 20% (v/v) solution being as effective as 30% solution. Addition of Agral-600 did not improve uptake and, in fact, lead to excessive drying of leaves. Hardened foliage was more suitable for treatment than unhardened, since it retained better colour and exhibited less tip wilt. Measurable respiration ceased within 1.5 days of commencing treatment with glycerol. Solution uptake was markedly reduced 2 days after treatment began, indicating failure of transpiration. Thus, metabolic functions ceased 1.5–2 days after uptake preservation commenced.