Glycerol uptake preserves cut juvenile foliage of Eucalyptus cinerea

This is the first report of experimentation aimed at developing a postharve st glycerol uptake treatment protocol for juvenile-form Eucalyptus cinerea foliage. Glycerol uptake and accumulation were monitored and the protocol w as varied by adding the surfactant nonylphenolpolyglycol ether (Agral-600) to the preservation solution. Visual characteristics of preserved unhardene d (soft or immature) and hardened (mature) foliage were assessed. Foliage r espiration rate was monitored during treatment to establish when metabolic function ceased. Glycerol proved a suitable preservative for E. cinerea fol iage, 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 r espiration ceased within 1.5 days of commencing treatment with glycerol. So lution uptake was markedly reduced 2 days after treatment began, indicating failure of transpiration. Thus, metabolic functions ceased 1.5-2 days afte r uptake preservation commenced.