Variation in first-harvest oil production in Eucalyptus radiata

Abstract

Summary This study was undertaken to provide information on variation in first-harvest oil yields within and between provenances of Eucalyptus radiata subsp. radiata (1,8-cineole variant), as a guide to those wishing to evaluate the economic viability of using this species for commercial oil production. Yield of oil per ha was estimated from an assessment of oil and growth traits at 23 months in 32 open-pollinated families of E. radiata subsp. radiata in a provenance/progeny trial in southern New South Wales. Analysis of the growth data showed survival and number of stems to vary significantly between provenances while families-within-provenance varied significantly in survival, basal area per tree and leaf biomass per tree. The data on oil traits was not amenable to statistical analysis but substantial variation was evident both within and between families in oil concentration. Variation in 1,8-cineole percentage was present but deemed of less importance than oil concentration in determining the economic worth of a plantation. or as a trait for selection in a tree improvement program. Families from Big Bulimbla Creek with the highest survival rates and oil concentrations gave the greatest average oil yields of 156 kg/ha compared to the trial average of 131 kg/ha.