Growth and form of Eucalyptus agglomerata provenances in New South Wales

Summary

Twelve range-wide provenance seedlots of Eucalyptus agglomerata with parent tree identity retained, together with two routine E. agglomerata seedlots and a control of coast blackbutt (Eucalyptus pilularis), were assessed for survival, growth and form at age 12 years, in two trials. There were highly significant differences among provenances at both sites, and significant provenance x site interaction, for all traits. Variation between families in provenances was very minor. Central and lower north coast E. agglomerata and the blackbutt were consistently superior in growth to southern and highland sources of E. agglomerata, although the latter material often ranked well for form traits. Individual heritability estimates for growth and form were low to very low at both sites (zero to 0.22), with mostly high standard errors. Genetic correlations were mostly positive though fairly weak (up to 0.68), and encouraging for simultaneous improvement of important traits. E. agglomerata appeared to be a viable plantation species when compared with E. pilularis, particularly at the northern site. For an improvement program targeting north/central coast sites, selection of limited numbers of trees from several to many high quality stands in the central and lower north coastal regions is recommended; southern and highland sources should be avoided.