Variation in growth of Eucalyptus camaldulensis provenances in Thailand

Variation in the growth of a wide range of Eucalyptus camaldulensis germplasm was evaluated in 2-year-old provenance/progeny trials planted on three different sites in Thailand. The trials compared 315 families, of which 305 families came from 32 provenances representing five regions in northern Australia and ten families from selected trees in the local land race representing Thailand. Significant differences (P < 0.001) in height, diameter and volume per tree were found between regions, provenances within regions and families within provenances. Overall, growth of provenances from Queensland and Thailand was found to be superior to that of sources from the Northern Territory and Western Australia. Provenances from the Petford region, especially the seed source from Petford Bridge, have performed well but so did many other Queensland provenances-Wrotham Park, Lynd Junction and Healeys Yard from the Walsh-Mitchell River catchment; Gilbert River near the Gulf of Carpentaria; Kennedy River and Morehead River on Cape York Peninsula. There was a significant and consistent negative trend west to east in volume growth between provenances within the Petford region; provenances to the western extremes of the region grew more vigorously than those to the east. There is a need for a rigorous specification of the boundaries of Petford provenance when selecting seed sources for Thailand.