Provenance variation in Douglas fir in Victoria.  L. A. Pederick.  July 1982.  20 pp. (unpubl.)

SUMMARY

This report evaluates the results of two series of Douglas fir Pseudotsuga menziesii Franco provenance trials, established to determine the best provenances for use in Victorian plantations. Only provenances of the coastal or ‘green’ form P. menziesii var. menziesii (Mint.) of the species have been tested, as the ‘blue’ or Rocky Mountains form P. menziesii var. glauca (Beissn.) Franco was known to grow poorly.

The first series use plants grown from commercial seedlots of 20 provenances; trials were established at Toombullup and Wandiligong in 1968. Results are given from a measurement in 1978 at 10 years of age.

The second series contained a total of 49 provenances, mainly from special collections by IUFRO (International Union of Forest Research Organisations), and was established in 1973 at Narbethong, with 25 of them also planted in a trial at Toombullup. Results are given from a measurement in 1981 at 8 years of age.

Provenances with the best growth rates were found to be those from the Coast Ranges of northern California, Oregon and Washington; these provenances also tended to produce straighter stems. Growth rate diminished with increasing altitude of the seed source. Latitude of seed source had little effect on growth rate of the low-altitude provenances, with the exception of those from northern Washington and British Columbia, which were slower growing than the best of the others.

The 1973 trials included trees grown from seeds collected in the Stanley and Aire Valley Plantations. The good growth of these trees suggests that seeds imported during the early 1930s for these Victorian plantations probably originated in the State of Washington and we're unlikely to have come from British Columbia.

A trial established at Narbethong in 1966 with stock from commercial seedlots (the same lots as were used for the 1968 trials mentioned above), and which has been abandoned for comparison of growth rates, was found to be very useful for the screening of provenances for susceptibility to Swiss needle cast disease (Phaeocryptopus gaeumannii (Rhode) Petr.). The least susceptible provenances were found to be those from the Coast Ranges of central Oregon and southern Washington. This trial could be converted to a seed stand, which should yield seeds giving better disease resistance and more assured growth rate than any other potential seed source, particularly imports from North America.

The results of these trials suggest that the best provenances for use in Victoria, for growth rate, form and disease resistance, are those from the Coast Ranges of central and northern Oregon, from low altitudes not exceeding 300 m.

Also published:

Griffin, A.R., Matheson, A.C. and Pederick, L.A. (1981)  Early height growth of some provenances from the I.U.F.R.O. Douglas fir collection in nine Australian Field trials.  Aust. For. Res 11: 1-11.