Seedling mortality due to Phytophthora cinnamomi in the Maramingo and Reedy Creek Pulpwood Demonstration Areas, East Gippsland.  I. W. Smith.  July 1981.  23 pp. (unpubl.)

SUMMARY

Eucalypt seedling stocking and recent mortality at the Reedy Creek (75 ha) and Maramingo (60 ha) Pulpwood Demonstration Areas (Cann River District, East Gippsland), harvested during 1976, were studied in July and September 1980.

At Reedy Creek and Maramingo, respectively, 89% and 58% of 4 m² plots contained at least one seedling. The percentage of plots at Reedy Creek containing at least one seedling of Eucalyptus sieberi L. Johnson (silvertop) was 71%, E. globoidea Blakely (white stringybark) 43%, E. obliqua L’Hérit. (messmate) 10% and E. cypellocarpa L. Johnson (mountain grey gum) 2 %, and at Maramingo, E. sieberi 23%, E. muellerana A. W. Howitt (yellow stringybark) 20%, E. agglomerata Maiden (blue stringybark) 16%, E. cypellocarpa 10%. E. sideroxylon A. Cunn. ex W. Woolls (red ironbark) 8% and E. consideniana Maiden (yertchuk) 4%. At Reedy Creek, plots on westerly aspects were better stocked than those on easterly aspects. There was no significant difference between stocking on burnt and unburnt sites in either area, though growth rates were significantly higher on burnt than unburnt sites at Reedy Creek. Overwood significantly reduced the stocking and mortality of E. sieberi at Reedy Creek but has not reduced growth rate.

Diseased seedlings were distributed over 56% of the large (800 m²) plots (which encompassed each 4 m² plot) at Reedy Creek and 8.3% at Maramingo. Recent mortality was 6.1 and 2.7% of E. sieberi seedlings at Reedy Creek and Maramingo, respectively. Disease occurrence at Reedy Creek was greatest on unburnt areas with slopes less than 5°. Phytophthora cinnamomi Rands (cinnamon fungus) was identified as an important cause of disease through girdling of the collar region of Eucalyptus sieberi seedlings. There was no recent disease of other species of eucalypts.