Pathogenicity of nine species of Phytopthora to Eucalyptus sieberi and E. obliqua.  G. C. Marks and F. Y. Kassaby.  December 1976.  9 pp. (unpubl.)

SUMMARY

The pathogenicity of Phytopthora cambivora, P. citricola, P. citrophthora, P. megasperma, P nicotianae var. nicotianae, P. nicotianae var. parasitica, P. drechsleri and P. cryptogea, to intermediate-age seedlings of Eucalyptus sieberi and E. obliqua was compared with the pathogenicity of P. cinnamomi. The tests were carried out at 20-26°C under soil moisture conditions ideally suited for root disease.

Only P. cinnamomi produced very destructive root-rot and all the E. sieberi seedlings died between 14-20 days after soil inoculation. P. megasperma, P. drechsleri and P. cryptogea killed a few seedlings 45-50 days after inoculation, and these fungi are rated as mildly injurious in comparison with P. cinnamomi.

The literature indicates that P. cinnamomi is the most destructive eucalypt root pathogen that has been found so far in Australia and the importance of the other Phytopthora species as potential pathogens is possibly over-rated.

Also published:

Marks. G.C. and Kassaby, F.Y. (1976)  Pathogenicity of nine species of Phytopthora to Eucalyptus sieberi and E. obliqua.  Aust. For. Res. 7: 59-63.