Above: Inoculating sheoak seedlings with frankia - inset frankia nodules - Bob Hingston

Wheatbelt NRM has been working with Avongro, trialling the addition of Frankia, a nitrogen fixing soil bacteria, to Casuarina obesa to improve survival and growth rates in saline areas in the Wheatbelt. This trial is building on work previously completed by Avongro and Wheatbelt NRM, determining the best provenance of Casuarina obesa to grow in wheatbelt conditions.

Five (5) provenances of Cas. obesa were selected for this trial and they have been planted with and without Frankia in  a randomised block pattern.The trial in Goomalling is one of two trials with a replica planted by Avongro in Aldersyde, with funding  from the Western Australian Government's State Natural Resource Management Program.

The trials have been planted for two years, with the early data showing that the trees have survived in greater numbers in the Goomalling site rather than the Aldersyde site. This is due to the less harsh conditions of the site in Goomalling. Growth and survival rates will be monitored for the next 2 years to identify the potential benefits of Frankia inoculation.

Casuarina obesa is a Western Australian native tree that has valuable timber for furniture, firewood, and it’s foliage has excellent forage value.  This is great value from a tree that is also able to grow in harsh saline conditions that has no cropping production value.