THE REGION AND CLIMATE
Manjimup is located approximately 300km south of Perth in a region that sustains broad acre agriculture, horticulture and forestry. The region experiences a Mediterranean style climate with hot summers and relatively mild winters. Annual rainfall in the region is winter-dominant and averages a high 1,010mm, although supplementary irrigation is required in the summer months to maintain soil moisture. Mean daily maximum temperatures in the region range between 14.3ºC in July and 27ºC in January (Bureau of Meteorology (BOM) 2008).
More than 85% of Australian winter truffles are produced in this small horticultural region. Rich loamy soil and an abundant supply of water ensure that the oak and hazel trees grow quickly. The lack of native fungal competition means that the melanosporum fungus thrives.
The Oak Valley property is situated on Seven Day Road, approximately 10km south-west of Manjimup. The Oak Valley property was selected for the trufferie because the region has a similar climate to the truffle growing regions in France. Oak Valley is an undulating property previously used for cattle grazing and adjoins a state forest. The property is comprised of 88ha of cleared land and another 40ha of land under native vegetation.
The Oak Valley property is serviced by a 300ML dam located to the west of the plantings. Improvements on the property include a three bedroom brick veneer home and a recently constructed building comprised of machinery shed, a truffle processing area, laboratory and office.
The farm is the largest planting in the region and indeed the southern hemisphere. Oak Valley was planted in 2006/7 when some 75 hectares or approximately 38,000 oak and hazel trees inoculated
with the melanosporum fungus were planted.
Hazelnut and English oak trees were planted in rows at a density of 500 trees per hectare. 50% of each species were planted alternately in rows, in order to spread the risk on the most suitable species for truffle production. The hazelnut tree is considered a natural undergrowth tree compared to the larger growing English oak. The 5m x 4m tree spacing allows for adequate machinery access without the risk of compacting the soil profile around the tree roots.
Water and fertigation for the property is delivered via an automatic micro-sprinkler irrigation system. The soil moisture levels are closely monitored and adjustments made to the watering schedules to optimise growing conditions.
The truffle season begins in June with a team of trained truffles dogs covering all areas of the farm on a weekly basis. With a scratch of a paw a truffle, with its strong aroma, is found. A tag is dropped and left for the harvesting team to inspect and if ripe, gather the truffle.
The harvested truffles are immediately cleaned, graded and refrigerated ready to be packed and delivered the next day.