Last month, Robert Chang and I visited Western Australia to explore several facets of their native truffle industry. While there, I was particularly keen to look at the issues many orchards are having with truffle rot.
Despite the fact that some plantations in Western Australia produce very good yields, there has been a localized problem with truffles rotting before they are harvested. This has been so extreme that in some cases up to 50% of the harvest has been lost. The high level of truffle degradation is specific to this truffle cultivation region. Many producing areas of Australia have particularly warm winter temperature averages when compared to other producing regions and this may be a contributing factor to their localized problem.
In 2009, the most productive plantation lost 39% of their harvest to rot—a figure largely unrecognized elsewhere in the truffle world. The mechanism of rot is complex and seems to be due to some form of animal damage followed by bacterial colonization. This is also largely a problem of surface-forming truffles, with the majority of cases occurring in truffles formed within the top 2 inches of the soil profile, with deeper truffles largely remaining unaffected.
Interestingly, results from experiments to cover developing truffles that are forming on the surface show no significant reduction in rot. However, a number of other trials have been successful and results have shown that levels of rotten truffles can be very significantly reduced by altered irrigation regimes, as well as different soil cultivation methods.
Although largely a localized problem, lessons can be learned and applied elsewhere. The issue in Australia also perfectly highlights why truffle cultivation practices need to be tailored to each individual plantation.
If you have any questions, or if you’re interested in cultivating your own truffle orchards, please contact us.