Inoculated Tree Seedling Batch-testing Scheme
AUSTRALIAN TRUFFLE GROWERS’ ASSOCIATION
Tree Seedling Testing Scheme for French Black Truffle, Tuber melanosporum
For a list of recommended Nurseries see below.
Until recently, an accepted standardised testing scheme has not been available to prospective truffle producers purchasing oak, or hazelnut tree seedlings inoculated with the French black truffle (Tuber melanosporum). The purpose of this is to indicate, with some confidence, the level of truffle colonisation, the health of the trees, or the presence of contaminants such as less-desirable Tuber species, or other mycorrhizae. As a result, if a truffière were to be unproductive, it has been difficult to determine the cause, as vital information may be missing, e.g. the quality of the seedlings and the quantity of Tuber colonisation on their roots at the time of planting.
Consequently the Association has worked for some years to establish an Australia-wide testing scheme for truffle-inoculated tree seedlings. The scheme, specifically for inoculated seedlings raised for producing the French black truffle, is broadly based on a similar scheme that is well established in Spain under a government programme to support truffle growing. Under the auspices of the Rural Industries Research and Development Corporation (RIRDC) the Association engaged in extensive consultation and research to examine the key issues relating to establishing such a scheme in Australia, and is pleased to announce that such a scheme has now been implemented. The scheme will enable nurseries to supply inoculated seedling stock, accompanied by data collected and analysed through an independent process, and will allow nurseries and prospective purchasers to have greater confidence in their product with respect to mycorrhization.
The scheme is open to all nurseries and is voluntary. Currently two nurseries have implemented the scheme and the Association anticipates that the number of participant nurseries will gradually increase over the coming years. A nursery can register to participate in the scheme simply by contacting the Association at firstname.lastname@example.org .
HOW THE SCHEME OPERATES
When a nursery has a “batch” of uniformly raised and treated seedlings ready for testing (say 500, or more which are of the same glasshouse, seed batch, inoculation procedure, growing medium and date of inoculation), an independent technician is engaged to randomly select 12 seedlings from the batch using a strict sampling protocol.
These representative sample seedlings are labelled, packed and sent to an independent laboratory where the individual seedlings are assessed according to prescribed criteria, including:
- plant condition and quality – general health and root architecture of the seedlings,
- the number and percentage of roots colonised by Tuber melanosporum,
- DNA verification of other Tuber mycorrhizae, specifically: indicum, T. aestivum, T. brumale, T. borchii and T. maculatum. Other mycorrhizal fungi found will be noted, but not identified.
The test results are aggregated to provide an overall assessment of the original batch of trees. Once data are available and the nursery operator is satisfied with the results of the “batch”, the Association allocates serially numbered tags for all the seedlings within that “batch”. Data on a tested “batch” can be obtained from the nursery, but can also be accessed through the Association. It is important to understand that the purchaser is acquiring seedlings derived from a batch that has been tested. The individual trees they purchase are therefore not guaranteed except that they are from a tested batch.
This scheme will help truffle growers to know that, for any tagged trees, independently assessed information is available for inspection prior to purchase and a copy should be required as part of the purchase agreement.
VERY IMPORTANT – PLEASE NOTE:
- It is important that the prospective truffle producers / purchasers note that purchasing a tagged tree seedling from a tested batch under this scheme is not a guarantee of success**. It is however, verification that the “batch” has been randomly sampled and tested independently in accordance with the scheme, and that the resultant data are available for use/interpretation by the purchaser or their agronomist/consultant. Although some guidelines on interpretation of the data will be provided with the results, prospective purchasers are urged to seek professional advice to ensure accurate interpretation of the report.
- This scheme is to assist seedling growers and truffle producers gain knowledge about seedling “batches”, but Australian Truffle Growers’ Association will not be responsible for the assessment and results provided by the independent technician or testing laboratory.
- Once seedlings are planted, their new environment will exert a very strong influence over the development, and even the survival of the truffle mycorrhizae on their roots. Proper site choice, preparation and maintenance of the plantation environment are critical to the ultimate success of the truffière.
- The scheme does not certify or provide a warranty for the nursery per se.
**As the testing procedure involves the complete destruction of the tested seedlings, a randomly selected sample from the same production “batch” has been tested but the tagged trees themselves have NOT been tested. Accordingly, there remains a degree of statistical error: that is indicated by the level of confidence (Confidence Index) in the test results. Potential purchasers of trees are advised to read a copy of the batch testing report before they commit to the purchase.
Nurseries participating in the tree certification program to date are:
- Note for all nurseries; please contact Association President, to confirm your participation and listing.