Project reference: 2000-02
Cattle Grazing and Diplodia Staining in Pinus radiata
Project description:
Recently, during thinning operations in Northland, there have been signs of stain in stands of radiata pine, reducing the value of the log, and perhaps the crop as a whole. The stands concerned had earlier been subject to cattle grazing, and questions arise as to:
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whether the staining was initiated by fungi such as Diplodia (Sphaeropsis sapinea) invading through wounds to the root collar region caused by cattle?
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how much of this degrade is present, and is it significant?
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do the fungi remain alive, and extend their effect within the tree during the rotation, once they have invaded?
The issue is of concern, because some of these stands have been given silvicultural auditing, and if staining is found to be significant, then the real value of the crop may actually be lower than certified.
It is proposed that an initial investigation be undertaken to see if this is a genuine problem, and if so to document it. Stumps and stems will be examined at time of early thinning, and spatial records made of any stain present, and of its extent up the tree. Sampling will be undertaken in a number of forests where information is available on early cattle grazing (or not: controls). Account will also be taken of soil category and variation. A sample of stained stumps will be dissected to see if early damage to roots and root collars can be identified, and if so, whether this can be related to the staining. Isolations will be attempted to test the viability of the fungi present, in relation to position within the tree.
Findings will be documented in a report, which will include recommendations on further work, if appropriate, and a consideration of how the issue can be realistically handled.
If this submission is deemed worthy of consideration, then the proposed work will be outlined in full detail, after further consultation with the relevant people, and it will probably be necessary to collaborate with one or more other parties, in order to achieve full value. It is envisaged that the field and most laboratory work will be undertaken in the first year, and report writing in the final year.
Research Provider:
Forest Research
