AU710256B2 - Biodestumping - Google Patents

Description

2 THIS INVENTION relates to a method of removing a tree stump from a plantation.

The method of the invention applies particularly to the removal of a plurality of remaining tree stumps from a plantation after tree felling.

It is necessary to remove remaining tree stumps after tree felling from plantations in order to be able to plant and grow new seedlings and also to be able to harvest a following crop. Particularly in relation to hardwoods, which do not rot quickly in the way that softwoods do, the removal of tree stumps is a very expensive operation that cannot always be afforded and, therefore, can result in delays in the planting of new seedlings, which in turn render associated land unproductive. The known ways of removing tree stumps essentially comprise the use of mechanical means such as bulldozers and stump chipping machines. The method of the invention includes the use of decay microorganisms by which is meant, within this specification, organisms including one or more decay fungus and/or one or more decay bacterium.

3 It is an object of this invention to provide a method of removing tree stumps from plantations which is relatively simple to carry out, while being more cost effective than the known mechanical methods.

According to the invention there is provided a method of removing a tree stump from a plantation, which includes the steps of introducing a systemic herbicide into a hole bored into the tree stump to S" be removed for killing off the tree stump; and 0 introducing decay microorganisms into a hole bored into the tree stump to be removed for inducing the growth and colonization of the microorganisms within the tree stump and thereby causing the tree stump to rot and effectively disintegrate.

9999 For a particular type tree stump to be removed, the method of the invention includes selecting the required decay microorganisms that through their growth and colonization within the tree stump will cause the tree stump to rot and effectively disintegrate, and inducing the growth and colonization of the selected decay microorganisms within the tree stump.

The decay microorganisms selected particularly are of types that can compete with and outgrow other microorganisms active in the region of the tree stump to be removed, that can rot and effectively disintegrate AIT.. /L i 3a both the rootwood and the heartwood and the sapwood of the tree stump to be removed and that are non-pathogenic with respect to growing trees.

As such, the decay microorganisms may include at least one of the decay fungus, a consortium of decay fungi and a decay bacterium.

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4- A decay fungus utilized may be of a wild-type culture that has been selected and adapted for the purpose and, similarly, a consortium of decay fungi utilized may be of wild-type cultures that have been selected and adapted for the purpose.

Particularly for removing a Eucalyptus tree stump, the decay microorganisms may include a consortium of cellulolytic, hemicellulolytic and ligninolytic saprophytic decay fungi, which preferably are of wild-type cultures that have been selected and adapted for the purpose.

Where the microorganisms include a bacterium, the bacterium may be of the Order Actinomycetales, or any other suitable group as will be determined by the type of 10: tree stump to be removed.

The method of the invention may include preparing freeze dried spores of the decay microorganisms and applying the spores to the tree stump to be removed for inducing the growth and the colonization of the microorganisms. The freeze dried spores of ::i the microorganisms may be mixed with a nitrogen source prior to the application to a tree stump, the nitrogen source typically being a nitrogen source in powder form such as urea.

The method of the invention particularly may include suspending the decay microorganism spores and the nitrogen source in water, with suitable surfactants therein where required, prior to application to a tree stump. Further according to the invention, the method may include applying the microorganism spores in their suspended form with a nitrogen source to a tree stump by boring at least one hole in the tree stump and pouring the suspended mixture into the hole where the micro organism spores can be allowed to incubate and hence grow and colonize the tree stump. Additionally, the decay microorganisms may be applied to all open wounds of a tree stump that have remained after felling of the tree.

Still further, the method of removing a tree stump from a plantation may include combining the application of the decay microorganisms with the application of a systemic herbicide that can serve to kill the tree stump after felling of the tree. It is envisaged that the systemic herbicide may be of a type known in the trade as "Chopper" as supplied by Agricura, or of a type known in the trade as "Timbrel" as S" supplied by Dow Elanco.

ooo i The method of the invention is now described, by way of an example which illustrates the use of the method of the invention in respect of the removal of Eucalyptus tree stumps.

In order to prepare for the removal of Eucalyptus tree stumps from a plantation, freeze-dried spores of suitable decay microorganisms are prepared, it being envisaged that the freeze-dried spores can be prepared in an organic vehicle such as a yeast extract to prolong spore viability. The decay fungi typically comprise cellulolytic, 6 hemicellulolytic and ligninolytic saprophytic decay fungi which are of wild-type cultures, rather than genetically manipulated organisms, the decay fungi being suitably screened, selected and adapted for the purpose. It must be appreciated, however, that genetically manipulated microorganisms can be utilized for carrying out the method of removing a tree stump from a planation, in accordance with the present invention, it being envisaged that it will be possible to create genetically manipulated organisms suitable for the purpose.

The fungi selected particularly are of types that can compete successfully and outgrow other fungi which may be in the forest and, furthermore, the fungi selected 1°0: are of types that will decompose and rot Eucalyptus rootwood, including heartwood and sapwood therein and that are non-pathogenic with respect to growing trees.

Similarly, suitable decay bacteria may be utilized, such bacteria particularly including spore forming Actinomycetes which play a role in the terminal succession pattern of wood decay.

Prior to application of the fungi to tree stumps, the freeze-dried spores are mixed with a nitrogen source, particularly a powdered nitrogen source such as urea, it being envisaged that this mixture can be suitably packaged as such prior to use.

For use, and in accordance with the method of the invention, after felling of trees, holes are bored into the remaining tree stumps while the freeze-dried spores and -7 powdered nitrogen source mixture are suspended in a suspension medium such as water with or without suitable surfactants. The nitrogen supplemented suspension of the spores is then poured into the holes, while being simultaneously applied over all exposed "wounds" of the tree stump, whereafter the spores are permitted to incubate and hence grow and colonize the tree stump, causing the tree stump to rot and effectively disintegrate.

It is envisaged that particularly in the South African climate, and that of other hot countries with hardwood plantations, such as Brazil and Australia, the method of the invention will be particularly applicable, insofar as incubation and growth of the i: microorganisms will occur rapidly, resulting in the decomposition of the cellulose, -hemicellulose and lignin of the tree stumps, with the nitrogen content being adjusted as described. The decay microorganisms particularly will be of types that will not result in damage to any neighbouring trees and it is envisaged that as a result of the decomposition of the tree stumps, the stumps either will collapse or, if such collapse does not occur, will disintegrate to the extent that they will offer little or no resistance when equipment is reintroduced to the land involved, for the purpose of preparing the land for the planting of new seedlings.

The method of the invention will provide for the rotting of the tree stumps within an acceptable period before the planting of new seedlings is required, while it is envisaged also that the method of the invention can be used in association with a S a a *Sa* a..

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a a 9 The claims defining the invention are as follows: 1. A method of removing a tree stump from a plantation, which includes the steps of introducing a systemic herbicide into a hole bored into the tree stump to be removed for killing off the tree stump; and introducing decay microorganisms into a hole bored into the tree stump to be removed for inducing the growth and colonization of the microorganisms within the tree stump and thereby causing the tree stump to rot and effectively disintegrate.

2. A method as claimed in Claim 1, which includes, for a particular type tree stump to be removed, selecting the required decay microorganisms that through their growth and colonization within the tree stump will cause the tree stump to rot and effectively disintegrate, and inducing the growth and colonization of the selected decay microorganisms within the tree stump.

3. A method as claimed in claim 1 or Claim 2, in which the decay microorganisms are of types that can compete with and outgrow other microorganisms active in the region of the tree stump to be removed, that can rot and effectively disintegrate both the rootwood and the heartwood and sapwood of the tree stump to be

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Claims (12)

1.0 The applicant submits that the above method of removing tree stumps from plantations is a simple, yet economic method of removing tree stumps and will result in shorter time periods between tree felling and the planting of new seedlings, which in turn will render the use of the associated land for the planting of trees more productive. This method further will reduce the amount of potentially harmful chemicals being introduced into the environment during conventional stump killing operations, using solely herbicides. This method also will alleviate soil compaction and consequent yield reduction associated with the use of mechanical stump removal means. Still further, it is envisaged that the method of the invention will result in increased soil fertility when planting new seedlings. removed and that are non-pathogenic with respect to growing trees.

4. A method as claimed in any one of Claims 1 to 3, in which the decay microorganisms include at least one of a decay fungus, a consortium of decay fungi and a decay bacteria. A method as claimed in Claim 4, in which the microorganisms include a decay fungus of a wild-type culture that has been 10 selected and adapted for the purpose. aV..

6. A method as claimed in Claim 4, in which the microorganisms include a consortium of decay fungi of wild-type cultures that have been selected and adapted for the purpose.

7. A method as claimed in Claim 4, in which, for removing a Eucalyptus tree stump, the decay microorganisms include a consortium of cellulolytic, hemi-cellulolytic and ligninolytic saprophytic decay fungi.

8. A method as claimed in Claim 7, in which the decay fungi are of wild-type cultures that have been selected and adapted for the purpose. 11

9. A method as claimed in any one of Claims 4 to 8, in which the decay microorganisms include a bacteria of the Order Actinomycetales.

10. A method as claimed in any one of the preceding claims, which includes preparing freeze dried spores of the decay microorganisms and introducing the spores to the tree stump to be removed for inducing the growth and colonization of the microorganisms within the tree stump.

11. A method as claimed in Claim 10, in which the freeze dried spores C of the microorganisms are mixed with a nitrogen source prior to their introduction into a bore formed in the tree stump. S.,

12. A method as claimed in Claim 11, in which the nitrogen source is a source in powder form such as urea.

13. A method as claimed in Claim 12, which includes suspending the decay microorganism spores and the nitrogen source in water, with suitable surfactants therein where required, prior to application into a tree stump.

14. A method as claimed in any one of the preceding claims, which includes introducing the systemic herbicide and the decay 12 microorganisms into the same hole bored into the tree stump to be removed. A method as claimed in any one of the preceding claims, which includes boring two or more holes into a tree stump to be removed and introducing the systemic herbicide and the decay microorganisms into all the holes bored. *4

16. A method as claimed in any one of the preceding claims, which includes applying the decay microorganisms to all open wounds of a tree stump that have remained after felling of the tree. "17. A method of removing a tree stump from a plantation substantially as described in the specification. 44 DATED this Seventh day of July 1999 BIOTECHNOLOGY INTELLECTUAL PROPERTY N.V. By its Patent Attorneys FISHER ADAMS KELLY ABSTRACT This invention relates to a method of removing tree stumps from a plantation after tree felling. The method includes selecting decay microorganisms that, through their growth and colonization within a tree stump, will cause the tree stump to rot and effectively disintegrate, producing freeze dried spores of the microorganisms selected and applying these spores in a suitable form to the tree stumps to be removed. The microorganism spores can then incubate, following which the o 0 microorganisms will grow, causing colonization thereof in the tree stumps and resulting in the tree stumps to rot and disintegrate. This in turn will allow new seedlings to be planted relatively quickly after tree felling occurred and, as such, the productive use of the associated land. 0* *00 .0. go