NZ765444A - Use of composition as an antifungal treatment for plants - Google Patents

Abstract

method of killing fungal pathogens of plants comprising the application of an effective amount of 1,3,5-Triazinane-2,4,6-Trithione (TMT) to a plant. Particularly, the TMT is in an aqueous solution in a concentration range of 0.01% w/v to 0.1% w/v. In one embodiment the aqueous solution is applied to the plant by foliar spray. In another embodiment aqueous solution containing the TMT is mixed with zeolite or composite material including zeolite. to the plant by foliar spray. In another embodiment aqueous solution containing the TMT is mixed with zeolite or composite material including zeolite.

Description

WO 2020/077384 PCT/AU2019/000129 USE OF COMPOSITION AS AN ANTIFUNGAL TREATMENT FOR PLANTS TECHNICAL FIELD This invention relates to the use of 1,3,5-Triazinane-2,4,6-Trithione in horticulture. In particular the present invention is described with reference to use of l,3,5—Triazinane-2,4,6- Trithione as an antifungal treatment for plants.

BACKGROUND Hereinafter l,3,5—Triazinane—2,4,6—Trithione ( chemical formula C3H3N3S3) will be referred to as “TMT” for ease of reference.

Since the l970’s it has been known to improve soil containing heavy metals. Metal ions such as Cd, Hg, Pb etc., typically discharged from industrial processes have accumulated in soil.

US Patent No. 3901677 (Nakamura et al.) describes the use of mercapto—s—triazines and water soluble salts to treat soil contaminated with heavy metals.

TMT (CAS No. l7766—26—6) is a reagent that binds to and precipitates heavy metals. and is typically commercially supplied in a 15% aqueous solution for such a purpose.

In China there is a significant portion of agricultural land that is polluted with heavy metals.

This is because the arable land is quite close to areas of urbanisation and industrial complexes, and the arable land has become polluted with heavy metals. Whilst crops are still capable of growing where such heavy metals exist in the soil, the heavy metals are drawn into the crop plants and therefore pose a health risk to humans and animals alike. Crops, especially rice grown on that land, have had to be withdrawn from sale due to the high levels of lead and other heavy metals. Remediation of the land with TMT mixed into the soil has been used to precipitate such heavy metals with high efficiency.

The earlier mentioned commercially supplied TMT (in a 15% aqueous solution) is for the abovementioned purpose of remediating soil by precipitating the heavy metals, and for adding same to waste water of production processes so that heavy metals are substantially removed, thereby minimizing the risk to humans and the environment at large.

All known uses to date of TMT in horticulture and remediation of land have been to act as a precipitant of heavy metals, and have been used as an additive to the soil. Prior art directed to soil remediation and repair include CNl05 1 54] 02A (Gong Canfeng), CNl06047367(Wang WO 2020/077384 PCT/AU2019/000129 Lu), CN 106479510 (Kuang Xinsheng) and DEl9715729(Maerker Umwelttechnik G1nbH). In all these prior art examples to be effective, the TMT must be mixed and distributed through the soil, namely turned into the soil to be effective as an immobiliser of heavy metals.

The present invention seeks to provide TMT for additional uses in horticulture.

SUMMARY OF INVENTION According to a first aspect of the invention, there is provided a method of killing fungal pathogens of plants comprising the application of an effective amount of TMT to a plant either upon the plant or to soil surrounding the plant.

Preferably said pathogens are any one or more of members of the genus Phytophthora spp, of the genus Pithium spp, of the genus Phellinus spp, or of the genus Fusarium spp.

In one preferred embodiment said pathogens are from the species Fusarium oxysporum.

In another preferred embodiment said pathogens are from the species Phytophthora cinnamomi.

In a preferred form said TMT is in an aqueous solution in a concentration range of 0.01% W/v to 0.1% w/v.

Preferably said aqueous solution is applied to said plant by foliar and/or stem spraying.

It is also preferred said TMT is in an aqueous solution in a concentration of about 0.03% w/v.

In another preferred form said TMT is absorbed into zeolite or a composite material including zeolite.

In one preferred embodiment said zeolite is in less than 2.2mm particle diameter.

In another preferred embodiment said zeolite is fine powdered zeolite of less than 40u.

In a further preferred embodiment said zeolite or said composite material including zeolite is disposed on a carrier material, and said carrier material is applied against the stem, roots or foliage of a plant.

Preferably said composite material includes biochar.

In another preferred embodiment said plant is any one of grass, Man gifera indica, Macadamia, Persea americana, Musa, Eucalyptus, Corymbia, Angophora, Araucaria, Cassia, Bauhinia and Grevillea.

WO 2020/077384 PCT/AU2019/000129 In another preferred embodiment said application of effective amount of TMT simultaneously promotes the growth of said plant.

According to a second aspect of the invention, there is provided a method of in combination killing fungal pathogens and promoting growth of plants comprising the application of an effective amount of T MT to a plant either by foliar spray to said plant or applied to the stem of said plant or to soil surrounding said plant, and wherein said TMT is in aqueous solution in a concentration range of 0.01% w/v to 0.1% w/v.

Preferably said pathogens are any one or more of members of the genus Phytophthora spp, of the genus Pithium spp, of the genus Phellinus spp, or of the genus Fusarium spp.

In one preferred embodiment said pathogens are from the species Fusarium oxysporum.

In another preferred embodiment said pathogens are from the species Phytophthora cinnamomi.

In another preferred embodiment said TMT is absorbed into zeolite or a composite material including zeolite and said zeolite or said composite material including zeolite is disposed on a carrier material, and said carrier material is applied against the stem, roots or foliage of a plant.

Preferably said composite material includes biochar.

In another preferred embodiment said plant is any one of grass, Mangifera indica, Macadamia, Persea americana, Musa, Eucalyptus, Corymbia, Angophora, Araucaria, Cassia, Bauhinia and Grevillea.

BEST MODE OF CARRYING OUT THE INVENTION TMT when diluted in water 1 in 1000 to l in 100, namely in a 0.1% to 1% w/v aqueous solution, can be used as a growth promotant when applied as a foliar spray to many species of plants. Growth is promoted to all vegetative tissues, roots, stems and leaves, as well as floral & fruiting tissues.

A number of examples will now be provided. It should be understood that in all of the examples given where the orchards, trees, pasture areas and surrounding soils are located these are not contaminated with accumulated heavy metals Example 1 In an avocado (Persea Americana) orchard in Queensland, an area of the orchard was selected with poor tree health.

TMT supplied in a 15% aqueous solution was diluted in collected rainwater at 1 in 400, namely in a 0.0375% w/v aqueous solution, was applied with fire—fighting pump and sprayed to the soil only beneath two trees. This spraying mimicked a tree sprinkler application and was applied as twenty litres per tree.

Within one week of spraying the two selected trees showed indications of marked new growth.

Within seven weeks of spraying the two treated trees were observed significantly different to the surrounding trees.

Within four months the two treated trees had significantly grown in size by about 20- % more than the surrounding trees.

At the time this area of the orchard was abandoned, at about seven and a half months after spraying, the feeder roots of the two trees were examined and healthy feeder roots and earthworms were found under the treated trees.

Example 2 On a property near Gin Gin, Queensland a pasture area of Rhodes grass was suffering from “pasture dieback”.

On 27 June 2017 TMT supplied in a 15% aqueous solution diluted in rainwater at l in 500 (10 ml/5L), namely in a 0.03% w/v aqueous solution was applied to a portion of that pasture area hereinafter referred to as the “treated grass”.

On 8 August 2017 grass samples were taken from the treated grass (as a test sample) and from the surrounding untreated grass (as a control sample), and each of these grass samples were placed in separate open containers containing 10ml of rainwater.

By 28 August 2017, the “treated grass” sample showed shoots and roots formed thereon and no change occurred on the untreated control sample.

WO 2020/077384 PCT/AU2019/000129 Example 3 On a property near Gin Gin, Queensland three native bloodwood (Eucalyptus) trees had been observed in April 2017 to have lost most of their leaves and appeared to be dying. On 10 April 2017 TMT supplied in a l5% aqueous solution diluted in rainwater at 1 in 500 (10 ml/5L), namely in 0.03% w/v aqueous solution was first applied by drenching the bark and surrounding soil for each of the three.

Second and third similar applications of a 0.03% w/v TMT aqueous solution were made to the three trees on 3 June and 27 June respectively.

Later new shoots from branch axils and new leaf growth appeared.

It has also been found that the functionality to stimulate growth is increased synergistically when TMT is mixed with a liquid humate solution containing fine powdered zeolite (<40u).

Example 4 Laboratory study on Phytophthora (30 September 2017 onwards to August 2018) Crop avocado soil with Phytophthora.

Treatment TMT supplied in a 15% aqueous solution diluted at 1:500 (10ml/5L) Result kills and stops lifecycle of Phytophthora. If spores breakout of sporangias they do not develop.

Similar studies were also carried out in December 2017 on Phellinus and Pithium pathogens found on avocado (Persea americana) and Eucalyptus with similar TMT aqueous solutions, and the result was that P/zellimzs and Pithium in the samples studied appeared to have been killed.

Example 5 On a mango (Mangifera indica) orchard in Queensland three mango trees were observed to be affected by fungal pathogens Phellinus and Phytophthora. TMT supplied in a 15% aqueous solution diluted in rainwater at 1 in 500 (10 ml/5L), namely in 0.03% w/v aqueous solution was used. These three trees were foliar and stem sprayed (2litre/tree each time) with the solution, once, twice or three times some two weeks apart. The fungal pathogen was killed.

The growth response was extraordinary, but in order of the number of sprays. Leaves in both WO 2020/077384 PCT/AU2019/000129 number and size followed suit as did flower spikes and fruit set. Fruit harvested was 10% greater in mass for each additional spray. It was observed but not measured that fruit was sweeter with increased spraying.

Example 6 In a second trial of mango trees (cv Kensington Pride), also in Queensland, using aqueous solution and similar foliar and stem spraying as in earlier mentioned Example 5, the fruits were noticeably sweeter with brix (sugar content measurement) measured at approximately % higher than the control trees. All the trees were sickly looking at the start and all had the Phellinus (fungal pathogen) fruiting bodies under the bark on the skin. The fungal pathogen was killed, and the treated trees had bigger brighter green leaves, much less disease and fewer insect predators than surrounding trees.

It was also noted that the trees that were treated were not affected by an unseasonal frost, whereas those nearby trees that were not sprayed were subject to frost damage.

Example 7 On a banana (Musa) plantation in Queensland, banana plants (cv Lady Finger) were identified to be affected with F usarium oxysporum (an ascomycete fungus). Vascular colourisation was seen where the fungus had colonised. A trial using foliar sprays was used. TMT supplied in a % aqueous solution diluted in rainwater at 1 in 500 (10 ml/5L), namely in 0.03% w/v aqueous solution was used for the foliar spraying of seven affected banana plants. This trial was 100% successful on killing off the fungus on the seven affected plants. A control group of a further seven affected plants were sprayed only with water, and no change was noted on the control group.

Various trials on other species will now be discussed generally.

Grass trials In addition to abovementioned Example 2, various grasses have been trialled.

Treatment of grass die back from Phellinus and Pithium were successful across a range of grass species including but not limited to blue grass, couch, Rhodes and turf grasses from different habitats. There is some difficulty in ascribing the cause of the results due to the presence of a mealy bug which is attacking the grass roots. However, treatment with TMT supplied in a 15% aqueous solution diluted in water at l in 500 (10 ml/5L), namely in 0.03% WO 2020/077384 PCT/AU2019/000129 W/V aqueous solution was used for spraying and overturned the mite infection. Quantification of increase in dry matter resulted in doubling the mass of the control (200% +/—4%).

Trials were performed on grazing land, a football field, a house front lawn with controls and on golf course couch greens. In all trials on soil with spray application (SOL/50m2) relative to controls with water only or TMT +humate solution applied in zeolite or in biochar +/— TMT and humate, lkg/l0m2 with 40L of solution/T of absorbent. Dead patches were resolved completely in 10-14 days, except for the football field which may have been compromised by using chlorinated town water, instead of rainwater for the aqueous solution.

Tree trials In addition to abovementioned Example 3, various trees and plants such as Araacaria (native soft woods), Cassia and Bauhinia (related to Acacia), Grevillea (related to Macadamia) have been trialled and by spraying with TMT supplied in a 15% aqueous solution diluted in water at l in 500 (lO1nl/5L), namely in 0.03% w/v aqueous solution. All these trees which were showing poor growth, showed marked improvement with growth after a few weeks of spraying.

Additional trials were also carried out on Eucalypts other than that described in Example 3.

Under current drought conditions and the presence of Phytophthora in the soil, all of the additional trees we trialled looked close to death. The bark of all the following trees were sprayed viz. blue gum, spotted gum, blood wood, lemon scented gum, Moreton Bay ash and Corymbia costata. In all cases there was a slow but consistent response, with epicormic buds appearing on the tree trunks, under the bark and new leaves appearing on apparently dead branches.

The various examples and trials described above clearly indicate that a small amount of TMT, in an aqueous solution in a concentration range of 0.01% w/v to 0.1% w/v, but typically about 0.3%w/v when sprayed (foliarly and stem) on plants and grasses, is effective as a growth proinotant on the plants, and/or a treatment for fungal pathogens.

Typically, when a plant is affected by a fungal pathogen, any other stress on the plant such as poor soil condition or drought synergistically compounds the stress on the plant. In the various abovementioned examples and trials it has been observed that the effectiveness of using a small amount of TMT in aqueous solution as a treatment for fungal pathogens, is markedly apparent when the plants prior to the application of TMT aqueous solution have also been WO 2020/077384 PCT/AU2019/000129 further stressed due to drought and/or poor soil. However, even when the plants appear to not otherwise be stressed initially other than by a fungal pathogen, the application of the TMT aqueous solution is effective as an anti—fun gal treatment and as a growth promotant.

In the prior art the use of spraying a TMT aqueous solution to plants was not known, and the only use of TMT was to deal with soil remediation in significantly higher concentrations.

The embodiments described herein have many applications for horticulture and agriculture and can be used to deal with problems not previously able to be dealt with in a cost—effective IIIEIIIIICI‘.

For example, there are over six hundred and fifty species of closely related genera, Eucalyptus, Corymbia & Angophora. Eucalyptus die back is a very serious problem in many parts of the World particularly where fine quality timber is used in furniture manufacture, but also on grazing land and in forests of high commercial value. In Eastern Australia the fungal pathogen is P/zytophthora cirmamoni, as it is also in SW Western Australia, in the Jarrah and Karri forests, and in the South Island of New Zealand in the soft wood Kauri forests. It is envisaged that Eucalypt die back can readily be treated with inexpensive spraying using TMT.

Various other crop trials In addition to trials on avocadoes and mangoes as described earlier in Examples 1,5 and 6, other crop vegetation, such as hemp, macadamias, grapes, citrus (mandarins) and capsicum have been treated by spraying using TMT supplied in a 15% aqueous solution diluted in water at 1 in 500 (10 1nl/5L), namely in 0.03% w/V aqueous solution. For all these crops the plants showed improvement of growth.

Use of TMT with zeolite Also, TMT diluted with water and absorbed into zeolite (<2.2mm particle diameter) when applied to topsoil provides improvement through uptake by roots. Furthermore, TMT, when diluted with water and absorbed into zeolite (<2.2mm particle diameter) and then applied onto soil, is slowly released into the topsoil after wetting sequentially up to ten times.

TMT diluted with water kills the soil borne fungal pathogens, P/zytothpliora cimzamomi, Pithium spp., and Phellinus spp. on contact.

WO 2020/077384 PCT/AU2019/000129 TMT diluted with water and absorbed into zeolite (<2.2mm particle diameter) retains its capability to kill such Phytophthora, Phellinus and Pithium pathogens with sequential wetting up to ten times.

The zeolite that absorbs the TMT may be provided by itself, or in a composite material, such as one primarily containing zeolite and biochar. Preferably the zeolite makes up about 50-70% of the composite material by mass.

As a number of the abovementioned examples have demonstrated the anti—fungal properties when using TMT as a spray, it is proposed that using TMT diluted with water and absorbed into zeolite or a composite material containing zeolite, can be used as an anti—fun gal agent.

Whilst it is envisaged that such treatment could be delivered by spraying, another preferable way of administering the TMT is as follows.

A thin mat, bandage or other carrier material is used to carry zeolite or the composite material comprising zeolite. One such carrier material is coir (coconut fibre) mat. TMT diluted with water is absorbed into the zeolite which in turn is deposited on the coir mat. This coir mat (carrier material) is then applied against the stem, roots or foliage of a plant. The TMT is slowly released from the zeolite by wetting, thereby contacting with the plant and acting as an anti—fungal treatment and/or preventative measure. At present trials are being carried out to assess the efficacy of same.

TMT diluted with water appears not to be toxic to other soil microbes including other pathogens, fungi, bacteria as well as other soil or water borne biota. Furthermore, TMT diluted with water as described in the abovementioned embodiments and examples has been observed to apparently be benign to most other small organisms including but not limited to insects, annelids, crustaceans, molluscs, arachnids etc as well as bigger ones like birds and animals.

The LD—50 for the rat is 2x the body mass of the rat, so it would drown before dying by ingestion.

In the abovementioned examples and trials it has been observed that the effectiveness of using the TMT aqueous solution as a growth prornotant for plants is markedly apparent when the plants prior to the application of TMT aqueous solution have been stressed for example due to drought, poor soil or fungal pathogens. However, even when the plants are not stressed initially, the application of the TMT aqueous solution acts as a growth promotant.

WO 2020/077384 PCT/AU2019/000129 It should be understood that the use of TMT in small effective amounts as earlier described, may be used for other orchard crops such as apple trees (Malus domestica) for the purposes of a growth promotant and/or treatment of fungal pathogens.

WO 2020/077384 PCT/AU2019/000129

Claims (12)

1. CLAIMS:1. A method of killing fungal pathogens of plants comprising the application of aneffective amount of TMT to a plant either upon the plant or to soil surrounding theplant.
2. 2. The method of claim 1, wherein said pathogens are any one or more of members ofthe genus Phytophthora spp, of the genus Pithium spp, of the genus Phellinus spp,or of the genus F usarium spp.
3. 3. The method of claim 2, wherein said pathogens are from the species F usariumoxysporum.
4. 4. The method of claim 2, wherein said pathogens are from the species Phytophthoracirmamomi.
5. 5. The method of claim 1, wherein said TMT is in an aqueous solution in aconcentration range of 0.01% w/v to 0.1% w/V.
6. 6. The method of claim 1, wherein said aqueous solution is applied to said plant byfoliar and/or stem spraying.
7. 7. The method of claim 1, wherein said TMT is in an aqueous solution in aconcentration of about 0.03% w/V.
8. 8. The method of any one of claims 1 to 7, wherein said TMT is absorbed into zeoliteor a composite material including zeolite.
9. 9. The method of claim 8, wherein said zeolite is in less than 2.2mm particlediameter.
10. 10. The method of claim 8, wherein said zeolite is fine powdered zeolite of less than40u.
11. 11. The method of claim 8, wherein said zeolite or said composite material includingzeolite is disposed on a carrier material, and said carrier material is applied againstthe stem, roots or foliage of a plant.
12. 12. The method of claim 8, wherein said composite material includes biochar.WO