CONTROLLING THE GROWTH OF VEGETATION

Abstract

A method for controlling the growth of vegetation includes a step of applying a composition to the foliage of the vegetation, without any pre-heating. The application of the composition induces osmosis on cells of the foliage and destroys those cells. The composition includes an aqueous solution of at least one sugar, and optionally further includes a penetrant and an additional component such as a fatty acid. The sugar may be selected from natural plant-based sugars, sugar substitutes and sugar alcohols. The concentrations of the active ingredients may be varied to give either a weed-killing effect, or a plant growth inhibitor effect, as desired.

Claims

1. A method for controlling the growth of vegetation, comprising applying to the foliage of the vegetation, without any pre-heating, a composition comprising an aqueous solution of at least one sugar, thereby to induce osmosis on cells of the foliage and destroy those cells.

2. The method as claimed in claim 1, wherein the sugar comprises at least one plant-based natural sugar.

3. The method as claimed in claim 2 wherein said at least one plant-based natural sugar is selected from the group consisting of sucrose, glucose, fructose, galactose, maltose, arabimose, lactose, inositol, mannose, ribose, trehalose, and xylose.

4. The method as claimed in claim 1, wherein the sugar comprises at least one sugar substitute.

5. The method as claimed in claim 4, wherein said at least one sugar substitute is selected from the group consisting of saccharin, sodium saccharin, stevia rebaudiana, siraitia grosvenori, aspartame, acesulfame potassium, sucralose, neotame, and advantame.

6. The method as claimed in claim 1, wherein the sugar comprises at least one sugar alcohol.

7. The method as claimed in claim 6, wherein said at least one sugar alcohol is selected from the group consisting of sorbitol, xylitol, lactitol, mannitol, erythritol, and maltitol.

8. The method as claimed in claim 1, wherein the solution comprises at least two sugars selected from the group consisting of natural sugar, sugar substitute and sugar alcohol.

9. The method as claimed in claim 1, wherein the sugar comprises sodium saccharine.

10. The method as claimed in claim 1, wherein the solution has a sugar concentration in the range of from 50 to 133 g/l.

11. (canceled)

12. The method as claimed in claim 1, wherein the composition further comprises a penetrant to promote the osmotic action of the solution.

13. The method as claimed in claim 12, wherein the penetrant comprises at least one component selected from the group consisting of a surfactant, a wetting agent and an adjuvant.

14. The method as claimed in claim 12, wherein the penetrant is selected from the group consisting of alkyl polyglucoside (apg), Validate and Yucca extract.

15. (canceled)

16. The method as claimed in claim 12, wherein the penetrant is present in the solution in an amount in the range of from 0.15% to 0.5% by volume, relative to the volume of water.

17. (canceled)

18. The method as claimed in claim 1, wherein the composition comprises at least one additional component selected from the group consisting of citric acid, a fatty acid, and an essential oil.

19. The method as claimed in claim 18, wherein the essential oil comprises at least one essential oil selected from pine oil, manuka oil and tea tree oil.

20. (canceled)

21. The method as claimed in claim 18, wherein the fatty acid comprises at least one fatty acid selected from pelargonic acid, acetic acid and caprylic acid.

22. (canceled)

23. The method as claimed in claim 18, wherein the composition comprises substantially 50% sugar solution and substantially 50% fatty acid.

24. The method as claimed in claim 20, wherein the fatty acid is present in the composition in an amount of substantially 9% by volume relative to the volume of water.

25. The method as claimed in claim 1, in which the composition is applied by spraying at ambient temperature, at a rate sufficient to wet the majority of the foliage of the plant being treated.

26. (canceled)

27. (canceled)

28. (canceled)

29. (canceled)

30. (canceled)

Description

[0035] In order that the invention may better be understood, it will now be described in more detail and certain specific examples thereof given, by way of illustration of the methods of controlling the growth of vegetation. In the following, reference will be made to the accompanying tables, and photographs, in which:

[0036] Table 1 lists various natural sugars which can be used in performing this invention, along with the origin of those sugars;

[0037] Table 2 lists various high intensity sugars which can be used in performing this invention, all of which are chemically synthesised except for stevia (stevia rebaudiana) and siraitia grosvenori, both of which are extracted from plants;

[0038] Table 3 lists various sugar alcohols which can be used in performing this invention, along with the origin of those sugars;

[0039] Table 4 sets out the formulations of various compositions used to control the growth of vegetation, along with control compositions (Examples 1 to 3) for comparative purposes, and the results obtained with the compositions; and

[0040] Table 5 sets out the formulations of various compositions with additional components, used to control the growth of vegetation, along with control compositions (Examples 13 and 14) for comparative purposes, and the results obtained with the compositions in further trials.

[0041] In order to test the methods of this invention several trials of sugar-containing compositions were conducted on a broad spectrum of plants commonly regarded as weeds, including creeping buttercup, grasses, dandelion, bindweed, common sorrel, fat hen, amaranth, field forget-me-not and so on. The composition formulations and results of the trials are set out in Table 4. In Table 4, 0 in the Days after application columns indicate zero phytotoxicity action, and 10 indicates an excellent performance with 100% plant killing. In each case, the compositions were applied to the plants by spraying at a rate sufficient to wet the foliage of the plants, this being assisted by the use of a penetrant and, in some cases, the use of APG.

[0042] Referring primarily to Table 4, APG is alkyl polyglucoside, a non-ionic surfactant. APG has been used in commercial applications of the method of WO94/26102, to assist in the application of the hot foam of that method to the foliage of plants. The inclusion of APG in the trials of this invention was to confirm that APG did not cause degradation of plant life in a cold water solutioni.e. that it did not take part in the method of controlling the growth of vegetation.

[0043] Validate is as has been defined hereinbefore; again, its inclusion in the trials of this invention was to confirm that Validate did not cause degradation of plant life in a cold water solutioni.e. that it did not take part in the method of controlling the growth of vegetation.

[0044] Yucca is an extract from the yucca plant; extracts from certain species are high in saponin content and so widely used as a natural surfactant or wetting agent.

[0045] Except for Examples 1 to 3 (APG alone, Validate alone and Yucca alone), the compositions of Table 4 were made up by mixing with water a weight of natural sugar and/or sugar substitutes with a surfactant/spreader/penetrant, all as shown in the various columns of Table 4.

[0046] Except for Examples 1 to 3 (APG alone, Validate alone and Yucca alone) where no phytotoxicity was observed, the result of application of the compositions by spraying across a broad spectrum of weeds indicate the physical mode of action of the sugar content, being that of plasmolysis, which exceeds the performance of other weedkillers such as glyphosate (e.g. Roundup).

[0047] Example 4 comprises 100 g of sodium saccharin and 2.5 ml of Validate mixed into 1000 ml of water. As can be seen, after 42 days the plant was killed with no re-growth even after 189 days.

[0048] Example 5 comprises 50 g of sodium saccharin and 50 g of stevia, together with 1.5 ml of APG, mixed into 1000 ml of water. As can be seen, though there was an initial reaction, after 42 days the plant largely recovered.

[0049] Example 6 comprises 100 g of stevia and 7.5 ml of yucca, mixed into 2000 ml of water. As can be seen, there was an initial reaction building to a maximum after 42 days, but then some re-growth occurred.

[0050] Example 7 comprises 100 g of natural sugar and 50 g of stevia together with 7.5 ml of yucca, mixed into 2000 ml of water. As can be seen, there was only limited phytotoxicity to the plants treated with this composition.

[0051] Example 8 comprises 100 g of natural sugar, 50 g of stevia and 5 ml of Validate mixed into 2000 ml of water. As can be seen, there was only limited toxicity to the plants treated with this composition, though a better performance than Example 7.

[0052] Example 9 comprises 100 g of sodium saccharin and 5 ml of Validate mixed into 2000 ml of water. As can be seen, after 42 days the plant was killed with no re-growth even after 189 days.

[0053] Example 10 comprises 75 g of sodium saccharin, 125 g of natural sugar and 10 ml of yucca mixed into 2000 ml of water. As can be seen, there was only limited phytotoxicity to the plants treated with this composition.

[0054] Example 11 comprises 50 g of sodium saccharin, 150 g of stevia and 2.5 ml of AGP mixed into 1500 ml of water. As can be seen, this composition had essentially no toxicity on the plants to which it was applied.

[0055] Example 12 comprises 75 g of sodium saccharin, 125 g of natural sugar and 7.5 ml of Validate mixed into 2000 ml of water. As can be seen, after 42 days the plant was killed with no re-growth even after 189 days.

[0056] From the results of the above trials, it will be appreciated that APG had no effect as an active ingredient in controlling the growth of plants (Example 1). Equally, when mixed with Validate there was no effect as an active ingredient in controlling the growth of plants (Example 2). By contrast, the use of sugar substitutes (sodium saccharin and stevia) together with Validate produced outstanding results in all mixture ratios.

[0057] Natural sugar alone at the ratios applied did not provide commercial acceptable results. Validate as a surfactant and penetrant provided best results in all Examples when compared to yucca. The action of yucca was inferior in all trials to that of Validate.

[0058] In the trials, it has been observed that on treating many perennial species there has been translocation resulting in complete destruction of the root system of the weeds. Thus, it seems that the osmotic action of the applied sugar has been carried down to the root system, and is not active solely on the foliage on to which the composition has been sprayed. This suggests the mode of action of this invention is one of foliar stimulated plasmolysis which then has a secondary effect by either shutting down osmotic action at the root of the plant (preventing the drawing of water into the plant) or some other translocating activity generated by the destruction of the foliage.

[0059] This can be contrasted with other contact methods of controlling the growth of vegetation, such as the use of paraquat and heat thermal treatments (such as in WO0207513) where limited die back has been observed.

[0060] Accompanying this specification are five sheets of photographs, each sheet carrying three photographs of a treated area. On each sheet, the plants (generally regarded as weeds) were treated with the specified compositions of Table 4, and photographed at the time of application, 7 days later and again 62 days later. As can be seen, complete killing of the weeds was achieved with Examples 4, 9 and 12.

[0061] Referring now to Table 5, further trials were carried out using compositions comprising a preferred sugar component, namely sodium saccharin, and a preferred additional component, namely pelargonic acid. Trials were carried out to observe potential benefits on weed kill of mixing these active ingredients, during the November/December winter season.

[0062] Example 13 is a control composition comprising pelargonic acid only, at the manufacturer's recommended concentration of 85 ml in 500 ml of water. As can be seen, the efficacy score, observed 15 days after application on the same scale as hereinbefore described, was 3.

[0063] Example 14 is a control composition comprising sodium saccharin only, at the manufacturer's recommended concentration of 100 g in 1000 ml of water. As can be seen, the efficacy score, observed 15 days after application on the same scale as hereinbefore described, was 2.

[0064] Example 15 comprises 100 g of sodium saccharin and 180 ml of pelargonic acid, together with 5 ml of Validate, in 2000 ml of water. The concentrations of both active ingredients are therefore substantially 50% of the recommended level. As can be seen, the efficacy score, observed 15 days after application on the same scale as hereinbefore described, was 7.

[0065] Example 16 comprises 100 g of sodium saccharin and 340 ml of pelargonic acid, together with 5 ml of Validate, in 2000 ml of water. The concentration of sugar is therefore substantially 50% of the recommended level, whilst the concentration of fatty acid is at the recommended level. As can be seen, the efficacy score, observed 15 days after application on the same scale as hereinbefore described, was again 7.

[0066] Example 17 comprises 200 g of sodium saccharin and 180 ml of pelargonic acid, together with 5 ml of Validate, in 2000 ml of water. The concentration of sugar is therefore at the recommended level, whilst the concentration of fatty acid is substantially 50% of the recommended level. As can be seen, the efficacy score, observed 15 days after application on the same scale as hereinbefore described, was again 7.

[0067] In conclusion, neither active ingredient alone produces a satisfactory result. Both active ingredients together however do provide a satisfactory result, even when the concentration on one of both active ingredients is reduced to 50% of the recommended level. There appears to be a synergistic effect between the two active ingredients.

TABLE-US-00001 TABLE 1 Natural sugars Sucrose Disacc C.sub.12H.sub.22O.sub.11 Sugar Beet & Sugar Cane Table Sugar Glucose Mono C.sub.6H.sub.12O.sub.6 Honey, Fruits, Vegetables Fructose Mono C.sub.6H.sub.12O.sub.6 Fruits, Honey Galactose Mono C.sub.6H.sub.12O.sub.6 Milk, Dairy Maltose Disacc C.sub.12H.sub.22O.sub.11 Barley Arabimose Mono C.sub.5H.sub.10O.sub.5 Pectin, hemicellulose Lactose Disacc C.sub.12H.sub.22O.sub.11 Milk, also made from Glucose & Galactose Inositol Mono C.sub.6H.sub.12O.sub.6 Cantaloupe, citrus, beans, rice etc Mannose Mono C.sub.6H.sub.12O.sub.6 Fruit, Mammalian Plasma Ribose Mono C.sub.5H.sub.10O.sub.5 A Glucose to pentose phosphate Trehalose Disacc C.sub.12H.sub.22O.sub.11 Mushrooms, honey, seafood Xylose Mono C.sub.5H.sub.10O.sub.5 Wood, Straw

TABLE-US-00002 TABLE 2 High Intensity Sweeteners Saccharin C.sub.7H.sub.5NO.sub.3S Laboratory produced Aspartame C.sub.14H.sub.18N.sub.2O.sub.5 Aspartic & phenylalamine amino acids Acesulfame Potassium C.sub.4H.sub.4KNO.sub.4 Acetoacetic acid Sucralose C.sub.12H.sub.19C.sub.13O.sub.8 Sugar plus chemical process Neotame C.sub.20H.sub.30N.sub.2O.sub.5 Aspartame and additives Advantame C.sub.24H.sub.30N.sub.2O.sub.7 Aspartame and Vanillin Stevia Various Stevia rebaudiana Siraitia Grosvenorii Various Monk fruit China Saccharin: 1,2-benzisothiazol-3(2H)-one 1,1-dioxide.

TABLE-US-00003 TABLE 3 Sugar Alcohols Sorbitol C.sub.6H.sub.14O.sub.6 From glucose Xylitol C.sub.5H.sub.12O.sub.5 Plants, fruit, vegetables Lactitol C.sub.12H.sub.24O.sub.11 Milk sugar Mannitol C.sub.6H.sub.14O.sub.6 Plants, fructose Erythritol C.sub.4H.sub.10O.sub.4 Fruits, corn Maltitol C.sub.12H.sub.24O.sub.11 Wheat, tapioca, corn, starches

TABLE-US-00004 TABLE 4 Trial Results Days after Application Eg Product Penetrant H.sub.2O 3 7 14 42 79 136 189 1 APG 200 ml Zero 1000 ml 0 0 0 0 0 0 0 2 APG 200 ml Validate 2.5 ml 1000 ml 0 0 0 0 0 0 0 3 APG 200 ml Yucca 7.5 ml 1000 ml 0 0 0 0 0 0 0 4 Sodium saccharin 100 g Validate 2.5 ml 1000 ml 4 6 7 10 10 10 10 5 Sodium saccharin 50 g APG 1.5 ml 1000 ml 1 2 2 3 0 0 0 Stevia 50 g 6 Stevia 100 g Yucca 7.5 ml 2000 ml 2 4 5 6 5 3 3 7 Natural sugar 100 g Yucca 7.5 ml 2000 ml 1 3 3 2 2 2 2 Stevia 50 g 8 Natural sugar 100 g Validate 5 ml 2000 ml 2 4 4 3 3 3 3 Stevia 50 g 9 Sodium saccharin 100 g Validate 5 ml 2000 ml 3 5 7 10 10 10 10 10 Sodium saccharin 75 g Yucca 10 ml 2000 ml 1 3 4 4 2 2 2 Natural sugar 125 g 11 Sodium saccharin 50 g APG 2.5 ml 1500 ml 1 2 2 1 0 0 0 Stevia 150 g 12 Sodium saccharin 75 g Validate 7.5 ml 2000 ml 5 7 8 10 10 10 10 Natural sugar 125 g

TABLE-US-00005 TABLE 5 Trial Results with Additional Component Days after application Eg Product Penetrant Component H.sub.2O 15 13 Zero Zero Pelargonic acid 85 ml 500 ml 3 14 Sodium saccharin 100 g Zero Zero 1000 ml 2 15 Sodium saccharin 100 g Validate 5 ml Pelargonic acid 180 ml 2000 ml 7 16 Sodium saccharin 100 g Validate 5 ml Pelargonic acid 340 ml 2000 ml 7 17 Sodium saccharin 200 g Validate 5 ml Pelargonic acid 180 ml 2000 ml 7