GEL USED AS A PLANT GROWTH REGULATOR AND / OR HERBICIDE

Description

Technical field of the invention

[0001] The present invention relates to a plant growth regulator and a herbicide. More particularly, the present invention relates to the use of a gel comprising nonanoic anhydride, a polymer, and water as a plant growth regulator and / or herbicide. The present invention also relates to compositions and methods for regulating plant growth and / or acting as herbicides. Prior art

[0002] The use of glyphosate as a herbicide is increasingly being challenged by regulatory authorities and the general public.

[0003] Alternative solutions to glyphosate available to farmers are manual or mechanical. Several are already used by French local authorities, who have been prohibited from using glyphosate in areas open to the public since January 2017.

[0004] Preventive methods include crop rotation (which regularly breaks the development of weeds, which vary depending on the cultivated plants), false sowing (preparing fields several weeks before sowing to allow weeds to germinate, and removing them mechanically before actual sowing), and mulching (which involves covering the soil with plant and mineral materials, or certain synthetic materials, to stop the growth of weeds).

[0005] Mechanical methods can also be used to control weed growth by uprooting or destroying the roots of unwanted plants. Different types of machines exist, depending on the crops and their specific needs. Some cut the roots several centimeters deep, while others use harrows, which work the soil surface. Farmers can also use thermal weeding, passing flames, hot water, or steam over the weeds to kill them.

[0006] However, these methods have drawbacks. In particular, they affect soil structure and can increase erosion. They also require significant energy expenditure and are not all suitable for large farms.

[0007] Currently, there is no biological product that has an effectiveness equivalent to glyphosate.

[0008] Therefore, finding an alternative to the use of glyphosate represents a major strategic challenge.

[0009] To be accepted, this alternative must be as effective as, or even more effective than, glyphosate and must not be harmful to the environment or human health. Ideally, in addition to its weed-killing action, the product should also act as a growth regulator to reduce the number of seasonal applications and the need for brush clearing and mechanical mowing.

[0010] The action of nonanoic acid (also called pelargonic acid) is known as a growth regulator and / or herbicide.

[0011] The applicants have already proposed the use of nonanoic anhydride as a growth regulator and / or herbicide (EP3704942). While this use offers numerous advantages, the formulation of these compositions still needs refinement to increase their effectiveness. Presentation of the invention

[0012] The present invention aims to solve the problems described above.

[0013] Thus, the present invention relates to the use of a gel comprising nonanoic anhydride, a polymer and water as a plant growth regulator and / or herbicide.

[0014] The applicant was able to demonstrate that a gel according to the invention did not behave like a solution of nonanoic acid nor like nonanoic anhydride alone. This formulation exhibits greater efficacy, both in intensity and duration, than that of nonanoic acid.

[0015] The presence of the polymer and water in the gel according to the invention acts as a reservoir of nonanoic acid, allowing it to remain active for a longer period than if it had been applied alone. The present invention also relates to a gel comprising nonanoic anhydride, a polymer, and water.

[0016] According to a preferred embodiment of the invention, said herbicide is a foliar herbicide.

[0017] According to a preferred embodiment of the invention, said herbicide is a root herbicide.

[0018] According to a preferred embodiment of the invention, said nonanoic anhydride is at a concentration greater than 30% by mass.

[0019] According to a preferred embodiment of the invention, the aqueous solution according to the invention comprises said nonanoic anhydride at a concentration of between 30% and 85% by mass.

[0020] According to a preferred embodiment of the invention, said aqueous solution comprises water at a concentration of less than 70% by mass.

[0021] According to a preferred embodiment of the invention, said aqueous solution comprises water at a concentration between 15% and 70% by mass.

[0022] In the context of the present invention, the term "polymer" refers more specifically to a water-soluble polymer.

[0023] According to a preferred embodiment, said polymer is chosen from the group consisting of Poly(phenylene oxide) (PPO), Polypropylene glycol (PPG), Polycaprolactone (PCL), Polylactic acid (PLA), Polyglycolic acid (PGA), polyester, polyamide, polyacrylate, polyurethane and their mixtures.

[0024] According to a preferred embodiment of the invention, said polymer is Polyethylene Glycol.

[0025] According to a preferred embodiment of the invention, said Polyethylene Glycol is at a concentration greater than 5% by mass.

[0026] According to a preferred embodiment of the invention, said Polyethylene Glycol is at a concentration of between 20% and 30% by mass.

[0027] According to a preferred embodiment of the invention, said Polyethylene Glycol has a molar mass greater than 3000 g.mol-1, preferably between 3000 and 10000 g.mol-1, even more preferably between 5000 and 7000 g.mol-1 and most preferably equal to 6000 g.mol-1.

[0028] The present invention also relates to a method for regulating plant growth or controlling harmful plants, characterized in that an effective quantity of a solution according to the invention is applied to plants, plant parts, plant seeds or to an area.

[0029] In the context of the present invention, the term "growth regulator" refers to a product and / or process that results in weaker growth of all or part of a plant compared to the same type of plant grown under the same conditions in the absence of said product and / or process.

[0030] According to a preferred embodiment of the invention, said herbicide is a foliar herbicide.

[0031] In the context of the present invention, the term "foliar herbicide" refers to the fact that the herbicidal effect is obtained in particular after contact between the nonanoic anhydride and the leaves of the plant to be treated.

[0032] According to a preferred alternative or complementary embodiment of the invention, said herbicide is a root herbicide.

[0033] In the context of the present invention, the term "root herbicide" refers to the fact that the herbicidal effect is obtained in particular after contact between the nonanoic anhydride and the roots of the plant to be treated.

[0034] The present invention also relates to a method for regulating plant growth or a method for controlling harmful plants, notable in that an effective quantity of a solution according to the invention is applied to plants, plant parts, plant seeds or to an area.

[0035] In the context of the present invention, the term "effective quantity" refers to a quantity of product sufficient to achieve the desired herbicidal and / or growth-regulating effect.

[0036] Preferably, said effective quantity is greater than 5g, preferably 10g and even more preferably 15g of nonanoic anhydride per m2< of surface to be treated.

[0037] [ Fig. 1] shows the action of a composition comprising nonanoic anhydride, PEG6000 and water, compared to that of a composition comprising pelargonic acid, PEG6000 and water sprayed at a dose of 0.05 l / m 2< on the leaves of weeds of different types of herbaceous weeds.

[0038] [ Fig. 2 ] shows the action of a composition comprising nonanoic anhydride, PEG6000 and water, compared to that of a composition comprising pelargonic acid, PEG6000 and water sprayed at a dose of 0.035 l / m 2< on the leaves of weeds of different types of herbaceous weeds.

[0039] [ Fig. 3] shows the action of a composition comprising nonanoic anhydride, PEG6000 and water, compared to that of a composition comprising pelargonic acid, PEG6000 and water sprayed at a dose of 0.02 l / m 2< on the leaves of weeds of different types of herbaceous weeds. Detailed description of the invention

[0040] The product according to the invention can be used on any type of surface (natural or artificial), and more particularly on roads, verges, access roads, parking lots, railways, green spaces, and terraces. The solution, for use according to the invention, may further comprise additional agents such as penetration enhancers, colorants, emulsifiers, dispersants, wetting agents, binders, thickeners, and / or preservatives.

[0041] The concentration of nonanoic anhydride in formulations usable within the scope of the present invention can be easily estimated by a person skilled in the art. However, it has been shown that concentrations greater than 10%, preferably greater than 20%, and even more preferably between 30 and 50% by mass, would provide sufficient efficacy.

[0042] In the context of the present invention, a mass percentage refers to an amount in grams of pure nonanoic anhydride per 100g of total mass of said solution.

[0043] Liquid formulations usable within the scope of the present invention may comprise one or more solvents. Surfactants may be used as penetration enhancers, emulsifiers, dispersants, wetting agents, or other agents in the formulation.

[0044] The amount of surfactant used is generally 0.1 to 50% by mass, preferably about 0.1 to 25% by mass, relative to a total amount of the solution.

[0045] According to a preferred embodiment, the solution according to the invention further comprises a colorant, preferably a colorant of natural origin. According to a most preferred embodiment, said colorant is chlorophyll.

[0046] In this last embodiment, the presence of a dye compensates for the loss of color on the treated surface due to the disappearance of the vegetation. The presence of this dye also allows the treated vegetation to be masked by using a dye of a color similar to that of the treated surface.

[0047] A person skilled in the art is able to select the appropriate dye and its concentration according to the characteristics of the surface being treated.

[0048] Binders and thickeners are well known to those skilled in the art. These include, for example, dextrin, carboxymethylcellulose salts, polyvinylpyrrolidone, polyvinyl alcohol, sodium mannitol, and sorbitol.

[0049] The method according to the invention is similar to a conventional application method for known agricultural chemicals and includes, for example, aerial spraying, soil spreading, or application to foliage.

[0050] The use according to the invention can be implemented alone or with at least one other herbicide, plant growth regulator, fungicide, insecticide, acaricide, nematocide or mixture thereof. Examples / Foliar application.

[0051] Different plant varieties were grown under controlled light, temperature and humidity conditions. More specifically, these plants were subjected to 8-hour night cycles (at 18°C) and 16-hour day cycles (at 23°C) at a constant humidity of 70% (+ / - 20).

[0052] These varieties were treated with solutions including: of nonanoic anhydride (38%), PEG 6000 (24.8%), and water (37.2%), or of nonanoic anhydride and PEG 6000, or, of nonanoic acid, PEG 6000, and water, or and a prior art herbicide (Herbistop super ®< ) as a positive control.

[0053] Untreated control plants were used as a negative control.

[0054] Solutions including nonanoic anhydride or nonanoic acid were spread with varying densities (0.05 l / m², 0.035 l / m² and 0.02 l / m²).

[0055] The action of its different compositions was monitored for 14 days with measurements taken at 24 hours, 7 days, 14 days, and 30 days. The results obtained are shown in [ Fig. 1], [Fig. 2 ] And [ Fig 3 The treatment effectiveness rating is established by comparing the evaluated treatment with the untreated control. The percentage of destruction is estimated by the ratio of destroyed biomass to remaining green biomass and the number of surviving plants in the treated area versus the control.

[0056] Weed degradation is observed after one day regardless of the product used. The drying effects are visible a few hours after spraying. For all application densities, aqueous solutions of nonanoic anhydride are more effective than those containing nonanoic acid. Furthermore, aqueous solutions of nonanoic anhydride maintain a constant efficacy after 14 days, while the efficacy of solutions containing nonanoic acid decreases after 14 days.

Claims

1. Use of a gel comprising nonanoic anhydride, a polymer and water as a plant growth regulator and / or herbicide.

2. Use according to one of the preceding claims characterised in that said herbicide is a leaf herbicide.

3. Use according to one of the preceding claims, characterised in that said herbicide is a root herbicide.

4. Use according to one of the preceding claims characterised in that said nonanoic anhydride is at a concentration greater than 30% by mass.

5. Use according to one of the preceding claims characterised in that said nonanoic anhydride is at a concentration between 30% and 85% by mass.

6. Use according to one of the preceding claims, characterised in that said polymer is polyethylene glycol.

7. Use according to one of the preceding claims, characterised in that said polyethylene glycol is at a concentration greater than 5% by mass.

8. Use according to one of the preceding claims, characterised in that said polyethylene glycol is at a concentration between 5% and 30% by mass.

9. Use according to one of the preceding claims, characterised in that said polyethylene glycol has a molar mass greater than 3000 g.mol -1, preferentially between 3000 and 10000 g.mol -1, even more preferentially between 5000 and 7000 g.mol -1 and entirely preferentially equal to 6000 g.mol -1.

10. Method for regulating plant growth or combating harmful plants, characterised in that an effective amount of a gel comprising nonanoic anhydride, a polymer and water is applied to plants, parts of plants, plant seeds or an area.