Maleic hydrazide formulations

Abstract

The present application relates to novel phytosanitary formulations of maleic hydrazide (MH) in the form of ethanolamine salts, and to the use thereof in diluted form for application to plant products.

Description

[0001] DESCRIPTION

[0002] TITLE: MALEIC HYDRAZIDE FORMULATIONS

[0003] The present invention relates to the phytosanitary treatment of plant products, and in particular the regulation of growth, and in particular the inhibition of germination.

[0004] Maleic hydrazide (MH) is used in agriculture as a growth regulator, particularly for the control of weeds and algae, as an anti-germination agent for bulbs and tubers and for the elimination of suckers from certain plants.

[0005] Maleic hydrazide refers to two isomeric structures with the following structures and names:

[0006] 1,2-dihydropyridazine-3,6-dione: 6-hydroxy-2H-pyridazin-3-one:

[0007] CAS 123-33-1 CAS 10071-13-3

[0008] Forms (I) and (II) are two tautomeric forms, the interconversion of which occurs spontaneously in aqueous solution.

[0009] The regulatory activity of MH depends partly on application conditions, such as relative humidity, as well as auxiliary agents that promote MH application and penetration.

[0010] Thus, US 4,182,621 describes growth regulating compositions based on MH or its salts and two agents (A) and (B) of ether and sulfated ether type, respectively, intended to be diluted before treatment.

[0011] However, concentrated compositions contain a maximum of only 30% MH. It is therefore still necessary to increase the MH concentration of concentrated compositions, in order to reduce the total quantities of products to be applied and the quantities of emulsifiers used. New compositions have now been developed that accept higher MH contents, which also have a potentiated regulatory activity.

[0012] According to a first subject, the present invention relates to a concentrated aqueous phytosanitary composition based on maleic hydrazide (MH), said composition comprising: maleic hydrazide (MH) in the form of ethanolamine salt, or a mixture of these salts, and

[0013] - at least one emulsifying agent, in particular of the polysorbate type.

[0014] The term "maleic hydrazide (MH)" used herein refers to either of the two tautomeric forms

[0015] 1,2-dihydropyridazine-3,6-dione: 6-hydroxy-2H-pyridazin-3-one:

[0016] CAS 123-33-1 CAS 10071-13-3 as well as their mixtures.

[0017] The concentrated composition according to the invention can advantageously support a high MH content.

[0018] Thus, the concentration of MH in said concentrated composition can generally be between 300 and 600g / l, expressed as mass of HM relative to the total volume of the concentrated composition.

[0019] The term "phytosanitary" refers to any treatment of plant products, aimed at protecting cultivated or stored plant species, as well as their seeds, against harmful insects and diseases, to improve their yields, and / or improve their conservation.

[0020] The said phytosanitary composition is said to be “concentrated” in that it is generally marketed and stored in this form, and is generally intended to be diluted on site, before use.

[0021] It is usually in the form of an aqueous solution. Ethanolamine refers to compounds with the formula H X N(CH2CH2OH)(1. X ) where 2 <x<3, notamment x est égale à 2 ou 3.

[0022] Ethanolamine salts of MH may be commercially available, or may be prepared by mixing MH and said amine.

[0023] According to one embodiment, the ethanolamine salts of HM are chosen from monoethanolamine salts of MH and diethanolamine salts of MH, and mixtures thereof.

[0024] Monoethanolamine has the formula NH2CH2CH2OH.

[0025] Diethanolamine has the formula HN(CH2CH2OH)2.

[0026] Polysorbates are esters of fatty acids and polyoxyethylene sorbitan (ethoxylated derivative of sorbitan). They consist of a hydrophobic aliphatic chain (the fatty acid or acids) and a hydrophilic ethoxylated head.

[0027] These compounds typically exhibit amphiphilic behavior (whose hydrophilic / lipophilic balance, HLB depends on the fatty acids involved and the number of ethoxy functions), allowing their emulsifying activity.

[0028] Polysorbates are sometimes referred to by the brand name Tween. Polysorbates have the advantage of being authorized as food additives, guaranteeing the safety of the phytosanitary compositions of the invention.

[0029] These include: Polyoxyethylene sorbitan monolaurate (polysorbate 20, E432), Polyoxyethylene sorbitan monooleate (polysorbate 80, E433), Polyoxyethylene sorbitan monopalmitate (polysorbate 40, E434), Polyoxyethylene sorbitan monostearate (polysorbate 60, E435), Polyoxyethylene sorbitan tristearate (polysorbate 65, E436).

[0030] Typically, said emulsifying agent is polysorbate 80 (Tween® 80).

[0031] The term "emulsifier" refers to agents capable of improving emulsion preparation and stabilization. The terms "emulsifier", "surfactant" and "emulsifier" can be used interchangeably.

[0032] Typically, the concentration of the polysorbate agent may be between 1 and 10% (by weight), preferably between 3 and 6% by weight of the concentrated composition. According to one embodiment, the concentrated composition according to the invention may comprise one or more additional emulsifying agents.

[0033] Various surfactants or emulsifiers are known per se. According to the present invention, the additional emulsifier may be chosen from ethoxylated fatty alcohols, ethoxylated fatty acids, ethoxylated alkylphenols, sorbitan esters and their ethoxylated derivatives, or any other non-ionic or anionic product such as salified sulfated fatty alcohol type.

[0034] More particularly, the additional emulsifier may be sodium lauryl sulfate. Generally, a concentration of less than 5% by weight of additional emulsifying agent(s) is desirable.

[0035] The addition of an additional emulsifier and / or their content depends on the MH salt used, the plant to be treated, the desired activity and the application conditions.

[0036] The concentrated compositions according to the invention may, if conditions require and / or permit, be applied as such to treat plant products. However, it is generally preferred to dilute them before application.

[0037] Thus, according to another object, the present invention also relates to a method for phytosanitary treatment of plant products comprising the step of diluting the concentrated composition according to the invention in water, the application of the diluted composition thus obtained to said plant products.

[0038] According to one embodiment, the dilution ratio of the concentrated composition is less than 10%; typically, the concentrated composition may be diluted from 0.1% to 5% to give rise to the diluted composition.

[0039] According to one embodiment of the treatment method according to the invention, it typically allows the application of MH at a dose of between 300 and 20,000 ppm (ie) between 300 and 20,000 mg / kg, expressed as mass of MH relative to the total mass of the diluted composition.

[0040] Typically, the diluted composition is a solution.

[0041] The diluted composition can be applied to plant products using application methods usually used to apply MH. Examples include the application of the diluted composition to plant products by sprinkling or spreading.

[0042] According to one embodiment, the dose of MH applied is typically between 1 and 10 kg per hectare.

[0043] The invention is illustrated in a purely indicative manner by the following exemplary embodiments.

[0044] Examples Molar mass maleic hydrazide = 1 12 g / mol

[0045] Molar mass of maleic hydrazide diethanolamine salt = 217 g / mol

[0046] Molar mass of monoethanolamine salt of maleic hydrazide = 173 g / mol

[0047] 1. Preparation of concentrated compositions [Table 1]

[0048] Table 1

[0049] Compositions 3 to 6 are prepared according to the invention and comparative compositions Comp 1 and Comp 2 according to US 4,182,621 by adding the different ingredients to the appropriate quantity of water with stirring, at room temperature. For compositions 4-5-6, the concentration of monoethanolamine salt is 69% w / w or 45% w / w in maleic hydrazide, or 540 g / L of maleic hydrazide because the product has a density of 1.2.

[0050] 2. Preparation of diluted compositions

[0051] The concentrated compositions obtained according to point 1 are diluted in water according to the dilution ratios explained below:

[0052] [Table 2]

[0053] Table 2

[0054] The concentration in the diluted composition is calculated as follows:

[0055] For example, for composition 6, the 0.2% dilution of the 69% (w / w) monoethanolamine salt leads to a solution at 1380 ppm in salt (0.2x0.69x10000).

[0056] The MH concentration in the dilute solution is therefore: 1380x (molar mass MH / molar mass of the salt) = 893 ppm (rounded to 900 ppm in the table).

[0057] 3. Regulatory activity Ten oat seeds were sown in each of the 12 cm diameter polyvinyl chloride pots and germinated in a greenhouse (28°C, 78% RH). On the 7th day after sowing, the length of each second leaf was measured.

[0058] Each of the diluted compositions obtained in point 2 above is applied to the seedlings of three pots in an amount of 10 ml per pot. On the 14th day after sowing, the elongation of the second leaf is measured. Based on a comparison with an untreated control group, the growth inhibition ratio (RI) is calculated from equation (I) below.

[0059] IR = (1 -Mn / Mo) x 100 (%) where Mo is the elongation of the second leaf in the control group, and Mn is that of the treated culture.

[0060] The results are given in the following Table 3:

[0061] [Table 3]

[0062] Table 3

[0063] These results demonstrate that at constant MH concentration, the compositions according to the invention exhibit a regulatory activity that is significantly greater than that of the compositions according to US 4,182,621. The compositions according to the invention exhibit synergistic activity.

Claims

CLAIMS 1. Concentrated aqueous phytosanitary composition based on maleic hydrazide (MH), said composition comprising: maleic hydrazide (MH) in the form of ethanolamine salt, or a mixture of these salts, and - at least one polysorbate-type emulsifying agent.

2. Concentrated composition according to claim 1, such that the ethanolamine salts of HM are chosen from monoethanolamine salts of MH and diethanolamine salts of MH, and mixtures thereof.

3. Concentrated composition according to claim 1 or 2, such that said emulsifying agent is polysorbate 80 (Tween® 80).

4. Concentrated composition according to any one of the preceding claims further comprising an emulsifier of salified sulfated fatty alcohol type, such as sodium lauryl alcohol sulfate.

5. Concentrated composition according to any one of the preceding claims such that the concentration of MH in said concentrated composition is between 300 and 600g / l, expressed as mass of HM relative to the total volume of the composition.

6. Method for phytosanitary treatment of plant products comprising: the step of diluting the concentrated composition according to any one of the preceding claims in water, the application of the diluted composition thus obtained to the plant products.

7. A treatment method according to claim 6 such that the concentrated composition is diluted from 0.1% to 5% to give rise to the diluted composition.

8. Treatment method according to claim 6 or 7 such that the application dose of MH is between 300 and 20,000 ppm. Treatment method according to any one of claims 6 to 8 such that the dose of MH applied is between 1 and 10 kg per hectare. Treatment method according to any one of claims 6 to 8 comprising the application of the diluted composition to the plant products by sprinkling or spreading.

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