NEW FORMULATIONS OF MALEIC HYDRAZIDE

Abstract

NEW FORMULATIONS OF MALEIC HYDRAZIDE This application concerns new plant protection formulations of maleic hydrazide (MH) in the form of ethanolamine salts, and their use in diluted form for application on plant products. Figure for abstract: None

Description

Title of the invention: NEW FORMULATIONS OF MALEIC HYDRAZIDE

[0001] 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.

[0002] Maleic hydrazide (MH) is used in agriculture as a growth regulator and in particular for the control of weeds and algae, or as an anti-germination agent for bulbs and tubers and for the elimination of suckers of certain plants.

[0003] Maleic hydrazide refers to two isomeric structures corresponding to the following structures and names:

[0004] 1,2-dihydropyridazine-3,6-dione: 6-hydroxy-2H-pyridazin-3-one:

[0005] CAS 123-33-1 CAS 10071-13-3

[0006] (I) (II)

[0007] Forms (I) and (II) are two tautomeric forms, the interconversion of which from one to the other takes place spontaneously in aqueous solution.

[0008] The regulatory activity of MH depends in part on the application conditions, such as relative humidity, as well as on auxiliary agents that promote the application and penetration of MH.

[0009] Thus, US 4,182,621 describes growth-regulating compositions based on MH or its salts and two agents (A) and (B) of the ether and sulfated ether type, respectively, intended to be diluted before treatment.

[0010] 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.

[0011] New compositions have now been developed that accept higher contents high in MH, which also exhibit potentiated regulatory activity.

[0012] According to a first object, the present invention relates to a concentrated aqueous plant protection composition based on maleic hydrazide (MH), said composition comprising: - maleic hydrazide (MH) in the form of the ethanolamine salt, or a mixture of these salts, and - at least one emulsifying agent, in particular of the polysorbate type.

[0013] The term "maleic hydrazide (MH)" used herein refers to either of the two tautomeric forms

[0014] 1,2-dihydropyridazine-3,6-dione: 6-hydroxy-2H-pyridazin-3-one:

[0015] CAS 123-33-1 CAS 10071-13-3

[0016] (I) (II)

[0017] as well as mixtures thereof.

[0018] The concentrated composition according to the invention can advantageously support a high MH content.

[0019] Thus, the concentration of MH in said concentrated composition can generally be between 300 and 600g / l, expressed as mass of MH relative to the total volume of the concentrated composition.

[0020] 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, improving their yields, and / or improving their preservation.

[0021] 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.

[0022] It is generally in the form of an aqueous solution.

[0023] Ethanolamine refers to compounds of the formula HxN(CH2CH2OH)(ix) where 2 <x<3, notamment x est égale à 2 ou 3.

[0024] Ethanolamine salts of MH may be commercially available, or may be prepared by mixing MH and said amine.

[0025] According to one embodiment, the ethanolamine salts of HM are selected from the monoethanolamine salts of MH and the diethanolamine salts of MH, and mixtures thereof.

[0026] Monoethanolamine corresponds to the formula NH2CH2CH2OH.

[0027] Diethanolamine corresponds to the formula HN(CH2CH2OH)2.

[0028] 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.

[0029] These compounds typically exhibit amphiphilic behavior (whose hydrophilic / lipophilic balance, HLB, depends on the fatty acids involved and the number of ethoxy functions), enabling their emulsifying activity.

[0030] 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 plant protection compositions of the invention.

[0031] Examples 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).

[0032] Typically, said emulsifying agent is polysorbate 80 (Tween® 80).

[0033] The term "emulsifier" refers to agents capable of improving the preparation and stabilization of emulsions. The terms "emulsifier," "surfactant," and "emulsifying agent" may be used interchangeably.

[0034] Typically, the concentration of the polysorbate agent can be between 1 and 10% (by weight), preferably between 3 and 6% by weight of the concentrated composition.

[0035] According to one embodiment, the concentrated composition according to the invention may include one or more additional emulsifying agents.

[0036] Various surfactants or emulsifiers are known per se. According to the present invention, the additional emulsifier can 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 a salified sulfated fatty alcohol.

[0037] More specifically, the additional emulsifier may be sodium lauryl sulfate. Generally, a concentration of less than 5% by weight of the additional emulsifying agent(s) is desirable.

[0038] The addition of an additional emulsifier and / or their content depends on the MH salt used, of the plant to be treated, the desired activity and the application conditions.

[0039] The concentrated compositions according to the invention can, if conditions so require and / or permit, be applied as is to treat plant products. However, it is generally preferable to dilute them before application.

[0040] Thus, according to another object, the present invention also relates to a phytosanitary treatment process for plant products comprising - the step of diluting the concentrated composition according to the invention in water, - the application of the diluted composition thus obtained on said plant products.

[0041] According to one embodiment, the dilution ratio of the concentrated composition is less than 10%; typically, the concentrated composition can be diluted from 0.1% to 5% to give rise to the diluted composition.

[0042] According to one embodiment of the treatment process according to the invention typically allows the application of MH at a dose between 300 and 20000 ppm (i.e.) between 300 and 20000 mg / kg, expressed as mass of MH relative to the total mass of the diluted composition.

[0043] Typically, the diluted composition is a solution.

[0044] The diluted composition can be applied to plant products according to application methods usually implemented for applying MH.

[0045] Thus, we can notably mention the application of the diluted composition to plant products by spraying or spreading.

[0046] According to one embodiment, the dose of MH applied is typically between 1 and 10 kg per hectare.

[0047] The invention is illustrated in a purely indicative manner by the following embodiment examples.

[0048] Examples

[0049] Molar mass of maleic hydrazide = 112 g / mol

[0050] Molar mass of diethanolamine salt of maleic hydrazide = 217 g / mol

[0051] Molar mass of maleic hydrazide monoethanolamine salt = 173 g / mol 1. Preparation of concentrated compositions

[0052] [Tables 1] Concentrated Composition No. Ingredients MH Salt (mass concentration w / w, %) Emulsifier (mass concentration, %) Additional Emulsifier (mass concentration, %) Comp 1 (according to Ex. 5 of US 4,182,621) Diethanolamine (18.0%) Polyoxyethylene(9)nonylphenyl ether (2%) Sodium polyoxyethylene(4)nonylphenyl ether sulfate (5%) Comp 2 (according to Comp Ex. 4 of US 4,182,621) Diethanolamine (30.0%) 3 Diethanolamine (30.0%) Polysorbate 80 (4%) - 4 Monoethanolamine (69%) - - 5 Monoethanolamine (69%) Polysorbate 80 (4%) - 6 Monoethanolamine (69%) Polysorbate 80 (4%) Sodium lauryl sulfate (2%)

[0053] Table 1

[0054] Compositions 3 to 6 according to the invention and comparative compositions Comp 1 and Comp 2 according to US 4,182,621 are prepared by adding the various ingredients to the appropriate quantity of water under stirring, at room temperature. For compositions 4-5-6, the concentration of monoethanolamine salt is 69% w / w, i.e., 45% w / w in maleic hydrazide, i.e., 540g / L of maleic hydrazide, since the product has a density of 1.2. 1. Preparation of diluted compositions

[0055] The concentrated compositions obtained according to point 1 are diluted in water according to the dilution ratios specified below:

[0056] [Tables2] Diluted Composition No. Dilution Ratio Mass Concentration of MH Salt Molar Mass (MH) / Molar Mass (MH Salt) Concentration expressed relative to MH in the diluted composition Comp 1 1% 1800 ppm 112 / 217 930 ppm Comp 2 1% 3000 ppm 112 / 217 1550 ppm 3 0.6% 1800 ppm 112 / 217 930 ppm 4 0.2% 1380 ppm 112 / 173 900 ppm 5 0.2% 1380 ppm 112 / 173 900 ppm 6 0.2% 1380 ppm 112 / 173 900 ppm

[0057] Table 2

[0058] The concentration in the diluted composition is calculated as follows:

[0059] For example, for composition 6, the 0.2% dilution of the 69% (w / w) monoethanolamine salt leads to a solution of 1380 ppm salt (0.2x0.69x10000).

[0060] The concentration of MH in the diluted solution is therefore: 1380x (molar mass of MH / molar mass of the salt) = 893 ppm (rounded to 900 ppm in the table). 1. Regulatory activity

[0061] Ten oat seeds are 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 is measured.

[0062] Each of the diluted compositions obtained in point 2 above is applied to the seedlings in three pots at a rate of 10 ml per pot. On day 14 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.

[0063] IR = (1-Mn / Mo) x 100 (%)

[0064] where Mo is the elongation of the second leaf in the control group, and Mn is that of the treated culture.

[0065] The results are given in the following Table 3:

[0066] [Tables3] Diluted Composition No. Concentration expressed relative to MH in the diluted composition Inhibition of oat plant growth LR. % Comp 1 930ppm 95.5 Comp 2 1550ppm 68.2 3 930ppm 97.7 4 900ppm 65.6 5 900ppm 96.8 6 900ppm 99.5

[0067] Table 3

[0068] These results demonstrate that, at constant MH concentration, the compositions according to the invention exhibit a regulatory activity far superior to that of the compositions according to US 4,182,621. The compositions according to the invention exhibit a synergistic activity.

Claims

Demands

1. Concentrated aqueous plant protection 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 emulsifying agent of the polysorbate type; said composition further comprising an emulsifier of the sulfated fatty alcohol type, such as sodium lauryl alcohol sulfate.

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

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

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

5. Phytosanitary treatment process for 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.

6. Processing method according to claim 5 wherein the concentrated composition is diluted from 0.1% to 5% to give the diluted composition.

7. Processing method according to claim 5 or 6 wherein the application dose of MH is between 300 and 20000 ppm.

8. Treatment method according to any one of claims 5 to 7 wherein the dose of MH applied is between 1 and 10 kg per hectare.

9. A treatment method according to any one of claims 5 to 7 comprising applying the diluted composition to plant products by spraying or spreading.