EP1526771A2

EP1526771A2 - Method for fighting against non-persistent virus propagation, composition and use

Info

Publication number: EP1526771A2
Application number: EP03750847A
Authority: EP
Inventors: Antoine Vielliard; Pierre Ravier
Original assignee: Novance SA
Current assignee: Novance SA
Priority date: 2002-07-26
Filing date: 2003-07-25
Publication date: 2005-05-04
Also published as: AU2003269061A8; AU2003269061A1; WO2004010782A3; FR2842706A1; FR2842706B1; WO2004010782A2

Abstract

The invention concerns a method for fighting against propagation of non-persistent virus in plants, by aphids, which consists in contacting the plants to be treated with a composition comprising at least one carboxylic acid ester including at least 14 carbon atoms and optionally at least one hydroxyl group and an alcohol including at least 1 to 12 carbon atoms per unit and bearing one or more hydroxyl groups; combined with at least one nonionic surfactant. The invention also concerns a composition comprising a mixture (i) of at least two carboxylic acid esters including at least 14 carbon atoms and optionally including at least one hydroxyl group and an alcohol including 1 to 12 carbon atoms per unit and bearing one or more hydroxyl groups; said carboxylic acid esters being obtained, at least for two of them, from alcohols having a number of different carbon atoms in the longest chain; combined with (ii) at least one nonionic surfactant. The invention further concerns the use of said composition.

Description

METHOD FOR CONTROLLING THE PROPAGATION OF NON-PERSISTENT VIRUSES, COMPOSITION AND USE

The subject of the present invention is a process limiting the spread of non-persistent viruses transmitted by aphids (aphids) to plants, a particular composition and its use.

Various means of transmitting a virus to a plant are known, such as in particular transmission by contact with infected plants or tools, by contact with fungi, or insects. In the latter category; the most common virus vector is the family of aphids, including aphids. Aphids are insects a few millimeters long with a flexible body and which can carry wings. They can also reproduce by parthenogenesis when conditions make it necessary. Among the aphids known to be the most likely to transmit viruses to plants, we can mention the green sinner aphid (Myzus persicae), the potato aphid (Myzus euphorbia), the greenhouse aphid (Aulacorthum solani), the green aphid of sin being the most widespread. These insects can carry two types of virus. The former are non-persistent viruses. They are originally transmitted to the insect when it feeds on the cells of the epidermis of a contaminated plant. Transmission of the virus is almost immediate and does not require an incubation period to make it active. Therefore, if the insect lands on another plant, it transmits the virus to it immediately. In return, the virus is active only for a very short time, at most two hours according to studies.

Potato viruses Y, A, and M and some strains of virus S, symptomless lily virus, tulip verse virus, cucumber mosaic virus, are examples of such viruses not persistent. Insects can also carry so-called persistent viruses, transmitted to the aphid by an infected plant when the latter feeds on the sap (phloem) of the plant. Contamination of the insect takes approximately 20 to 30 minutes and an incubation period is required before the insect can transmit this virus to another plant. In addition, the virus remains active throughout the life of the insect. Examples of this are the potato leaf curly virus, lily virus X.

The present invention relates to limiting the spread of non-persistent viruses. Infection of the vegetative part of the plant and subsequently the bulb or tuber produced by it is a factor limiting the yield of the plant. This is why various antiviral struggles have already been considered.

It is first of all important to note that the use of insecticides is not an appropriate method if one only wants to avoid the transmission of non-persistent viruses, due to the absence of an incubation period and the short lifespan of this type of virus.

Among the means of control envisaged, there may be mentioned a biological control consisting in using trap cultures. Studies have shown that aphids are attracted to dark green leaves. Thus, at the edge of the field are planted plants having this characteristic of coloring and playing the role of "trap", such as for example soybeans. In this way, we favor the arrival of aphids on these leaves, rather than on the leaves of the crop to be protected. Aphids, by feeding on these trap plants, then get rid of the virus they carry and their possible arrival on the plants to be protected then poses no more risk of infection.

However, this method is not completely effective and depends on external conditions, like simply the wind.

Other methods are also used, such as spraying on the plants to be protected, a mineral oil. This, by depositing on the leaves creates a film which protects the plant and limits the transfer of the virus.

The disadvantages of using this type of compound is that it is not perfectly biodegradable and that it does not come from renewable origin.

The present invention therefore aims to provide a method for combating the transmission of non-persistent virus does not have the drawbacks of known methods.

These aims and others are achieved by the present invention which therefore relates to a method for controlling the spread of non-persistent viruses to plants, by aphids, in which the plants to be treated are brought into contact with a composition comprising at least one ester of a carboxylic acid comprising at least 14 carbon atoms, linear or branched, saturated or not, optionally comprising at least one hydroxyl group and of an alcohol, linear or branched, comprising 1 to 12 carbon atoms per motif and carrier of one or more hydroxyl groups; associated with at least one nonionic surfactant.

It should be noted that the proposed method has the advantage of not being significantly phytotoxic. It therefore does not damage the treated plants.

Another subject of the invention consists of a composition comprising a mixture (i) of at least two carboxylic acid esters comprising at least 14 carbon atoms, linear or branched, saturated or not, optionally comprising at least PCTJFRO 3 / ϋ i * 6 B

at least one hydroxyl group and of an alcohol, linear or branched, comprising 1 to 12 carbon atoms per unit and carrying one or more hydroxyl groups; said esters of carboxylic acids being obtained, for at least two of them, from alcohols having a different number of carbon atoms in the longest chain; associated with (ii) at least one nonionic surfactant.

The present invention likewise relates to the use of this composition during which the composition is diluted in an aqueous phase, before application to the plant to be treated.

Finally, it relates to the use of this composition during which the composition is mixed with a phytosanitary formulation, before or after dilution of said formulation in an aqueous phase.

Without wishing to be linked to any theory, it is believed that the ester acts on the aphid so as to neutralize the vectorization pathways of the virus within it. It is therefore believed that the ester does not act as an insecticide. However, other advantages will appear more clearly on reading the description which follows.

As indicated above, the subject of the invention is a process for combating the spread of non-persistent viruses in which the plant to be treated is brought into contact with a composition comprising at least one ester of a carboxylic acid comprising at least 14 carbon atoms, linear or branched, saturated or not, optionally comprising at least one hydroxyl group and of an alcohol, linear or branched, comprising 1 to 12 carbon atoms per unit and carrying one or more hydroxyl groups; associated with at least one nonionic surfactant.

More specifically, the ester is derived from a carboxylic acid comprises at least 16 carbon atoms, and preferably from 18 to 22 carbon atoms.

Examples of acids from which the ester is derived include, in particular, stearic acid, isostearic acid, behenic acid, gadoleic acid, myristic acid; myristoleic acid, palmitoleic acid, oleic acid, isooleic acid, petroselenic acid, doeglic acid, gadoleic acid, erucic acid; linoleic acid; linolenic acid; isanic acid, stearodonic acid, arachidonic acid, chypanodonic acid; ricinoleic acid and their mixtures.

The alcohol from which the ester is derived can be either a simple molecule (consisting of a single motif, such as methanol, glycerol, etc.) or a molecule comprising two or more, identical or different, repeated motifs (such as dipentaerythritol , polyethylene glycol for example). In the latter case, they are assimilated to dimers, trimers or polymers.

As regards the alcohol from which the ester is prepared, it can be more especially chosen from methanol, ethanol, propanol, ispropanol, butanol, isobutanol, octanol, 2 ethyl hexanol, glycerol, glycol, propylene glycol, ethylene glycol, polyethylene glycol, polypropylene glycol, neopentylglycol, pentaerythritol, neopentylglycol hydroxy pivalate, dipentaerythritol, trimethylolpropane, di-trimethylolpropane, glucose, fructose, arabinose, sorbitol and its optical enantiomers, sucrose, mannitol, xylitol, mesoerythritol, alone or as a mixture.

The ester used as a constituent element of the composition can also be chosen from products resulting from the transformation of triglycerides of animal or vegetable origin. Triglycerides of animal or vegetable origin are generally called animal or vegetable oils, and consist of a triester of three fatty acid chains (carboxylic acid) and a triol (glycerol). In the present application, the term “ester” does not cover triesters. The ester used therefore does not cover oils of animal or vegetable origin.

Triglyceride transformation operations can consist of carrying out an alcoholysis, a transesterification, a hydrolysis reaction followed by an esterification reaction.

As oils of animal origin, there may be mentioned, among others, sperm whale oil, dolphin oil, whale oil, seal oil, sardine oil, herring, shark oil, cod liver oil; beef foot oil, fat from beef, pork, horse, sheep (tallow).

As examples of oils of vegetable origin, mention may be made, inter alia, of rapeseed oil, sunflower oil, peanut oil, olive oil, nuts, corn oil, soybean oil, linseed oil, hemp oil, grape seed oil, coconut oil, palm oil, palm kernel, cottonseed oil, babassu oil, jojoba oil, sesame oil, castor oil, tall oil.

Preferably, rapeseed oil, sunflower oil, soybean oil, tall oil are used. It should be noted that these oils may or may not be enriched in a particular fatty acid chain, thanks to varietal selections or to genetic modifications of the plants which produce them. Examples of such oils include, among others, sunflower oil enriched in fatty chains of oleic acid; rapeseed oil enriched with fatty chains of oleic acid or fatty chains of erucic acid.

It is also specified that the triglycerides can comprise fatty chains of acids comprising less than 14 carbon atoms. In such a case, the proportion in this type of fatty chains is less than 50% by weight of the fatty chains which enter into the composition of the triglycerides concerned.

Advantageously used as ester is a 2-ethylhexyl ester, preferably the 2-ethylhexyl ester of rapeseed. According to a first embodiment, the composition comprises only one ester or a mixture of esters derived from the same alcohol. Preferably, said ester is chosen from compounds derived from an alcohol comprising at least 4 carbon atoms per unit in the longest chain. According to a second embodiment of the invention, the composition comprises a mixture of at least two esters of carboxylic acids obtained, for at least two of them, from alcohols having a number of carbon atoms different.

The carboxylic acid parts from which the esters come may also have a number of different carbon atoms, as soon as the alcohol part of said ester, for at least two of them, have a different number of carbon atoms.

In accordance with a preferred variant of this embodiment of the invention, the composition comprises on the one hand at least one ester derived from an alcohol comprising less than 4 carbon atoms per unit in the longest chain, for example from methanol, and on the other hand, comprises at least one ester derived from an alcohol comprising at least 4 carbon atoms per unit in the longest chain. For example, in other words, the composition may comprise, on the one hand, a methyl ester, and on the other hand, an ester of an alcohol comprising at least 4 carbon atoms per longest chain. Advantageously, the proportion by weight of ester (s) derived from an alcohol comprising less than 4 carbon atoms / ester (s) derived from an alcohol comprising at least 4 carbon atoms is between 10/90 and 90/10.

The composition further comprises at least one nonionic surfactant.

Examples of such compounds that may be mentioned, without intending to be limited thereto, fatty alcohols which may be alkoxylated; optionally alkoxylated triglycerides; optionally alkoxylated fatty acids; optionally alkoxylated sorbitan esters; fatty amines possibly alkoxylated; optionally polyalkoxylated amides and superamides; alkoxylated di (phenyl-1 ethyl) phenols; alkoxylated tri (1-phenylethyl) phenols; alkoxylated alkylphenols, alone or as a mixture. The alkoxylated groups are more particularly ethoxylated, propoxylated groups, or their combinations.

The number of these units is such that the value of the hydrophilic / lipophilic balance is more particularly greater than or equal to 8, preferably to 10.

The optionally alkoxylated fatty alcohols generally contain from 6 to 22 carbon atoms, the alkoxylated units being excluded from these numbers.

The alkoxylated triglycerides can be triglycerides of plant or animal origin. We can refer to the lists given above. Fatty acids, linear or branched, generally contain from 10 to 22 carbon atoms, the alkoxylated units being excluded from these numbers.

The optionally alkoxylated sorbitan esters are cyclized fatty acid sorbitol esters comprising from 10 to 20 carbon atoms such as lauric acid, stearic acid or oleic acid.

The fatty alkoxylated amines generally have from 10 to 22 carbon atoms, the alkoxylated units being excluded from these numbers.

Alkoxylated superamides are derived from fatty acid esters having from 10 to 22 carbon atoms. They are obtained by first reacting a fatty acid ester with an alkanolamine, optionally in the presence of a basic compound; then in a second step, the product obtained is reacted with ethylene or propylene oxide.

Alkoxylated alkylphenols generally have one or two alkyl groups, linear or branched, having 4 to 12 carbon atoms. By way of example, mention may in particular be made of octyl, nonyl or dodecyl groups.

Preferably, the surfactants are chosen from polyalkoxylated nonionic surfactants.

The content and nature of the nonionic surfactant (s) in the composition is such that a direct emulsion prepared with stirring from this composition and with a water content of between 70 and 99% by weight of the composition, is stable . By stable is meant that the emulsion thus obtained, either does not show, in all or part of the range of water concentration indicated, of phase separation when it is left without stirring for 30 minutes, between 20 and 30 ° C. ; or shows a phase separation corresponding to a volume not exceeding 2% of the volume of the emulsion, under the same conditions as above (measurement made by a Cl PAC MT36 test - stability of emulsions).

As an indication, the content of nonionic surfactant is such that the ester / surfactant weight ratio is between 80/20 and 99/1.

The composition can also comprise at least one liquid or solid phytosanitary active material, soluble or not, miscible or not in the composition.

The designation "phytosanitary active ingredient" covers both pesticides (herbicides, fungicides, acaricides, insecticides, etc.) but also nutrients promoting the growth and development of plants. Preferably, insecticides are used, such as, for example, products from the pyrethroid class such as cypermethrin, permethrin, deltamethrin, betacypermethrin, alphacypermethrin, etc.

If the phytosanitary active ingredient is not soluble or miscible in the composition, it may be advantageous to incorporate into the composition, at least one compatibilizing additive chosen from pH correcting agents and / or anionic surfactants.

Among the pH correcting agents, mention may very particularly be made of carboxylic acids comprising 1 to 10 carbon atoms. It is specified that the pH of the composition, when it is in emulsion in water at a content of 1% by weight, is more particularly advantageously between 5 and 9. The content of pH correcting agent will be such that the pH measured under these conditions remains within the range given above.

Among the suitable anionic surfactants, the following surfactants may be mentioned, alone or in mixtures:

- alkyl ester sulfonates, for example of formula R-CH (SO ₃ M) -CH 2 COOR ', where R represents a hydrocarbon radical with C ₈ -C _20, preferably C io- _Ci-6, optionally bearing one or several unsaturations, R ′ an alkyl radical in C C- ₆ , preferably in CC and M is a hydrogen atom, an alkali cation (sodium, potassium, lithium) or unsubstituted or substituted ammonium (methyl-, dimethyl-, trimethyl-, tetramethylammonium, dimethyl piperidinium ...) or derived from an alkanolamine (monoethanolamine, diethanolamine, triethanolamine ...). Mention may very particularly be made of methyl ester sulfonates whose radical R is Cι ₄ -C ₁₆ ; the alkylestersulphates, for example of formula R-CH (OSO ₃ M) -CH ₂ COOR ', where R represents a C ₈ -C ₂₀ , preferably C _{1 0} -C ₁₆ hydrocarbon radical, optionally carrying one or more unsaturations, R ′ a C 1 -C 6, preferably CC _3, alkyl radical and M has the above meaning; alkylbenzenesulfonates, more particularly C ₉ -C ₂ o, primary or secondary alkylsulfonates, in particular C ₈ -C ₂₂ , alkylglycerol sulfonates;

- The alkyl sulphates, for example of formula ROSO ₃ M, where R represents a C ₁₀ -C ₂₄ , preferably C ₁₂ -C ₂₀ , alkyl or hydroxyalkyl radical; M has the above meaning; - The alkyl ether sulfates, for example of formula RO (AO) _n SO ₃ M where R represents a C ₁₀ -C ₂₄ alkyl or hydroxyalkyl radical, preferably Cι ₂ -C ₂₀ ; OA representing an ethoxylated and / or propoxylated group; M has the above meaning, n generally varying from 1 to 4, for example laurylethersulfate with n = 2; - the alkylamide sulfates, for example of formula RCONHR'OSO ₃ M where R represents an alkyl radical in C ₂ -C ₂₂ , preferably in C ₆ -C ₂₀ , R 'an alkyl radical in C ₂ -C ₃ , M a the above meaning, as well as their polyalkoxylated derivatives (ethoxylated and / or propoxylated); the salts of saturated or unsaturated fatty acids, for example like those in C ₈ - C ₂₄ , preferably in Cι -C ₂₀ and a cation having the same definition as M, N-acyl N-alkyltaurates, alkylisethionates, alkylsuccinamates, monoesters or diesters of sulfosuccinates, N-acyl sarcosinates, polyethoxycarboxylates; and

- alkyl- or dialkyl-sulfosuccinates, for example such as those in C ₆ -C ₂₄ ; the cation being of the same definition as M; especially sodium dioctylsulfosuccinate;

- the mono and di phosphate esters, for example of the following formula: (RO) _x -P (= O) (OM) _x or R represents an alkyl, alkylaryl, arylalkyl, aryl radical, optionally polyalkoxylated, x and x ′ being equal to 1 or 2, provided that the sum of x and x 'is equal to 3, M has the above meaning; especially derived from polyalkoxylated fatty alcohols, di- and tri- (1-phenylethyl) polyalkoxylated phenols; polyalkoxylated alkylphenols; alone or in mixtures.

Preferably, the content of anionic surfactant represents 1 to 50% by weight of the surfactants present in the composition.

The composition used in the process according to the invention can comprise conventional additives in the field of phytosanitary formulations. Thus, the composition can comprise at least one additive chosen from antifoaming agents (silicones), marking agents (dyes), anti-rebound agents (polysaccharides), anti-drift agents (polysaccharides).

If they are present, the total content of these additives is generally less than 10% by weight of the composition. The composition as just described is advantageously diluted before use, preferably with water.

More particularly, the content The content of aqueous phase, preferably of water, generally represents 70 to 99% by weight of the composition, preferably 70 to 95% by weight of the composition. Finally, the doses of use of this composition correspond to contents of composition on the plant to be treated, between 3 and 15 liters of composition per hectare, preferably between 7 and 15 liters of composition per hectare.

According to the invention, the method consists in treating the vegetative part of the plant. Generally, the treatment is carried out by spraying the composition, possibly in combination with another phytosanitary formulation.

The plants to be treated according to the process of the invention are more especially chosen from the families of liliaceae (lilies, tulips, hyacinths, etc.), solanaceae (potatoes, tomatoes, etc.) cucurbits (zucchini, peppers, eggplant, etc.) or any other vegetable crop.

The present invention likewise relates to a composition comprising a mixture (i) of at least two carboxylic acid esters comprising at least 14 carbon atoms, linear or branched, saturated or not, optionally comprising at least one hydroxyl group and an alcohol, linear or branched, comprising 1 to 12 carbon atoms per unit and carrying one or more hydroxyl groups; said esters of carboxylic acids being obtained, for at least two of them, from alcohols having a different number of carbon atoms in the longest chain; associated with (ii) at least one nonionic surfactant.

Preferably, the proportion by weight of ester / nonionic surfactant is between 80/20 and 99/1.

The esters (i) present in the compositions each derive from a carboxylic acid, linear or branched, comprising at least 16 carbon atoms, and preferably from 18 to 22 carbon atoms.

According to a particular implementation, the esters present in the composition are chosen from products resulting from the transformation of triglycerides of animal or vegetable origin.

Reference may be made to the lists of carboxylic acids and triglycerides, indicated above.

As specified above, the esters of carboxylic acids present in the composition are obtained, for at least two of them, from alcohols having a different number of carbon atoms in the longest chain.

Preferably, at least one of the esters is derived from an alcohol comprising less than 4 carbon atoms per unit in the longest chain, for example methanol, the other or the other esters are derived from an alcohol comprising at least minus 4 carbon atoms per unit in the longest chain. For example, in other words, the composition may comprise, on the one hand, a methyl ester, and on the other hand, an ester of an alcohol comprising at least 4 carbon atoms per longest chain.

In addition, the proportion by weight of ester (s) derived from an alcohol comprising less than 4 carbon atoms per unit / ester (s) derived from an alcohol comprising at least 4 carbon atoms per unit, is more particularly between 10 / 90 and 90/10.

Although this is not an obligation, the composition according to the invention can comprise at least one liquid or solid phytosanitary active material, soluble or not in the composition. This phytosanitary active ingredient can be chosen from pesticides, and more particularly insecticides, but also from nutrients promoting the growth and development of plants. The composition can also comprise the conventional additives of phytosanitary formulations, such as anti-foaming agents, marking agents, anti-rebound agents, anti-drift agents, or mixtures thereof.

If such compounds are used, their content is generally less than 10% by weight of the composition.

If the phytosanitary active ingredient is not soluble or miscible in the composition, it may be advantageous to incorporate into the composition, at least one compatibilizing additive chosen from pH correcting agents and / or anionic surfactants. The lists of these additives have been given previously and may be referred to.

The content of pH correcting agent is such that the composition, when it is in the form of an emulsion at 1% by weight in water, is between 5 and 9.

If present, the content of anionic surfactant represents 1 to 50% by weight of the surfactants present in the composition. A final object of the invention consists of the use of the composition as described.

This composition can be used alone, as a complete phytosanitary composition (use in "built-in"). In this case, the composition may or may not comprise a phytosanitary active material whose action is similar or not to that of the composition. For example, the active material can be chosen from insecticides in order to avoid the proliferation of aphids, while the composition according to the invention (comprising the combination of esters and a nonionic surfactant) has a limiting role virus transmission to the plant.

According to this possibility, before applying the composition to the plants to be treated, the composition is diluted in an aqueous phase, which is preferably water.

The content of aqueous phase, preferably water, generally represents 70 to 99% by weight of the composition, preferably 70 to 95% by weight of the composition.

In accordance with another mode of use, the composition according to the invention, whether or not it comprises a phytosanitary active ingredient, is used in combination with a phytosanitary formulation comprising an active ingredient which may or may not have a role similar to that desired. by the use of the composition (use in

"Tank mix").

This phytosanitary formulation with which the composition according to the invention is mixed, can be in any form customary for this type of formulations, in particular in the form of a solution, an emulsion, a suspo-emulsion, d '' a microemulsion, an emulsifiable concentrate, a dispersible granule. The entire composition / phytosanitary formulation is diluted before application, in an aqueous phase, preferably water, whether this dilution takes place before or after bringing the composition and the formulation into contact.

The dosages, whatever the use (built-in, tank-mix) depend on usual criteria which can be determined without difficulty by a person skilled in the art.

However, by way of indication, the content of composition deposited on the plants to be treated is between 3 and 15 liters of composition per hectare, preferably between 7 and 15 liters of composition per hectare.

The composition is deposited once diluted, on the vegetative part of the plant, by spraying.

Other details or advantages of the invention will appear more clearly in the light of the examples given below for information.

Application of treatments on plants:

Tests are carried out in a greenhouse (20 ° C. and 16 h of light exposure) on potato plants, according to the following protocol: Preparations of different products of plant origin (treatment) are formulated with a surfactant non-ionic (ethoxylated nonylphenol, 6 EO: IGEPAL BC / 6, Rhodia) using a treatment / surfactant volume ratio of 95/5. These formulations are then diluted in 50 volumes of water. A direct emulsion containing 98% water and 2% by volume of treatment formulated is thus obtained by manual stirring. The emulsion is placed in a manual garden sprayer. The weight of the sprayer is noted before and after application by spraying on the plant: approximately 20 mL is sprayed on each plot of plant (area of 0.24 m ² ). This corresponds to approximately a dose of 15 L of treatment per hectare. For each formula tested, a plot of 30 plants is treated. A control plot of 30 plants is also preserved, without treatment, as well as another plot of 30 plants for the reference product (comparative example) of mineral origin (Luxan 11 H).

Inoculation of PVY ^N virus with aphids and contact with plants Male aphids (clones M2 Myzus Persicae) are starved for 3 hours before being contacted with a potato plant leaf contaminated with PVY ^N virus . "Cages" equipped with clip fasteners are filled with 5 aphids and fixed on one of the leaves of the plant (inoculation sheet), 5 days after treatment of the plant (1 cage of 5 aphids per plant). The cages are left for 2 hours and then removed.

Evaluation of virus transmission to the plant

After 34 days, for each plant, the inoculation sheet and one of the systemic leaves (1 or 2 leaves above the inoculation sheet) are subjected to an ELISA test (Enzyme-Linked ImmunoSorbent Assay) to determine the presence or absence of PVY ^N virus in the leaf. The results are expressed as a percentage of the total number of leaves per treatment (30).

Evaluation of the Phytotoxicity of the treatment

The phytotoxicity of the treatment applied to the potato plant is assessed visually, and quantified according to the following scale 0 = no symptoms of phytotoxicity 1 = Some brown spots on the leaves, slight growth retardation of the plant

2 = Brown spots and some holes on the leaves, noticeable growth retardation

3 = dead or heavily stained leaves with holes, dramatic growth retardation

The results of the evaluations for different formulations are presented in the following table 1:

Table 1

Claims

1. Method for controlling the spread of non-persistent viruses to plants, by aphids, in which the plants to be treated are brought into contact with a composition comprising at least one ester of a carboxylic acid comprising at least 14 carbon atoms , linear or branched, saturated or not, optionally comprising at least one hydroxyl group and of an alcohol, linear or branched, comprising 1 to 12 carbon atoms per unit and carrying one or more hydroxyl groups; associated with at least one nonionic surfactant.

2. Method according to the preceding claim, characterized in that the ester is derived from a carboxylic acid comprising at least 16 carbon atoms, and preferably from 18 to 22 carbon atoms.

3. Method according to one of the preceding claims, characterized in that the ester is derived from a carboxylic acid chosen from stearic acid, isostearic acid, behenic acid, gadoleic acid, myristic acid ; myristoleic acid, palmitoleic acid, oleic acid, isooleic acid, petroselenic acid, doeglic acid, gadoleic acid, erucic acid; linoleic acid; linolenic acid; isanic acid, stearodonic acid, arachidonic acid, chypanodonic acid; ricinoleic acid and their mixtures.

4. Method according to one of the preceding claims, characterized in that the ester derived from an alcohol chosen from methanol, ethanol, propanol, ispropanol, butanol, isobutanol, octanol, 2 ethyl hexanol, glycerol, glycol, propylene glycol, ethylene glycol, polyethylene glycol, polypropylene glycol, neopentylglycol, pentaerythritol, neopentylglycol hydroxy pivalate, dipentaerythritol, trimethylolpropane, di- trimethylolpropane, glucose, fructose, arabinose, sorbitol and its optical enantiomers, sucrose, mannitol, xylitol, mesoerythritol, alone or as a mixture.

5. Method according to one of the preceding claims, characterized in that the ester is chosen from products resulting from the transformation of triglycerides of animal or vegetable origin.

6. Method according to one of the preceding claims, characterized in that the composition comprises a mixture of at least two acid esters carboxylic acids obtained, for at least two of them, from alcohols having a different number of carbon atoms in the longest chain.

7. Method according to the preceding claim, characterized in that at least one of the esters is derived from an alcohol comprising less than 4 carbon atoms in the longest chain, the other or the other esters are derived from a alcohol comprising at least 4 carbon atoms in the longest chain.

8. Method according to one of claims 6 or 7, characterized in that the proportion by weight ester (s) derived from an alcohol comprising less than 4 carbon atoms / ester (s) derived from an alcohol comprising at least 4 carbon atoms is between 10/90 and 90/10.

9. Method according to one of the preceding claims, characterized in that the surfactant is chosen from fatty alcohols optionally alkoxylated; alkoxylated triglycerides; optionally alkoxylated fatty acids; optionally alkoxylated sorbitan esters; fatty amines possibly alkoxylated; polyalkoxylated superamides; alkoxylated di (phenyl-1 ethyl) phenols; alkoxylated tri (1-phenylethyl) phenols; alkoxylated alkylphenols, alone or as a mixture

10. Method according to one of the preceding claims, characterized in that the ester / surfactant weight ratio is between 80/20 and 99/1.

11. Method according to one of the preceding claims, characterized in that the composition comprises at least one liquid or solid phytosanitary active material, soluble or not, miscible or not, in the composition.

12. Method according to one of the preceding claims, characterized in that the composition comprises at least one compatibilizing additive chosen from pH correcting agents, anionic surfactants, or their mixtures.

13. Method according to the preceding claim, characterized in that the content of pH correcting agent is such that the composition, when it is in the form of an emulsion at 1% by weight in water is between 5 and 9.

14. Method according to claim 12, characterized in that the content of anionic surfactant represents 1 to 50% by weight of the surfactants present in the composition.

15. Method according to one of the preceding claims, characterized in that the composition comprises at least one additive chosen from anti-foaming agents, marking agents, anti-rebound agents, anti-drift agents.

16. Method according to one of the preceding claims, characterized in that the composition comprises water.

17. Method according to the preceding claim, characterized in that the water content is between 70 and 99% by weight of the composition, preferably between 70 and 95% by weight of the composition.

18. Method according to one of the preceding claims, characterized in that the quantity of composition brought into contact with the plant is between 3 and 15 liters of composition per hectare, preferably between 7 and 15 liters of composition per l 'hectare.

19. Method according to one of the preceding claims, characterized in that the vegetative part of the plant is treated.

20. Method according to one of claims 1 to 19, characterized in that the treated plants are from the family of liliaceae, solanaceae, cucurbits.

21. Composition comprising a mixture (i) of at least two carboxylic acid esters comprising at least 14 carbon atoms, linear or branched, saturated or not, optionally comprising at least one hydroxyl group and of an alcohol, linear or branched, comprising 1 to 12 carbon atoms per unit and carrying one or more hydroxyl groups; said esters of carboxylic acids being obtained, for at least two of them, from alcohols having a different number of carbon atoms in the longest chain; associated with (ii) at least one nonionic surfactant.

22. Composition according to the preceding claim, characterized in that the proportion by weight of ester / nonionic surfactant is between 80/20 and 99/1.

23. Composition according to one of claims 21 or 22, characterized in that the ester is derived from a carboxylic acid comprising at least 16 carbon atoms, and preferably from 18 to 22 carbon atoms.

24. Composition according to one of claims 21 to 23, characterized in that the ester is chosen from products obtained from the transformation of triglycerides of animal or vegetable origin.

25. Composition according to one of claims 21 to 24, characterized in that at least one of the esters is derived from an alcohol comprising less than 4 carbon atoms in the longest chain, the other or the others esters are derived from an alcohol having at least 4 carbon atoms in the longest chain.

26. Composition according to one of claims 21 to 25, characterized in that the proportion by weight of ester (s) derived from an alcohol comprising less than 4 carbon atoms / ester (s) derived from an alcohol comprising at least 4 carbon atoms is between 10/90 and 90/10.

27. Composition according to one of claims 21 to 26, characterized in that the composition comprises at least one liquid or solid phytosanitary active material, soluble or not, miscible or not, in the composition.

28. Composition according to one of claims 21 to 27, characterized in that the composition comprises at least one compatibilizing additive chosen from pH correcting agents, anionic surfactants, or their mixtures.

29. Composition according to the preceding claim, characterized in that the content of pH correcting agent is such that the composition, when it is in the form of an emulsion or solution at 1% by weight in water, has a pH between 5 and 9.

30. Composition according to Claim 28, characterized in that the content of anionic surfactant represents 1 to 50% by weight of the surfactants present in the composition.

31. Use of the composition according to one of claims 29 or 30, characterized in that the composition is diluted in an aqueous phase, preferably water, before application to the plant to be treated.

32. Use according to the preceding claim, characterized in that the content in aqueous phase, preferably in water is between 70 and 99% by weight of the composition, preferably between 70 and 95% by weight of the composition.

33. Use of the composition according to one of claims 29 to 32, characterized in that the composition is mixed with a phytosanitary formulation, before or after dilution of said formulation in an aqueous phase.