WO2023052174A1

WO2023052174A1 - Method for protecting crops by means of an aqueous dispersion of caryophyllene

Info

Publication number: WO2023052174A1
Application number: PCT/EP2022/075979
Authority: WO
Inventors: Alberto Sardo
Original assignee: Xeda International
Priority date: 2021-09-29
Filing date: 2022-09-19
Publication date: 2023-04-06
Also published as: FR3127367A1; WO2023052175A1

Abstract

The present application relates to a method for implementing a crop protection treatment using aqueous dispersions of caryophyllene, free of emulsifying agents, such as aqueous suspensions or emulsions of caryophyllene. Said treatment is particularly suitable for preventing or eradicating infestations of nematodes and/or insects.

Description

DESCRIPTION

METHOD FOR PHYTOSANITARY TREATMENT BY MEANS OF AQUEOUS DISPERSION OF CARYOPHYLLENE

The present invention relates to a process for the phytosanitary and in particular nematicide and/or insecticide treatment of plants, such as horticultural plants, in particular fruits or vegetables.

Plant-parasitic nematodes belong to two orders, Dorylaimida and Tylenchida. We distinguish: root nematodes - whose entire cycle takes place in the soil, some being mobile at all stages, external parasites (Tylenchus) or internal ones (Pratylenchus), others sedentary: cyst nematodes (Heterodera, Globodera) ; root-knot nematodes (Meloidogyne, etc.); aerial part nematodes (Ditylenchus, Aphelenchoides).

The direct damage is above all a weakening of the plant, sometimes deformations, discolorations, galls, etc. ; indirect damage consists of the aggravation of fungal and viral diseases.

Galls designate tumors, growths, bushes, etc., abnormal plants, produced in reaction to the bite or the installation within their tissues of said nematode (known as root-knot). Galls can affect all plant organs. Except in special cases (where galls are sought after products), their presence affects the vigor and yield of the plant. In Europe, the main root-knot insects are midges, weevils, aphids, phylloxera, mites, phytopes, and in particular root-knot nematodes (Meloidogyne spp.). These are dangerous for many crops.

Furthermore, the presence of Meloidogyne promotes or aggravates the attacks of fungi such as Fusarium or Verticillium albo-atrum which, from the ground, can invade the conductive vessels of the whole plant.

However, the chemical treatments of the fruits or vegetables usually used exhibit phytotoxicity with regard to the treated plants and are not without harm for the consumer. It is therefore particularly desirable to provide a method of preventing or eradicating nematodes for plants, especially fruits and vegetables.

SUBSTITUTE SHEET (RULE 26) vegetables. The treatment must therefore be harmless for the treated plant, acceptable in terms of food and easy and economical to implement.

WO 2008/122728 proposes a nematicide treatment by means of a composition comprising a terpene, such as eugenol and lecithins, in an oily base.

It is therefore important to make a less expensive treatment available.

In addition, it is important to provide a phytosanitary treatment with a limited phytotoxic effect and of natural origin for food compatibility.

The insecticidal or nematicidal activity of plant extracts or essential oils is widely reported, but the specific activity of their ingredients often remains unknown to date.

Caryophyllene is a sesquiterpene found in many essential oils. However, Kollner et al The plant cell 20, 482-494, 2008 reports that caryophyllene attracts nematodes. The effect of caryophyllene on nematodes or insects is therefore doubtful.

The Applicant has now discovered unexpected properties of caryophyllene: It exhibits, against all expectations, significant phytosanitary activity and in particular nematicide and/or insecticide, with a negligible phytotoxic effect: unlike other terpenes, caryophyllene does not show aggressiveness towards plant and animal tissues.

According to a first object, the present invention therefore relates to the use of caryophyllene as a nematicide and/or insecticide active agent in aqueous dispersion.

According to another object, the present invention also relates to a method of nematicide and/or insecticide treatment comprising the application of caryophyllene as a nematicide and/or insecticide active agent in aqueous dispersion.

The following embodiments apply equally to each of the objects mentioned above and are understood individually or in combination.

The term caryophyllene used herein designates p-caryophyllene (also trans-caryophyllene, CAS 87-44-5) of IUPAC nomenclature 1β,4E,9S)-4,11,11-trimethyl-8-methylidenebicyclo[7.2. 0]undec-4-ene and corresponding to the general formula:

By emulsifying agent is meant the surfactants or emulsifiers usually used for this purpose, such as ethoxylated fatty alcohols, ethoxylated fatty acids, ethoxylated alkylphenols, sorbitan esters and their ethoxylated derivatives, or any other nonionic or anionic product such as ethoxylated sodium lauryl sulfate.

By "phytotoxicity" is meant, according to the invention, any damage to fruits and vegetables, resulting from the direct action of the active ingredient, for example terpenes, illustrated by the modification of the visual appearance of said fruits and vegetables. or their leaves.

Preferably, according to the invention, "phytotoxicity" designates the direct alteration by said active ingredient of the integrity of the skin of said fruits and vegetables, in particular by modifying the color or the texture of their skin. More specifically, phytotoxicity can be illustrated by a homogeneous yellowish coloration, red pigmentation, the formation of yellow or brown spots or areas of necrosis, punctual or extensive, or even the formation of microlesions on the skin.

These microlesions then constitute a breeding ground for mold or the rotting of fruits and vegetables.

According to the invention, said phytotoxicity defined above results directly from the action of the active ingredient and consequently excludes natural aging phenomena, such as senescence in particular.

The phytosanitary process refers to the protective effect of cultivated plant species, against insects and harmful organisms and diseases, and/or more broadly to the improvement of yields. According to the invention, the phytosanitary treatment is illustrated in particular by an insecticidal, bactericidal or nematicidal activity, more particularly a nematicide and/or insecticide treatment.

Phytosanitary treatment aims in particular to eradicate or prevent attacks by external nematodes such as Tylenchus, internal nematodes such as Pratylenchus, cyst nematodes such as Heterodera or Globodera, galls such as Meloidogyne, or aerial part nematodes such as Ditylenchus, Aphelenchoides.

The term "nematicide" designates any treatment allowing the prevention of a future infestation or the eradication of an existing infestation of nematodes.

The nematicide treatment according to the invention is particularly suitable for nematodes which attack the roots of plants, such as the root-knot nematodes Meloidogyne spp.

The "insecticidal" activity refers in particular to the ability to eradicate and/or prevent the attack of insects, their larvae and/or their eggs, and in particular the eradication and/or repulsion of species such as aphids of the family of aphids such as the aphids in particular, the psyllidae such as the psyllae, or even butterflies such as carpocapsa.

The phytosanitary activity according to the invention is aimed at all plants affected by these parasites, and in particular horticultural plants. Horticultural plants are understood to mean plants relating to market gardening, vegetable gardening, arboriculture and floriculture. These targeted plants are in particular cereals, fruits or vegetables such as solanaceae (tomato, eggplant, potato), cucurbits (melon, cucumber), legumes (beans), fruit trees, bulbs and tubers, carrots , scorzonera, lettuce, endive, artichoke, chard, celery, spinach, lettuce, radish, cucumbers, melons, watermelons etc..

The term “aqueous dispersion” used here refers to dispersions of solids, also called suspensions, and dispersions of liquids, also called emulsions, within an aqueous phase.

According to the invention, the aqueous dispersions comprise an absorption agent or an ensapsulating agent.

According to a first embodiment, the caryophyllene can be applied in the form of an aqueous suspension.

Aqueous suspension means a suspension of solid particles comprising caryophyllene, in water.

Typically, the aqueous suspension comprises solid particles acting as an absorption agent on which the caryophyllene is absorbed. Said solid particles may in particular be solid particles impregnated with caryophyllene. Mention may thus be made of solid particles of clay or of hydroxyapatite impregnated with caryophyllene, in suspension in water.

More particularly, caryophyllene-impregnated bentonite particles suspended in water are considered as an aqueous suspension.

According to an alternative embodiment, the caryophyllene can be applied in the form of an aqueous emulsion.

By aqueous emulsion is meant a phase comprising fine droplets of caryophyllene dispersed in water.

Typically, the aqueous emulsion includes an encapsulating agent encapsulating the caryophyllene.

As such, said stabilized encapsulating agent makes it possible to stabilize said emulsion and therefore makes it possible to avoid using an additional emulsifying agent.

In this respect, mention may in particular be made of emulsions of encapsulated caryophyllene nanoparticles, such as caryophyllene nanoparticles encapsulated with a cyclodextrin, or lecithin.

Typically, the cyclodextrin can be chosen from the cyclodextrins of families a, p and y, respectively comprising 6, 7 and 8 members, such as cyclodextrins with CAS number 10016-20-3, CAS 7585-39-9 and CAS 17465- 86-0, as well as their derivatives, in particular the chemically modified derivatives of these compounds. For the purposes of the invention, mention may in particular be made of cyclodextrin p.

For each of these embodiments, the caryophyllene can be used alone, that is to say as the sole insecticidal and/or nematicidal active agent, or alternatively in combination with one or more other active agents with nematicidal activity and/or or insecticide.

As additional active agents with nematicidal and/or insecticidal activity, mention may in particular be made of cinnamaldehyde, eugenol, eucalyptol, carvone, geraniol, thymol and citronellol, more particularly eugenol, or cinnamaldehyde.

According to one embodiment, the aqueous dispersions of the invention may comprise one or more emulsifying agents.

The expression "emulsifying agents" denotes various surfactants or emulsifiers, generally known per se. According to the present invention, the term "agent emulsifier" any type of agent usually used for this purpose, such as ethoxylated fatty alcohols, ethoxylated fatty acids, ethoxylated alkylphenols, sorbitan esters and their ethoxylated derivatives, or any other nonionic or anionic product such as sodium lauryl sulphate The invention is not however limited to the use of these particular surfactants According to one embodiment, the emulsifying agents, when they are present, are distinct from cyclodextrins and lecithin.

Typically, said emulsifiable concentrated composition may additionally comprise from 3 to 60% of surfactant(s).

According to an advantageous alternative embodiment, the aqueous dispersions of the invention are devoid of emulsifying agents.

The aqueous dispersions according to the invention can be prepared in a manner conventional per se by simply mixing their constituents.

Typically, the method may comprise the step of preparing an aqueous dispersion of the adsorption or encapsulation agents, then the addition of the caryophyllene with stirring to achieve the absorption or encapsulation of the caryphyllene, within the aqueous dispersion. .

According to one embodiment, the aqueous dispersions can be diluted in water before their application. The dilution is typically carried out at a height of between 0.01 and 10% (by volume) in water.

According to one embodiment, said aqueous dispersions can typically be applied by spraying, sprinkling, watering, irrigation or spreading.

Generally, said dispersions can be applied to fields, to the ground, in particular once or several times during the period between sowing and the ripening fruit or vegetables.

Said dispersions can be applied at room temperature.

Said dispersions can be applied once or several times, during the cultivation stage of the plant. The treatment can therefore be repeated several times, depending on the length of the crop cycle and the risk linked to attacks by nematodes in particular.

The amount of aqueous dispersion applied depends on the nature of the fruits or vegetables concerned and on the mode of application selected. It also depends on the amount of active to apply. Typically, said emulsifiable concentrated composition is applied at a dose of 1 to 50 L/ha, at doses of between 100 and 10,000 ppm, in particular between 150 and 3,000 ppm.

According to one embodiment, the method can be applied to any type of plant subject to infestation by nematodes and/or undesirable insects, and more particularly to fruit trees, bulbs and tubers, tomatoes, cucumbers, melons, watermelons.

The following examples are given by way of non-limiting illustration of the present invention.

EXAMPLES

The insecticidal activity of caryophyllene was evaluated and compared in the following tests:

The following formulations were prepared:

A. witness

B. aqueous dispersion of cinnamaldehyde encapsulated by cyclodextrin p, at 39.6 g/l

C. aqueous dispersion of caryophyllene encapsulated by cyclodextrin at 37.1 g/l

D. aqueous dispersion of caryophyllene encapsulated by cyclodextrin (19.3 g/l) and of cinnamaldehyde encapsulated by cyclodextrin (19.3 g/l)

E. aqueous dispersion of caryophyllene encapsulated by cyclodextrin (40 g/l) and eugenol encapsulated by cyclodextrin (30 g/l)

The aqueous dispersions were prepared as follows:

Cyclodextrin is added to water with stirring. Then, still under agitation, the caryophyllene is added and the agitation is maintained for 2-3 hours.

The dispersions thus obtained are then diluted. The formulations obtained were applied by spraying with an atomizer, on different plants at a dose of 200 ppm, i.e. at the following doses reported for each formulation:

Insecticidal activity has been tested in the field for the following species:

• Psylla pyri

The above formulations A-E were applied to pear buds once a week for 3 weeks. The extent of the infestation was measured after 4 weeks:

The number of larvae and pupae is summarized below:

These results demonstrate the insecticidal activity of caryophyllene in aqueous dispersion, and the synergistic effect of caryophyllene with cinnamaldehyde or eugenol.

• Aphis fabae

The above A-E formulations were applied to sugar beet tubers twice, fifteen days apart. The extent of the infestation was measured after 2 weeks:

The number of aphids is summarized below:

• Carpocapsa melo The formulations A-E above were applied to apple buds 3 times at 10 day intervals. The extent of the infestation was measured 15 days after the last application:

The percentage of fruits attacked by insects is summarized below:

These results demonstrate the insecticidal activity of caryophyllene in aqueous dispersion, and the synergistic effect of caryophyllene with cinnamaldehyde.

Claims

1. Use of caryophyllene as an active nematicide and/or insecticide in aqueous dispersion.

2. Use according to any one of the preceding claims such that the caryophyllene is applied in the form of an aqueous suspension.

3. Use according to claim 2 such that said aqueous suspension comprises solid particles of clay or hydroxyapatite impregnated with caryophyllene suspended in water.

4. Use according to claim 3 such that said suspension comprises bentonite particles impregnated with caryophyllene.

5. Use according to claim 1 such that the caryophyllene is in the form of an aqueous emulsion, encapsulated by nanoparticles of cyclodextrin in emulsion in water.

6. Use according to any one of the preceding claims for the eradication or prevention of aphid attacks.

7. Use according to any one of the preceding claims, such that the caryophyllene is used alone or in combination with other active agents with nematicidal and/or insecticidal activity.

8. Nematicide and/or insecticide treatment process comprising the application of caryophyllene as a nematicide and/or insecticide active agent in aqueous dispersion.

9. Process according to claim 8 comprising the application of the caryophyllene in the form of an aqueous suspension.

10. Process according to claim 9, such that the said aqueous suspension comprises solid particles of clay or of hydroxyapatite impregnated with caryophyllene in suspension in water.

11. Process according to claim 9 or 10 such that said suspension comprises particles of bentonite impregnated with caryophyllene.

12. Method according to claim 9 comprising the application of caryophyllene in the form of nanoparticles encapsulated by a cyclodextrin in aqueous emulsion.

13. Process according to claim 9, such that caryophyllene is the only active nematicide and/or insecticide agent, or is in combination with one or more additional active agents with nematicide and/or insecticide activity.

14. Treatment process according to claim 13, such that said additional active agents with nematicide and/or insecticide activity are chosen from cinnamaldehyde, eugenol, eucalyptol, carvone, geraniol, thymol and citronellol, more particularly eugenol, thymol and cinnamaldehyde.

15. Method according to any one of claims 9 to 14, such that the application is carried out with irrigation water or by sprinkling.