ES2749225B2 - Synergistic insecticidal combination of vinegar and citrus essential oil - Google Patents

Description

Synergistic insecticidal combination of vinegar and citrus essential oil

Technical sector

The present invention consists of a formulation of a product for application within the agricultural sector, based on a compound of citrus essential oils, limonene, combined with a derivative of vinegar for use as a natural insecticide on crop pests.

State of the art

Citrus peel has a large number of compounds that can be obtained and used for commercial purposes. The oil contained in sacks located on the external part of the mesocarp of the fruit can be released by breaking them. According to several authors, the essential oil of citrus fruits is a mixture of volatile compounds and consists mainly of monoterpene hydrocarbons, which have a high level of unsaturation ( Stashenko et al., 1996; Virot et al., 2008,).

D-limonene (1-methyl-4- (1-methylethenyl) cyclohexane) is the most common monocyclic monoterpene in nature. It is an important component in several citrus oils (orange, lemon, tangerine, lime and grapefruit) and can reach a concentration in them of 95-98%. Additionally, D-limonene is listed in the Code of Federal Regulations Recognized as Safe (GRAS) as a flavoring agent and can be found in common foods such as fruit juices, soft drinks, baked goods, ice cream, and puddings.

Some products generated in the oxidation of Limonene and combined with surfactants such as APSA-80, have been shown to be effective as repellents and / or deterrents for mosquitoes and mealybugs. However, it is complex for Limonene to mix well, thus preventing spots / drops from forming and having a good homogenization (Hollingsworth, 2005).

Some mixtures described in patent WO 03/011054 A2 with synergistic effect used for pest control contain at least two of these ingredients: D-limonene, thyme oil, lemon oil, lilac flower oil ( Syringa sp), Nigella sativa oil, Wintergreen oil, Linalol, Tetrahydrolinalol, Vanilline, Isopropyl myristate, Piperonal, Geraniol, Triethyl citrate and / or Methyl salicylate.

Patent US 8,133,921 B2 describes different formulations of a natural insecticide containing between 1-20% by weight of D-Limonene, 1-25% by weight of a non-toxic emulsifying agent (Alkamuls EL 620) and a 55 -98% by weight of a non-toxic hydrophilic solvent (depending on the formulation) with effect on ants, aphids, mealybugs, whiteflies, spider, cicadas, lice, defoliating beetles and their larvae and cockroaches.

Components such as allyl isothiocyanate, (E) -Nerolidol, Limonene, p-Cimene and y-Terpinene extracted from Eucalyptus globulus show strong larvicidal activity against Aedes aegypti Linn. (Park et al., 2011).

In other studies, compositions of essential oils extracted from Eucalyptus tereticornis with a repellent and insecticidal effect and containing monoterpenes such as Mircenol, Citronelic Acid, P-Mentane-3,8-diol, Citronellol, Citronellal and 2,2-dimethyl-5 - (1-methylethyl) -tetrahydrofuran have been tested on Drosophila melanogaster in bean crops (Murillo-Arango et al. 2014). It was also evaluated whether there was foliar phytotoxicity on the plant, not observing this effect in any case.

Some formulations containing limonene such as that described in patent WO 2011045596 have been used as attractants for lepidopterans such as Helicoverpa armígera to use them as decoy insects and reduce the number of pest insects in certain crops.

In other patents such as WO 2007025197 or WO 2009135289 they focus on the improvement of composition and deterrent and repellent systems against chironomids using elements from citrus fruits or from the oxidation of products such as Limonene. The components with this repellent and / or deterrent capacity that have been observed are Neril Acetate, Citronellyl Acetate, Geraniol Acetate, Hydroxy-P-Cimeno, Citral, Aterpineol, Citronellal, Linalyl Acetate, Citranellol, Terpen-4-ol , Limonene oxidation products such as d- and l-carvone, (+) Limonene oxide, (-) Limoneo oxide, cis and trans carveol, diolaldehydes and mixtures of these.

The toxicity and repellent effect of pure compounds of plant origin such as Terpineol have been studied on Tribolium confusum (Coleoptera: Tenebrionidae), which is an insect pest of stored cereal products. Neither the repellent effect nor the degree of toxicity of Terpineol were significantly relevant for the control of this pest insect (Ojimelukwe & Adler, 1999)

The use of chemical pesticides can cause phytotoxicity problems that appear quickly in plants (burned leaves, roots and flowers) or be taken by it and appear in products intended for human or animal consumption, persisting in the food chain and causing health problems. that affect the immune and neurological system (Stella-Nerio et al., 2009)

The increase in the problems of synthetic pesticides associated with cross resistance, risks to public health and damage to the environment (accumulating by bioconcentration in the different links of the food chain, in the soil and in the water), have promoted the search of natural products with pesticidal properties. These biopesticides have a unique mode of action, are not toxic to humans, plants or animals and act selectively on the species to be eradicated without affecting others. They are products with a low environmental impact and, as they are organic molecules, they degrade quickly, avoiding environmental problems of accumulation of waste.

The present invention advantageously manages to act on harmful insects in agriculture, without involving an increase in environmental residues as it is a product resulting from the synergistic combination in a certain proportion, of two products of natural origin, vinegar and essential oil of citrus fruits, in their purified versions of acetic acid and limonene.

References

WO 03/011054 A2 (Andersch, W .; Wachenhoff-Neuman, U. and Hansler, G. Combination of active agent. Bayer Aktiengesellschaft). 06-26-2000

WO 2009135289 A1 (Mullen, B. & Fleming, L. Biological pest control mixture containing d-limonene and nutmeg oil.) 12-11-2009

WO 2011045596 A2 (Cork, A. Insect attractant compositions. University of Greenwich) 04-21-2001.

US 8,133,921 B2. (McPartland, T. Edible Plant Extract Based Insecticidal Composition) 03-13-2012

WO 2007025197 A2 (Deboukian, R.H. & Weldon, P. Spatial inhibitors, deterrents and repellents for mosquitoes and midges. Bedoukian Research Inc.) 03-01-2007.

Hollingsworth, RG 2005. Limonene, a Citrus Extract, for control of Mealybugs and Scale insects. Journal of Economic Entomology, 98 (3): 772-779.

Murillo-Arango, W .; Araque Marín, P .; Henao-Murillo, B .; Peláez-Jaramillo, CA Insecticide activity of oil / water emulsion of Eucalyptus tereticornis essential oil. http://www.bvs.sld.cu/revistas/pla/vol 18_1_13 / pla13113.htm.

Ojimelukwe, PC & Adler, C. 1999. Potential of Zimtaldehyde, 4-Allyl-anisole, Linalool, Terpineol and other Phytochemicals for the Control of the Confused Flour Beetle (Tribolium confusum J. d. V.) (Col., Tenebrionidae) . AnzeJgerfi r Sch idlingskunde Journal of Pest Science, 72: 81-86.

Park, HM; Kim, J .; Chang, KS; Kim, BS; Yang, YJ; Kim, GH; Shin, SC & Park, KIL 2011. Larvicidal Activity of Myrtaceae Essential Oils and Their Components against Aedes aegypti, Acute Toxicity on Daphnia magna, and Aqueous Residue. Journal of Medical Entomology, 48 (2): 405-410.

Stashenko, EE; Doors, MA; Combariza & MY 1996. Volatile secondary metabolites from Spilanthes Americana obtained by simultaneous steam distillation-solvent extraction and supercritical fluid extraction. Journal of Chromatography A, (752): 223-232.

Stella Nerio, L .; Olivero-Verbel, J & Stashenko, EE 2009. Repellent activity of essential oils: A review. Bioresource Technology, 101 (2010): 372-378.

Virot, V., Tomao, V., Giniers, C., Visinoni, F., & Chemat, F. 2008. Green procedure with a green solvent for fats and oils determination. Microwave integrated soxhlet using limonene followed by microwave Clevenger distillation. Journal of Chromatography A, (1196): 147-152.

Detailed description of the invention

The formulation of a product of organic origin composed of

Limonene (40-70%) and Acetic Acid (60-30%). The combination of both components

produces a synergistic effect that gives the product a significant insecticidal capacity

on pests in crops that is not obtained by using the components separately,

Therefore, a synergistic action between the two substances is responsible for the efficacy

of the present invention. In addition, this synergistic action is effective only in a

specific range of the limonene / acetic ratio and outside this range does not work with the

same efficiency.

Complementarily, the invention is illustrated below by means of

corresponding examples.

Brief description of the figures

Figure 1 . Evolution of the level of aphids per leaf in pepper crops under the tested treatments. The thick arrows in the direction of the abscissa axis indicate the day of treatment. The thinner arrows next to the references to the treatments indicate to which line the evolution of the accompanying treatment corresponds.

Figure 2 . Evolution of the whitefly population in pepper cultivation for different treatments. The thick arrows in the direction of the abscissa axis indicate the day of treatment. The thinner arrows next to the references to the treatments indicate to which line the evolution of the accompanying treatment corresponds.

Preferred embodiments of the invention

The present invention is further illustrated by the following 2 examples, which are not intended to be limiting of its scope.

The product is prepared from the following compounds:

-Acetic Acid with a purity of 99.7%, is added in a percentage of 30-60%.

-Limoneno with a purity of 92-99% is added at a percentage of 70-40%.

For the preparation of the mixture, the order when adding the components is acetic acid first followed by limonene. It is necessary to stir this mixture. The generated product is soluble in water.

The application of the synergistic mixture is carried out by means of foliar spraying on the foliar mass of the crop object of the treatment, previously carrying out a combination of the synergistic mixture with water in the spraying tank. The function of water is to act as a dispersion vehicle and guarantee a homogeneous distribution of the synergistic mixture over the entire surface to be treated.

The percentage or dose of the mixture and the amount of application water is variable and will depend on the total foliar surface of the crop to be treated (in order to achieve maximum dispersion) and on applying a sufficient dose of the synergistic mixture to guarantee the insecticidal efficacy of the treatment. It is for this reason that the percentages of synergistic mixing in the Treatment broths are carried out at 1 ppm, this concentration being merely indicative and not intending to be limiting in its use, since the use at other concentrations may be effective.

Example 1

The evaluation of the effect of the product formulated with limonene was carried out on a greenhouse scale to determine the influence on aphids. The study was carried out during the months of December 2014 and January 2015 in a greenhouse in full production with organic cultivation of pepper of the 141 Rijkzman variety.

The irrigation system is drip irrigation and at the time of the test the presence of aphids is observed with very high population levels. The greenhouse area is 9000 m2 and the pepper plants are in a 0.4 m x 1 m planting frame.

The pepper plants were treated with four different theses: water (as negative blank), limonene 94%, acetic acid 99.7% and finally, product formulated with limonene and acetic acid (60:40). With each of these products, the treatment was carried out on the pepper plants by means of a manual spraying equipment at 20 bars of pressure.

The concentration of the products used was 1 ppm (0.1%) and 40 plants were treated per treatment. A count of the level of plague was carried out prior to the application to subsequently determine the reduction of insects in them.

The counts were made 24 and 72 hours after the application, evaluating the mortality of insects present on the leaves and a treatment was carried out with each of the products. The results of the counts are shown in Figure 1 where the days on which the treatments were applied are marked with an arrow.

The average number of aphids observed on the days of application of the products is prior to said treatment.

For this, four random treatments were established, which are detailed in Table 2: .

The different treatments were applied weekly for 2 weeks, making 4 replications per treatment and establishing plots of 10 pepper plants where aphid counts were made on leaves (10 per plot) prior to treatment, at 24 and 72 hours.

Analyzing the results of the study, we observed that T4 remains below the rest of the treatments from the beginning of the individual counts after the first day of treatment. As evidenced by the trend line for this treatment, the decrease in the number of aphids per leaf is gradual and constant during the evolution of the trial.

The control remains above all the other treatments as expected, while T2 and T3 follow a very similar trend without exerting control over the aphid infestation, so it is concluded that the components of the mixture separately do not have a significant effect on the pest, T4 being the most effective treatment for its management (figure 1).

Example 2

The objective of this trial is to analyze the effectiveness of the product on whitefly in different formulations to know the effectiveness of the mixture.

The plot under test has an area of approximately 3,000 m2 planted in full and paired rows, with a 1 x 0.5 m planting frame of the California pepper variety in the productive phase.

Its irrigation system is drip irrigation and has a moderate infestation of pests that

are appropriate for the realization of this experience.

4 treatments were evaluated using a statistical design in random blocks of 2

x 7 m with 45 plants per test plot and 4 repetitions of each treatment therefore

180 plants were analyzed per treatment.

No type of wetting agent or pH regulator was added to the broths made

for each of the treatments. A single application was made with a machine

manual sprayer at 20 bar pressure and a total of 3 applications for each

treatment.

The products used and the dose used in the test are those shown in

the following table:

Table 2 . Doses used in the different treatments for this trial.

For the counts, plants were taken at random and the leaves were observed, both the upper side and the underside. Counts were made the same day before treatment, after 24 hours and after 72 hours.

Regarding the results for the whitefly (figure 2), we found that the plants treated with T-1 decreased their presence at the time of application but days later their presence increased again, being the initial percentage and the final percentage after all the essay almost the same or even greater.

With the T-2 test, at the beginning, the same process is followed as with the T-1, but at the end of the test the percentage of whitefly has not increased with such intensity.

In the case of T-3, the fly population continues its growth without apparently being affected by the treatments (figure 2).

In the case of the T4 treatment, a constant decrease in the number of whitefly individuals is observed until their virtual disappearance.

The presence of auxiliary fauna such as bees and ladybugs is not damaged by treatments T-2, T-3 and T-4.

Claims (2)

1.- Preparation characterized in that it consists of a combination of limonene obtained from citric extracts and acetic acid obtained from vinegars in a range of proportions by weight ranging from 40 to 70% limonene and 60 to 30% acetic acid. 2. Insecticide characterized in that it comprises a preparation according to claim 1.