WO2007144694A2

WO2007144694A2 - Natural pesticide

Info

Publication number: WO2007144694A2
Application number: PCT/IB2006/003946
Authority: WO
Inventors: Genaro Casas Jassan; Jose Represas De Aimeida
Original assignee: Genaro Casas Jassan; Jose Represas De Aimeida
Priority date: 2005-10-14
Filing date: 2006-10-13
Publication date: 2007-12-21
Also published as: CA2626000A1; JP2009511567A; WO2007144694A3; MX2008004819A; AU2006344450A1; EP1956916A2; BRPI0617387A2

Abstract

A natural pesticide includes a combination of garlic oil and mustard oil impregnated in a carrier. The carrier may be an absorbent composition formed from corncob particles, and in particular the woody ring and chaff of the corncob. The combination of garlic and another essential oil, such as mustard oil, has a synergistic effect for inhibiting the growth of bacteria, fungi, and eradicating insect pests.

Description

NATURAL PESTICIDE

BACKGROUND OF THE INVENTION

Field of the Invention The present invention relates to an absorbent composition of matter, such as corncob particles, which are used to gradually release an active ingredient, such as a natural pesticide, made from garlic and one or more essential oils, which have a synergistic effect for inhibiting the growth of bacteria, fungi and eradicating insect pests.

Description of the Related Art

Commercially available insecticides, including those available for home use, commonly comprise active ingredients or "poisons" which are not only toxic to the target insect pests, but, if used in relatively confined environments and delivered as aerosol sprays, can be present in sufficient concentration to also be toxic to humans and household pets. Various undesirable side effects may include immediate or delayed neurotoxic reactions, and/or suffocation. Even the noxious odor of such materials can cause headaches or upset stomachs in some individuals. These adverse side effects are exacerbated when such compositions come in contact with persons of increased sensitivity, or persons of small body mass such as children or babies.

For some time, efforts have been made to develop insecticidal compositions, particularly those intended for residential use in aerosol form, which are effective in killing the targeted insect pests completely and quickly, but non-toxic to humans and pets. The Environmental Protection Agency (EPA) in the United States of America regulates the use of potentially toxic ingredients in pesticidal compositions under the Federal Insecticide, Fungicide and Rodenticide Act. Certain materials considered to be either active or inert materials by the EPA have been deregulated or otherwise identified as acceptable "safe" substances offering minimum risk in normal use. Other materials are currently undergoing investigation and may be deregulated in due course. Deregulated substances are generally considered non-poisonous by the consumer. Thus, the term "non-poisonous" as used herein is intended to convey a composition that, while highly effective in killing targeted insect pests, is safe to use around humans, particularly small children, and pets.

Unfortunately, non-poisonous insecticidal compositions available heretofore incorporating deregulated materials as the active ingredient have had limited efficacy. Attempts to use deregulated essential oils as the active ingredient in such insecticides, while having limited success, have generally been found to be either cost prohibitive, inadequately lethal to control a range of targeted insect pest species, or too slow- acting to enable the user to confirm that the insect has been killed and to dispose of the dead insect so as to avoid polluting the environment.

Garlic (Allium sativum Linn.) and/or its extract have been reported to have antibacterial and/or antifungal properties. It is known that Allicin isolated from the cloves of garlic had antibacterial properties against both Gram positive and Gram negative bacteria. Further, aqueous extracts of garlic have been reported to inhibit the growth of a variety of yeast-like fungi in the genera Candida, Cryptococcus, Rhudotoruto, Torulopsis and Trichosporon. It has also been previously reported that garlic extract and chips inhibit the growth of fungi such as Candida albicans, Aspergillus fumigatus and Aspergillus parasiticus. Because of its antifungal and antibacterial properties, garlic or its extract have been used as pesticides to control plant diseases such as mildew. It has also been used as an insecticide to control plant insects such as army worms, aphids and Colorado beetles. Most recently, garlic extract and water has been used to repel mosquitoes.

Therefore, there is a need in art for a safe, cost effective and highly efficient absorbent composition of matter that provides for a controlled time release of an aromatic substance, such as one or more essential oils with garlic that have a synergistic effect, for inhibiting the growth of bacteria, fungi and insect pests. SUMMARY OF THE INVENTION

The concept of the new product derived from the present invention, is enlarged in its range of applications. For example, uses in agriculture, home and industry are possible by combining its qualities to gradually release an aromatic substance to repel plagues of insects like cockroaches in kitchens or mosquitoes as well as other agricultural crop damaging insects. Good results are obtained by combining garlic or garlic extract, known for its qualities as a repellent for garden or agriculture damaging insects, and essential oils, such as mustard oil (or AITC), with this absorbent carrier to create a synergistic effect to yield an improved extermination of bacteria, fungi and insect pests.

Additionally the absorbent carrier has the capacity to gradually release these forms of repellent aromas providing for a long lasting product; malodor, if present is also absorbed. Inversely, attractant substances can be used, being of particularly useful application for household pets, for example, the use of an attractant aroma or fragrance in the production of cat litter. Additionally, the composition of matter in the present invention provides for a controlled time release of the different active ingredients, such as a natural pesticide, applied to the preferred embodiment (e.g., corncob particles).

Essential Oil is defined as a subtle, volatile liquid obtained from plants and seeds or artificially obtained substitutes, for example, allyl isothiocyanate (AITC) as a substitute for mustard seed oil. Garlic or garlic extract is defined as any liquid removed from cloves of garlic and may therefore include garlic oil and water. Garlic extract has the same meaning as garlic juice.

In one aspect of the invention, a natural pesticide, comprises a combination of garlic and mustard oil (or AITC) impregnated in a carrier, wherein the combination of garlic and mustard oil (or AITC) has a synergistic effect for inhibiting the growth of bacteria, fungi, and eradicating insect pests. DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment of the product object of the present invention consists of two basic elements: a carrier characterized by its great capacity for odor and malodor absorption and a gradual release of other active substances toward the air or surrounding atmosphere, and secondly, a combination of garlic with one or more essential oils that has a synergistic effect, for inhibiting the growth of bacteria, fungi and insect pests.

In one embodiment, the carrier is a material obtained from the threshed ear of corn (lea Maiz) whose special physical and chemical qualities allow the previously described functions, of absorption and gradual release. To obtain the different components that comprise the threshed ear of corn, an industrial process, well known in the state of the art is required, which consists of separation, classification and sizing of each one of the components that constitute corncobs. The threshed ear of the corn, also known as "olote" in Mexico, "spiga de maiz" in Castilian, corncob in English, "sabugo" in Portuguese and "balle de maϊs" in French, if cut transversely, is constituted by three concentric rings. Starting with the inner ring as a reference, they are known in English as pith, woody ring and chaff. The material of the present invention uses the woody ring and chaff portions. The woody ring, as well as the chaff portion, has similar characteristics; both can be used as carriers for active ingredients as described in the body of the present invention. The main differences reside in the difference of absorption capacity and in the particle hardness. Other differences exist and are described below.

In order for the woody ring to comply with the requirements of the present invention it must have the following characteristics: woody ring should be 99% free of other cob particles, it should have no more than 1% dust or fines (the product should be air washed). By definition, fines are particles that can pass through U.S. standard screen size 400 (37 microns). The woody ring must be subjected to heat treatment that guarantees microbiology content and moisture levels under 10%. For correct functionality, the particle size should be uniform in size and ranges should not exceed a maximum of 3987 microns and a minimum of 42 microns. The woody ring of corncobs is characterized by the following: a hardness of 4.5 on the Mohs scale, a fast absorbency of oil (e.g., soybean oil) of 1-to-l on weight basis and the typical molecular structure of a natural fiber. Ideally, particle sizing for the present invention should be between the following ranges: 1) retained or larger than a mesh of 3987 microns, 2) particles between 3987 and 1191 microns, 3) particles between 1191 and 841 microns, and 4) particles between 841 and 42 microns. The main characteristic of the particle size is the surface area that each one represents; for example, particles between 1410 and 841 microns have an average surface area of 5.88 square meters per gram. Particles between 841 and 420 microns have an average surface area of 7.20 square meters per gram. This characteristic is decisive in the qualities of absorption of different substances on the part of the carrier that embodies the product object of the present invention.

It is necessary to highlight that woody ring particles are characterized by having a structure that seen on an electron microscope resembles that of a sea sponge. One can infer that this type structure has capacity to admit and retain substances of small and large molecular size. This allows superior qualities of absorption^, in comparison to other products such as Cyclodextrin that as is known in the state of the art, only admits malodor molecules of small size. The separate and classified sizes of woody ring have unique qualities for the absorption of scents from the air in contact with them. To illustrate this, diverse laboratory tests were made with surprising results as follows: Example 1

A 100 gram portion of mature Camembert cheese, a 20 gram portion of bacon and a 10 cm dish containing 25 grams of woody ring particles sized between 1410 and 841 microns where all placed in a sealed glass container. Another glass container with the same components except for the woody ring particles was also prepared as a control sample. Both glass containers were inspected at intervals of 24hs, 3 days, 5 days and 8 days; the container with the absorbent material practically didn't manifest the characteristic scent of the decomposition of products contained, while the control glass container presented potent and unpleasant scents. Example 2

10 grams of tobacco where incinerated in two sealed glass containers. One of the containers had a 10cm diameter dish containing 10 grams of woody ring, sized between 1410 and 841 microns. The other container remained as a control sample. After 24 hours both containers where opened. The container with the absorbent woody ring particles did not present the characteristic scent of tobacco, while the control sample presented potent scents characteristic of tobacco smoke.

In both tests the evaluation of the scents or aromas were carried out by the authors of the present invention, as well as by a professional perftimist whose educated sense of the smell surrendered an objective opinion of these tests.

The characteristics of the Chaff portion of the corncob are similar to the woody ring portion in its ability to function as a carrier for fragrances and other active ingredients. The most distinguishing differences are: 1) more absorption; between 1.5 and 3 times it's weight in oil, 2) Particles size between 841 and 73 microns and 3) less particle flowability. Woody ring particles are rounder in shape than chaff and therefore flow better. This physical difference between woody ring particles and chaff particles is translated into functional differences in the ability to absorb undesirable scents from the air. Additionally the granular form of the woody ring allows for more interparticle space for air-flow. While the smaller closer chaff particles allow less airflow.

Both woody ring and chaff are characterized by having an almost neutral pH, in the order of 6. This quality makes it an ideal inert carrier with all type of substances, since it does not react with active ingredients. Some other types of carriers have to be disactivated first to neutralize their pH content. The physical and chemical characteristics of corncobs are not favorable for the development of microorganisms, therefore not providing fertile ground for bacteria or fungi that in turn cause malodor or disagreeable scents. It is known in the state of the art that a whole corncob can be stored without cover for periods of one year.

The functional differences of the woody ring portion (i.e., flowability and larger interparticle space) and that of the chaff (i.e., more absorption) allow for a great diversity of applications and use. These corncob fractions can be used combined or separately, for different applications, that are described for the absorbent carrier that integrates the product object of the present invention. For example, if the functional objective is the absorption of an active substance to be slowly released in the air and at the same time allowing the flow of malodor air to be absorbed, the suitable product is the one obtained from the woody ring. If, on the contrary, the functional object is to achieve absorption of an active substance to be slowly released in the air and the absorption of malodors or scents is not important, the elected product would be the chaff portion. Other approaches to select the corncob fraction may include the convenience of not having powders or fines. An example of such an application is the integration of the absorbent agent to active filtration systems where the use of the product from the woody ring is most suitable. If the active ingredient required is thick in nature, or, if product were required to be molded in a three-dimensional object (e.g., including the making of pellets), one would be inclined to select the chaff portion.

Another object of the present invention includes aromas, perfumes, flavors or other natural or chemical agents that are integrated to the product derived from the carrier's composition of matter. In general these substances are available in a liquid, powder or granular state and depending on the active agents chemical constitution, soluble in oil or water. Under these conditions, the absorbent carrier, depending on the type of active ingredients used, can absorb a larger or smaller quantity of said agent. This depends primarily on the size of the active ingredient molecule size, the absorbent carriers gradual release will also depend on this molecular size. The absorption of malodor or scents is simultaneously achieved. The intensity, duration, and brightness of the aroma, with fragrances, will depend on factors of the active ingredient or agent's composition. For example, larger molecular size is equal to longer duration, while the presence of smaller molecular sizes such as those in an ester evaporate quickly.

Some examples for the formulation of the absorbent carrier with active substances in a liquid state are: Example 3

For fragrances, perfumes, and therapeutic aromas, generally using a base of polyvinyl glycol, light mineral oil or microencapsulated powder or granular base, the concentration on a weight basis of the woody ring to active ingredient, is from 0.01% to 18%. A larger amount saturates the absorbent carrier and product flowability is greatly reduced. The concentration on a weight basis of the chaff portion to active ingredient is from 0.01% to 36%. Example 4

For repellents and attractants, generally in oleaginous or microencapsulated powder or granular bases, such as Givaudans Flavor Burst™ products, the recommended concentration ranges for the woody ring as well as the chaff portion are similar to the previous example. Concentrations depend on the active ingredient or agent used and the functionality desired in the end product.

Example 5 For oxidizers and chemical reducers or neutralizers, generally in a liquid or solid microencapsulated powder or granular base, the concentration ranges on a per weight basis, both for woody ring and chaff are from 0.05% to 5% of active ingredient or substance. Being that the determinant factor is not the capacity of carrier absorption, but rather the capacity to stay stable and not be affected by the active substance.

Example 6

For antibacterial and fungicidal use, when these are in a water, oleaginous or microencapsulated powder or granular base, the proportion of active ingredient or agent on a per weight basis to absorbent carrier is the same as that of Example 3. When the active ingredient uses a water base, the concentrations on a per weight basis can range from 0.01% to 25% with the woody ring fraction and 0.01% to 50% with chaff. The concentration to choose will be determined by the experience of whom ever prepares formulations according to the known state of the art.

Additionally, as mentioned in previous examples, the formulation of the composition of matter or product object of the invention, can be made using liquid based active ingredients added to the absorbent carrier. The possibility also exists for the use of solid materials as active ingredients, usually in the form of pure or microencapsulated products. This variation allows more flexibility in the absorbent carrier applications. It can also take advantage of factors like stronger concentrations of active ingredients. Many pure substances come in solid form; the use of a liquid as dilutent or dispersant of the pure substance implies a reduction in its concentration or strength. For example table salt NaCl is more intense to the palate than its version diluted in water, commonly called brine.

On the other hand, the use of active ingredients in solid state can adhere and/or adsorb to the surface of the absorbent corncob carrier, allowing it to use a larger proportion of it's inner absorbent capacity for malodor or other applications. The opposite occurs when using active ingredients in a liquid state, since these occupy more of the corncob carriers odor absorbent capacity thus partially reducing it's ability to absorb undesirable malodor. The option of using active ingredients in solid state instead of liquid, is possible with the concurrence of four basic elements: 1) an absorbent carrier, constituted by a fraction derived from corncobs, 2) an active ingredient or agent that is in liquid or solid state; 3) a combination resulting from the mix of a mineral or organic carrier with a liquid base active ingredient and finally, 4) a substance that assures that, the active ingredients absorb or adsorb to the corncob carrier (avoiding the separation among carriers or agents and assuring correct homogeneity, functionality and dispersion).

To exemplify the above mentioned, two practical examples are described below. The results obtained, using two types of active ingredients, one in liquid form, and the other solid, were both dispersed in the corncob carrier; a woody ring sized between 1410 and 841 microns was used. The liquid active ingredient is a concentrated floral fragrance perfume using polyvinyl glycol as a carrier. Example 7 A corncob carrier mixed with an active ingredient in a liquid base. The density of the active ingredient determined a saturation point of 18% on a per weight basis to the corncob granules. 180 grams of active ingredient where mixed with a kilogram of corncob carrier. This proportion maintains carrier flowability, absorption of odors and slow release of active ingredient (fragrance). Results: the perfuming active ingredient was released gradually and perceived smell lasted 30 days. The corncob carrier continued absorbing scents in the air after 30 days. Example 8

Two active ingredients, one utilizing an encapsulated active ingredient, commercially available, like Givaudan fragrance or flavor, in powder form and the other, using a laboratory sample, made by mixing Silicon Dioxide (SiO2), in proportion of l-to-4 on the base of liquid active ingredient to Silicon Dioxide weight. The absorbent corncob carrier was impregnated with an adherent coating, in this case consisting of a 0.5% per weight basis, foamed solution of anionic surfactant with water. Once the corncob carrier was mixed with the foam, an adherent coating of foam was formed on the corncob granules. Immediately after, the active ingredients in solid form were added. The active ingredient particles adhered to the coating and allowed for a homogeneous mixture without separation. Results: in both cases the adhesion of solid particles to the corncob granules allowed a more intense and prolonged duration of the perfuming scent, which was slowly released over a 60 day period, in comparison to the 30 days obtained in Example 7 with a liquid active ingredient perfume mixed directly with corncob granules. In both cases the corncob absorbed odors in the air even after 60 days.

Both examples, one with liquid and the other with solid active ingredients were performed at the same time. The new product was exposed to the air by placing it in a 40cm by 5cm dish. The product was placed in two separate rooms measuring 3 by 4 by 2.4 meters. The adherents used to form a coating on corncob particles are within the following ranges: Example 9

Using surfactants, such as, for example, anionic, cationic and amphoteric, as adherent coating. The formulation is foam obtained from adding water to 0.02% to 5% of surfactant by weight. The quantity of foam on a per weight basis to corncob woody ring fraction (carrier) is between 0.5% and 3.5%. Larger proportions do not allow for an appropriate mixture when adding active ingredients in solid form. Example 10

Using mineral oils as an adherent coating, which should be highly refined and preferably odor- and color-less. Viscosity on the Saybolt scale (SUS/210 F) should be between 40 and 300. The concentration of mineral oil by weight to woody ring is between 0.5% and 18%. Example 11

For natural pesticides, generally using a base of essential oil or microencapsulated powder or granular base. The concentration on a weight basis of the woody ring to active ingredient is from 0.01% to 18%. A larger amount saturates the absorbent carrier and product flowability is greatly reduced. The concentration on a weight basis of the chaff portion to active ingredient is from 0.01% to 36%.

Tests were conducted to determine the effectiveness of the absorbent composition used as a carrier for the active ingredient comprising an essential oil of the extract of garlic and/or allyl isothiocyanate (AITC) for the controlled release of the active ingredient against golden nematode in alpha potato. Test #1

The treatment consisted of the application of 7 kg/hectare, 10 kg/hectare and 15 kg/hectare of the carrier and essential oil. The results indicate that the golden nematodes were greatly reduced as compared to a control, while productivity was greatly increased. Test #2

The effectiveness of the absorbent composition used as a carrier for the essential oil active ingredient of garlic and/or AITC for the controlled release of the active ingredient against Meloidogyne Incognita nematode. Meloidogyne Incongmita soil was obtained from a farm in Mexico. The farmer had previously reported nematode infestation. The farmer mostly exports Tomato and other agricultural product to other countries. The carrier and garlic in the form of powder garlic was suspended in water at a concentration of 10.0 ml/1. The results indicated that the amount of larva of Meloidogyne Incongmita in 200 cc of soil was virtually eliminated, as shown in Table I below. Further tests conducted in laboratories and greenhouses indicate similar results. Table 1

Note: The above date in each repetition is referred to amount of larvae (j2) present in each 200 cc of soil.

In conclusion, the effects of garlic against root knot nematode {Meloidogyne Incongmita) are consistently equal or better when compared against leading brand nematicides at the application rate of 10.0 ml/1 of drench. These tests confirm previous laboratory findings.

SYNERGISTIC EFFECT OF GARLIC AND ONE OR MORE ESSENTAIL OILS

A combination of garlic extract and one or more essential oils have a synergistic effect that significantly increases the effectiveness of garlic and/or garlic extract alone. Ratio of garlic extract to mustard oil (or AITC) can be in the range of from 95:5 to 60:40. However, the ideal ratio of garlic to essential oil is 85% garlic to 15% essential oil, such as mustard oil, AITC, or the like. Active ingredients can be polymers, perfumes, oxidizers, attractants, repellents, reducers, antibacterials, etc, in solid form. These ingredients are mixed and dispersed with the granular corncob carrier sized between 42 and 3987 microns. The quantity of solid active ingredient dispersed should be between 1% and 40% per weight basis. It will be appreciated that the combination of garlic oil and mustard seed oil (or AITC) can be used for the treatment of seeds. There are at least two options for the treatment of seeds. One option is by mixing seed coloring liquid with micro caps and coating the seed. It is noted that all industrially produced seeds are color coded to avoid direct human consumption since the have insecticide and fungicides applied, so this option does not cause an additional step in the seed treatment process.

Another option in the treatment of seeds is placing a micro caps with or without a carrier (corncob or similar) to a pouch adhesive strip or similar devise, which can be adhered aggressively to the inside of the bag or thrown in the bag along with the seeds. A pouch adhesive strip or a similar devise and its contents should preferably be of a biodegradable material to complete the green/natural concept and also to be non-contaminating if the pouch for any reason should fall along with seeds into the seed planting farm equipment.

In conclusion, the incorporation of corncob fractions mentioned with active ingredients whether chemically synthesized or natural, such as garlic and mustard oil, ATIC, or the like, improves the qualities and functionality that both elements have for them separately. However, the use of corncob fractions as absorbent of odoriferous substances from the environment is also a novel concept. The forms of carrying out the mixture or integration of these elements can vary according to the circumstance. The types of active ingredients that will be used depending on the functional objective that is pursued, equipment available and the experience of those skilled in the art.

While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.

Claims

CLAIMSWhat is claimed is:

1. A natural pesticide, comprising:

an active ingredient comprising a combination of garlic and mustard oil impregnated in a carrier, wherein the combination of garlic and mustard oil has a synergistic effect for inhibiting the growth of bacteria, fungi, and eradicating insect pests.

2. The natural pesticide according to Claim 1, wherein the carrier includes at least a chaff portion and a woody ring of a corncob.

3. The natural pesticide according to Claim 2, wherein a concentration on a weight basis of the woody ring to the active ingredient is from 0.01% to 18%.

4. The natural pesticide according to Claim 2, wherein a concentration on a weight basis of the chaff portion to the active ingredient is from 0.01% to 36%

5. The natural pesticide according to Claim 1, wherein the combination of garlic oil and mustard oil is in a ratio of 85:15, respectively.

6. The natural pesticide according to Claim 1, wherein the carrier has a particle size of between 42 and 3987 microns.

7. The natural pesticide according to Claim 1, wherein the garlic is in the form of garlic powder.