MXPA98003069A - Pesticide compositions containing saved from most - Google Patents

Abstract

The present invention relates to pesticide precursor compositions comprising bran from a mustard of the Brassica genus, and methods for controlling soil pests by application of the pesticide precursor compositions to the soil, the invention also provides pesticides comprising aqueous suspensions or extracts thereof. mustard bran

Description

PESTICIDE COMPOSITIONS CONTAINING SAVED FROM MUSTARD FIELD OF THE INVENTION The present invention relates to compositions and methods for controlling pests. More particularly, the invention relates to pesticide precursor compositions comprising mustard bran, and to methods of using these compositions.

BACKGROUND OF THE INVENTION Soil pests affect the majority of cultivated crops and cause extensive damage, for example, to crops of fruits, vegetables, cereals and ornamental plants, with consecutive economic losses. Efforts have been made to control these soil pests by introducing pesticide formulations into the soil, before sowing, at the time of sowing or after sowing. For example, the synthetic compound methyl isothiocyanate has been used as a soil fumigant against a variety of pests, including insects, nematodes, mites and different microorganisms. However, in recent years, it has been found that many of the peeticides of current use are toxic and inconvenient to the environment, and there is a need to find practical alternatives that are not harmful to the environment. Many Brassica species contain glucosinolates, which can be converted by the endogenous plant enzyme, irosinase, into a variety of compounds. For example, the glucosinolate sinidine, found in mustards, can be converted by myrosinase into allyl isothiocyanate (AITC). As early as 1945, mustard oil and AITC were examined as a means of controlling nematodes (Ellenby (1945), Annals of Applied Biol., V. 32, pp. 67-70; (1951), Annals of Applied Biol ., v. 38, p.859-875 However, it has been seen that mustard oil is not a practical pesticide for its application in agriculture due to its management requirements, as it is an irritant liquid that produces harmful vapors, and due to its immiscibility with soil moisture, there is a need for a practical and cost-effective treatment for soil pests, which is at the same time less harmful to the environment and to the user.

BRIEF DESCRIPTION OF THE INVENTION In the commercial preparation of mustard seasonings, the whole mustard seed is milled to separate the outer covering or sheath of the seed, grain or seed tissue. The grain is milled into mustard flour, which is sold as a dry powder of mustard seasoning or treated to be converted into other mustard condiments. The ground pod or bran is a waste product that was previously considered to have no commercial value and therefore was discarded. The present authors have surprisingly found that the mustard bran of some mustard species is a significant source of sinigrin and AITC, and that it can be used as a cheap, effective, pesticide or soil fumigant and that manages without danger to control pests such as insects, nematodes, mites, fungi and bacteria. Mustard bran can be applied to the soil in a similar way to the application of a granular fertilizer. The mustard bran can be mixed with a vehicle suitable for agriculture, to optimize its handling properties. In contact with the water in the soil, the mustard bran sinigrin is converted by the bran myrosinase into the active pesticide AITC. Mustard bran can also be used to prepare aqueous extracts or aqueous pesticide suspensions that can be applied to pests or soil to achieve their role. In accordance with one embodiment of the present invention, a pesticide precursor composition comprising bran from a Brassica mustard is provided. According to a further embodiment of the present invention, there is provided a method for controlling a pest in the soil, comprising applying to the soil an effective amount of a pesticide precursor composition comprising a bran of a mustard of the Brassica genus., wherein the bran contains an effective amount of sinigrin capable of being converted to allyl isothiocyanate by contact with water in the soil. According to a further embodiment of the invention, a pesticide is provided which comprises a pesticidally effective amount of an aqueous extract of the bran of a Brassica mustard. According to a further embodiment of the invention, a pesticide is provided which comprises a pesticidally effective amount of an aqueous suspension of the bran of a Brassica mustard. According to a further embodiment of the invention, there is provided a method for controlling a pest that comprises applying to the pest an effective amount of an aqueous extract of the bran of a Brassica mustard. According to a further embodiment of the invention, there is provided a method for controlling a pest which comprises applying to the pest an effective amount of an aqueous suspension of the bran of a Brassica mustard.

DETAILED DESCRIPTION OF THE INVENTION The terms listed below have the following meanings: "Mustard" means a species or a plant of the Brassica genus. "Mustard seasoning" means a product or food seasoning prepared from a plant, or from the seeds of a plant, of the genus Brassica. "Bran" or "mustard bran" means the outer sheath or coating of the seeds of a Brassica plant. separated from the grain by means of grinding or other suitable procedure. Mustards with a high concentration of grain sinigrin are valuable for human consumption as condiments, and are used for the preparation of mustard condiments and other food products. First the mustard seed is milled to separate the outer sheath, typically by an abrasive process, and the grain is ground to turn it into flour for the production of the seasoning. Prior to the work of the present inventors, the residual bran was considered a waste product and was discarded. It has now been shown that mustard bran can be a useful and effective precursor of pesticide, which provides syigrine and myrosinase. Under humid conditions, the sinigrin is converted by the myrosinase into the pesticidal compound AITC. This is exemplified in Example 2 in which aqueous extracts of mustard bran were compared with mustard meal extracts, which are known to contain high levels of sinigrin, with respect to their nematicidal activity. It was found that the bran has excellent nematicidal activity. In contrast, extracts of whole mustard seed or mustard seed showed very low nematicidal activity. In accordance with one embodiment of the invention, a method for controlling soil pests is provided by applying a pesticide precursor composition comprising mustard bran to the soil. Mustard bran can be applied to the soil in a manner similar to the application of materials such as granular fertilizers, and using similar commercially available agricultural equipment. For example, the bran can be watered on the surface of the soil or incorporated into the soil with a rotating disc or cultivator. The application can be * before sowing, at the time of sowing or after sowing, as necessary. According to a further embodiment of the invention, the mustard bran can be mixed with an agriculturally acceptable vehicle to improve its handling properties before it is applied to the ground. The person skilled in the art will be familiar with the vehicle materials that are suitable for the formulation of pesticide compositions for application to the soil. Such vehicles include finely ground clay, plastic or starch-based polymers, surfactants, or organic vehicles such as ground corn kernels. The split mustard seed can also be used as a vehicle. The mustard seed of lower grade, of insufficient quality to be converted into flour for preparation of seasoning, can be used for this purpose. According to a further embodiment, the mustard bran can be formulated with a mixture of vehicles, and optionally can be formulated in a variety of forms; for example, it can be formulated in stratified granules, to obtain a convenient rate of release of the pesticide into the soil. Said methods of formulation are known to the person skilled in the art. Mustard bran is not a pesticide harmful to the environment, being a natural and biodegradable product. It is also handled much more easily and safely than pesticides such as synthetic methyl isothiocyanate, since dried bran is non-toxic and the effective pesticide, the irritant and toxic compound AITC, is formed from the sinigrin contained in the saved only after applying the composition on the ground and its contact with water in the soil. Dry bran can be formulated, managed and applied without the precautions that would be required to work with AITC. According to a further embodiment of the invention, a pesticide comprising an aqueous extract or an aqueous suspension of mustard bran can be prepared and applied to pests or soil to achieve pest control. The application can be carried out, for example, by sprinkling the suspension or extract on the pests or on the ground. As will be understood by the person skilled in the art, effective mustard bran as a pesticide precursor can be obtained from any Brassica species, or from a variety that has a sufficient amount of sinigrin content to give a desired level of pest control. by conversion in AITC. As exemplified herein, a mustard having a sinigrin content of about 2.5% by weight, provides an effective level of pesticidal activity. Sinigrin can be measured by a standard technique, such as that described by Minchinton, I. et al., (1982), J. Chro atog., V. 247, pp. 141-148; Sang, J.P. and others, (1984), Can J. Plant. Sci., V. 64, p. 77-93; Betz, J.M. and Fox, W.D., (1994) in "Food Phytochemicals for Cancer Prevention," ACS Symposium Series 546, American Chemical Society, p. 181-193. Mustards having a higher or lower shelled sinigrin content can also be used in the pesticide precursor compositions of the invention. It is within the skill of the skilled person to determine whether the bran of any mustard variety is effective to give a desired level of pest control. Suitable varieties of Brassica can be found, for example, in the following species: Brassica júncea; Brassica ca pestris; and Brassica nigra. Brassica júncea, vc Forge and Brassica júncea, vc Cutlass, are the preferred varieties of B. júncea. Brassica species or varieties can also be bred or engineered to increase the sheath content of sinidrine. It has already been seen that Brassica species, such as Brassica napus, are susceptible to successful genetic manipulation to improve various properties. These techniques can be used to convert species or varieties with low-pod content in nature, in varieties with useful levels; or they can be used to further increase the sinigrin pod of varieties with high sinigrin content. The transgenic or hybrid Brassica species produced in this manner can also be used in the compositions of the invention. Since the AITC is considered to act against pests by a mechanism similar to that of methyl isothiocyanate, it is expected that the pesticide precursor compositions and the pesticides of the invention combat a similar range of pests, including nematodes, insects, mites, fungi. and bacteria that parasitize plants. The following examples are described for purposes of illustration and are not intended to limit the scope of the invention.

EXAMPLE 1 Samples of mustard bran and mustard meal were obtained from various types of mustard from a commercial mustard milling company. The content of sinigrin was determined by extracting a portion of bran or flour in phosphate buffer, pH 7.0, at 100 ° C for 20 minutes. The aqueous extract was purified by chromatography on a C18 solid phase extraction cartridge and the purified sinigrin was determined by high performance liquid chromatography. The available AITC was calculated as 23.9% of the concentration of sinigrin, based on the relative molecular weights and the demonstrated quantitative conversion of sinigrin in AITC by means of myrosinase (data not shown). The results are shown in table 1.

TABLE 1 a Brassica júncea, vc Forge (oriental mustard) b Brassica napus (yellow mustard or rapeseed) c Eastern mustard mixture and yellow mustard nd = not detected EXAMPLE 2 The nematicidal efficacy of several mustard-derived materials was determined using aqueous extracts of the materials applied to the Pratilenchus penetrans injury nematode. The materials extracted were from Brassica júncea, vc Forge, as follows: 1. Seed intact. 2. Seed split. 3. Mustard bran. 4. Mustard flour. 5. Formulated bran: 1 gram of mustard bran was mixed well with 1.5 g of canola oil. After 30 minutes, 2.5 g of powdered clay was added and the mixture stirred well in a mortar. 6. Formulated bran: the bran was formulated as in 5, except that Tween 20 was used instead of canola oil. The heavy portions of each sample were extracted with 50 ml of water at room temperature, for 30 minutes or 60 minutes, and filtered. A 1 ml portion of each filtered aqueous extract was mixed with 2 ml of a suspension of Pratylenchus penetrans (100 or 200 ne of 2 ml) and determined to the nematodes by mobility and mortality at different intervals. Mobility was determined by microscopic observation. Mortality was determined after 68 to 72 hours of exposure to the extracts, observing the lack of movement by visual inspection and no reaction to mechanical stimulation. The results are shown in tables 2 (30 minute extraction) and 3 (60 minute extraction).

TABLE 2 Number Weight Mobility Mobility% of that of the 2 hrs. 4 hrs mortality shows sample treatment 68-72 hrs. extracted 1 231 all active 100.0 10.0 2 231 most 4.4 14.1 inactive 301 ditto, 1.3 45.8 lazy 189 light 5.1 54.9 light movement 1506 1.4 46.0 movement TABLE 3 Number Weight Mobility% Mobility% Of that of the 4 hrs. mortality shows sample nematodes treatment 68-72 hrs. extracted 2 hrs. of treatment 1 231 all active 100.0 2.7 2 231 light 3.6 4.0 movement 301 light 12.5 84.5 movement 189 light 15.8 72.8 movement 1506 slightly 5.7 69.3 more than up 1506 slightly 13.4 69.1 more than above Although only preferred embodiments of the present invention have been described, this is not limited to the features of these embodiments, but includes all variations and modifications within the scope of the claims.

Claims (28)

NOVELTY OF THE INVENTION CLAIMS

1. - A pesticide precursor composition for soil comprising bran from a Brassica mustard.

2. The composition according to claim 1, further characterized in that it comprises an acceptable vehicle.

3. The composition according to claim 2, characterized in that the bran is from a mustard of a species selected from the group consisting of (a) Brassica júncea; (b) Brassica ca pestris; and (c) Brassica ni ra.

4. The composition according to claim 2, characterized in that the bran is from a mustard of the species Brassica júncea.

5. The composition according to claim 4, characterized in that the mustard is of the variety B. júncea vc Forge or B. júncea vc Cutlass.

6. The composition according to claim 4, characterized in that the vehicle comprises split mustard seed.

7. The composition according to claim 4, characterized in that the vehicle is selected from the group consisting of finely ground clay, at least one polymer, at least one surfactant and at least one organic vehicle.

8. The composition according to claim 4, characterized in that the composition is nematicidal.

9. The composition according to claim 1, characterized in that the bran contains an effective amount of sinigrin capable of being converted to allyl isothiocyanate by contact with water.

10. A method for controlling a pest in the soil comprising applying to the soil an effective amount of a pesticide precursor composition comprising a bran of a mustard of the Brassica genus, wherein the bran contains an effective amount of sinigrin capable of converting in allyl isothiocyanate by contact with water in the soil.

11. The method according to the claim 10, characterized in that the composition further comprises an acceptable vehicle.

12. The method according to the claim 11, characterized in that the bran is from a mustard of a species selected from the group consisting of (a) Brassica júncea; (b) Brassica campestris; and (c) Brassica nigra.

13. The method according to claim 11, characterized in that the bran is from a mustard of the species Brassica júncea.

14. - The method according to claim 13, characterized in that the mustard is of the variety B. júncea vc Forge or B. júncea vc Cutlass.

15. The method according to claim 13, characterized in that the vehicle comprises split mustard seed.

16. The method according to the claim 13, characterized in that the carrier is selected from the group consisting of finely ground clay, at least one polymer, at least one surfactant and at least one organic carrier.

17. The method according to claim 13, characterized in that the pest is selected from the group consisting of nematodes, mites, insects, fungi and parasitic bacteria of plants.

18. The method according to claim 13, characterized in that the pest comprises parasite nematodes of silver.

19. A soil pesticide comprising a pesticidally effective amount of an aqueous extract of bran from a Brassica mustard.

20. A soil pesticide comprising a pesticidally effective amount of an aqueous suspension of bran of a Brassica mustard.

21. The pesticide according to claim 19, characterized in that the bran is selected from a mustard of a species selected from the group consisting of (a) Brassica júncea; (b) Brassica campestris; and (c) Brassica nigra.

22. The pesticide according to claim 19, characterized in that the bran is from a mustard of the species Brassica júncea.

23. The pesticide according to claim 22, characterized in that the mustard is of the variety B. júncea vc Forge or B. júncea vc Cutlass.

24. The pesticide according to claim 20, characterized in that the bran is selected from a mustard of a species selected from the group consisting of (a) Brassica júncea; (b) Brassica campestris; and (c) Brassica nigra.

25. The pesticide according to claim 20, characterized in that the bran is from a mustard of the Brassica júncea species.

26. The pesticide according to claim 25, characterized in that the mustard is of the variety B. júncea vc Forge or B. júncea vc Cutlass.

27. A method for controlling a pest that comprises applying to the pest an effective amount of an aqueous extract of bran from a Brassica mustard. 28.- A method for controlling a pest that comprises applying to the pest an effective amount of an aqueous suspension of bran of a Brassica mustard.