WO2010028012A1

WO2010028012A1 - Method for controlling nematode pests

Info

Publication number: WO2010028012A1
Application number: PCT/US2009/055688
Authority: WO
Inventors: Deborah L. Freerksen; Isaac Billy Annan; Johan Desaeger
Original assignee: E. I. Du Pont De Nemours And Company
Priority date: 2008-09-04
Filing date: 2009-09-02
Publication date: 2010-03-11

Abstract

Disclosed is a method for protecting a plant from a phytophagous nematode comprising applying a nematocidally effective amount of a mixture consisting essentially of (a) methomyl and (b) a neonicotinoid component consisting of one or more neonicotinoids to the plant, its seed or its growing medium. Also disclosed is the aforesaid method wherein the mixture is in a composition further comprising at least one additional component selected from the group consisting of surfactants, solid diluents and liquid diluents. Also disclosed is a seed treated with a nematocidally effective amount of the mixture described above (e.g., in a composition comprising at least one additional component selected from the group consisting of surfactants, solid diluents and liquid diluents).

Description

TITLE METHOD FOR CONTROLLING NEMATODE PESTS

FIELD OF THE INVENTION

This invention pertains to a method for protecting a plant from phytophagous nematodes using active ingredient combinations of methomyl with neonicotinoids.

BACKGROUND OF THE INVENTION

Nematocide treatments that can be applied at as low a dose as possible and be effective in controlling pest species of nematodes while causing as little harm as possible to beneficial arthropods and minimal disturbance in the environment are in demand by the farming community. Nematodes are very destructive to crop plants. Nematode plant damage can result in significant loss of crop yield and quality, which results in economic loss to the grower and increased costs to the consumer.

Methomyl is sold by DuPont as the active ingredient in Lannate® insecticide for foliar application to control numerous insect pests of agricultural crops including, but not limited to, insects from the order Lepidoptera (e.g., corn earworm, loopers, armyworms, cutworms, leafrollers, diamondback moth), Coleoptera (e.g., cucumber beetles, flea beetles, Mexican bean beetle), Homoptera (e.g., aphids, leafhoppers), Hemiptera (e.g., plant bugs, stink bugs, lygus bugs), and Thysanoptera (e.g., thrips). Methomyl is a systemic active ingredient and is most commonly applied as a foliar treatment. Methomyl has only moderate nematocidal activity, and is generally not used as a soil treatment to control soil pests such as root nematodes.

Neonicotinoids, including the pyridylmethylamines such as acetamiprid and thiacloprid, the nitromethylenes such as nitenpyram, and the nitroguanidines such as clothianidin, dinotefuran, imidacloprid and thiomethoxam, are also useful for controlling insect pests in agricultural crops. Neonicotinoids act as acute contact and stomach poisons, combine systemic properties with relatively low application rates, and are relatively nontoxic to vertebrates. All neonicotinoids act as agonists at the nicotinic acetylcholine receptor in the central nervous system of insects. This causes excitation of the nerves and eventual paralysis, which leads to death. A review of the neonicotinoids is described in Pestology 2003, 27, 60-63; Annual Review of Entomology 2003, 48, 339-364; and references cited therein. Although neonicotinoids are efficacious for controlling many insect pests, they have little effect on nematodes.

SUMMARY OF THE INVENTION

This invention provides a method for protecting a plant from a phytophagous nematode comprising applying a nematocidally effective amount of a mixture consisting essentially of (a) methomyl and (b) a neonicotinoid component consisting of one or more neonicotinoids to the plant, its seed or its growing medium.

This invention also relates to the aforesaid method wherein the mixture is in a composition further comprising at least one additional component selected from the group consisting of surfactants, solid diluents and liquid diluents.

This invention also provides a seed treated with a nematocidally effective amount of the mixture described above (e.g., in a composition comprising at least one additional component selected from the group consisting of surfactants, solid diluents and liquid diluents). DETAILED DESCRIPTION OF THE INVENTION

As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). Also, the indefinite articles "a" and "an" preceding an element or component of the invention are intended to be nonrestrictive regarding the number of instances (i.e. occurrences) of the element or component. Therefore "a" or "an" should be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular. The term "foliar" refers to leaves, stems, flowers, fruits and other parts of plants not covered by or immersed in the growing medium. "Growing medium" refers to the primarily solid or liquid medium in which plant roots grow. For crop plants grown in a field, the growing medium is typically soil containing varying amounts of sand, silt, clay and organic matter, but growing media can include any of a variety of processed and artificial media including water, rock wool, fiberglass, vermiculite, perlite, peat moss, bark, shredded coconut husks, etc. "Germination medium" refers to the primarily solid or liquid medium in which or on which seeds are germinated. Therefore a germination medium is a growing medium used to germinate seeds. Accordingly, a germination medium can also include varying amounts of sand, silt, clay, organic matter, water, rock wool, fiberglass, vermiculite, perlite, peat moss, bark, shredded coconut husks, etc. The germination medium of a plant grown from seed can be the same or different from the growing medium of the plant at time of application of the mixture of methomyl and neonicotinoids.

In the present description and claims, the term "consisting essentially of in the definition of the mixture of methomyl and the neonicotinoid component means that the combination of methomyl with the neonicotinoid component provides the nematocidal activity of the mixture. Therefore while "consisting essentially of accommodates the presence of other components, significant amounts of other nematocidal active ingredients are excluded from the mixture. In particular, oxamyl is excluded from the mixture.

The present invention relates to the protection of plants from feeding or other damage caused by phytophagous nematodes. Therefore in the context of the present disclosure and claims, "control" or "controlling" a invertebrate pest such as a phytophagous nematode means reducing the ability of the pest to feed on or otherwise damage plants; related expressions are defined analogously. More particularly, "protecting a plant from a phytophagous nematode" means reducing the ability of the nematode to feed on or otherwise damage the plant. Furthermore "nematode control" and "controlling nematodes" includes any effect decreasing the ability of nematodes to feed on or otherwise damage plants. Such effects can include reducing feeding, increasing disorientation, reducing motility, inhibiting development, disrupting mating and/or increasing mortality. In the present disclosure and claims the terms "nematocidal" and "nematocidally", as well as related terms such as "nematocidally effective amount", refer to any of the effects decreasing the ability of nematodes to feed on or otherwise damage plants. More particularly, "nematocidally effective amount" means an amount reducing feeding or other damage to plants caused by phytophagous nematodes.

Combinations of methomyl and neonicotinoids when applied to the growing medium of a plant in a liquid or granular form, or when applied as a seed treatment, have now been found to not only protect plants from phytophagous nematodes but to provide control which is substantially and surprisingly enhanced over the expected additive effect by said components.

Embodiments of the present invention include: Embodiment 1. The method described in the Summary of the Invention wherein the methomyl and the neonicotinoid component are applied simultaneously. Embodiment 2. The method described in the Summary of the Invention wherein the methomyl is applied first and then the neonicotinoid component is applied. Embodiment 3. The method described in the Summary of the Invention wherein the neonicotinoid component is applied first and then methomyl is applied. Embodiment 4. The method described in the Summary of the Invention wherein the mixture is applied to the growing medium by a spot gun. Embodiment 5. The method described in the Summary of the Invention wherein the mixture is applied to the growing medium through an irrigation system. Embodiment 6. The method of Embodiment 5 wherein the irrigation system uses drip emitters.

Embodiment 7. The method of Embodiment 5 wherein the irrigation system uses micro- sprinklers.

Embodiment 8. The method described in the Summary of the Invention wherein the methomyl and the neonicotinoid component are applied in a granular composition to the growing medium. Embodiment 9. The method described in the Summary of the Invention wherein the methomyl and the neonicotinoid component are applied by injection into the growing medium. Embodiment 10. The method described in the Summary of the Invention wherein the methomyl is applied to the growing medium in a precursor form. Embodiment 11. The method of Embodiment 10 wherein the methomyl is applied as thiodicarb.

Embodiment 12. The method described in the Summary of the Invention wherein methomyl and the neonicotinoid component are applied in a weight ratio between about 1000:1 and about 1 :125. Embodiment 13. The method of Embodiment 12 wherein the weight ratio is between about 125:1 and about 1 :50.

Embodiment 14. The method of Embodiment 13 wherein the weight ratio is between about 25 : 1 and about 1 :5.

Embodiment 15. The method described in the Summary of the Invention wherein the phytophagous nematode is selected from the group consisting of Belonolaimus spp., Globodera spp., Heterodera spp., Meloidogyne spp., Pratylenchus spp. or

Tylenchorhynchus spp. Embodiment 16. The method of Embodiment 15 wherein the phytophagous nematode is selected from Belonolaimus spp. Embodiment 17. The method of Embodiment 15 wherein the phytophagous nematode is selected from Globodera spp.

Embodiment 18. The method of Embodiment 15 wherein the phytophagous nematode is selected from Heterodera spp. Embodiment 19. The method of Embodiment 15 wherein the phytophagous nematode is selected from Meloidogyne spp. Embodiment 20. The method of Embodiment 15 wherein the phytophagous nematode is selected from Pratylenchus spp. Embodiment 21. The method of Embodiment 15 wherein the phytophagous nematode is selected from Tylenchorhynchus spp. Embodiment 22. The method described in the Summary of the Invention wherein the plant is in the family Cucurbitaceae.

Embodiment 23. The method described in the Summary of the Invention wherein the plant is in the family Solanaceae.

Embodiment 24. The method described in the Summary of the Invention wherein the plant is a legume. Embodiment 25. The method described in the Summary of the Invention wherein the mixture is applied to a germination medium for a seed before the seed planted in the germination medium germinates.

Embodiment 26. The method described in the Summary of the Invention wherein at least 80% of each of methomyl and the neonicotinoid component is applied to the growing medium instead of the plant foliage.

Embodiment 27. The method described in the Summary of the Invention wherein at least 90% of each of methomyl and the neonicotinoid component is applied to the growing medium instead of the plant foliage.

Embodiment 28. The method described in the Summary of the Invention wherein at least 95% of each of methomyl and the neonicotinoid component is applied to the growing medium instead of the plant foliage. Embodiment 29. The method described in the Summary of the Invention wherein at least 99% of each of methomyl and the neonicotinoid component is applied to the growing medium instead of the plant foliage. Embodiments of this invention can be combined in any manner.

Methomyl (Chemical Abstracts name: methyl N-[[(methylamino)carbonyl]oxy]- ethanimidothioate) has the molecular formula depicted as Formula I.

SCH₃

/

CH₃NHCO₂N=C

'CH₃

Although methomyl is most conveniently obtained as a commercial product, it can be prepared as described in U.S. Patent 3,576,834. Thiamethoxam has the following formula and is known from EP 580,553 A2 (Syngenta).

Clothianidin has the following formula and is known from EP 376,279 A2 (Takeda/Sumitomo) .

Thiacloprid has the following formula and is known from the EP 235,725 A2 (Bayer).

Dinotefuran has the following formula and is known from EP 649,845 Al (Mitsui).

Acetamiprid has the following formula and is known from U.S. Patent 5,304,566

(Nippon Soda).

Nitenpyram has the following formula and is known from EP 302,389 A2 (Takeda/Sumitomo) .

Imidacloprid has the following formula and is known from EP 192,060 Al (Bayer/Nihon).

Methomyl and neonicotinoids according to the method of the present invention will generally be used in a formulation or a composition with an agriculturally suitable carrier comprising at least one of a liquid diluent, a solid diluent or a surfactant. Mixtures of methomyl and neonicotinoids can be formulated in two ways:

1. methomyl and neonicotinoids can be formulated separately and applied separately or applied simultaneously in an appropriate weight ratio, e.g., as a tank mix; or

2. methomyl and neonicotinoids can be formulated together in the weight ratios as defined herein.

Therefore useful for the method of the present invention are compositions comprising methomyl and an agriculturally suitable carrier comprising at least one of a surfactant, a solid or a liquid diluent; a neonicotinoid and an agriculturally suitable carrier comprising at least one of a surfactant, a solid or liquid diluent; or a mixture of methomyl and a neonicotinoid and an agriculturally suitable carrier comprising at least one of a surfactant, a solid or liquid diluent. The agriculturally suitable carriers are selected consistent with the physical properties of the active ingredients, mode of application and environmental factors such as soil type, moisture and temperature. Useful formulations of methomyl and a neonicotinoid, either separately or together, can be prepared in conventional ways. Useful formulations include liquids such as solutions (including emulsifiable concentrates), suspensions, emulsions (including microemulsions and/or suspoemulsions) and the like which optionally can be thickened into gels. Useful formulations further include solids such as dusts, powders, granules, pellets, tablets, films, and the like which can be water- dispersible ("wettable") or water-soluble. Active ingredient(s) can be (micro)encapsulated and further formed into a suspension or solid formulation; alternatively the entire formulation of active ingredient can be encapsulated (or "overcoated"). Encapsulation can control or delay release of the active ingredient(s). Sprayable formulations can be extended in suitable media and used at spray volumes from about one to several hundred liters per hectare. High-strength compositions are primarily used as intermediates for further formulation.

The formulations will typically contain effective amounts of active ingredient(s), diluent and surfactant within the following approximate ranges which add up to 100 percent by weight.

Weight Percent

Active

Ingredients Diluent Surfactant

Water-Dispersible and Water- 0.001-90 0-99.999 0-15 soluble Granules, Tablets and Powders.

Suspensions, Emulsions, 1-50 40-99 0-50 Solutions (including Emulsifiable Concentrates)

Dusts 1-25 70-99 0-5

Granules and Pellets 0.001-99 5-99.999 0-15

High Strength Compositions 90-99 0-10 0-2

Typical solid diluents are described in Watkins, et al., Handbook of Insecticide Dust Diluents and Carriers, 2nd Ed., Dorland Books, Caldwell, New Jersey. Typical liquid diluents are described in Marsden, Solvents Guide, 2nd Ed., Interscience, New York, 1950. McCutcheon 's Detergents and Emulsiβers Annual, Allured Publ. Corp., Ridgewood, New Jersey, as well as Sisely and Wood, Encyclopedia of Surface Active Agents, Chemical Publ. Co., Inc., New York, 1964, list surfactants and recommended uses. All formulations can contain minor amounts of additives to reduce foam, caking, corrosion, microbiological growth and the like, or thickeners to increase viscosity.

Surfactants include, for example, polyethoxylated alcohols, polyethoxylated alkylphenols, polyethoxylated sorbitan fatty acid esters, dialkyl sulfosuccinates, alkyl sulfates, alkylbenzene sulfonates, organosilicones, Λf,iV-dialkyltaurates, lignin sulfonates, naphthalene sulfonate formaldehyde condensates, polycarboxylates, glycerol esters, poly- oxyethylene/polyoxypropylene block copolymers, and alkylpolyglycosides where the number of glucose units, referred to as degree of polymerization (D. P.), can range from 1 to 3 and the alkyl units can range from C₆ to C₁₄ (see Pure and Applied Chemistry 72, 1255— 1264). Solid diluents include, for example, clays such as bentonite, montmorillonite, attapulgite and kaolin, starch, sugar, silica, talc, diatomaceous earth, urea, calcium carbonate, sodium carbonate and bicarbonate, and sodium sulfate. Liquid diluents include, for example, water, N,Λ/-dimethylformamide, dimethyl sulfoxide, iV-alkylpyrrolidone, ethylene glycol, polypropylene glycol, propylene carbonate, dibasic esters, paraffins, alkylbenzenes, alkylnaphthalenes, glycerine, triacetine, oils of olive, castor, linseed, tung, sesame, corn, peanut, cotton-seed, soybean, rape-seed and coconut, fatty acid esters, ketones such as cyclohexanone, 2-heptanone, isophorone and 4-hydroxy-4-methyl-2-pentanone, acetates such as hexyl acetate, heptyl acetate and octyl acetate, and alcohols such as methanol, cyclohexanol, decanol, benzyl and tetrahydrofurfuryl alcohol.

Useful formulations of this invention may also contain materials well known to those skilled in the art as formulation aids such as antifoams, film formers and dyes. Antifoams can include water dispersible liquids comprising polyorganosiloxanes like Rhodorsil® 416. The film formers can include polyvinyl acetates, polyvinyl acetate copolymers, polyvinylpyrrolidone-vinyl acetate copolymer, polyvinyl alcohols, polyvinyl alcohol copolymers and waxes. Dyes can include water dispersible liquid colorant compositions like Pro-lzed® Colorant Red. One skilled in the art will appreciate that this is a non-exhaustive list of formulation aids. Suitable examples of formulation aids include those listed herein and those listed in McCutcheon 's 2001, Volume 2: Functional Materials published by MC Publishing Company and PCT Publication WO 03/024222.

Solutions, including emulsifiable concentrates, can be prepared by simply mixing the ingredients. Dusts and powders can be prepared by blending and, usually, grinding as in a hammer mill or fluid-energy mill. Suspensions are usually prepared by wet-milling; see, for example, U.S. 3,060,084. Granules and pellets can be prepared by spraying the active material upon preformed granular carriers or by agglomeration techniques. See Browning, "Agglomeration", Chemical Engineering, December 4, 1967, pp 147-48, Perry's Chemical Engineer's Handbook, 4th Ed., McGraw-Hill, New York, 1963, pages 8-57 and following, and WO 91/13546. Pellets can be prepared as described in U.S. 4,172,714. Water-dispersible and water-soluble granules can be prepared as taught in U.S. 4,144,050, U.S. 3,920,442 and DE 3,246,493. Tablets can be prepared as taught in U.S. 5,180,587, U.S. 5,232,701 and U.S. 5,208,030. Films can be prepared as taught in GB 2,095,558 and U.S. 3,299,566. For further information regarding the art of formulation, see T. S. Woods, "The Formulator's Toolbox - Product Forms for Modern Agriculture" in Pesticide Chemistry and Bioscience, The Food-Environment Challenge, T. Brooks and T. R. Roberts, Eds., Proceedings of the 9th International Congress on Pesticide Chemistry, The Royal Society of Chemistry, Cambridge, 1999, pp. 120-133. See also U.S. 3,235,361, Col. 6, line 16 through Col. 7, line 19 and Examples 10-41; U.S. 3,309,192, Col. 5, line 43 through Col. 7, line 62 and Examples 8, 12, 15, 39, 41, 52, 53, 58, 132, 138-140, 162-164, 166, 167 and 169-182; U.S. 2,891,855, Col. 3, line 66 through Col. 5, line 17 and Examples 1-4; Klingman, Weed Control as a Science, John Wiley and Sons, Inc., New York, 1961, pp 81-96; Hance et al, Weed Control Handbook, 8th Ed., Blackwell Scientific Publications, Oxford, 1989; and Developments in formulation technology, PJB Publications, Richmond, UK, 2000.

In the following Examples, all percentages are by weight and all formulations are prepared in conventional ways.

Example A

Wettable Powder methomyl 13.7% imidacloprid 51.3% dodecylphenol polyethylene glycol ether 2.0% sodium ligninsulfonate 4.0% sodium silicoaluminate 6.0% montmorillonite (calcined) 23.0%

Example B

Granule methomyl 4.3% clothianidin 5.7% attapulgite granules (low volatile matter,

0.71/0.30 mm; U.S.S. No. 25-50 sieves) 90.0%

Example C

Seed Treatment methomyl 25% thiamethoxam 20% methyl methacrylate ethoxylated copolymer 3% ethylene oxide block copolymer 2% glycerine 3% xanthan gum 0.3% silicone emulsion 0.3% water 46.4%

Example D Emulsifϊable Concentrate methomyl 0.8% thiacloprid 19.2% blend of oil soluble sulfonates and polyoxy ethylene ethers 10.0% isophorone 70.0%

A composition comprising methomyl can be combined with a composition comprising a neonicotinoid to form a physical mixture prior to application, e.g., a tank mix, and applied simultaneously. Alternatively, a composition comprising only one of methomyl or a neonicotinoid can be applied followed by application of a composition comprising the other of methomyl or a neonicotinoid. The methomyl and a neonicotinoid can be applied to the soil surface or below the soil surface so that they reach by diffusion and/or flow the root zone of the plants to be protected. Application methods include spot-gun application, chemigation (i.e. application through an irrigation system) using drip irrigation or micro- sprinklers, injection of liquid compositions below the soil surface, and soil application of granules. Spot-gun applicators are hand-held metered volume dispensers, typically comprising an adjustable graduated cylinder or syringe operated by squeezing a handle. Some of the application methods according to this invention such a spot-gun application and micro-sprinklers may result in methomyl and a neonicotinoid being applied to a portion of the above ground portion of the plant (i.e. foliage) as well as the growing medium.

Optimal rates of application for methomyl and neonicotinoids according to the method of this invention, as well as the ratio of the active ingredients to each other, can be influenced by many factors of the environment and should be determined under actual use conditions. Plants can normally be protected from nematode pests when the growing medium in their root zone (i.e. portion of growing medium from which the plant roots obtain moisture and nutrients) is treated at a rate (i.e. nematocidally effective amount) of generally from about 200 g/ha to about 6000 g/ha (corresponding to the surface area of the root zone) per application of aggregate active ingredient, more typically about 400 g/ha to about 4000 g/ha, and most typically from about 600 g/ha to about 2000 g/ha. Aggregate active ingredient is defined as the total combined weight of the methomyl and neonicotinoid active ingredients.

A preferred active ingredient combination for the method of the present invention contains the active ingredients methomyl and imidacloprid. In this combination the weight ratio of the methomyl to imidacloprid is typically between 1000 to 1 and 1 to 125, more typically between 125 to 1 and 1 to 50 and most typically between 25 to 1 and 1 to 5.

Another preferred active ingredient combination for the method of the present invention contains the active ingredients methomyl and acetamiprid. In this combination the weight ratio of the methomyl to acetamiprid is typically between 1000 to 1 and 1 to 125, more typically between 125 to 1 and 1 to 50 and most typically between 25 to 1 and 1 to 5.

Another preferred active ingredient combination for the method of the present invention contains the active ingredients methomyl and nitenpyram. In this combination the weight ratio of the methomyl to nitenpyram is typically between 1000 to 1 and 1 to 125, more typically between 125 to 1 and 1 to 50 and most typically between 25 to 1 and 1 to 5.

Another preferred active ingredient combination for the method of the present invention contains the active ingredients methomyl and dinotefuran. In this combination the weight ratio of the methomyl to dinotefuran is typically between 1000 to 1 and 1 to 125, more typically between 125 to 1 and 1 to 50 and most typically between 25 to 1 and 1 to 5. Another preferred active ingredient combination for the method of the present invention contains the active ingredients methomyl and thiacloprid. In this combination the weight ratio of the methomyl to thiacloprid is typically between 1000 to 1 and 1 to 125, more typically between 125 to 1 and 1 to 50 and most typically between 25 to 1 and 1 to 5.

Another preferred active ingredient combination for the method of the present invention contains the active ingredients methomyl and thiamethoxam. In this combination the weight ratio of the methomyl to thiamethoxam is typically between 1000 to 1 and 1 to

125, more typically between 125 to 1 and 1 to 50 and most typically between 25 to 1 and 1 to 5.

Particularly preferred active ingredient combinations are methomyl and imidacloprid, methomyl and clothianidin, methomyl and thiacloprid, and methomyl and thiamethoxam.

The methomyl and neonicotinoid mixtures for the method of the present invention can be applied to a plant or seedling root system, to the growing medium, to the germination medium or to the plant seed prior to germination using conventional application methods.

Examples include immersion (transplant tray dip) or spraying of plant roots, or single or multilayered coating of seeds.

The methomyl and neonicotinoid mixtures for the method of this invention are suitable for the treatment of seed. A large portion of crop damage is caused by phytophagous nematodes already present in the soil when a seed is planted. These nematodes infest the seed after the introduction of the seed into the soil as well as during and after the germination of the plants. This phase is particularly critical, since the roots and stem of the growing seedling are particularly sensitive and relatively minor damage can destroy the viability of the seedling.

In the context of the present disclosure and claims, treating a seed means contacting the seed with (i.e. applying to the seed) a nematocidally effective amount of a methomyl and neonicotinoid mixture, which is typically formulated as a composition. This seed treatment protects the seed as well as the seedling's developing roots and other plant parts in contact with the soil from phytophagous nematode damage. The seed treatment may also provide protection of foliage by translocation of the methomyl and neonicotinoid mixture within the developing plant. Seed treatments can be applied to all types of seeds, including those from which plants genetically transformed to express specialized traits will germinate. Representative examples include those expressing proteins toxic to invertebrate pests, such as Bacillus thuringiensis toxin or those expressing herbicide resistance such as glyphosate acetyltransferase, which provides resistance to glyphosate. Accordingly, an embodiment of the present method is the treatment of transgenic seed and transgenic plants with the methomyl and neonicotinoid mixture.

One method of seed treatment is by spraying or dusting the seed with a methomyl and neonicotinoid mixture (i.e. as a formulated composition) before sowing the seeds. Compositions formulated for seed treatment generally comprise a film former or adhesive agent as a solid or liquid diluent. Therefore typically a seed coating composition comprises a nematocidally effective amount of a mixture of methomyl and the neonicotinoid component, and a film former or adhesive agent. Seed can be coated by spraying a flowable suspension concentrate directly into a tumbling bed of seeds and then drying the seeds. Alternatively, other formulation types such as wetted powders, solutions, suspoemulsions, emulsifiable concentrates and emulsions in water can be sprayed on the seed. This process is particularly useful for applying film coatings on seeds. Various coating machines and processes are available to one skilled in the art. Suitable processes include those listed in P. Kosters et al, Seed Treatment: Progress and Prospects, 1994 BCPC Mongraph No. 57, and references listed therein.

The treated seed typically comprises a mixture of methomyl and the neonicotinoid component in an amount (i.e. nematocidally effective amount) from about 0.1 g to 1 kg per 100 kg of seed (i.e. from about 0.0001 to 1% by weight of the seed before treatment). A flowable suspension formulated for seed treatment typically comprises from about 0.5 to about 70% of the active ingredients, from about 0.5 to about 30% of a film-forming adhesive, from about 0.5 to about 20% of a dispersing agent, from 0 to about 5% of a thickener, from 0 to about 5% of a pigment and/or dye, from 0 to about 2% of an antifoaming agent, from 0 to about 1% of a preservative, and from 0 to about 75% of a volatile liquid diluent.

The active ingredient combinations for the method of the present invention are suitable for the protection of seed irrespective of planting location, including seed used in agriculture, greenhouses, forests or horticulture. The active ingredient combinations demonstrate particularly effective nematode control when applied to seed of corn, peanut, canola, rapeseed, poppy, soybean, cotton, carrot, rice, millet, wheat, barley, oat, rye, sunflower and tobacco. Particularly suitable for seed treatment are the mixture of methomyl and imidacloprid and the mixture of methomyl and clothianidin. A notable advantage of the present method is that seed, seedling developing from a germinating seed or plant can be protected before the infestation of nematode pests. Due to the systemic properties of the methomyl and neonicotinoid combinations, treatment of the seed with these active ingredient combinations protects not only the seed, but also the emerging roots and plants themselves. As a result, the crop does not require an immediate nematode control treatment after planting.

A preferred embodiment of the present invention relates to the method wherein the plant was grown from seed and is still young (e.g., a seedling) at the time of application. For such application of methomyl and the neonicotinoid component, the growing medium to which methomyl and the neonicotinoid component are applied is the germination medium if the plant has not been transplanted. If the plant is transplanted the growing medium to which methomyl and the neonicotinoid component are applied is the medium in which the plant is or will be growing. Preferably methomyl and the neonicotinoid component are applied to the growing medium no more than about 60 days from when (i.e. after) the seed of the plant was placed in or on germination medium, more preferably no more than about 45 days, most preferably no more than about 30 days. However, the methomyl and neonicotinoid component can be applied to the growing medium 120 days from when the seed of the plant was placed in or on the germination medium or even much longer, as for perennial crops, including shrubs and trees.

Typically methomyl and the neonicotinoid component are applied to the growing medium according to the present method at about the same time or after a seed of a plant, a seedling or an older (i.e. more mature) plant is placed in the growing medium (e.g., "seeded", "planted", "transplanted"). However, as protecting a plant according to the present method requires only that methomyl and the neonicotinoid component be present in the growing medium, methomyl and the neonicotinoid component can be applied to the growing medium before the seed, seedling or older plant is placed in the growing medium. Because methomyl degrades on prolonged contact with most growing media, methomyl is most advantageously applied to the growing medium no more than about a week before and preferably no more than about two days before the seed, seeding or older plant is placed in the growing medium.

To maintain protection as plants grow and to obtain the greatest protection of large plants repeated applications of methomyl and the neonicotinoid component to the growing medium can be beneficial. Preferably most of the plant roots are located in the region of the growing medium to which the mixture of methomyl and the neonicotinoid component is applied; for plants with extensive deep root systems (e.g., trees) injection of methomyl and the neonicotinoid component into the root zone can be advantageous. Application of methomyl and neonicotinoid mixtures to the growing medium not only protects roots and other geotropic plant parts from nematodes but also can protect plants against nematodes infesting foliage which is above the growing medium. This method requires not only absorption of methomyl and the neonicotinoid mixture by the roots but systemic translocation of said mixture to the above ground portions of plants on which stem nematodes feed. Combination of methomyl with one or more neonicotinoids in the present method provides a synergistic effect in controlling phytophagous nematodes living on roots and other geotropic plant parts and also on foliage. Due to this synergism, combination of methomyl with neonicotinoids may provide substantially more nematode control from application to a plant, its seed or its growing medium than would be expected from additive effects. Furthermore such combination may provide synergistic control of both soil and foliar insect pests.

One skilled in the art appreciates that methomyl can be applied to the growing medium as a precursor substance that is converted to methomyl on exposure to the environment of the growing medium, which typically comprises water, oxygen and microbes, as well as exposure to light on the surface of the growing medium. Of particular note as a precursor to methomyl is thiodicarb. One skilled in the art recognizes that the application rate and ratio for a precursor of methomyl can be easily calculated from the relative molecular weight of the precursor and methomyl and the application rates and ratios for methomyl and neonicotinoid described herein. The active ingredient combinations for the method of the present invention are particularly suitable for controlling nematodes. They are effective at any nematode development stage. The nematode pests controlled include but are not limited to Anguina spp., Aphelenchoides spp., Belonolaimus spp., Bursaphelenchus spp., Ditylenchus dipsaci, Globodera spp., Helicotylenchus spp., Heterodera spp., Longidorus spp., Meloidogyne spp., Pratylenchus spp., Radopholus similis, Rotylenchus spp., Trichodorus spp., Tylenchorhynchus spp., Tylenchulus spp. such as Tylenchulus semipenetrans, and Xiphinema spp.

The method of the present invention is useful for protecting a broad range of plants vulnerable to nematode pests. Plants benefiting from the protection provided by the present method include both herbaceous plants and woody plants.

Illustrative of the wide variety of plants that can be protected from nematode pests by the method of the present invention are fruit trees such as plant species in the family Rosaceae including pome fruits (e.g., apple {Malus pumila P. Mill.), pear (Pyrus communis L.)) and stone fruits (e.g., cherry (Prunus species such as P. avium (L.) L. and P. cerasus L.), apricot {Prunus armeniaca L.), almond {Prunus dulcis (P. Mill) D. A. Webber), peach {Prunus persica (L.), nectarine {Prunus persica (L.) Batsch var. nucipersica (Suckow) C. Schneider), plum {Prunus domestica L.)), in the family Rutaceae (i.e. citrus, including orange {Citrus sinensis (L.) Osbeck, tangerine {Citrus reticulata Blanco), lemon {Citrus limon (L.) Burm. f), lime {Citrus aurantifolia (Christm.) Swingle), pummelo {Citrus maxima (Burm. f.) Merr.) and grapefruit {Citrus maxima x sinensis)), in the family Sapindaceae (e.g., longan {Dimocarpus longan Lour.), rambutan {Nephelium lappaceum L.), pulasan {Nephelium mutabile Blume), lychee {Litchi chinensis Sonn.)), in the family Anacardiaceae (e.g., mango {Mangifera indica L.)), in the family Bombacaceae (e.g., durian {Durio zibethinus Murray)), in the family Moraceae (e.g., jackfruit (e.g., Artocarpus heterophyllus Lam.)), and in the family Myrtaceae (e.g., rose apple {Syzygium jambos (L.) Alston)). Also illustrative are shrubs in the family Rubiaceae such as coffee (e.g., Coffea arabica L., Coffea canephora Pierre ex Froehner)) and the family Malvaceae such as cotton (e.g., Gossypium hirsutum L., Gossypium barbadense L.), vines in the family Vitaceae such as grape (e.g., Vitis labrusca L., Vitis vinifera L.) and grasses in the family Poaceae (e.g., maize {Zea mays L.), sugarcane {Saccharum ojficinarum L.)).

The method is particularly valuable for protecting plants in the families Asteraceae, Brassicaceae (alternatively named Cruciferaceae), Chenopodiaceae, Cucurbitaceae and Solanaceae. Asteraceae includes crop plants such as lettuce {Lactuca sativa L.). Brassicaceae includes crop plants such as Brassica species including cabbage, cauliflower, broccoli and brussels sprouts (all Brassica oleracea L.). Chenopodiaceae includes crop plants such as garden beets and sugarbeets (both Beta vulgaris L.). Cucurbitaceae includes crop plants including Cucumis, Cucurbita and Citrullus species such as cucumbers (e.g., garden cucumber {Cucumis sativus L.)), squash (e.g., winter squash {Cucurbita maxima Duchesne), crookneck squash {Cucurbita moschata (Duchesne ex Lam.) Duchesne ex Poir.), pumpkin {Cucurbita pepo L.)) and melons (e.g., cantaloupe and honeydew {Cucumis melo L.), watermelon {Citrullus lanatus (Thunb.) Matsumura & Nakai)). Solanaceae includes crop plants including Solanum and Capsicum species such as tomato (Solarium lycopersicum L.), Cayenne and other garden peppers (Capsicum annuum L.), eggplant (Solanum melongena L.) and Irish potato (Solanum tuberosum L.).

Additional crop plants which can be treated by the present method include but are not limited to cereal grain crops such as wheat, barley, oats, rye, triticale, rice, maize, sorghum and millet; vine crops such as table and wine grapes; field crops such as oilseed rape (canola) and sunflower, sugar beets, sugar cane, soybeans, peanuts (groundnut), tobacco, alfalfa, clover, lespedeza, trefoil and vetch; pome fruits such as apple; pear, crabapple; loquat; mayhaw; quince; stone fruits such as peaches, cherries, plums, apricots and nectarines; almonds; citrus fruits such as lemons, limes, oranges, grapefruit, mandarin (tangerines) and kumquat; root and tuber vegetables and field crops (and their foliage) such as artichoke, garden and sugar beet, carrot, cassava, ginger, ginseng, horseradish, parsnip, potato, radish, rutabaga, sweet potato, turnip and yam; bulb vegetables such as garlic, leek, onion and shallot; leafy vegetables such as arugula (roquette), celery, cress, endive (escarole), fennel, head and leaf lettuce, parsley, radicchio (red chicory), rhubarb, spinach and Swiss chard; Brassica (cole) leafy vegetables such as broccoli, broccoli raab (rapini), Brussels sprouts, cabbage, bok choy, cauliflower, collards, kale, kohlrabi and mustard greens; legume vegetables (succulent or dried) such as lupin; bean (Phaseolus spp.) including field bean, kidney bean, lima bean, navy bean, pinto bean, runner bean, snap bean, tepary bean and wax bean; bean (Vigna spp.) including adzuki bean, asparagus bean, blackeyed pea, catjang, Chinese longbean, cowpea, crowder pea, moth bean, mung bean, rice bean, southern pea, urd bean and yardlong bean; broad bean (fava); chickpea (garbanzo); guar; jackbean; lablab bean; lentil; pea (Pisum spp.) including dwarf pea, edible-podded pea, English pea, field pea, garden pea, green pea, snowpea and sugar snap pea; pigeon pea; fruiting vegetables such as eggplant; groundcherry (Physalis spp); pepino; pepper including bell pepper, chili pepper, cooking pepper, pimento and sweet pepper; tomatillo; tomato; cucurbit vegetables such as chayote (fruit); Chinese waxgourd (Chinese preserving melon); citron melon; cucumber; gherkin; edible gourds including hyotan, cucuzza, hechima and Chinese okra; Momordica spp. including balsam apple, balsam pear, bittermelon and Chinese cucumber; muskmelon including cantaloupe; pumpkin; summer and winter squash including butternut squash, calabaza, hubbard squash, acorn squash and spaghetti squash; watermelon; berries such as blackberry (including bingleberry, boysenberry, dewberry, lowberry, marionberry, olallieberry and youngberry), blueberry, cranberry, currant, elderberry, gooseberry, huckleberry, loganberry, raspberry and strawberry; tree nuts such as almond, beech nut, Brazil nut, butternut, cashew, chestnut, chinquapin, filbert (hazelnut), hickory nut, macadamia nut, pecan and walnut; tropical fruits and other crops such as bananas, plantains, mangos, coconuts, papaya; guava, avocado, lichee, agave, coffee, cacao, oil palm, sesame, rubber, spices and fiber crops such as cotton, flax and hemp.

Notable crops which benefit from synergistic nematode protection include wheat, oat, barley, rye, corn, soybeans, millet, rice, sugar cane, sunflowers, potatoes, cotton, rapeseed, canola, tobacco, and sugar beets. Protection of corn, soybeans, rice and cotton is especially important.

In the method of the present invention, the methomyl and neonicotinoid mixtures can also be further mixed with one or more other biologically active compounds or agents including insecticides, fungicides, nematocides, bactericides, acaricides, herbicides, herbicide safeners, growth regulators such as insect molting inhibitors and rooting stimulants, chemosterilants, semiochemicals, repellents, attractants, pheromones, feeding stimulants, other biologically active compounds or entomopathogenic bacteria, virus or fungi to form a multi-component pesticide giving an even broader spectrum of agronomic and nonagronomic utility. The other biologically active compounds or agents can be formulated together with the present mixtures to form a premix, or the other biologically active compounds or agents can be formulated separately from the present mixtures and the two formulations combined together before application (e.g., in a spray tank) or, alternatively, applied in succession.

Examples of such biologically active compounds or agents with which mixtures for the method of this invention can be formulated are insecticides such as abamectin, acephate, acequinocyl, acrinathrin, amidoflumet, amitraz, avermectin, azadirachtin, azinphos-methyl, bifenthrin, bifenazate, bistrifluron, borate, 3-bromo-l-(3-chloro-2-pyridinyl)-iV-[4-cyano-2- methyl-6-[(methylamino)carbonyl]phenyl]-lH-pyrazole-5-carboxamide, buprofezin, cadusafos, carbaryl, carbofuran, cartap, carzol, chlorantraniliprole, chlorfenapyr, chlorfluazuron, chlorpyrifos, chlorpyrifos-methyl, chromafenozide, clofentezin, cyflumetofen, cyfluthrin, beta-cyfluthrin, cyhalothrin, gamma-cyhalothrin, lambda- cyhalothrin, cypermethrin, alpha-cypermethrin, zeta-cypermethrin, cyromazine, deltamethrin, diafenthiuron, diazinon, dieldrin, diflubenzuron, dimefluthrin, dimehypo, dimethoate, diofenolan, emamectin, endosulfan, esfenvalerate, ethiprole, etofenprox, etoxazole, fenbutatin oxide, fenothiocarb, fenoxycarb, fenpropathrin, fenvalerate, fipronil, flonicamid, flubendiamide, flucythrinate, flufenerim, flufenoxuron, fluvalinate, tau-fluvalinate, fonophos, formetanate, fosthiazate, halofenozide, hexaflumuron, hexythiazox, hydramethylnon, indoxacarb, insecticidal soaps, isofenphos, lufenuron, malathion, metaflumizone, metaldehyde, methamidophos, methidathion, methiodicarb, methoprene, methoxychlor, metofluthrin, monocrotophos, methoxyfenozide, nithiazine, novaluron, noviflumuron, parathion, parathion-methyl, permethrin, phorate, phosalone, phosmet, phosphamidon, pirimicarb, profenofos, profluthrin, propargite, protrifenbute, pymetrozine, pyrafluprole, pyrethrin, pyridaben, pyridalyl, pyrifluquinazon, pyriprole, pyriproxyfen, rotenone, ryanodine, spinetoram, spinosad, spirodiclofen, spiromesifen, spirotetramat, sulprofos, tebufenozide, tebufenpyrad, teflubenzuron, tefluthrin, terbufos, tetrachlorvinphos, tetramethrin, thiosultap-sodium, tolfenpyrad, tralomethrin, triazamate, trichlorfon, triflumuron, Bacillus thuringiensis delta-endotoxins, entomopathogenic bacteria, entomopathogenic viruses and entomopathogenic fungi.

Of note are insecticides such as abamectin, acrinathrin, amitraz, avermectin, azadirachtin, bifenthrin, 3-bromo-l-(3-chloro-2-pyridinyl)-Λ/-[4-cyano-2-methyl-6- [(methylamino)carbonyl]phenyl]-lH-pyrazole-5-carboxamide, buprofezin, cadusafos, carbaryl, cartap, chlorantraniliprole, chlorfenapyr, chlorpyrifos, cyfluthrin, beta-cyfluthrin, cyhalothrin, gamma-cyhalothrin, lambda-cyhalothrin, cypermethrin, alpha-cypermethrin, zeta-cypermethrin, cyromazine, deltamethrin, dieldrin, diofenolan, emamectin, endosulfan, esfenvalerate, ethiprole, etofenprox, etoxazole, fenothiocarb, fenoxycarb, fenvalerate, fϊpronil, flonicamid, flubendiamide, flufenoxuron, fluvalinate, formetanate, fosthiazate, hexaflumuron, hydramethylnon, indoxacarb, lufenuron, metaflumizone, methiodicarb, methoprene, methoxyfenozide, nithiazine, novaluron, pymetrozine, pyrethrin, pyridaben, pyridalyl, pyriproxyfen, ryanodine, spinetoram, spinosad, spirodiclofen, spiromesifen, spirotetramat, tebufenozide, tetramethrin, thiosultap-sodium, tralomethrin, triazamate, triflumuron, Bacillus thuringiensis delta-endotoxins, all strains of Bacillus thuringiensis and all strains of Nucleo polyhydrosis viruses.

Biological agents for mixing with mixtures of this invention include entomopathogenic bacteria such as Bacillus thuringiensis, and the encapsulated delta-endotoxins of Bacillus thuringiensis (e.g., Cellcap, MPV, MPVII); entomopathogenic fungi such as green muscardine fungus; and entomopathogenic (both naturally occurring and genetically modified) viruses including baculovirus, nucleopolyhedro virus (NPV) such as Helicoverpa zea nucleopolyhedrovirus (ΗzNPV), Anagrapha falcifera nucleopolyhedrovirus (AfNPV); and granulosis virus (GV) such as Cydia pomonella granulosis virus (CpGV).

Of particular note is such a combination where the other invertebrate pest control active ingredient belongs to a different chemical class or has a different site of action than methomyl or neonicotinoids. In certain instances, a combination with at least one other invertebrate pest control active ingredient having a similar spectrum of control but a different site of action will be particularly advantageous for resistance management. Thus, a composition of the present invention can further comprise a biologically effective amount of at least one additional invertebrate pest control active ingredient having a similar spectrum of control but belonging to a different chemical class or having a different site of action. These additional biologically active compounds or agents include, but are not limited to, sodium channel modulators such as bifenthrin, cypermethrin, cyhalothrin, lambda- cyhalothrin, cyfluthrin, beta-cyfluthrin, deltamethrin, dimefluthrin, esfenvalerate, fenvalerate, indoxacarb, metofluthrin, profluthrin, pyrethrin and tralomethrin; cholinesterase inhibitors such as chlorpyrifos and triazamate; insecticidal macrocyclic lactones such as spinetoram, spinosad, abamectin, avermectin and emamectin; GABA (γ-aminobutyric acid)- gated chloride channel antagonists such as avermectin or blockers such as ethiprole and fϊpronil; chitin synthesis inhibitors such as buprofezin, cyromazine, flufenoxuron, hexaflumuron, lufenuron, novaluron, noviflumuron and triflumuron; juvenile hormone mimics such as diofenolan, fenoxycarb, methoprene and pyriproxyfen; octopamine receptor ligands such as amitraz; molting inhibitors and ecdysone agonists such as azadirachtin, methoxyfenozide and tebufenozide; ryanodine receptor ligands such as ryanodine, anthranilic diamides such as chlorantraniliprole (see U.S. Patent 6,747,047, PCT Publications WO 2003/015518 and WO 2004/067528) and flubendiamide (see U.S. Patent 6,603,044); nereistoxin analogs such as cartap; mitochondrial electron transport inhibitors such as chlorfenapyr, hydramethylnon and pyridaben; lipid biosynthesis inhibitors such as spirodiclofen and spiromesifen; cyclodiene insecticides such as dieldrin or endosulfan; pyrethroids; carbamates; insecticidal ureas; and biological agents including nucleopolyhedro viruses (NPV), members of Bacillus thuringiensis, encapsulated delta-endotoxins of Bacillus thuringiensis, and other naturally occurring or genetically modified insecticidal viruses.

Further examples of biologically active compounds or agents with which mixtures of this invention can be formulated are: fungicides such as acibenzolar, aldimorph, amisulbrom, azaconazole, azoxystrobin, benalaxyl, benomyl, benthiavalicarb, benthiavalicarb-isopropyl, binomial, biphenyl, bitertanol, blasticidin-S, Bordeaux mixture (Tribasic copper sulfate), boscalid/nicobifen, bromuconazole, bupirimate, buthiobate, carboxin, carpropamid, captafol, captan, carbendazim, chloroneb, chlorothalonil, chlozolinate, clotrimazole, copper oxychloride, copper salts such as copper sulfate and copper hydroxide, cyazofamid, cyfiunamid, cymoxanil, cyproconazole, cyprodinil, dichlofiuanid, diclocymet, diclomezine, dicloran, diethofencarb, difenoconazole, dimethomorph, dimoxystrobin, diniconazole, diniconazole-M, dinocap, discostrobin, dithianon, dodemorph, dodine, econazole, etaconazole, edifenphos, epoxiconazole, ethaboxam, ethirimol, ethridiazole, famoxadone, fenamidone, fenarimol, fenbuconazole, fencaramid, fenfuram, fenhexamide, fenoxanil, fenpiclonil, fenpropidin, fenpropimorph, fentin acetate, fentin hydroxide, ferbam, ferfurazoate, ferimzone, fiuazinam, fiudioxonil, fiumetover, fiuopicolide, fiuoxastrobin, fluquinconazole, fluquinconazole, fiusilazole, flusulfamide, flutolanil, fiutriafol, folpet, fosetyl-aluminum, fuberidazole, furalaxyl, furametapyr, hexaconazole, hymexazole, guazatine, imazalil, imibenconazole, iminoctadine, iodicarb, ipconazole, iprobenfos, iprodione, iprovalicarb, isoconazole, isoprothiolane, kasugamycin, kresoxim-methyl, mancozeb, mandipropamid, maneb, mapanipyrin, mefenoxam, mepronil, metalaxyl, metconazole, methasulfocarb, metiram, metominostrobin/fenominostrobin, mepanipyrim, metrafenone, miconazole, myclobutanil, neo-asozin (ferric methanearsonate), nuarimol, octhilinone, ofurace, orysastrobin, oxadixyl, oxolinic acid, oxpoconazole, oxycarboxin, paclobutrazol, penconazole, pencycuron, penthiopyrad, perfurazoate, phosphonic acid, phthalide, picobenzamid, picoxystrobin, polyoxin, probenazole, prochloraz, procymidone, propamocarb, propamocarb-hydrochloride, propiconazole, propineb, proquinazid, prothioconazole, pyraclostrobin, pryazophos, pyrifenox, pyrimethanil, pyrifenox, pyrolnitrine, pyroquilon, quinconazole, quinoxyfen, quintozene, silthiofam, simeconazole, spiroxamine, streptomycin, sulfur, tebuconazole, techrazene, tecloftalam, tecnazene, tetraconazole, thiabendazole, thifluzamide, thiophanate, thiophanate-methyl, thiram, tiadinil, tolclofos-methyl, tolyfluanid, triadimefon, triadimenol, triarimol, triazoxide, tridemorph, trimoprhamide tricyclazole, trifloxystrobin, triforine, triticonazole, uniconazole, validamycin, vinclozolin, zineb, ziram, and zoxamide; nematocides such as aldicarb, imicyafos, oxamyl and fenamiphos; bactericides such as streptomycin; acaricides such as amitraz, chinomethionat, chlorobenzilate, cyhexatin, dicofol, dienochlor, etoxazole, fenazaquin, fenbutatin oxide, fenpropathrin, fenpyroximate, hexythiazox, propargite, pyridaben and tebufenpyrad.

Synergism manifested by mixtures of methomyl and neonicotinoids may allow a substantial reduction in the application rates of one or both of these active ingredients, while maintaining good nematocidal efficacy. The greater than expected effect may persist for days after application, facilitating rapid knockdown and mortality. Decreasing application rates reduces treatment cost to the farmer and also eases the burden on the environment both from manufacturing waste and crop protection chemical residues.

The presence of a synergistic effect between two active ingredients can be established with the aid of the Colby equation (see Colby, S. R., "Calculating Synergistic and Antagonistic Responses of Herbicide Combinations", Weeds 1967, 15, 20-22):

A x B p = A +B -

100

Using the method of Colby, the presence of a synergistic interaction between two active ingredients is established by first calculating the predicted activity, p, of the mixture based on activities of the two components applied alone. In the equation above, A is the biological (e.g., nematocidal) activity in percentage control of one component applied alone at rate x. The B term is the biological activity in percentage control of the second component applied at rate y. The equation calculates p, the predicted biological activity of the mixture of A at rate x with B at rate y if their effects are strictly additive and no interaction has occurred. If the experimentally established effect of the mixture is greater than the predicted activity, p, synergism is present. To use the Colby equation the active ingredients of the mixture are applied in a test separately as well as in combination.

BIOLOGICAL EXAMPLES OF THE INVENTION

The following test demonstrates the control efficacy of mixtures or compositions of this invention on root-knot nematode. The nematode control protection afforded by the present mixtures or compositions is not limited, however, to this nematode species.

TEST A

Control of the southern root-knot nematode (Meloidogyne incognita) through contact and/or systemic means was evaluated in test units consisting of small open 15 mL containers filled with a sandy soil mixture and cucumber seedlings. Test compounds were formulated by dissolving the test compound in acetone (1 part test compound:300 parts acetone by weight). The resulting stock solution was diluted with water to the appropriate final concentration. The diluted mixtures of the test compounds (300 μL) were applied directly to the soil of the test units. Each test was replicated 3 times. After treatment, the test units were allowed to dry for 1 hour, after which time about 250 second-stage juvenile (J2) larvae were pipetted into the soil. The test units were held at 27 ⁰C and watered as needed for 7 days.

Nematocidal efficacy was determined by the amount of root gall formation observed when compared to an untreated control. No gall formation was indicative of 100% nematode control. Gall formation equivalent to that found in the untreated control was indicative of 0% control.

Tables A to F list the observed % reduction in nematode-caused galls calculated as a mean average of the results from 3 replicates along with the expected % reduction calculated using the Colby equation.

Table A Methomyl and Thiacloprid

* calculated using the Colby equation

Table B Methomyl and Dinotefuran

* calculated using the Colby equation

Table C Methomyl and Acetamiprid

* calculated using the Colby equation

Table D Methomyl and Nitenpyram

* calculated using the Colby equation

Table E Methomyl and Imidacloprid

* calculated using the Colby equation

Table F Methomyl and Thiamethoxam

* calculated using the Colby equation

Accordingly, as the experimental results indicate, this invention provides improved methods of use of these compositions for control of nematodes in agronomic environments. The compositions of this invention demonstrate a high controlling effect on nematodes, and consequently, their use as nematocides can reduce crop production losses from nematode infestations.

Claims

CLAIMSWhat is claimed is:

1. A method for protecting a plant from a phytophagous nematode comprising applying a nematocidally effective amount of a mixture consisting essentially of (a) methomyl and (b) a neonicotinoid component consisting of one or more neonicotinoids to the plant, its seed or its growing medium.

2. The method of Claim 1 wherein the mixture is in a composition further comprising at least one additional component selected from the group consisting of surfactants, solid diluents and liquid diluents.

3. The method of Claim 2 wherein the composition is granular.

4. The method of Claim 1 wherein the neonicotinoid component is selected from the group consisting of imidacloprid, clothiothianidin, thiomethoxam, thiacloprid, acetamiprid, nitenpyram, dinotefuran and mixtures thereof.

5. The method of Claim 4 wherein the neonicotinoid component consists of imidacloprid.

6. The method of Claim 4 wherein the neonicotinoid component consists of clothianidin.

7. The method of Claim 4 wherein the neonicotinoid component consists of thiamethoxam.

8. The method of Claim 4 wherein the neonicotinoid component consists of thiacloprid.

9. The method of Claim 1 wherein the mixture is applied to a root of the plant.

10. The method of Claim 1 wherein the mixture is applied to the growing medium of the plant.

11. The method of Claim 1 wherein the mixture is applied to the seed of the plant.

12. The method of Claim 1 wherein the plant is a transgenic plant.

13. The method of Claim 1 wherein the methomyl and the neonicotinoid component are applied simultaneously.

14. The method of Claim 1 wherein the methomyl is applied first and then the neonicotinoid component is applied.

15. The method of Claim 1 wherein the neonicotinoid component is applied first and then the methomyl is applied.

16. A seed treated with a nematocidally effective amount of the mixture according to Claim 1.