Claims:WE CLAIM:

1. A stable synergistic pesticidal composition comprising neonicotinoid compound and pyridine azomethine compound for management of a broad spectrum of sucking pests of rice crop plant, wherein the weight percentage by composition of neonicotinoid compound is 1 to 25%, the weight percentage by composition of pyridine azomethine compound is 3 to 55%, and the weight percentage by composition of agriculturally acceptable additives is 20 to 96%.

2. The stable synergistic pesticidal composition as claimed in claim 1, wherein the neonicotinoid compound is selected from acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid and thiamethoxam.

3. The stable synergistic pesticidal composition as claimed in claim 1, wherein the neonicotinoid compound is dinotefuran.

4. The stable synergistic pesticidal composition as claimed in claim 1, wherein the pyridine azomethine compound is pymetrozine.

5. The stable synergistic pesticidal composition as claimed in claim 1, wherein agriculturally acceptable additives are selected from carrier, solvent, emulsifier, dispersant, wetting agent, binder, stabilizer, pH adjuster, and/or coloring agent.

6. The stable synergistic pesticidal composition as claimed in claim 1, wherein said composition can be formed to several types of formulations, such as soluble granule, wettable powder, water dispersible granules and suspension concentrate.

7. A method of pre-mix application of the stable synergistic pesticidal composition as claimed in claim 1 for management of sucking pests of rice.

8. A method for preparation of the suspension concentrate formulation of the stable synergistic pesticidal composition as claimed in claim 1 comprising the steps of:

(a) mixing the active ingredients, surfactant and anti-freezing agent by dissolving or dispersing in water;
(b) wet milling of the mixture using a defoamer further comprising preliminary milling by a homogenizer such as a colloid mill and then milling by a bead mill till median diameter reaches to 1 to 10 micrometer; and
(c) adding aqueous solution of thickener containing preservative to milled mixture.

9. A method for preparation of the wettable powder formulation of the stable synergistic pesticidal composition as claimed in claim 1 comprising the steps of:
(a) mixing the active ingredients, surfactant, carrier and other formulation additives uniformly in a mixer; and
(b) milling by a mill such as an air jet mill to median diameter 5 to 50 micrometer.

Description:

1. TITLE OF THE INVENTION

STABLE SYNERGISTIC PESTICIDAL COMPOSITION FOR MANAGEMENT OF SUCKING PESTS OF RICE, METHOD OF ITS PREPARATION AND METHOD OF ITS APPLICATION

2. APPLICANT

(a) PI INDUSTRIES LTD.
(b) an Indian company,
(c) of Post Box No. 20, Udaisagar Road, Udaipur, Rajasthan- 313001, INDIA,

3. PREAMBLE TO THE DESCRIPTION

The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION

The present invention generally relates to a composition for the control of pests. More particularly, the present invention relates to a stable synergistic pesticidal composition for the management of sucking pests of rice, method of its preparation and method of its application.

BACKGROUND OF THE INVENTION

Pests can have adverse and damaging impacts on agricultural production by affecting crops and food production. In addition, pests can have detrimental effect on environment and human health. In order to control pests of plant, various pesticides or combination of pesticides are being used by farmers.

In order to control sucking pests of rice crop plant, several pesticides or combinations of pesticides have been developed and are currently in use for example pesticides such as acephate, buprofezin, dichlorovos, ethofenprox, imidacloprid, thiamethoxam; combination of pesticides such as deltamethrin and buprofezin, ethiprole and imidacloprid, buprofezin and acephate etc. However, such pesticides or combination of pesticides show reduced efficacy against sucking pests of rice due to development of resistance to said pesticides or combination of pesticides.

The pesticides or combination of pesticides can be applied in different ways for example sequential application, tank-mix application and pre-mix application.

In sequential application, farmers use different pesticides, wherein the pesticide selection is not based on the technical knowhow and pesticides having the same mode of action are being used, which leads to resistance development. In tank-mix application, farmers use different combinations of pesticides, most of the times without having training to properly mix products. Homemade tank mixes may therefore not be as stable as a pre-mix. The tank-mix usually results in non-judicious use of individual pesticides and end up with poor pest control. Moreover, the tank mixture is less convenient and potentially hazardous to people who are not trained to properly mix products.

The pre-mix application is a combination of two or more pesticides as active ingredients but the rates of the active ingredients are unchangeable, the components rates and formulation are optimized during development, hence no mixing or stability issue exists. The pre-mix application also helps in reducing the development of pesticide resistance.

The sequential application and tank-mix application of pesticides, when employed to address sucking pests of rice, result in development of pesticide resistance. The pre-mix application being convenient to use have not been applied so far for controlling sucking pests of rice.

It is therefore desired to provide an improved composition and convenient method that is efficient against sucking pests of rice, serves as good tool for resistance management, shows technical advancement over existing art and is of economic significance.

OBJECTS OF THE INVENTION

The primary object and advantage of the present invention is to provide a pesticidal composition that shows synergistic effect against sucking pests of rice crop plant.

Another object and advantage of the present invention is to provide a pesticidal composition that efficaciously contributes in pest resistance management.

Another object and advantage of the present invention is to provide a pesticidal composition that is stable.

Another object and advantage of the present invention is to provide a pesticidal composition that is efficacious against wide variety of sucking pests of rice crop plant.

Another object and advantage of the present invention is to provide a stable synergistic pesticidal composition that has economic significance.

Another object and advantage of the present invention is to provide a stable synergistic pesticidal composition that shows technical advancement over the existing pesticides or combination of pesticides.

Yet another object and advantage of the present invention is to provide a cost-effective and convenient method for the preparation of said composition, which is effective against sucking pests of rice crop plant.

SUMMARY OF THE INVENTION

In one aspect of the present invention, there is provided a stable synergistic pesticidal composition comprising neonicotinoid compound and pyridine azomethine compound for management of a broad spectrum of sucking pests of rice crop plant, wherein the weight percentage by composition of neonicotinoid compound is 0.5 to 30%, the weight percentage by composition of pyridine azomethine compound is 1 to 60%, and the weight percentage by composition of agriculturally acceptable additives is 10 to 98.5% .

Further, the present invention provides a stable synergistic pesticidal composition comprising neonicotinoid compound and pyridine azomethine compound for management of a broad spectrum of sucking pests of rice crop plant, wherein the weight percentage by composition of neonicotinoid compound is 1 to 25%, the weight percentage by composition of pyridine azomethine compound is 3 to 55%, and the weight percentage by composition of agriculturally acceptable additives is 20 to 96%.

In one of the embodiments, there is provided a stable synergistic pesticidal composition that exhibits synergistic effect for management of sucking pest of rice crop plant.

According to another embodiment, there is provided a stable synergistic pesticidal composition, which functions as a broad spectrum pesticide acting against wide variety of rice crop plant pests such as, not being limited to, brown plant hopper (BPH) and white backed plant hopper (WBPH).

According to yet another aspect of the present invention, there is provided a convenient and cost-effective method for the preparation of said stable synergistic pesticidal composition comprising neonicotinoid compound and pyridine azomethine compound for management of sucking pest of rice crop plant.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a stable pesticidal composition comprising neonicotinoid compound and pyridine azomethine compound for management of sucking pests of rice crop plant. The stable pesticidal composition shows synergistic effect against sucking pests of rice crop plant.

The neonicotinoid compound is selected from such as, not being limited to, acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid and thiamethoxam.

Preferably, the neonicotinoid compound is dinotefuran. Dinotefuran is a furanicotinyl insecticide which belongs to the third generation of neonicotinoids and has the below structure:

Neonicotinoids are a class of insecticides, which act on the nervous system of insects with lower toxicity to mammals. Its mechanism of action involves the disruption of the insect’s nervous system and thus paralyzing them.

The content of neonicotinoid compound in said stable synergistic pesticidal composition of the present invention is 0.5 to 30% by weight of composition. The content of neonicotinoid compound is preferably 1 to 25% by weight of composition.

Preferably, the pyridine azomethine compound is pymetrozine which has the below structure:

Pymetrozine is the only representative of the pyridine azomethines, a novel class of insecticides, highly active and specific against sucking pests such as whiteflies, hoppers and aphids. It has a unique mode of action and can be applied as both foliar and soil application. It has no direct toxicity against insects, but it blocks stylet penetration of sucking pests, which may cause immediate and irreversible cessation of feeding within few hours of application of the pesticide, followed eventually by starvation and death. Even if insertion of the stylet into plant cells is achieved, it takes considerably more time than normal, and pest can ingest sap only for a short time. Mortality is slow and depending on the climatic conditions, treated pests may appear normal for several days before they die from starvation. These positive features make pymetrozine an ideal component in situations where sucking pests have to be controlled and natural enemies can play a substantial role as complementary control tools.

The content of pyridine azomethine compound in said stable synergistic pesticidal composition of the present invention is 1 to 60% by weight of composition. The content of pyridine azomethine compound is preferably 3 to 55% by weight of composition.

The stable synergistic pesticidal composition of the present invention may further include conventional agriculturally acceptable formulation additives such as surfactant, carrier, binder, disintegrant, pH adjuster, thickener, preservative, anti-freezing agent, defoamers and/or coloring agent.

Suitable surfactants are nonionic or anionic or a combination of these surfactants. It is preferred to use more than two kinds of surfactants which have different chemical structure. Suitable surfactants are, for example, sugar esters (such as sorbitan monolaurate, polyoxyethylene sorbitan monolaurrate), polyoxyethylene alkyl ethers (such as polyoxyethylene lauryl ether or polyoxyethylene coconut fatty alcohol ether), polyoxyethylene aryl ethers (such as polyoxyethylene nonylphenyl ether or polyoxyethylene trystyrylphenyl ether), polyoxyethylene vegetable oil ethers (such as polyoxyethylene castor oil), polyoxyethylene fatty acid esters (such as polyoxyethylene monolaurate), polyoxyethylene polyoxypropylene block co-polymers, polyoxyethylene alkyl amines (such as polyoxyethylene stearyl fatty amine), alkyl sulfates (such as sodium lauryl sulfate), polyoxyethylene alkyl ether sulfates (such as sodium polyoxyethylene lauryl ether sulfate), polyoxyethylene aryl ether sulfates (such as sodium polyoxyethylene nonylphenyl ether sulfate or ammonium polyoxyethylene tristyrylphenyl ether sulfate), alkane sulfonates (such as sodium dodecyl sulfonate), ‘alpha’-olefin sulfonate, aryl sulfonates (such as sodium dodecylbenzene sulfonate, sodium alkylnaphthalene sulfonate, sodium ‘beta’-naphthalene sulfonate formaldehyde condensate or sodium alkyl diphenyl ether sulfonate), alkylsulfosuccinates (such as sodium dioctylsulfosuccinate), lignosulfonates, polyoxyethylene alkyl ether phosphate, polyoxyethylene aryl ether phosphates (such as polyoxyethylene phenyl ether phosphate) and polyoxyethylene polyoxypropylene block co-polymer phosphate.

Suitable carriers are, for example, talc, kaolinite, pyrophyllite, montmorillonite, attapulgite, bentonite, calcite, diatomaceous earth, synthetic minerals (such as precipitated silica, fumed silica and calcium carbonate). Different types of carriers may be used by mixture.

Suitable binders are, for example, polyvinyl alcohol, dextrin, denatured dextrin, soluble starch, carboxymethyl cellulose and bentonite.

Suitable disintegrants are, for example, sodium tripolyphosphate, sodium hexametaphosphate, carboxymethyl cellulose and bentonite.

Suitable pH adjusters are, for example, sodium or potassium carbonate, sodium or potassium hydrogen carbonate, sodium or potassium dihydrogenphosphate, disodium or dipotassium hydrogenphosphate, citric acid, malic acid and triethanolamine.

Suitable thickeners are, for example, xanthan gum, welan gum, guar gum, polyvinyl alcohol, carboxymethyl cellulose and its salt, silica and bentonite

Suitable preservatives are, for example, 4-hydroxybenzoic acid esters, 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one and 1,2-benzisothiazolin-3-one.

Suitable anti-freezing agents are, for example, glycerin, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol and urea.

Suitable defoamers are, for example, silicone compounds and organic fluorine compounds.

Suitable coloring agents are, for example, organic dyestuffs (such as azo dye, phthalocyanine dye or alizarin dye) and inorganic pigments (such as iron oxide).

The content of agriculturally acceptable additives in said stable synergistic pesticidal composition of the present invention is 10 to 98.5% by weight of composition. The content of agriculturally acceptable additives is preferably 20 to 96% by weight of composition.

The stable synergistic pesticidal composition of the present invention comprising neonicotinoid compound and pyridine azomethine compound can be formed to several types of formulations, such as, not being limited to, soluble granule, wettable powder, water dispersible granules and suspension concentrate.

In one embodiment of the present invention, the composition of the wettable powder formulation is provided. The composition of wettable powder comprises the neonicotinoid compound and pyridine azomethine compound as active ingredients, surfactant and carrier. Other formulation additives such as pH adjuster and colorant may be additionally used.

A method for preparing the wettable powder formulation of the present invention is also provided. The wettable powder formulation can be prepared by mixing the active ingredients, surfactant and carrier. Usually active ingredients, surfactant, carrier and other formulation additives are mixed uniformly in a mixer and milled by a mill such as an air jet mill to median diameter 5 to 50 micrometer.

In another embodiment of the present invention, the composition of the water dispersible granule formulation is provided. The composition of water dispersible granule comprises the neonicotinoid compound and pyridine azomethine compound as active ingredients, surfactant, binder, disintegrant and carrier. Other formulation additives such as pH adjuster and colorant may be additionally used.

A method for preparing the water dispersible granule formulation of the present invention is also provided. The water dispersible granule formulation can be prepared by mixing the active ingredients, surfactant, binder, disintegrant and carrier. Usually the active ingredients, surfactant, binder, disintegrant, carrier and other formulation additives are mixed uniformly in a mixer and milled by a mill such as an air jet mill to median diameter 5 to 50 micrometer. The milled mixture is kneaded by adding 2 to 10 % of water, extruded and dried. Other granulation method such as spray dry may be used. In this case, the milled mixture is well mixed with enough amount of water to get slurry.

In yet another embodiment of the present invention, the composition of the suspension concentrate formulation is provided. The composition of suspension concentrate comprises the neonicotinoid compound and pyridine azomethine compound as active ingredients, surfactant, thickener, preservative, anti-freezing agent and water. Other formulation additives such as defoamer, pH adjuster and colorant may be additionally used.

A method for preparing the suspension concentrate formulation formulation of the present invention is also provided. The suspension concentrate formulation can be prepared by wet milling of the active ingredients mixed with surfactant, water and other formulation additives. Usually the active ingredients, surfactant and anti-freezing agent are mixed by dissolving or dispersing in water. The mixture is preliminary milled by a homogenizer such as a colloid mill and then milled by a bead mill till median diameter reaches to 1 to 10 micrometer. Defoamer may be used during milling. After the milling, aqueous solution of thickener containing preservative is added.

It has been found that the stable pesticidal composition of the present invention comprising neonicotinoid compound and pyridine azomethine compound shows synergistic effect against wide variety of sucking pests of rice such, as not being limited to, brown plant hopper (BPH) and white backed plant hopper (WBPH). In this respect, the stable pesticidal composition of the present invention shows synergistic effect when compared with the individual effect of pesticides known in the prior art such as, not being limited to, dinotefuran, pymetrozine, buprofezin, acephate for management of sucking pests of rice.

The stable synergistic pesticidal composition of the present invention controls sucking pests of rice crop plant through premix application. The premix application of pesticides is economical, convenient to use. Moreover, the premix application of combination of pesticides slows down the development of pesticide resistance. Further advantages of premix application are such as the rates of active ingredients are unchangeable, the component rate and formulation are optimized during development, no mixing or stability issue exists, at least one compound is usually applied at a lower rate than labeled rate etc.

It has been found that the stable synergistic pesticidal composition of the present invention comprising neonicotinoid compound and pyridine azomethine compound serves as an efficacious composition for pesticide resistance management. In this respect, the stable synergistic pesticidal composition of the present invention effectively reduces the development of pesticide resistance, when compared with the pesticides or combination of pesticides known in the prior art such as, not being limited to, acephate, buprofezin, imidacloprid; deltamethrin and buprofezin; buprofezin and acephate etc. for management of sucking pests of rice.

It has been further found that the stable pesticidal composition of the present invention shows synergistic effect on sucking pests of rice found in different regions such as, not being limited to, Karnataka.

In order to more clearly describe the nature of the present invention, examples will hereinafter be described. It should be understood, however, that this is done solely by way of example, and is not intended to limit the scope of present invention.

Example: Water dispersible granule (WG)

Composition of Dinotefuran 10% Pymetrozine 40 % WG

Dinotefuran Technical (purity 99.5%) 10.1% (w/w)
Pymetrozine Technical (purity 98.5%) 40.6
Sodium lauryl sulfate 8.0
Polyvinyl alcohol 2.0
Carboxymethyl cellulose 2.0
Calcined diatomaceous earth 8.0
Clay 29.3

Total 100.0% (w/w)

The active ingredients dinotefuran technical, pymetrozine technical, sodium lauryl sulfate, polyvinyl alcohol, carboxymethyl cellulose, calcined diatomaceous earth and clay are mixed and pulverized in a high speed mixer. The resulting mixture is kneaded with water, extruded through a screen (0.8 mm diameter opening) and dried.

Following test results illustrate the present invention and not intended to limit the present invention:

Table 1: Effect of Dinotefuran + Pymetrozine 50% WG against BPH (Nilaparvata lugens)

Location: Karnataka
Village: Huvinamadu
District: Davangere
Season: Kharif 2014
Water volume: 500 lit/ha

Tr.No. Treatments Dose g.a.i/ha Mean No. of Insects/hill
BS 1 DAS 3 DAS 7 DAS 10 DAS 15 DAS 18 DAS 21 DAS
1 Dinotefuran + Pymetrozine 50% WG 25+100 14.50 2.20 2.10 2.00 2.00 3.15 4.00 5.50
2 Dinotefuran 20% SG 40 16.20 9.00 6.80 2.30 2.00 36.00 19.10 20.20
3 Pymetrozine 50% WG 150 11.50 10.40 9.00 2.60 2.60 8.10 15.12 21.00
4 Buprofezin 25% SC 200 16.40 11.20 7.90 7.70 9.40 29.10 75.00 93.00
5 Acephate 75% SP 500 17.00 10.00 7.70 7.30 11.90 36.60 81.70 105.00
6 Untreated Control - 23.40 23.10 25.40 25.60 26.80 63.90 106.30 151.70
SEm(±) 1.12 0.90 0.91 0.87 0.95 2.74 7.94 7.92
CD(p=0.05) 3.5 2.86 2.89 2.74 3.00 8.63 25.03 24.96

Table 2: Effect of Dinotefuran + Pymetrozine 50% WG against WBPH (Sogatella furcifera)

Location: Karnataka
Village: Huvinamadu
District: Davangere
Season: Kharif 2014
Water volume: 500 lit/ha
Tr.No. Treatments Dose g.a.i/ha Mean No. of Insects//hill
BS 1 DAS 3 DAS 7 DAS 10 DAS 15 DAS 18 DAS 21 DAS
1 Dinotefuran + Pymetrozine 50% WG 25+100 22.50 12.40 6.10 1.90 3.10 3.90 4.10 4.60
2 Dinotefuran 20% SG 40 23.90 20.90 8.90 9.10 8.90 11.30 12.20 13.30
3 Pymetrozine 50% WG 150 21.70 19.00 9.20 8.90 9.50 12.60 12.00 14.10
4 Buprofezin 25% SC 200 24.50 19.50 20.00 21.60 23.10 26.40 27.20 29.80
5 Acephate 75% SP 500 26.70 21.60 18.10 21.60 22.60 24.50 25.50 30.50
6 Untreated Control - 29.50 30.40 26.20 40.80 37.90 76.70 75.50 81.50
SEm(±) 1.50 1.45 1.11 1.32 1.22 2.45 2.40 2.63
CD(p=0.05) 4.73 4.57 3.49 4.18 3.85 7.73 7.57 8.31

The above test results are in the form of example and to maintain brevity. There can and are many more test results that can be provided.

In all the test results described above, following specific terminologies are used:

The abbreviation BPH refers to Brown Plant Hopper
The abbreviation WBPH refers to White Backed Plant Hopper
The abbreviation SG refers to Soluble Granule
The abbreviation WG refers to a Water dispersible granule
The abbreviation BS refers to Before Spraying
The abbreviation DAS refers to Days after spraying

From the test results shown above, it is evident that there is an unexpected and surprising result i.e. the synergistic effect of the pesticidal composition comprising neonicotinoid compound (dinotefuran) and pyridine azomethine compound (pymetrozine) in the management of sucking pests of rice. As, it can be seen that by using the stable synergistic pesticidal composition of the present invention, the mean number of insects/hill becomes significantly less as compared to the independent use of other insecticides such as dinotefuran, pymetrozine, acephate, buprofezin.

The data provided is also indicative of the increased efficacy of the invention over the existing art, for example significant increase (around 85 percent) in the percentage mortality of the pests has been observed before spraying and three days after spraying of said stable synergistic pesticidal composition of the present invention. None of the individual pesticides known in the prior art shows such advancement and efficacy. Hence, it can be seen that the present invention shows significant advancement over the existing knowledge.

From the foregoing description, it will be apparent to one ordinarily skilled in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein. Accordingly, it is not intended that the scope of the foregoing description be limited to the description set forth above, but rather that such description be construed as encompassing all of the features that reside in the present invention, including all the features and embodiments that would be treated as equivalents thereof by those skilled in the relevant art.