WO2017216776A1

WO2017216776A1 - A synergistic fungicidal composition

Info

Publication number: WO2017216776A1
Application number: PCT/IB2017/053610
Authority: WO
Inventors: Jayprakash Gopalkrishnan RAO; Avinash Vitthal BAGLE; Jitendra Gajanan PATIL
Original assignee: Indofil Industries Limited
Priority date: 2016-06-17
Filing date: 2017-06-17
Publication date: 2017-12-21
Also published as: CN109310088A; RU2018144260A; PH12018502636A1; CO2018013439A2; RU2018144260A3; RU2738360C2

Abstract

The present disclosure relates to a synergictic fungicidal composition comprising active ingredients including a combination of Metalaxyl-M, Cymoxanil and Azoxystrobin having weight ratio in the range of 1:1:0.5 to 1:3:30, and excipient selected from the group consisting of dispersing agent, defoamer, wetting agent, disintegrating agent, anti-caking agent, carrier, and binder. The fungicidal composition of the present disclosure combats resistance to fungi for a long time and has enhanced fungicidal activity.

Description

A SYNERGISTIC FUNGICIDAL COMPOSITION

FIELD

The present disclosure relates to a synergistic fungicidal composition. BACKGROUND Plants, fruits, and vegetables are prone to attack by fungi. In agriculture and horticulture, fungicides are most commonly used for protection against fungi. The most common and widely used method of protection against fungi is achieved by the use of synthetic fungicides. Synthetic fungicides of many types have been known and an extensive variety of formulations based on these synthetic fungicides are being marketed by various producers for protection against fungi. Various compounds such as azoxystrobin, anilazine, cymoxanil and the like are commonly used as fungicides.

It is always advisable to minimize the use of fungicides to reduce the risks to human beings and to the environment. Accordingly, there is a continuing need for improving the fungicidal properties of fungicides without increasing its toxicity to human beings and the environment so that the desired bioefficacy is achieved at low application rates.

Therefore, the present disclosure envisages a synergistic fungicidal composition having enhanced efficacy.

OBJECTS

Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.

It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.

An object of the present disclosure is to provide a synergistic fungicidal composition.

Another object of the present disclosure is to provide a synergistic fungicidal composition that has enhanced fungicidal activity. Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

SUMMARY

The present disclosure relates to a synergistic fungicidal composition comprising active ingredients including a combination of Metalaxyl-M, Cymoxanil and Azoxystrobin having weight ratio in the range of 1 :1 :0.5 to 1 :3:30 respectively, and at least one excipient selected from the group consisting of dispersing agent, defoamer, wetting agent, disintegrating agent, anti-caking agent, carrier, and binder.

The present disclosure further relates to a method for preparation of synergistic fungicidal composition comprising the step of blending predetermined quantities of an anti-caking agent, a carrier and Metalaxyl-M technical to obtain a substantially homogenized mixture A; blending predetermined quantities of Azoxystrobin technical, Cymoxanil technical, a wetting agent, a dispersing agent, a disintegration agent to obtain a substantially homogenized mixture B; blending the substantially homogenized mixture A and the substantially homogenized mixture B to obtain a substantially homogenized mixture C followed by grinding to obtain substantially homogenized powder, having a particle size in the range of 3 μπι to 10 μπι. The predetermined quantities of the substantially homogenized powder, water, and defoamer can be blended, followed by kneading to obtain dough; and extruding the dough to obtain wet extruded granules. The so obtained wet extruded granules are dried under controlled drying conditions followed by sieving to obtain dried extruded granules having granule size in the range of 0.5 mm to 2 mm.

DETAILED DESCRIPTION

It is observed that Azoxystrobin, Cymoxanil and Metalaxyl-M show good fungicidal activity. However, they are prone to resistance owing to their single mode of action. The present disclosure, therefore, envisages a synergistic fungicidal composition that has enhanced fungicidal activity and is not prone to resistance towards fungi.

It is a chance finding by the applicant that a synergistic fungicidal composition comprising a specific combination of Metalaxyl-M, Cymoxanil, and Azoxystrobin as the active ingredient has a synergistic fungicidal activity. A synergistic fungicidal product needs a right combination to prevent resistance development by fungi. The fungicidal composition of the present disclosure is successful in achieving an enhanced fungicidal activity and prevents resistance development in fungi. The fungicidal composition of the present disclosure shows a surprising fungicidal activity that exceeds the sum of the activities of the individual components when used alone.

In one aspect of the present disclosure, the synergistic fungicidal composition comprises the active ingredient which comprises a combination of Metalaxyl-M, Cymoxanil and Azoxystrobin having weight ratio in the range of 1 : 1 :0.5 to 1 :3:30, and a least one excipient selected from the group consisting of dispersing agents, defoamers, wetting agents, disintegrating agents, anti-caking agents, carriers, and binders.

The dispersing agent is used for uniformly dispersing the ingredients of the fungicidal composition, especially the active ingredient, throughout the dosage form. In an embodiment, the dispersing agent can be at least one selected from the group consisting of sodium lignosulfonate, calcium lignosulfonate, sodium salt of alkyl naphthalene sulfonate, sulfonated aromatic polymer sodium salt, polycarboxylic acid homopolymer, sodium salt of polycarboxylic acid homopolymer, polycarboxylic acid copolymer, Ethylene oxide/Propylene oxide (EO/PO) block copolymers and sodium salt of polycarboxylic acid copolymer. Typically, the alkyl group can be a C₁-C2₀ alkyl group and the aromatic group in the sulfonated aromatic polymer is a Q to C2₀ aromatic group. The defoamer can be used to prevent foaming of the formulation. In an embodiment, the defoamer can be at least one selected from the group consisting of polydimethylsiloxane powder and polydimethylsiloxane liquid.

The wetting agent is used to wet the ingredients of the formulation with water by lowering their surface tension. In an embodiment, the wetting agent used in the composition of the present disclosure can be at least one selected from the group consisting of non-ionic surfactant, anionic surfactant, and combinations thereof. Non-limiting examples of the non- ionic surfactant can be alcohol alkoxylates having moles of ethylene oxide in the range of 9 to 15. Non-limiting examples of the anionic surfactant are alkyl naphthalene sulfonate, dialkyl naphthalene sulfonates, alkyl naphthalene sulfonate condensate, and sodium lauryl sulphate and sodium dodecyl benzene sulfonate. Other wetting agents that may be used are at least one selected from the group consisting of alkyl ethylene oxide condensates, aryl ethylene oxide condensates, alkyl propylene oxide condensates, aryl propylene oxide condensates, alkylethoxylates, and arylethoxylates. Typically, the alkyl group and aryl group in the wetting agent is a C₁-C20 alkyl group.

Disintegrating agents are compounds which help a substance to disintegrate in water quickly. In an embodiment, the disintegrating agent used in the composition of the present disclosure can be at least one selected from the group consisting of sodium chloride, sodium sulphate, ammonium sulphate, sodium carbonate, sodium bicarbonate, starch and starch derivatives, sodium tripolyphosphate, cross linked sodium carboxymethyl cellulose, cross linked polyvinyl pyrrolidone. The anti-caking agent is used to prevent cake formation in the fungicidal composition during storage. In an embodiment, the anti-caking agent can be at least one selected from the group consisting of clays, precipitated silica, and metal stearates. In another embodiment, the metal stearate can be selected from the group consisting of zinc stearate, calcium stearate, magnesium stearate, and aluminium stearate. The carrier is included to act as a diluent or a bulking agent in the formulation. The carrier can be selected from the group consisting of clay, minerals, and talc.

The binder is used to bind the ingredients in the composition together to give it the desired strength. In an embodiment, the binder can be at least one selected from the group consisting of polyvinyl alcohol, polyvinyl-pyrrolidone, polyacrylamides, dextrose, sucrose, and lactose. The fungicidal composition of the present disclosure can be in the form selected from the group consisting of water dispersible granules, wettable powder, and suspension concentrate

In another aspect of the present disclosure, there is provided a method for the preparation of the fungicidal composition. The method is given in detail below:

Predetermined quantities of an anti-caking agent, a carrier, and Metalaxyl-M technical is taken and blended together using a blender to obtain a substantially homogenized mixture A. In an embodiment, Metalaxyl-M can be warmed to a temperature in the range of 35 °C to 80 °C and sprayed over anti-caking agent, a carrier and blended to obtain a substantially homogenized mixture A. Predetermined quantities of Azoxystrobin technical, Cymoxanil technical, a wetting agent, a dispersing agent, a disintegrating agent and a binder are taken and blended together using a blender to obtain a substantially homogenized mixture B.

The substantially homogenized mixture A and the substantially homogenized mixture B are blended together in a blender to obtain a substantially homogenized mixture C. The substantially homogenized mixture C is then pounded into a fine particle size to obtain a substantially homogenized powder. In a specific embodiment, the particle size of the substantially homogenized powder can be in the range of 3 μπι to 10 μπι. In an embodiment, the substantially homogenized mixture C is pounded using an air jet mill. Predetermined quantities of the substantially homogenized powder, water, and defoamer are added to a dough maker and kneaded to obtain dough. The dough is then processed in an extruder to obtain wet extruded granules. The wet extruded granules are dried under controlled drying conditions to obtain dried extruded granules.

In an embodiment, the dried extruded granules can be, further, sieved to obtain dried extruded granules having granule size in the range of 0.5 mm to 2 mm.

In an alternative method according to the present disclosure, Azoxystrobin technical and Cymoxanil technical can be pounded/ground first to obtain a powder using an air jet mill followed by blending the powder with Metalaxyl-M technical along with water, dispersing agents, wetting agents, binders, defoamers, disintegrating agents and carriers to obtain slurry having total solids in the range of 40 % to 65%. The so obtained slurry can undergo spray drying in spray dryer or fluid bed spray dryer to obtain dried granules. The dried granules are sieved through a sieve to obtain granules having granule size in the range of 100 μπι to 850 μπι.

In another alternative method of the present disclosure, Azoxystrobin technical and Cymoxanil technical are blended with water and a wetting agent in a homogenizer to obtain a substantially homogenized mixture D. The substantially homogenized mixture D is pounded to a fine particle size mixture D. In an exemplary embodiment, the pounding is carried out using a wet mill. In an embodiment, the particle size of the fine particle size mixture D can be in the range of 2 μπι to 5 μπι. The fine particle size mixture D can further blended with Metalaxyl-M technical along with water, a dispersing agent, a binder, an anti-caking agent, a disintegrating agent, a defoamer, and a carrier to obtain slurry having total solids in the range of 40 % to 65 %. This is then followed by spray drying the slurry using a spray dryer or in a Fluid bed spray dryer to obtain dried granules. The dried granules are sieved through a sieve to obtain granules of granule size in the range of 100 μηι to 850 μηι.

In another alternative method according to the present disclosure, Azoxystrobin technical, Cymoxanil technical, Metalaxyl technical are blended with an anticaking agent and a carrier to obtain a substantially homogenized mixture E. The substantially homogenized mixture E is pounded in an air jet mill to obtain a premix powder, having a particle size in the range of 3 μπι to 10 μπι. In another vessel, predetermined quantities of water, a dispersing agent, a binder, a wetting agent, a disintegrating agent, and a defoamer are taken and mixed to obtain a substantially homogenized mixture F. The substantially homogenized mixture F is sprayed over the substantially homogenized mixture E in a fluidized bed processor under controlled temperature conditions in the range of 30 °C to 50 °C to obtain a substantially homogenized mixture G. The substantially homogenized mixture G is further dried under controlled temperature conditions to obtain dried granules having granule size in the range of 100 μπι to 1000 μπι.

Other possible variations of the methods of the present disclosure are also envisaged.

The present disclosure, thus, provides a stable and ready-to-use synergistic fungicidal composition comprising Metalaxyl-M, Cymoxanil and Azoxystrobin and a method for preparing the same. The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial scale.

EXPERIMENTAL DETAILS

A: Synergistic Fungicidal composition and process for preparation thereof EXAMPLE 1

35 gms of Silica and 153 gms of Kaolin clay were charged into a Sigma blender, and blended for 10 minutes. 110 gms of Metalaxyl-M technical was warmed to a temperature in the range of 35 °C to 80 °C to obtain melted Metalaxyl-M technical which was added in the blender and resultant mixture was blended for 2 hours to obtain Mixture A.

215 gms of Azoxystrobin technical, 211 gms of Cymoxanil technical, 40 gms of Sodium Alkyl naphthalene sulphonate, 100 gms of Polycarboxylate, 19 gms of sodium lignosulphonate, 5 gms of lactose, 110 gms of sodium sulphate were charged into a Ribbon blender and blended for 2 hours to obtain Mixture B.

Mixture A was charged into Mixture B in a Ribbon blender and further blended for 2 hours to obtain Mixture C.

Mixture C was ground in the jet Mill to obtain a wettable powder, having a particle size in the range of 3 to 10 micron.

The wettable powder was charged into a dough maker by adding 2 gms of silicone and 40 gms of water and blended to obtain a dough.

The dough was extruded using a basket extruder to obtain granules having granule size in the range of 0.8 mm to 1.2 mm, which was further dried in fluid bed dryer at 40 °C to obtain a product of the final composition.

EXAMPLE 2

80 gms of Silica and 153 gms of kaolin clay were charged into a Sigma blender, and blended for 10 minutes. 110 gms of melted Metalaxyl-M technical were charged into the blender and the resultant mixture was blended for 2 hours to obtain Mixture A. 215 gms of Azoxystrobin technical, 225 gms of Cymoxanil technical, 40 gms of Sodium Alkyl naphthalene sulphonate, 60 gms of Sodium alkyl naphthalene condensate, 40 gms of sodium lignosulphonate,75 gms of sodium Carbonate were charged into a ribbon blender and blended for 2 hours to obtain Mixture B.

Mixture C was ground in the Jet Mill to obtain a wettable powder, having particle size in the range of 3 to 10 microns. The wettable powder was charged into a dough maker; 2 gm of silicone and 40 gms of water was charged and blended to obtain a dough.

The so obtained dough was extruded using a basket extruder to obtain granules having granule size in the range of 0.8 mm to 1.2 mm, which was further dried in fluid bed dryer at 40 °C to obtain a product of final composition.

EXAMPLE 3

80 gms of Silica and 153 gms of kaolin clay were charged into a Sigma blender, and blended for 10 minutes. 110 gms of melted Metalaxyl-M warmed to a temperature in the range of 35 °C to 80 °C Metalaxyl-M technical was charged into the blender and the resultant mixture was blended for 2 hours to obtain Mixture A.

232 gms of Azoxystrobin technical, 211 gms of Cymoxanil technical, 40 gms of Sodium Alkyl naphthalene sulphonate, 100 gms of Polycarboxylate, 24 gms of sodium lignosulphonate, 48 gms of sodium sulphate was charged into a ribbon blender and blended for 2 hours to obtain Mixture B. Mixture A was charged into Mixture B in a Ribbon blender and further blended for 2 hours to obtain Mixture C.

Mixture C was ground in the jet Mill to obtain a wettable powder, having particle size in the range of 3 to 10 micron.

The wettable powder was charged into a dough maker, along with 2 gm of silicone (as antifoaming agent) and 40 gms of water and blended to obtain a dough. The dough was extruded using basket extruder to obtain granules having granule size in the range of 0.8 mm to 1.2 mm, which was further dried in a fluid bed dryer at 40 degree to obtain a product of the final composition.

EXAMPLE 4 40 gms of Silica and 153 gms of kaolin clay were charged into a Sigma blender and blender for 10 minutes. 100 gms of melted Metalaxyl-M warmed to a temperature in the range of 35 °C to 80 °C Metalaxyl-M technical was charged into the blender and the resultant mixture was blended for 2 hours to obtain Mixture A. 232 gms of Azoxystrobin technical, 211 gms of Cymoxanil technical, 25 gms of Sodium Alkyl naphthalene sulphonate, 50 gms of Polycarboxylate, 21 gms of sodium lignosulphonate, 166 gms of sodium sulphate were charged into a ribbon blender and blended for 2 hours to obtain Mixture B. Mixture A was charged into Mixture B in a Ribbon blender and further blended for 2 hours to obtain Mixture C. Mixture C was ground in the Jet Mill to obtain a wettable powder, having particle size in the range of 3 to 10 micron.

The wettable powder was charged into a dough maker, along with 2 gm of silicone (as an antifoaming agent) and 40 gms of water and blended to obtain a dough. The dough was extruded using the basket extruder to obtain granules having granule size in the range of 0.8 mm to 1.2 mm, which was further dried in fluid bed dryer at 40 degree to obtain the product of final composition.

EXAMPLE 5

40 gms of Silica and 250 gms of Kaolin clay were charged into a Sigma blender, and blended for 10 minutes. 13 gms of Metalaxyl-M technical was warmed to a temperature in the range of 35 °C to 80 °C to obtain melted Metalaxyl-M technical which was added in the blender and resultant mixture was blended for 2 hours to obtain Mixture A.

321 gms of Azoxystrobin technical, 33 gms of Cymoxanil technical, 25 gms of Sodium Alkyl naphthalene sulphonate, 50 gms of Polycarboxylate, 21 gms of sodium lignosulphonate, 10 gms of lactose, 235 gms of sodium sulphate were charged into a Ribbon blender and blended for 2 hours to obtain Mixture B.

The wettable powder was charged into a dough maker by adding 2 gms of silicone and 40 gms of water and blended to obtain a dough. The dough was extruded using a basket extruder to obtain granules having granule size in the range of 0.8 mm to 1.2 mm, which was further dried in fluid bed dryer at 40 °C to obtain a product of the final composition

Table 1 illustrates the storage stability of the synergistic fungicidal composition by optimizing with active ingredients and excipients in accordance with the present disclosure.

TABLE 1

AHS-accelerated storage studies

WST- wet sieve test

From table 1 it is observed that Examples 1-5 are stable and there is no appreciable drop suspensibility parameter even after accelerated storage study. B: Bio-Efficacy Study and Phytotoxicitv study of the synergistic fungicidal composition Bio-efficacy:

The synergistic fungicidal formulation prepared in accordance with the Example 1 to 5 of the present disclosure were tested at given concentrations with two way possible tank mix combinations ie. Cymoxanil 50% WP + Azoxystrobin 25% SC (Tank Mix), Metalaxyl M 25% WP + Azoxystrobin 25% SC (Tank Mix) & Cymoxanil 50% WP + Metalaxyl M 25% WP (Tank Mix) along with solo individual fungicides ie. Azoxystrobin 25% SC, Cymoxanil 50% WP & Metalxyl M 25% WP and Untreated Control against Early and Late blight of Potato. The fungicides were applied as a foliar spray with Knapsack Sprayer fitted with solid cone nozzle. Application was initiated with initiation of disease in the field. The sprayings were done at 10 days interval.

The appearance of the visible symptom of the diseases was recorded before 1^st spray and subsequent observations were recorded after 10 days of each spray. For recording the observations the leaves of ten plants from each plot were graded on (0-9) disease scoring scale for Late blight and early blight as provided in Table 2.

Table 2: Disease Ratings

Percent disease index (PDI) was calculated using the following formula:

Sum of all numerical ratings

PDI = X 100

Total plants observed X Maximum rating scale The PDI values were transformed by angular transformation and analyzed statistically. The disease control DC (%) was calculated by the following formula.

Disease % in control - Disease % in treatment

DC (%) = X 100

Disease % in control

Yield:

Individual plot wise yield was recorded and treatment wise yield was calculated and converted into yield per hectare (q/ha) at harvest and statistically analyzed the data. Phytotoxicity:

Observations were taken on damage caused to plants, if any, by the application of different treatments taking into the account phytotoxic symptoms viz. leaf injury on tips and leaf surface, wilting, vein clearing, necrosis, epinasty and hyponasty on ten plants per plot. The observations were recorded before spray and 1, 3, 5, 7, 10 & 15^th day after applications. For Phytotoxicity study on leaf injury on tips and leaf surface the Scale (0-10) used is given below in Table 3.

Table 3: Phytotoxicity Rating Scale (PRS)

Statistical Analysis: Analysis of variance was calculated by using OPSTAT Computer Software Program.

Table 4: Bio-efficacy of different Fungicides treatments against Late Blight of Potato (Rabi 2016-17)

WP + (0.00) (9.59) (15.32) (21 .67)

Azoxystrobin 25%

SC (Tank mix)

Cymoxanil 50%

WP + Metalaxyl- 1200+40

Τπ 600+1 00 81 .1 9 M 25% WP (Tank 0 0.00 1 .86 4.08 1 0.38

mix) (0.00) (6.37) (1 1 .56) (18.77)

0.00 10.75 25.1 9 55.19

Tl2 Untreated

(0.00) (19.07) (30.12) (47.99)

CD (P = 0.05) NS 3.36 3.24 4.04 -

PDl- Percent Disease Incidence

PDC- Percent Disease Control

DAA- Days after Application

NS- Non significant

g a.i./ha- g of active ingredient per hector

The results summarized in table 4 exhibits that at the time of initiation of the trial there was no Late blight disease in any plant, which indicates the uniformity of trial plot across all the treatments. 10 days after first application, highest infection of Late blight was recorded in control T12 (10.75%). It is observed that all the fungicide treatments were capable of significantly reducing the disease severity as compared to the untreated control. Lowest infection of Late blight disease was observed in Tl to T3 (0.00%), which was at par with T4 (0.38%). These treatments (Tl to T4) are significantly superior over rest of the treatments. 10 days after the second application, highest infection of the disease was recorded in control (25.19%). Lowest infection of Late blight disease was observed in Tl (1.12%) which was at par with treatments T2 (1.49%), T3 (1.86%) and T4 (1.86%). These treatments (Tl to T4) are significantly superior over rest of the treatments.

10 days after the third application, similar trend was observed as in case of the second application. Lowest infection of Late blight disease was observed in Tl (2.97%) which was at par with T2 (3.71%), T3 (4.08%) and T4 (4.45%). The highest infection of the disease was observed in untreated control (55.19%). These treatments (Tl to T4) were significantly superior over rest of the treatments.

The highest percent disease control (PDC) was recorded in treatment Tl (94.62%), followed by T2 (93.28%), T3 (92.61 %) and T4 (91.94%). The lowest disease control was recorded in treatment T8 (55.03%), followed by T7 (67.78%) and T6 (69.80%). Table 5: Bio-efficacy of different Fungicide treatments against Early Blight of Potato (Rabi 2016-17)

PDI- Percent Disease Incidence

PDC- Percent Disease Control

5 DAA- Days after Application

NS- Non significant

g a.i./ha- g of active ingredient per hector

The results depicted in Table 5 shows that at the time of initiation of trial the early blight was 10 initiated but there was no significant difference between the treatments which indicates the uniform spread of disease. 10 days after the first application, the highest infection of the disease was recorded in control (5.19%). The lowest infection of the disease was observed in Tl (0.00%) and T5 (0.00%), which were at par with T2 (0.38%), T3 (0.75%), and T4 (0.75%). These treatments (Tl to T5) were significantly superior over rest of the treatments.

10 days after second application, no sign of the disease was observed in treatments Tl to T5. The highest infection of the disease was recorded in control (13.71%). The lowest infection of the disease was observed in Tl (0.00%) and T5 (0.00%), which were at par with T2 (0.38%), T3 (0.75%), and T4 (0.75%). These treatments (Tl to T5) were significantly superior over rest of the treatments.

10 days after third application, similar trend was observed. The lowest infection of the disease was observed in treatment T5 (0.00%), which was at par with Tl & T2 (0.38%) followed by T4 (0.75%) and T3 (1.12%). The highest infection of the disease was observed in untreated control (17.41%). The treatments (Tl to T5) were superior over rest of the treatments.

The highest percent disease control (PDC) was recorded in treatment T5 (100%) followed by Tl & T2 (97.82%), T4 (95.69%), T3 (93.57%). The lowest disease control was recorded in treatment T7 (27.63%) followed by T6 & Ti l (31.88%), T10 (48.94) and T9 (55.31%).

Table 6: Effect of different Fungicide treatments on Yield of Potato (Rabi 2016- 17)

Tio Metalaxyl-M 25% WP + Azoxystrobin 25% SC 100+125 400+500 21 1 .00 (Tank mix)

Tii Cymoxanil 50% WP + Metalaxyl-M 25% WP 600+100 1200+400 213.67 (Tank mix)

T_l2 Untreated - - 178.67

CD (P = 0.05) 12.66

From Table 6, it is illustrated that all the treatments significantly increase the yield as compared to that of the Untreated Control (178.67 q/ha). The highest yield was observed in treatment Tl (246 q/ha), which was significantly superior over the rest of the treatment and at par with T2 (240.33 q/ha), T3 (238 q/ha) and T4 (230 q/ha) and followed by T5 (226.67 q/ha). The lowest yield was recorded in Untreated Control (178.67 q/ha).

Table 7: Phyto-toxicity effect of different Fungicide treatments on Potato (Rabi 2016-17)

22% + Metalaxyl-M 10% WG

(Example No. 2)

Azoxystrobin 22% + Cymoxanil

τ₈ 20% + Metalaxyl-M 10% WG

220+200+100 1000 0 0 0 0 0 0 0 (Example No. 3)

Azoxystrobin 22% + Cymoxanil

22% + Metalaxyl-M 9% WG

T₉ 220+220+90 1000 0 0 0 0 0 0 0 (Example No. 4)

Azoxystrobin 30% + Cymoxanil

3% + Metalaxyl-M 1% WG

Tio 300+30+1 0 1000 0 0 0 0 0 0 0 (Example No. 5)

T„ Untreated - - 0 0 0 0 0 0 0

For phototoxic symptoms- Leaf injury on tips and Leaf surface, Wilting, Vein Clearing, Necrosis, Epinasty and Hyponas

g a.i./ha- g of active ingredient per hector

Various fungicide combinations were sprayed at doses X (500 g/ha) and 2X (1000 g/ha) and the phytotoxic effects like leaf injury on tips/surface, vein clearing, wilting, necrosis, hyponasty and epinasty on the Potato crop were tabulated in Table 7. The observations on these phytotoxicity parameters were observed before spray and at 3, 5, 7, 10, and 15 days after application. There was no phytotoxicity observed on Potato crop after spraying with the treatments. There was no adverse effect noticed on Potato crop in the field applied with fungicides combinations at the highest dose of @ 1000 g/ha.

Therefore, the synergistic fungicidal composition of the present disclosure (Azoxystrobin, Cymoxanil, and Metalaxyl M) effectively controls Early and Late blight of Potato. Among them Azoxystrobin 20% + Cymoxanil 20% + Metalaxyl-M 10% WG is highly effective. Efficacy of the synergistic fungicides of the present disclsoure are far superior than the commercially availablefungicides (Azoxystrobin 25% SC, Cymoxanil 50% WP and Metalaxyl M 25% WP) and their two way possible tank mix combinations. The synergistic fungicidal composition produces higher yield of Potato. No phytotoxicity effect on Potato was observed by using the synergistic fungicidal compositionof the present disclsoure.

Therefore, the fungicidal composition of the present disclosure exhibits synergistic effect for controlling the disease. Also, the fungicial composition is effective over prolonged usage and combats resistance by fungi, thereby limiting crop losses as compared to solo use of Azoxystrobin 25% SC, Cymoxanil 50% WP and Metalaxyl M 25% WP and their two way possible tank mix combinations.

TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE

The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a fungicidal composition that:

- has enhanced fungicidal activity; and

- combats resistance shown by fungi.

The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Claims

CLAIMS:

1. A synergistic fungicidal composition comprising:

a. Metalaxyl-M;

b. Cymoxanil;

c. Azoxystrobin; and

d. at least one excipient.

2. The synergistic fungicidal composition as claimed in claim 1, wherein, the weight ratio of Metalaxyl-M, Cymoxanil, and Azoxystrobin is in the range of 1 : 1 :0.5 to 1 :3:30.

3. The synergistic fungicidal composition as claimed in claim 1, wherein said excipient is selected from the group consisting of dispersing agent, defoamer, wetting agent, disintegrating agent, anti-caking agent, carrier, and binder.

4. The synergistic fungicidal composition as claimed in claim 3, wherein said dispersing agent is at least one selected from the group consisting of sodium lignosulfonate, calcium lignosulfonate, sodium salt of alkyl naphthalene sulfonate, sulfonated aromatic polymer sodium salt, polycarboxylic acid homopolymer, sodium salt of polycarboxylic acid homopolymer, polycarboxylic acid copolymer, Ethylene oxide/Propylene oxide (EO/PO) block copolymers and sodium salt of polycarboxylic acid copolymer.

5. The synergistic fungicidal composition as claimed in claim 3, wherein said defoamer is at least one selected from the group consisting of polydimethylsiloxane powder and polydimethylsiloxane liquid.

6. The synergistic fungicidal composition as claimed in claim 3, wherein said wetting agent is at least one selected from the group consisting of non-ionic surfactant, anionic surfactant, and combinations thereof.

7. The synergistic fungicidal composition as claimed in claim 3, wherein said disintegrating agent is at least one selected from the group consisting of sodium chloride, sodium sulphate, ammonium sulphate, sodium carbonate, sodium bicarbonate, starch and starch derivatives, sodium tripolyphosphate, cross linked sodium carboxymethyl cellulose, cross linked polyvinyl pyrrolidone.

8. The synergistic fungicidal composition as claimed in claim 3, wherein said anti- caking agent is at least one selected from the group consisting of clays, precipitated silica and metal stearates selected from the group consisting of zinc stearate, calcium stearate, magnesium stearate and aluminium stearate.

9. The synergistic fungicidal composition as claimed in claim 3, wherein said carrier is selected from the group consisting of clay, minerals, and talc.

10. The synergistic fungicidal composition as claimed in claim 3, wherein said binder is at least one selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamides, dextrose, sucrose, and lactose.

11. The synergistic fungicidal composition as claimed in claim 1, wherein said fungicidal composition is in at least one dosage form selected from the group consisting of water dispersible granules, wettable powder, and suspension concentrate.