Fungicidal composition

Abstract

A fungicidal composition is provided, the composition comprising: Component (A): prothioconazole; and Component (B): chlorothalonil. There is also provided a method for the control and/or prevention of fungal infestations in a plant, the method comprising applying to the plant, plant parts or the locus thereof: Component (A): prothioconazole; and Component (B): chlorothalonil. The combination of prothioconazole and chlorothalonil exhibits synergy and also exhibits a reduction in phytotoxicity.

Claims

1. A method for the control of fungal infestations in a plant comprising applying a composition to a plant, plant parts or the locus thereof, wherein the composition comprises: Component (A): prothioconazole; and Component (B): chlorothalonil, wherein the weight ratio of component (A) prothioconazole and component (B) chlorothalonil is 1:14.1.

2. The method according to claim 1, wherein the application rate of the total amount of component (A) prothioconazole and component (B) chlorothalonil is in the range of from 10 to 3000 grams of active ingredients per hectare (g/ha).

3. The method according to claim 1, wherein the application rate of prothioconazole is in the range of from 10 to 300 g/ha.

4. The method according to claim 1, wherein the application rate of chlorothalonil is in the range of from 100 to 2500 g/ha.

5. A method of reducing the phytotoxicity of chlorothalonil, comprising combining chlorothalonil with prothioconazole and applying the chlorothalonil and prothioconazole to a plant, plant parts or the locus thereof, wherein the weight ratio of prothioconazole and chlorothalonil is 1:14.1.

Description

DETAILED DESCRIPTION

(1) The aspects of the present invention are further described, for illustration purposes only, by way of the following working examples.

(2) Unless stated otherwise, percentages are weight percent.

Formulation Examples

(3) The following formulation examples illustrate the compositions of the present invention.

(4) The compositions of Examples 1 to 14 and the Control are summarized in Table 1 below. The compositions summarized in Table 1 were prepared as follows.

Water-dispersible Granule (WG)

(5) Water-dispersible granule (WG) formulations were prepared by intimately mixing finely ground components (A) and (B) in the amounts indicated in Table 1 with auxiliaries, grinding through superfine mill and then granulating by paste extrusion to obtain water-dispersible granules. The auxiliaries included 2% w/w of MORWET® EFW powder (sodium alkylnaphthalene sulfonate and anionic surfactant), 5% w/w of MORWET® D-425 powder (sodium alkylnaphthalenesulfonate-formaldehyde condensate), 1% w/w of AGNIQUE® L soap (fatty acids, tallow, sodium salts) and mannitol (balance to 100%).

(6) For use, the water-dispersible granules were diluted with water to the desired concentration of active ingredients.

Aqueous Suspension Concentrate (SC)

(7) Aqueous suspension concentrate (SC) formulations were prepared by mixing finely ground prothioconazole and chlorothalonil with auxiliaries, which included 8% w/w of propylene glycol, 0.5% w/w of SAG 1529 (modified polydimethylsiloxane), 3% w/w of MORWET® D-425 powder (sodium alkylnaphthalenesulfonate-formaldehyde condensate), 2% w/w of ATLAS™ G-5000 (polyalkylene glycol ether), 0.2% of AG-RHO POL 23/W (xanthan gum), 0.1% w/w of NIPACIDE BIT 20 (1,2-Benzisothiazol-3-one) and water (balance to 100%).

(8) In Table 1 below, the formulations of Examples 1 to 8 are embodiments of the present invention. The remaining formulations are presented for comparison purposes only.

(9) TABLE-US-00001 TABLE 1 Active Active ingredient ingredient Application rate (A) (B) (g/ha) Example Formulation prothioconazole chlorothalonil Ratio (A) (B) No. type (%) (%) (A):(B) prothioconazole chlorothalonil 1 WG 1 50 1:50 50 2500 2 SC 1 30 1:30 50 1500 3 SC 2 40 1:20 72 1440 4 WG 2 28.2   1:14.1 47 663 5 SC 3 30 1:10 108 1080 6 SC 4 20   1:14.1 94 1326 7 WG 30 3 10:1  400 40 8 SC 20 20 1:1  400 400 9 SC 36 0 / 72 0 10 SC 47 0 / 47 0 11 WG 47 0 / 94 0 12 WG 0 40 / 0 1440 13 SC 0 28.2 / 0 663 14 WG 0 28.2 / 0 1326 Control SC 0 / 0 0

Biological Examples

(10) The following biological examples were conducted using the formulations summarized in Table 1 above.

(11) A combination of two or more active compounds has synergistic effect when the efficacy of the combination of two or more active compounds is greater than the sum of the efficacy of each active compound when applied individually.

(12) The expected activity for a given combination of two active compounds can be calculated by the “Colby equation” (S. R. Colby, Weeds 15, 20-22, 1967), as follows:
E=A+B−(A×B/100)
where:
A=the percent efficacy of compound A when compound A is employed at a dose of m (gram per hectare, i.e. g/ha);
B=the percent efficacy of compound B when compound B is employed at a dose of n (g/ha);
E=the percent estimated efficacy when compounds A and B are employed together at a dose of m (g/ha) and n (g/ha), respectively.

Example 1

Phytoxicity

(13) The following tests were conducted to investigate the phytotoxicity to target plants of the compositions summarized in Table 1 above.

(14) Grape, apple, miniature rose and Pittosporum plants were planted in beds of good agricultural peat based growth medium and grown in separate greenhouses. After the plants had emerged and grown to a height of about 4 inches, separate beds of the plants were sprayed with one of the compositions of Examples 1 to 14 and the Control at the application rates (g ai/ha) indicated in Table 1. After treatment, the beds were maintained for about 1 week under greenhouse conditions conducive for good plant growth.

(15) Visual ratings of phytotoxicity were made after 1 week. Phytotoxicity was ranked 0 to 5, where 5 indicates severe phytotoxicity (leaves and stems showed severe yellowing, burning, or necrosis) and 0 indicated no phytotoxicity.

(16) The results are set forth below in Table 2.

(17) TABLE-US-00002 TABLE 2 Phytotoxicity Ranking (1-5) Example No. Grape Apple miniature rose Pittosporum 1 5 4.5 4 4 2 4 3.5 3 3.5 3 1 1 0.5 1.5 4 0.5 0.5 0 0.5 5 3 3.5 3 2.5 6 0.5 0.5 0 1 7 3.5 4 3.5 3.5 8 4.5 3.5 4.5 4.5 9 2 2 2 2 10 1.5 1.5 1.5 2 11 2 2 2.5 3 12 4 5 4.5 5 13 3 4.5 3 4 14 4 3.5 4.5 4.5 Control 0 0 0 0

(18) The results set out in Table 2 above show that combining chlorothalonil with prothioconazole significantly reduces the phytotoxicity of chlorothalonil to the treated plants. Similarly, the phytotoxic effects exhibited by prothioconazole when used alone are reduced when chlorothalonil is present. The reduction in phytotoxicity is particularly marked at a weight ratio of prothioconazole to chlorothalonil of from 1:10 to 1:20, in particular, the compositions of Examples 3, 4 and 6.

Example 2

Fungicidal Activity on Grape-Downy Mildew (Plasmopara Viticola)

(19) Soybean plants were sprayed with a conidial suspension of plasmopara viticola and incubated at conditions of 20° C. and 100% relative atmospheric humidity for 48 hours. The plants were then sprayed with compositions prepared according to Examples 3, 4, 6, 9, 10, 11, 12, 13, 14 and Control formulation as set out in Table 1 above.

(20) Thereafter, the treated plants were held in a greenhouse at conditions of 15° C. and 80% relative atmospheric humidity for 10 days, after which the severity of the fungal infestation was assessed. The efficacy of the composition in treating the fungal infestation was then determined.

(21) The results of the efficacy of the fungicidal compositions are set out in Table 3 below.

(22) TABLE-US-00003 TABLE 3 Application rate (g/ha) Example Ratio (A) (B) Expected No. (A):(B) prothioconazole chlorothalonil Efficacy efficacy 3 1:20   72 1440 90 56 4 1:14.1 47 663 95 28 6 1:14.1 94 1326 98 47.5 9 / 72 0 20 / 10 / 47 0 10 / 11 / 94 0 25 / 12 / 0 1440 45 / 13 / 0 663 20 / 14 / 0 1326 30 / Control / 0 0 0 /

(23) The results set out in Table 3 above show that the combination of prothioconazole and chlorothalonil exhibits a significantly improved effect in the treatment of plants infested with grape-downy mildew, compared with the activity of prothioconazole and chlorothalonil applied individually, and a significantly greater effect than that expected from the performance of the two active compounds when used alone. This indicates that the combination of prothioconazole and chlorothalonil exhibits a significant synergy in the control of grape-downy mildew.

Example 3

Fungicidal Activity on Rose Powdery Mildew (Sphaerotheca Pannosa Var. Rosae)

(24) Miniature rose plants were sprayed with a conidial suspension of Sphaerotheca pannosa var. rosae and incubated at conditions of 20° C. and 100% relative atmospheric humidity for 48 hours. The plants were then sprayed with compositions of the formulations in Examples 3, 4, 6, 9, 10, 11, 12, 13, 14 and the Control set out in Table 1 above.

(25) Thereafter, the treated plants were held in a greenhouse at conditions of 15° C. and 80% relative atmospheric humidity for 10 days, after which the severity of the fungal infestation was assessed. The results of the efficacy of the fungicidal compositions of the different formulations are set out in the Table 4 below.

(26) TABLE-US-00004 TABLE 4 Application rate (g/ha) Example Ratio (A) (B) Expected No. (A):(B) prothioconazole chlorothalonil Efficacy efficacy 3 1:20   72 1440 92 65 4 1:14.1 47 663 94 40.5 6 1:14.1 94 1326 98 64 9 / 72 0 30 / 10 / 47 0 15 / 11 / 94 0 40 / 12 / 0 1440 50 / 13 / 0 663 30 / 14 / 0 1326 40 / Control / 0 0 0 /

(27) The results set out in Table 4 above show that the combination of prothioconazole and chlorothalonil exhibits a significantly improved effect in the treatment of plants infested with rose powdery mildew, compared with the activity of prothioconazole and chlorothalonil applied individually, and a significantly greater effect than that expected from the performance of the two active compounds when used alone. This indicates that the combination of prothioconazole and chlorothalonil exhibits a significant synergy in the control of rose powdery mildew.

Example 4

Fungicidal Activity on Apple Scab (Venturia inaequalis)

(28) Apple (Pink Lady) plants were sprayed with a conidial suspension of Venturia inaequalis and incubated at conditions of 20° C. and 100% relative atmospheric humidity for 48 hours. The plants were then sprayed with compositions of the formulations in Examples 3, 4, 6, 9, 10, 11, 12, 13, 14 and the Control set out in Table 1.

(29) Thereafter, the treated plants were held in a greenhouse at conditions of 15° C. and 80% relative atmospheric humidity for 10 days, after which the severity of the fungal infestation was assessed. The results of the efficacy of the fungicidal compositions of the different formulations are set out in the Table 5 below.

(30) TABLE-US-00005 TABLE 5 Application rate (g/ha) Example Ratio (A) (B) Expected No. (A):(B) prothioconazole chlorothalonil Efficacy efficacy 3 1:20   72 1440 95 68 4 1:14.1 47 663 92 37 6 1:14.1 94 1326 95 62.5 9 / 72 0 20 / 10 / 47 0 10 / 11 / 94 0 25 / 12 / 0 1440 60 / 13 / 0 663 30 / 14 / 0 1326 50 / Control / 0 0 0 /

(31) The results set out in Table 5 above show that the combination of prothioconazole and chlorothalonil exhibits a significantly improved effect in the treatment of plants infested with apple scab, compared with the activity of prothioconazole and chlorothalonil applied individually, and a significantly greater effect than that expected from the performance of the two active compounds when used alone. This indicates that the combination of prothioconazole and chlorothalonil exhibits a significant synergy in the control of apple scab.

Example 5

Fungicidal Activity on Alternaria Leafspot—(Alternaria tenuissima)

(32) Pittosporum plants were sprayed with a conidial suspension of Alternaria tenuissima and incubated at conditions of 20° C. and 100% relative atmospheric humidity for 48 hours. The plants were then sprayed with compositions of the formulations in Examples 3, 4, 6, 9, 10, 11, 12, 13, 14 and the Control set out in Table 1.

(33) Thereafter, the treated plants were held in a greenhouse at conditions of 15° C. and 80% relative atmospheric humidity for 10 days, after which the severity of the fungal infestation was assessed. The results of the efficacy of the fungicidal compositions of the different formulations are set out in the Table 6 below.

(34) TABLE-US-00006 TABLE 6 Application rate (g/ha) Example Ratio (A) (B) Expected No. (A):(B) prothioconazole chlorothalonil Efficacy efficacy 3 1:20   72 1440 92 66 4 1:14.1 47 663 95 46 6 1:14.1 94 1326 98 64 9 / 72 0 15 / 10 / 47 0 10 / 11 / 94 0 20 / 12 / 0 1440 60 / 13 / 0 663 40 / 14 / 0 1326 55 / Control / 0 0 0 /

(35) The results set out in Table 6 above show that the combination of prothioconazole and chlorothalonil exhibits a significantly improved effect in the treatment of plants infested with alternaria leafspot, compared with the activity of prothioconazole and chlorothalonil applied individually, and a significantly greater effect than that expected from the performance of the two active compounds when used alone. This indicates that the combination of prothioconazole and chlorothalonil exhibits a significant synergy in the control of alternaria leafspot.