FUNGICIDAL COMPOSITIONS

Abstract

Abstract: A fungicidal composition comprising a mixture of components (A) and (B), wherein components (A) and (B) are as defined in claim 1, and use of the compositions in agriculture or horticulture for controlling or preventing infestation of plants by phytopathogenic microorganisms, preferably fungi.

Claims

1. A fungicidal composition comprising a mixture of components (A) and (B) as active ingredients, wherein component (A) comprises a cyclic depsipeptide of formula (I-A1) or a stereoisomer thereof: ##STR00011## component (B) is selected from the group consisting of MAP / histidine kinase inhibitors: quinoxyfen, proquinazid, fluoroimid, iprodione, chlozolinate, dimethachlone, procymidone, vinclozolin or fludioxonil.

2. The composition according to claim 1, wherein the weight ratio of (A) to (B) is from 100:1 to 1:1000, preferably from 100:1 to 1:200, more preferably from 50:1 to 1:100, and even more preferably from 20:1 to 1:40.

3. The composition according to claim 1, wherein component (A) further comprises one or more other cyclic depsipeptides of formula (I-A) or stereoisomers thereof: ##STR00012## wherein R.sup.1 is methyl or ethyl; each of X.sup.1, X.sup.2 and X.sup.3 is hydrogen, or X.sup.1, X.sup.2 and X.sup.3 are hydrogen, fluorine or hydroxyl, with the proviso that only one of X.sup.1, X.sup.2 and X.sup.3 is fluorine or hydroxyl; X.sup.4 is CH, S or hydroxymethylene; A.sup.3 is an α-amino acid residue selected from the group consisting of N-methyl-L-phenylalanine (L-MePhe), L-phenylalanine (L-Phe), β-hydroxy-N-methyl-L-phenylalanine (L-β-OH-MePhe), ortho-fluoro-N-methyl-L-phenylalanine (L-o-F-MePhe), meta-fluoro-N-methyl-L-phenylalanine (L-m-F-MePhe), para-fluoro-N-methyl-L-phenylalanine (L-p-F-MePhe), meta-bromo-N-methyl-L-phenylalanine (L-m-Br-MePhe), para-bromo-N-methyl-L-phenylalanine (L-p-Br-MePhe), meta-iodo-N-methyl-L-phenylalanine (L-m-I-MePhe), para-iodo-N-methyl-L-phenylalanine (L-p-I-MePhe), 3-phenyl-N-methyl-L-phenylalanine, 4-phenyl-N-methyl-L-phenylalanine, 3-(4-fluorophenyl)-N-methyl-L-phenylalanine, 4-(4-fluorophenyl)-N-methyl-L-phenylalanine, 3-(4-pyridinyl)-N-methyl-L-phenylalanine, 4-(4-pyridinyl)-N-methyl-L-phenylalanine, 3-(1-pyridinyl)-N-methyl-L-phenylalanine, 4-(1-pyridinyl)-N-methyl-L-phenylalanine, 4-(2-chloro-4-pyridinyl)-N-methyl-L-phenylalanine, 3-(2-chloro-5-pyridinyl)-N-methyl-L-phenylalanine, 4-(2-chloro-5-pyridinyl)-N-methyl-L-phenylalanine, 3-[4-(piperazin-1-yl)phenyl]phenyl-N-methyl-L-phenylalanine, 4-[4-(piperazin-1-yl)phen-1-yl]phenyl-N-methyl-L-phenylalanine,3-[4-(4-methylpiperazin-1-yl)phenyl]phenyl-N-methyl-L-phenylalanine, 4-[4-(4-methylpiperazin-1-yl)phen-1-yl]phenyl-N-methyl-L-phenylalanine, β-oxo-N-methyl-L-phenylalanine (L-β-oxo-MePhe), β-acetoxy-N-methyl-L-phenylalanine (L-β-AcO-MePhe), N-methyl-L-tyrosine (L-MeTyr), O-methyl-N-methyl-L-tyrosine [L-MeTyr(Me)], N-methyl-L-alanine (L-MeAla), N-methyl-L-serine (L-MeSer), N-methyl-D-phenylalanine (D-MePhe), N-methyl-D-alanine (D-MeAla), N-methyl-D-valine (D-MeVal), N-methyl-D-serine (D-MeSer) and N-methyl-L-serine (L-MeSer) residues; A.sup.5 is an α-amino acid residue selected from the group consisting of L-allo-isoleucine (L-Alle), L-leucine (L-Leu), L-norleucine (L-Nle), L-norvaline (L-Nva) and L-valine (L-Val) residues; A.sup.6 is an α-amino acid residue selected from the group consisting of N-methyl-L-valine (L-MeVal), N-methyl-L-leucine (L-MeLeu), N-methyl-L-allo-isoleucine (L-MeAlle) and L-valine (L-Val) residues; A.sup.7 is an α-amino acid residue selected from the group consisting of L-leucine (L-Leu), L-allo-isoleucine (L-Alle) and L-norvaline (L-Nva) residues; and A.sup.8 is an α-amino acid residue selected from the group consisting of β-hydroxy-N-methyl-L-valine (L-β-OH-MeVal), γ-hydroxy-N-methyl-L-valine (L-γ-OH-MeVal), N-methyl-L-valine (L-MeVal), L-valine (L-Val), N-methyl-2,3-didehydro-L-valine (L-MeDH.sub.2,3Val), N-methyl-3,4-didehydro-L-valine (L-MeDH.sub.3,4Val), N-methyl-L-phenylalanine (L-MePhe), β-hydroxy-N-methyl-L-phenylalanine (L-β-OH-MePhe), N-methyl-L-threonine (L-MeThr), sarcosine (Sar) and N,β-dimethyl-L-aspartic acid (L-N,β-MeAsp) residues.

4. The composition according to claim 1, wherein component (A) further comprises at least one other cyclic depsipeptide of formula (I-A) or a stereoisomer thereof selected from the group consisting of Aureobasidin E and Aureobasidin G.

5. The composition according to claim 1, wherein component (A) comprises: from 10% to 99.9% by weight, preferably from 20% to 99.9% by weight, more preferably from 40% to 99.9% by weight of a cyclic depsipeptide of formula (I-A1) or a stereoisomer thereof, and from 0.1% to 90% by weight, preferably from 0.1% to 80% by weight, more preferably from 0.1% to 60% by weight of one or more other cyclic depsipeptides of formula (I-A) or stereoisomers thereof.

6. The composition according to claim 1, wherein component (A) further comprises one or more cyclic depsipeptides of formula (I-B) or stereoisomers thereof: ##STR00013## wherein R.sup.1 is methyl or ethyl; X.sup.4 is CH, S or hydroxymethylene; A.sup.5 is an α-amino acid residue selected from the group consisting of L-allo-isoleucine (L-Alle), L-leucine (L-Leu), L-norleucine (L-Nle) and L-valine (L-Val) residues; A.sup.6 is an α-amino acid residue selected from the group consisting of N-methyl-L-valine (L-MeVal), N-methyl-L-leucine (L-MeLeu), L-allo-isoleucine (L-AlIe) and N-methyl-L-allo-isoleucine (L-MeAlIe) residues; A.sup.7 is an α-amino acid residue selected from the group consisting of L-leucine (L-Leu), L-allo-isoleucine (L-AlIe) and L-norvaline (L-Nva) residues; and A.sup.8 is an α-amino acid residue selected from the group consisting of β-hydroxy-N-methyl-L-valine (L-β—OH—MeVal), γ-hydroxy-N-methyl-L-valine (L-γ—OH—MeVal), N-methyl-L-valine (L-MeVal), N-methyl-2,3-didehydro-L-valine (L-MeDH.sub.2,3Val), N-methyl-3,4-didehydro-L-valine (L-MeDH.sub.3,4Val), N-methyl-L-phenylalanine (L-MePhe), β-hydroxy-N-methyl-L-phenylalanine (L-β—OH—MePhe), N-methyl-L-threonine (L-MeThr), sarcosine (Sar) and N,β-dimethyl-L-aspartic acid (L-N,β—MeAsp) residues.

7. The composition according to claim 1, wherein component (B) is a compound selected from the group consisting of proquinazid, iprodione and fludioxonil.

8. The composition according to claim 1, further comprising an agriculturally acceptable carrier and/or formulation adjuvant, and optionally, a surfactant.

9. A method of controlling or preventing phytopathogenic diseases, especially phytopathogenic fungi, on useful plants or on propagation material thereof, which comprises applying to the useful plants, the locus thereof or propagation material thereof a composition as defined in claim 1.

10. The method according to claim 9, wherein the component (A) is applied at a rate of from 10 g a.i./ha to 500 g a.i./ha in association with 50 g a.i./ha to 1000 g a.i./ha of component (B).

11. The method according to claim 9, wherein the phytophathogenic fungi are selected from the group consisting of Alternaria, Botrytis, Cercospora, Colletotrichum, Corynespora, Guignardia, Mycosphaerella, Monilinia, Penicillium, Phakopsora, Phomopsis, Podosphaera, Pseudopezicula, Septoria, Uncinula and Venturia.

12. The method according to claim 1, wherein the useful plant is selected from grains, fruits and tree nuts, vegetables, field crops, oil seed crops, forage crops, forest plants, horticulture crops, floriculture, greenhouse and nursery plants, propagative materials, culinary herbs and spices, and medicinal herbs.

13. The method according to claim 1, wherein the useful plant is selected from the group consisting of wheat, barley, rice, soybean, apples, almonds, cherries, raspberries, grapes, cucumbers, peanuts, tomatoes, strawberries, citrus and bananas.

14. Use of a composition comprising component (A) and component (B) as defined in claim 1 as a fungicide.

Description

BIOLOGICAL EXAMPLES

[0225] The compositions according to the invention are tested for their biological (fungicidal) activity using application rates wherein the component (A) is applied at a rate of from 10 g a.i./ha to 500 g a.i./ha in association with 50 g a.i./ha to 1000 g a.i./ha of component (B).

[0226] The compositions according to the invention are tested for their biological (fungicidal) activity as dimethylsulfoxide (DMSO) solutions using one or more of the following protocols (Examples 1-1 and 1-2). A standard description of the liquid culture tests is provided in Example 1.

[0227] Aureobasidin A and its synthesis are known from Takesako et al., The Journal of Antibiotics, 1991, 44, 919-924. Aureobasidin A is separated from the fermentation broth by extraction with ethyl acetate, followed by extraction of the ethyl acetate concentrate with a mixture of MeOH:H.sub.2O (80% by volume) and cyclohexane (20% by volume), and purified by silica gel column chromatography (silica-gel, elution with hexane:ethyl acetate) followed by reverse phase column chromatography (RP18, elution with acetonitrile:H.sub.2O). As already indicated, components (B) of the compositions are known and are commercially available and/or can be prepared using procedures known in the art and/or procedures reported in the literature.

Example 1: Liquid Culture Tests in Well Plates

[0228] Mycelia fragments or conidia suspensions of a fungus, prepared either freshly from liquid cultures of the fungus or from cryogenic storage, are directly mixed into nutrient broth. DMSO solutions of the test compound (max. 10 mg/mL) is diluted with 0.025% Tween20 by factor 50 and 10 .Math.L of this solution is pipetted into a microtiter plate (96-well format). The nutrient broth containing the fungal spores/mycelia fragments is then added to give an end concentration of the tested compound. The test plates are incubated in the dark at 24° C. and 96% relative humidity (rh). The inhibition of fungal growth is determined photometrically and visually after 3 - 7 days, depending on the pathosystem, and percent antifungal activity relative to the untreated check is calculated.

Example 1-1: Botrytis Cinerea (Gray Mould)

[0229] Conidia of the fungus from cryogenic storage were directly mixed into nutrient broth (PDB potato dextrose broth). After placing a DMSO solution of the test compositions into a microtiter plate (96-well format), the nutrient broth containing the fungal spores was added. The test plates were incubated at 24° C. and the inhibition of growth was determined photometrically after 72 hours.

Example 1-2: Alternaria Solani (Early Blight of Tomato/Potato)

[0230] Conidia of the fungus from cryogenic storage were directly mixed into nutrient broth (PDB potato dextrose broth). After placing a DMSO solution of the test compositions into a microtiter plate (96-well format) the nutrient broth containing the fungal spores was added. The test plates were incubated at 24° C. and the inhibition of growth was determined photometrically after 48 hours.

Results

[0231] Results from the tests outlined above are shown below in Tables 1 to 3. These data show that synergistic fungicidal activity is observed for the combination of Aureobasidin A and another active ingredient of component (B) against Botrytis cinerea and Alternaria solani at certain weight ratios. According to COLBY, in mathematical terms the synergism factor SF corresponds to O/E. In the agricultural practice an SF of ≥ 1.1 indicates significant improvement over the purely complementary addition of activities (expected activity), while an SF of ≤ 0.9 in the practical application routine signals a loss of activity compared to the expected activity.

TABLE-US-00003 Fungicidal activity of a composition of Aureobasidin A and iprodione against Botrytis cinerea as described in Example 1-1 above Aureobasidin A (A) (ppm) Iprodione (B) (ppm) Ratio compound (A):(B) (A) inhibition (%) (B) inhibition (%) Expected (additive) activity (Colby) (%) Combined inhibition (observed) (%) 0.01 18 0.02 60 0.125 4 0.250 0 0.01 0.125 1 : 12.5 21 56 0.01 0.250 1 : 25 18 41 0.02 0.250 1 : 12.5 60 69

TABLE-US-00004 Fungicidal activity of a composition of Aureobasidin A and iprodione against Alternaria solani as described in Example 1-2 above Aureobasidin A (A) (ppm) Imazalil (B) (ppm) Ratio compound (A):(B) (A) inhibition (%) (B) inhibition (%) Expected (additive) activity (Colby) (%) Combined inhibition (observed) (%) 0.005 11 0.5 35 0.005 0.5 1 : 100 42 47

TABLE-US-00005 Fungicidal activity of a composition of Aureobasidin A and fludioxonil against Botrytis cinerea as described in Example 1-1 above Aureobasidin A (A) (ppm) Fludioxonil (B) (ppm) Ratio compound (A):(B) (A) inhibition (%) (B) inhibition (%) Expected (additive) activity (Colby) (%) Combined inhibition (observed) (%) 0.01 22 0.0063 0 0.01 0.0063 1.5 : 1 22 45