FUNGICIDAL COMPOSITIONS COMPRISING A CARBOXAMIDE

Abstract

A method of controlling phytopathogenic diseases on useful plants or on propagation material thereof, which comprises applying to the useful plants, the locus thereof or propagation material thereof a combination of components (A) and (B) in a synergistically effective amount, wherein component (A) is a compound of formula I compound of formula I

##STR00001## wherein R is hydrogen or methoxy; Q is

##STR00002## R.sub.1 is hydrogen, halogen or C.sub.1-C.sub.6alkyl; R.sub.2 is hydrogen, halogen, C.sub.1-C.sub.6alkyl, C.sub.2-C.sub.6alkenyl, C.sub.3-C.sub.6alkinyl, C.sub.3-C.sub.6cycloalkyl-C.sub.3-C.sub.6alkinyl, halophenoxy, halophenyl-C.sub.3-C.sub.6alkinyl, C(C.sub.1-C.sub.4alkyl)=NO-C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.6haloalkyl, C.sub.1-C.sub.6haloalkoxy, C.sub.2-C.sub.6haloalkenyl, or C.sub.2-C.sub.6haloalkenyloxy; R.sub.3 is hydrogen, halogen, C.sub.1-C.sub.6alkyl; R.sub.4, R.sub.5 and R.sub.6, independently from each other, are hydrogen, halogen or --R.sub.7; with the proviso that at least one of R.sub.4, R.sub.5 and R.sub.6 is different from hydrogen; R.sub.7 is hydrogen, C.sub.1-C.sub.6alkyl, C.sub.1-C.sub.6haloalkyl or C.sub.1-C.sub.4alkoxyalkyl; and R.sub.8 is hydrogen or methoxy; and agrochemically acceptable salts/isomers/structural isomers/stereoisomers/diastereoisomers/enantiomers/tautomers and N-oxides of those compounds; and component (B) is a compound selected from compounds known for their fungicidal and/or insecticidal activity, is particularly effective in controlling or preventing fungal diseases of useful plants.

Claims

1. A fungicidal composition, comprising: (A) 3-(difluoromethyl)-N-methoxy-1-methyl-N-[1-methyl-2-(2,4,6-trichlorophenyl)ethyl]-1H-pyrazole-4-carboxamide and (B) fludioxonil, wherein the weight ratio of (A) to (B) is 1:4 to 4:1.

2. The fungicidal composition of claim 1, wherein the weight ratio of (A) to (B) is 1:4 to 4:1.

3. A method of controlling 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) 3-(difluoromethyl)-N-methoxy-1-methyl-N-[1-methyl-2-(2,4,6-trichlorophenyl) ethyl]-1H-pyrazole-4-carboxamide and (B) fludioxonil, wherein the weight ratio of (A) to (B) is 1:4 to 4:1.

Description

BIOLOGICAL EXAMPLES

[0363] A synergistic effect exists whenever the action of an active ingredient combination is greater than the sum of the actions of the individual components.

[0364] The action to be expected E for a given active ingredient combination obeys the so-called COLBY formula and can be calculated as follows (COLBY, S. R. Calculating synergistic and antagonistic responses of herbicide combination. Weeds, Vol. 15, pages 20-22; 1967):

[0365] ppm=milligrams of active ingredient (=a.i.) per liter of spray mixture

[0366] X=% action by active ingredient (A) using p ppm of active ingredient

[0367] Y=% action by active ingredient (B) using q ppm of active ingredient.

[0368] According to COLBY, the expected (additive) action of active ingredients (A)+(B) using p+q ppm of active ingredient is

[00002]$E=X+Y-\frac{X.Math.Y}{100}$

[0369] If the action actually observed (O) is greater than the expected action (E), then the action of the combination is super-additive, i.e. there is a synergistic effect. In mathematical terms the synergism factor SF corresponds to O/E. In the agricultural practice an SF of 1.2 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.

Liquid Culture Tests in Well Plates

[0370] Mycelia fragments or conidia suspensions of a fungus, prepared either freshly from liquid cultures of the fungus or from cryogenic storage, were directly mixed into nutrient broth. DMSO solutions of the test compound (max. 10 mg/ml) was diluted with 0.025% Tween20 by factor 50 and 10 l of this solution was pipetted into a microtiter plate (96-well format). The nutrient broth containing the fungal spores/mycelia fragments was then added to give an end concentration of the tested compound. The test plates were incubated in the dark at 24 C. and 96% rh. The inhibition of fungal growth was determined visually after 2-7 days, depending on the pathosystem, and percent antifungal activity relative to the untreated check was calculated.

Example B1: Fungicidal Action Against Botryotinia fuckeliana (Botrytis cinerea)/Liquid Culture (Gray Mould)

[0371] Conidia of the fungus from cryogenic storage were directly mixed into nutrient broth (Vogels broth). After placing a (DMSO) solution of the test compounds 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 visually 3-4 days after application.

Example B2: Fungicidal Action Against Pythium ultimum/Liquid Culture (Seedling Damping Off)

[0372] Mycelia fragments and oospores of a newly grown liquid culture of the fungus were directly mixed into nutrient broth (PDB potato dextrose broth). After placing a (DMSO) solution of the test compounds into a microtiter plate (96-well format), the nutrient broth containing the fungal mycelia/spore mixture was added. The test plates were incubated at 24 C. and the inhibition of growth was determined visually 2-3 days after application.

Example B3: Fungicidal Action Against Sclerotinia sclerotiorum/Liquid Culture (Cottony Rot)

[0373] Mycelia fragments of a newly grown liquid culture of the fungus were directly mixed into nutrient broth (PDB potato dextrose broth). After placing a (DMSO) solution of the test compounds into a microtiter plate (96-well format) the nutrient broth containing the fungal material was added. The test plates were incubated at 24 C. and the inhibition of growth was determined visually 3-4 days after application.

Example B4: Fungicidal Action Against Mycosphaerella arachidis (Cercospora arachidicola)/Liquid Culture (Early Leaf Spot)

[0374] 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 compounds 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 visually 4-5 days after application.

Example B5: Fungicidal Action Against Tapesia yallundae W-Type

(Pseudocercosporella herpotrichoides)/Liquid Culture (Eyespot)

[0375] 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 compounds 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 visually 3-4 days after application.

Example B6: Fungicidal Action Against Mycosphaerella graminicola (Septoria tritici)/Liquid Culture (Septoria Blotch)

[0376] 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 compounds 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 visually 4-5 days after application.

Example B7: Fungicidal Action Against Fusarium culmorum/Liquid Culture (Head Blight)

[0377] 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 compounds 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 visually 3-4 days after application.

Example B8 Fungicidal Action Against Thanatephorus cucumeris (Rhizoctonia solani)/Liquid Culture (Foot Rot. Damping-Off)

[0378] Mycelia fragments of a newly grown liquid culture of the fungus were directly mixed into nutrient broth (PDB potato dextrose broth). After placing a (DMSO) solution of the test compounds into a microtiter plate (96-well format), the nutrient broth containing the fungal material was added. The test plates were incubated at 24 C. and the inhibition of growth was determined visually 3-4 days after application.

Leaf Disk or Leaf Segment Tests in Well Plates

[0379] Leaf disks or leaf segments of various plant species were cut from plants grown in the greenhouse. The cut leaf disks or segments were placed in multiwell plates (24-well format) onto water agar. The leaf disks were sprayed with a test solution before (preventative) or after (curative) inoculation. Compounds to be tested were prepared as DMSO solutions (max. 10 mg/ml) which were diluted to the appropriate concentration with 0.025% Tween20 just before spraying. The inoculated leaf disks or segments were incubated under defined conditions (temperature, relative humidity, light, etc.) according to the respective test system. A single evaluation of disease level was carried out 3-9 days days after inoculation, depending on the pathosystem. Percent disease control relative to the untreated check leaf disks or segments was then calculated.

Example B9 Fungicidal Action Against Plasmopara viticola/Grape/Leaf Disc Preventative (Late Blight)

[0380] Grape vine leaf disks were placed on water agar in multiwell plates (24-well format) and sprayed with the formulated test compound diluted in water. The leaf disks were inoculated with a spore suspension of the fungus 1 day after application. The inoculated leaf disks were incubated at 19 C. and 80% rh under a light regime of 12 h light/12 h darkness in a climate cabinet and the activity of a compound was assessed as percent disease control compared to untreated when an appropriate level of disease damage appears in untreated check leaf disks (6-8 days after application).