CN1794914A - Fungicidal mixtures for controlling rice pathogens - Google Patents

Abstract

The invention relates to fungicide compound for rice pathogen, which contains nitrile azoxystrobin of formula (I) and compound of formula (II) as active component. The invention also relates to a mixture of compounds of formula (I) and (II) as fungicide for parasitic fungi, the purpose of the compounds of formula (I) and (II), and reagent containing the mixture.

Description

Fungicidal mixtures for the control of rice pathogens

The present invention relates to a fungicidal mixture for controlling rice pathogens, comprising as active ingredients a synergistically effective amount of the following ingredients:

1) azoxystrobin of formula I:

and

2) Formula II compound:

Furthermore, the present invention relates to a method for controlling rice pathogens using mixtures of compounds I and II and the use of compounds I and II for the preparation of such mixtures and compositions comprising these mixtures.

The compounds of formula I, their preparation and their action against harmful fungi are known (common name: azoxystrobin; EP-A 382375).

Compound II, namely 5-chloro-7-(4-methylpiperidin-1-yl)-6-(2,4,6-trifluorophenyl)-[1,2,4]triazolo[1 , 5-a] pyrimidines, their preparation and their action against harmful fungi are likewise known from the literature (WO 98/46607).

Mixtures of triazolopyrimidines and azoxystrobin are described in a general manner in EP-A 988 790. Compound II is included in the general disclosure of this document, but not explicitly mentioned. Therefore, the combination of compound II with azoxystrobin is novel.

The synergistic mixtures known from EP-A 988 790 are described as having fungicidal activity against various diseases of cereals, fruits and vegetables, especially mildew of wheat and barley or gray mold of apples.

Due to the special cultivation conditions of rice plants, the requirements that must be fulfilled by fungicides for rice differ significantly from those that must be met by fungicides used in the growth of cereals or fruits. Significant differences exist in modern rice cultivation systems: In addition to the usual spray application in many countries, the fungicides are in this case applied directly on the soil during or immediately after sowing. The fungicide is taken up into the plant via the roots and transported in the plant's sap to the part of the plant that needs protection. A high systemic action is therefore necessary for rice fungicides. In contrast, in cereal or fruit growth, fungicides are usually applied to the foliage or fruit; therefore, the systemic action of the active compound is apparently less important in these crops.

Furthermore, rice pathogens are generally distinct from those found in cereals or fruits. Pyricularia oryzae and Corticium solani (synonym Rhizoctoniasasakii) are the most prevalent disease pathogens in rice plants. Rhizoctonia sasakii is the only pathogen of agricultural importance from the subclass Agaricomycetidae. In contrast to most other fungi, this fungus attacks plants not via spores, but via mycelial infection.

For this reason, findings concerning fungicidal activity in cereal or fruit cultivation cannot be applied to rice crops.

It was an object of the present invention to provide mixtures which have an improved effect on harmful fungi at reduced total application rates of active compounds, from the point of view of more effective control of rice pathogens at the lowest possible application rates.

We have found that this object is achieved by the mixtures defined at the outset. We have also found that simultaneous, ie combined or separate application of compound I and compound II, or sequential application of compound I and compound II, provides better control of rice pathogens than would be possible with the individual compounds.

When preparing mixtures, preference is given to using the pure active compounds I and II, to which further active compounds against harmful fungi or other pests, such as insects, arachnids or nematodes, or herbicidal or growth-regulating active compounds or fertilizers can be added as required.

Further suitable active compounds in the above sense are in particular active compounds selected from the group consisting of:

Acylalanines such as benalaxyl, metalaxyl, ofurace or oxadixyl,

Amine derivatives, such as aldimorph, dodine, dodemorph, fenpropimorph, fenpropidin, guazatine, iminoctadine ), spiroxamine or tridemorph,

Anilinopyrimidines such as pyrimethanil, mepanipyrim or cyrodinyl,

Antibiotics such as cycloheximide, griseofulvin, kasugamycin, natamycin, polyoxin or streptomycin,

Azoles, such as bitertanol, bromoconazole, cyproconazole, difenoconazole, dinitroconazole, epoxiconazole, nitrile Fenbuconazole, fluquinconazole, flusilazole, flutriafol, hexaconazole, imazalil, ipcanazole, metconazole, myclobutanil, penconazole, propiconazole, prochloraz, prothioconazole, simeconazole, tebuconazole, fluteconazole (tetraconazole), triadimefon, triadimenol, triflumizole, or triticonazole,

Dicarboximides such as iprodione, myclozolin, procymidone or vinclozolin,

Dithiocarbamates, such as ferbam, nabam, maneb, mancozeb, metam, metiram ), propineb, polycarbamate, thiram, ziram or zineb,

Heterocyclic compounds, such as anilazine, benomyl, boscalid, carbendazim, carboxin, oxycarboxin, Cyazofamid, dazomet, dithianon, famoxadone, fenamidone, fenarimol, fuberidazole, Flutolanil, furametpyr, isoprothiolane, mepronil, nuarimol, picobenzamide, probenazole, proquinazid, pyridine Pyrifenox, pyroquilon, quinoxyfen, silthiofam, thiabendazole, thifluzamide, thiophanate-methyl (thiophanate- methyl), tiadinil, tricyclazole, or triforine,

Copper fungicides, such as Bordeaux mixture (Bordeaux mixture), copper acetate, copper king or basic copper sulfate,

Nitrophenyl derivatives such as binapacryl, dinocap, dinobuton or nitrophthal-isopropyl,

Phenylpyrroles such as fenpiclonil or fludioxonil,

·sulfur,

Other fungicides such as acibenzolar-S-methyl, benthiavalicarb, carpropamid, chlorothalonil, cyflufenamid, cymoxanil , dazomet, diclomezine, diclocymet, diethofencarb, edifenphos, ethaboxam, fenhexamid ), fentin acetate, fenoxanil, ferimzone, fluazinam, fosetyl, fosetyl-aluminum, Isoprophyllum iprovalicarb, hexachlorobenzene, metrafenone, pencycuron, propamocarb, phthalide, tolclofos-methyl, pentachloronitrate quintozene or zoxamide,

strobilurins, such as fluoxastrobin, kresoxim-methyl, metominostrobin, orysastrobin, picoxystrobin, pyraclostrobin ) or trifloxystrobin (trifloxystrobin),

sulfenic acid derivatives such as captafol, captan, dichlofluanid, folpet or tolylfluanid,

• Cinnamamides and similar compounds such as dimethomorph, flumetover or flumorph.

In one embodiment of the mixtures according to the invention, the compounds I and II are admixed with a further fungicide III or with two fungicides III and IV.

Suitable components III and IV are especially the azoles mentioned.

Preference is given to mixtures of compounds I and II with component III. Particular preference is given to mixtures of compounds I and II.

The mixture of compounds I and II or at the same time, i.e. compound I and compound II used in combination or alone have significant activity against rice pathogens selected from Ascomycetes, Deuteromycetes and Basidiomycetes active. They have a high systemic action and can therefore be used for the treatment of seeds and as foliar and soil-acting fungicides.

They are especially important for controlling harmful fungi on rice plants and their seeds, such as the genera Bipolaris and Drechslera and Pyricularia oryzae. They are particularly suitable for controlling rice sheath blight caused by Corticium solani (synonym Rhizoctoniasasakii).

Furthermore, the combination according to the invention of compounds I and II is also suitable for controlling other pathogens, such as Septoria and Puccinia in cereals and Alternaria in vegetables, fruit and vines (Alternaria) and Botrytis (BotrytiS).

The compound I and the compound II can be applied simultaneously, ie jointly or individually, or in succession, and in the case of individual application, the result of the control measures generally does not have any influence on the sequence of application.

In general, compound I and compound II are administered in a weight ratio of 100:1 to 1:100, preferably 20:1 to 1:50, especially 5:1 to 1:20.

If desired, components III and IV are added to compound I in a ratio of 20:1 to 1:20.

Depending on the compound and the desired effect, the application rates of the mixtures according to the invention are from 5 to 2000 g/ha, preferably from 50 to 1500 g/ha, especially from 50 to 750 g/ha.

Correspondingly, the application rates of the compounds I are generally 1-1000 g/ha, preferably 10-750 g/ha, especially 20-500 g/ha.

Correspondingly, the application rates of the compounds II are generally 1-1000 g/ha, preferably 10-750 g/ha, especially 20-500 g/ha.

In seed treatment, the application rate of the mixture is generally 1-1000 g/100 kg seed, preferably 1-200 g/100 kg, especially 5-100 g/100 kg.

In the control of pathogenic harmful fungi of rice plants, the single or combined application of compounds I and II or the application of a mixture of compounds I and II is carried out by treating seeds, seedlings, Spray or dust the plants or soil. The compounds are preferably applied jointly or individually by application of granules or by dusting the soil.

The mixtures or compounds I and II according to the invention can be converted into customary formulations, for example solutions, emulsions, suspensions, dusts, powders, pastes and granules. The application form depends on the particular purpose; in each case it should ensure a fine and uniform distribution of the compound according to the invention.

The formulations are prepared in a known manner, for example by mixing the active compounds with solvents and/or carriers, if necessary using emulsifiers and dispersants. Suitable solvents/auxiliaries are mainly:

- Water, aromatic solvents (such as Solvesso products, xylene), paraffins (such as mineral oil fractions), alcohols (such as methanol, butanol, pentanol, benzyl alcohol), ketones (such as cyclohexanone, gamma-butanol lactones), pyrrolidones (NMP, NOP), acetates (ethylene glycol diacetate), diols, fatty acid dimethylamides, fatty acids and fatty acid esters. In principle it is also possible to use solvent mixtures.

- Carriers such as ground natural minerals (such as kaolin, clay, talc, chalk) and ground synthetic minerals (such as highly dispersed silica, silicates); emulsifiers such as nonionic and anionic emulsifiers (such as polyoxyethylene fatty alcohol ethers, alkyl sulfonates and aryl sulfonates) and dispersants such as lignosulfite waste liquor and methyl cellulose.

Suitable surfactants are the alkali metal, alkaline earth metal and ammonium salts of lignosulfonic acid, naphthalenesulfonic acid, phenolsulfonic acid, dibutylnaphthalenesulfonic acid, alkylarylsulfonates, alkyl sulfates, Alkyl sulfonates, fatty alcohol sulfates, glycol ethers of fatty acids and sulfated fatty alcohols, also condensates of sulfonated naphthalene with formaldehyde and condensates of naphthalene derivatives with formaldehyde, naphthalene or naphthalenesulfonic acid with phenol and Condensate of formaldehyde, polyoxyethylene octylphenol ether, ethoxylated isooctylphenol, octylphenol, nonylphenol, alkylphenol polyglycol ether, tributylphenyl polyglycol ether, Tristearylphenyl polyglycol ether, alkylaryl polyether alcohol, alcohol and fatty alcohol/ethylene oxide condensate, ethoxylated castor oil, polyoxyethylene alkyl ether, ethoxylated polyoxypropylene , lauryl polyglycol ether acetal, sorbitol esters, lignosulfite waste liquor and methylcellulose.

Substances suitable for the preparation of sprayable solutions, emulsions, pastes or oil dispersions are medium to high boiling mineral oil fractions such as kerosene or diesel oil, but also coal tars and oils of vegetable or animal origin, aliphatic, cyclic and aromatic Hydrocarbons such as toluene, xylene, paraffin, tetralin, alkylated naphthalene or its derivatives, methanol, ethanol, propanol, butanol, cyclohexanol, cyclohexanone, isophorone, strong polar solvents such as Dimethylsulfoxide, N-methylpyrrolidone and water.

Powders, materials for spreading and dustable products can be prepared by mixing or grinding together the active substances and solid carriers.

Granules (eg coated granules, impregnated granules and homogeneous granules) can be prepared by binding the active compounds to solid carriers. Examples of solid carriers are mineral earths such as silica gel, silicates, talc, kaolin, attaclay, limestone, lime, chalk, red basalt, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, Magnesium oxide, ground synthetic minerals, fertilizers such as ammonium sulphate, ammonium phosphate, ammonium nitrate, urea, products of vegetable origin such as grain, bark, wood and nut shell meal, cellulose powder and other solid carriers.

The formulations generally contain 0.01-95% by weight, preferably 0.1-90% by weight, of active compound. The active compounds are used in a purity (according to NMR spectrum) of 90% to 100%, preferably 95% to 100%.

The following are examples of formulations:

1. Products diluted with water

A) Water Soluble Concentrate (SL)

10 parts by weight of the active compound are dissolved in water or a water-soluble solvent. Alternatively, wetting agents or other auxiliaries are added. The active compound dissolves upon dilution with water.

B) Dispersible Concentrate (DC)

20 parts by weight of active compound are dissolved in cyclohexanone and a dispersant such as polyvinylpyrrolidone is added. Dilution with water gives a dispersion.

C) Emulsifiable concentrate (EC)

15 parts by weight of active compound are dissolved in xylene and calcium dodecylbenzenesulfonate and castor oil ethoxylate (5% strength in each case) are added. Dilute with water to give an emulsion.

D) Emulsion (EW, EO)

40 parts by weight of the active compound are dissolved in xylene and calcium dodecylbenzenesulfonate and castor oil ethoxylate (5% strength in each case) are added. The mixture was introduced into water by means of an emulsifier (Ultraturax) and made into a homogeneous emulsion. Dilute with water to give an emulsion.

E) Suspension (SC, OD)

In a stirred ball mill, 20 parts by weight of the active compound are comminuted and a dispersant, wetting agent and water or an organic solvent are added to give a finely divided active compound suspension. Dilution with water gives a stable active compound suspension.

F) Water Dispersible Granules and Water Soluble Granules (WG, SG)

50 parts by weight of the active compound are ground finely and dispersants and wetting agents are added to form water-dispersible or water-soluble granules by means of industrial equipment (eg extruders, spray towers, fluidized beds). Dilution with water gives a stable dispersion or solution of the active compound.

G) Water dispersible powder and water soluble powder (WP, SP)

75 parts by weight of active compound are ground in a rotor-stator mill with addition of dispersants, wetting agents and silica gel. Dilution with water gives a stable dispersion or solution of the active compound.

2. Products to be applied undiluted

H) Dustable Powder (DP)

5 parts by weight of active compound are ground finely and mixed intimately with 95% finely divided kaolin. This gives a dustable product.

I) Granules (GR, FG, GG, MG)

0.5 part by weight of the active compound is ground finely and combined with 95.5% carrier. Current methods are extrusion, spray drying or fluidized bed methods. This gives granules which are applied undiluted.

J) ULV solution (UL)

10 parts by weight of the active compound are dissolved in an organic solvent such as xylene. This gives the product to be applied undiluted.

The active compounds can be used directly, in the form of their formulations or in the use forms prepared therefrom (e.g. directly sprayable solutions, powders, suspensions or dispersions, emulsions, oil dispersions, pastes, dustable products, spreading materials or granules form), by spraying, misting, dusting, spreading or watering. The use forms depend entirely on the intended purpose; they are intended to ensure the best possible distribution of the active compounds according to the invention in each case.

Aqueous use forms can be prepared from emulsion concentrates, pastes or wettable powders (sprayable powders, oil dispersions) by adding water. To prepare emulsions, pastes or oil dispersions, the substances are homogenized in water as such or dissolved in an oil or solvent with the aid of wetting agents, tackifiers, dispersants or emulsifiers. Alternatively, concentrates consisting of active substance, wetter, tackifier, dispersant or emulsifier and, if appropriate, solvent or oil can be prepared and are suitable for dilution with water.

The active compound concentrations in the ready-to-use preparations can be varied within relatively wide ranges. Usually 0.0001-10%, preferably 0.01-1%.

The active compounds can also be used successfully in the ultra-low volume process (ULV), it being possible to apply formulations comprising more than 95% by weight of active compound, or even to apply the active compound without additives.

Oils of various types, wetting agents, adjuvants, herbicides, fungicides, other pesticides or bactericides can be added to the active compounds, if appropriate, just before use (tank mix). These agents can generally be mixed with the agents of the present invention in a weight ratio of 1:10 to 10:1.

Compounds I and II or mixtures or corresponding formulations by treating harmful fungi or plants, seeds, soils, areas, materials or spaces in which their control is to be controlled, with a fungicidally effective amount of the mixture, or in the case of individual application, compounds I and II And apply. Application can take place before or after infestation by the harmful fungi.

The fungicidal action of compounds and mixtures can be confirmed by the following tests:

The active compounds were prepared individually or in combination as stock solutions in acetone or DMSO containing 0.25% by weight of active compound. 1% by weight of the emulsifier ^Uniperol® EL (wetting agent with emulsifying and dispersing action based on ethoxylated alkylphenols) is added to the solution and the solution is diluted with water to the desired concentration.

Application example - activity against rice sheath blight caused by Corticium solani (synonym Rhizoctonia sasakii)

Potted rice plants of the cultivar "Tai-Nong 67" are sprayed to the trickle point with an aqueous suspension at the concentration of active compound indicated below. The next day oat kernels infected with P. solani were placed in pots (in each case 5 kernels per pot). The plants are then placed in a chamber at 26°C and maximum atmospheric humidity. After 11 days, the sheath blight on untreated, infested control plants had developed to such an extent that the percent infestation could be determined visually.

Evaluation is carried out by measuring the % infected leaf area. These percentages were converted to efficacy.

Efficacy (E) was calculated using Abbot's formula as follows:

E＝(1-α/β)·100

α corresponds to the percent fungal infestation of the treated plants, and

β corresponds to the percent fungal infection of untreated (control) plants.

An efficacy of 0 indicates that the level of infection in treated plants corresponds to that of untreated control plants; an efficacy of 100 indicates that treated plants are not infected.

The expected potency of a mixture of active compounds is determined using the Colby formula [R.S. Colby, Weeds 15, 20-22 (1967)] and compared to the observed potency.

Colby's formula: E=x+y-x y/100

E Expected potency in % relative to untreated control using a mixture of active compounds A and B at concentrations a and b,

x Potency of active compound A at concentration a expressed in % relative to the untreated control,

y Efficacy at concentration b of active compound B expressed in % relative to the untreated control.

The comparative compound used is compound A, which is known from the mixture described in EP-A 988790:

Table A - Individual Active Compounds Example active compound Concentration of active compound in spray solution [ppm] Potency, % relative to untreated control 1 Control (untreated) - (81% infected) 2 I (Azoxystrobin) 41 261 3 II 1 26 4 Comparative compound A 1 26

Table B - Mixtures of the invention Example Mixture Concentration Mixing Ratio of Active Compounds The power of observation Calculated potency ^* ) 5 I+II1+1ppm1:1 63 27 6 I+II4+1ppm4:1 63 45

^* ) Potency calculated using Colby's formula

Table C - Comparative tests - Mixtures known from EP-A 988780 Example Mixture Concentration Mixing Ratio of Active Compounds The power of observation Calculated potency ^* ) 7 I+A1+1ppm1:1 0 27 8 I+A4+1ppm4:1 0 45

^* ) Potency calculated using Colby's formula

The test results show that the inventive mixture has a synergistically increased activity against rice sheath blight, whereas the mixture known from EP-A 988780 is ineffective.

Claims (11)

1. A fungicidal mixture comprising the following compounds in a synergistically effective amount: 1) Azoxystrobin of formula I:

and 2) Compounds of formula II: 2. A fungicidal mixture comprising a compound of formula I and a compound of formula II in a weight ratio of 100:1 to 1:100. 3. The fungicidal mixture as claimed in claim 1 or 2, additionally comprising an active compound III selected from the group consisting of bisbenzotriazole, furconazole, cyconazole, difeconazole, diniconazole, oxaconazole , fenconazole, quinconazole, flusilazole, fenconazole, hexaconazole, carbendazim, metconazole, metconazole, mycloconazole, penconazole, propiconazole, propylchloride prothioconazole, simeconazole, tebuconazole, fluteconazole, triadimefon, pyraclostrobin, fluconazole, or triconazole. 4. A fungicidal composition comprising a liquid or solid carrier and a mixture as claimed in any one of claims 1-3. 5. A method for preventing and controlling harmful fungi that are rice pathogens, comprising treating fungi, their habitat or plants, soil or seeds that need to be protected from fungal infection with a synergistically effective amount of compound I and compound II as claimed in claim 1 . 6. The method as claimed in claim 5, wherein compounds I and II as claimed in claim 1 are administered simultaneously, ie jointly or separately, or sequentially. 7. The method as claimed in claim 5, wherein the mixture as claimed in any one of claims 1-3 is applied in an amount of 5-2000 g/ha. 8. The method as claimed in claim 5 or 6, wherein the mixture as claimed in any one of claims 1-3 is applied in an amount of 1-1000 g/100 kg seed. 9. The method as claimed in any one of claims 5-8, wherein the harmful fungus P. solani is controlled. 10. Seed comprising a mixture as claimed in any one of claims 1-3 in an amount of 1-1000 g/100 kg. 11. Use of compound I and compound II as claimed in claim 1 in the preparation of a composition suitable for controlling harmful fungi.