Synergistic combination of microbicides to combat fungi on plants

A plant-microbicidal composition having synergistic action, comprising at least two active ingredient components, wherein component I is a compound selected from the group (IA) 1-[3-(2-chlorophenyl)-2-(4-fiuorophenyl)oxiran-2-ylmethyl]-1H-1,2,4-triazo le ("epoxiconazol"); (IB) 4-(4-chlorophenyl)-2-phenyl-2-(1,2,4-triazol-1-ylmethyl)-butyronitrile ("fenbuconazol"); (IC) 5-(4-chlorobenzyl)-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)-cyclopenta nol ("metconazol"); (ID) 2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propyl-1,1,2,2-tetrafluoro ethyl ether ("tetracon azol"); (IE) .alpha.-[2-(4-chlorophenyl)ethyl]-.alpha.-(1,1-dimethylethyl)-1H-1,2,4-tri azole-1-ethanol ("tebuconazol"); (IF) 1-[4-bromo-2-(2,4-dichlorophcnyl)tetrahydrofurfuryl]-1H-1,2,4-triazole ("bromuconazol"); or in each case one of the salts or metal complexes thereof; and component II is (IIA) 1-[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triaz ole ("propiconazol") and/or (IIB) 4-cyclopropyl-6-methyl-N-phenyl-2-pyrimidineamine ("cyprodinil"), or in each case one of the salts or metal complexes thereof.

The present invention relates to novel microbicidal active ingredient 
mixtures having synergistically enhanced action, comprising at least two 
active ingredient components, and to methods of using such mixtures in 
plant protection. 
Component I is a compound selected from the group: 
(IA) 
1-[3-(2-chlorophenyl)-2-(4-fluorophenyl)oxiran-2-ylmethyl]-1H-1,2,4-triazo 
le ("epoxiconazol"; reference: EP-A-196 038); 
(IB) 4-(4-chlorophenyl)-2-phenyl-2-(1,2,4-triazol-1-ylmethyl)-butyronitrile 
("fenbuconazol"; reference: EP-A-251 775); 
(IC) 
5-(4-chlorobenzyl)-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)-cyclopenta 
nol ("metconazol"; reference: EP-A-267 778); 
(ID) 
2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propyl-1,1,2,2-tetrafluoro 
ethyl ether ("tetraconazol"; reference: EP-A-234 242); 
(IE) 
.alpha.-[2-(4-chlorophenyl)ethyl].alpha.-(1,1-dimethylethyl)-1H-1,2,4-tria 
zole-1-ethanol ("tebuconazol"; reference: EP-A-40 345); 
(IF) 1-[4-bromo-2-(2,4-dichlorophenyl)tetrahydrofurfuryl]-1 
H-1,2,4-triazole ("bromuconazol"; reference EP-A-246 982), 
or in each case one of the salts or metal complexes thereof; and 
component II is the compound: 
(IIA) 
1-[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triaz 
ole ("propiconazol"; reference: GB-1 522 657) and/or 
(IIB) 4-cyclopropyl-6-methyl-N-phenyl-2-pyrimidineamine ("cyprodinil"; 
reference: EP-A-310 550) 
or in each case one of the salts or metal complexes thereof. 
Of the acids that can be used for the preparation of salts of compounds of 
formulae I and II, the following may be mentioned: 
hydrohalic acids, such as hydrofluoric acid, hydrochloric acid, hydrobromic 
acid or hydriodic acid; sulfuric acid, phosphoric acid, nitric acid; and 
organic acids, such as acetic acid, trifluoroacetic acid, trichloroacetic 
acid, propionic acid, glycolic acid, thiocyanic acid, lactic acid, 
succinic acid, citric acid, benzoic acid, cinnamic acid, oxalic acid, 
formic acid, benzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic 
acid, salicylic acid, p-aminosalicylic acid, 2-phenoxybenzoic acid, 
2-acetoxybenzoic acid and 1,2-naphthal-ene-disulfonic acid. 
The term salts also includes metal complexes of basic components I and II. 
Those complexes may as desired involve only one component or both 
components independently. It is also possible to produce metal complexes 
in which the two active ingredients I and II are linked to one another to 
form a mixed complex. 
Metal complexes consist of the underlying organic molecule and an inorganic 
or organic metal salt, for example a halide, nitrate, sulfate, phosphate, 
acetate, trifluoroacetate, trichloroacetate, propionate, tartrate, 
sulfonate, salicylate, benzoate, etc., of an element of main group II, 
such as calcium and magnesium, and of main groups III and IV, such as 
aluminium, tin or lead, and of subgroups I to VIII, such as chromium, 
manganese, iron, cobalt, nickel, copper, zinc, etc.. Preference is given 
to the subgroup elements of the 4th period. The metals may have any of the 
different valencies in which they occur. The metal complexes can be mono- 
or poly-nuclear, i.e. they can contain one or more organic molecule 
components as ligands. 
Further agrochemical active ingredients, such as insecticides, acaricides. 
nematicides, herbicides, growth regulators and fertilisers, but especially 
additional microbicides, may also be added to the active ingredient 
mixture according to the invention. 
Synergistic mixtures are known wherein 
a) component I is compound IA ("epoxiconazol") and component II is compound 
IIB ("cyprodinil"); 
b) component I is compound IB ("fenbuconazol") and component II is compound 
IIB ("cyprodinil"); 
c) component I is compound IE ("tebuconazol") and component II is compound 
IIB ("cyprodinil") (reference for a), b) and c): EP-A-548 025); and 
d) component I is compound IE ("tebuconazol") and component II is compound 
IIA ("propiconazol") (reference: EP-A-393 746). 
The present invention does not relate to those mixtures. 
It has now been found, surprisingly, that the fungicidal action of mixtures 
according to the invention of components I and II is not merely additive 
but is clearly synergistically enhanced. 
Preference is given to two-component mixtures wherein 
(1) component I is a compound selected from the group IA ("epoxiconazol"), 
IB ("fenbuconazol"), IC ("metconazol"), ID ("tetraconazol") and IE 
("tebuconazol"); and 
component II is compound IIA ("propiconazol") and/or IIB ("cyprodinil"); 
(2) component I is a compound selected from the group IA ("epoxiconazol"), 
IB ("fenbuconazol"), IC ("metconazol"), ID ("tetraconazol") and IF 
("bromuconazol"); and 
component II is compound IIA ("propiconazol"); 
(3) component I is a compound selected from the group IC ("metconazol"), 
ID ("tetraconazol") and IF ("bromuconazol"); and 
component II is compound IIB ("cyprodinil"). 
(4) A further preferred group is formed by three-component mixtures wherein 
component I is a compound selected from the group IA ("epoxiconazol"), 
IB ("fenbuconazol"), IC ("metconazol"), ID ("tetraconazol"), IE 
("tebuconazol") and IF ("bromuconazol"); and 
component II is a mixture of IIA ("propiconazol") and IIB ("cyprodinil") 
and the ratio by weight of IIA:IIB=1:6 to 6:1. 
(5) Of the above, preference is given especially to three-component 
mixtures wherein component I is compound IE ("tebuconazol") and 
component II is a mixture of 
IIA ("propiconazol") and IIB ("cyprodinil"). 
The present invention relates also to a method of controlling fungi which 
comprises treating a site infested by or threatened with infestation by 
fungi with, in any desired sequence or simultaneously, a) a compound of 
formula I or one of the salts thereof and b) the compound of formula II or 
one of the salts thereof, it being possible also for the salts to be so 
selected that the two compounds are bonded to an acid radical or, in the 
case of a metal complex, to a central metal cation. 
Advantageous mixing ratios of the two compounds are I:II=1:10 to 10:1, 
preferably I:II=1:6 to 6:1 and especially I:II=1:3 to 3:1. 
Other advantageous mixing ratios I:II are, for example, 1:1, 1:2, 1:4, 2:1, 
2:3. 
In the three-component mixtures, preferred mixing ratios IIA:IIB for 
component II =1:6 to 6:1 and especially 1:5 to 1:1. 
The compound mixtures I+II according to the invention have very 
advantageous curative, preventive and systemic fungicidal properties for 
protecting plants. The compound mixtures of the invention can be used to 
inhibit or to destroy the microorganisms occurring on plants or on pans of 
plants (the fruit, blossom, leaves, stems, tubers or roots) of different 
crops of useful plants, while at the same time parts of plants that grow 
later are also protected against such microorganisms. They can also be 
used as dressings in the treatment of plant propagation material, 
especially seed (fruit, tubers, grains) and plant cuttings (for example 
rice), to provide protection against fungal infections and against 
phytopathogenic fungi occurring in the soil. The compound mixtures 
according to the invention are distinguished by the fact that they are 
especially well tolerated by plants and are environmentally friendly. 
The compound mixtures are effective against phytopathogenic fungi belonging 
to the following classes: Ascomycetes (e.g. Venturia, Podosphaera, 
Erysiphe, Monilinia, Uncinula); Basidiomycetes (e.g. the genera Hemileia, 
Rhizoctonia, Puccinia); Fungi imperfecti (e.g. Botrytis, Helminthosporium, 
Rhynchosporium, Fusarium, Septoria, Cercospora, Alternaria, Pyricularia 
and Pseudocercosporella herpotrichoides); and Oomycetes (e.g. 
Phytophthora, Peronospora, Bremia, Pythium and Plasmopara). 
Target crops to be protected within the scope of the present invention 
comprise, for example, the following species of plants: cereals: (wheat, 
barley, rye, oats, rice, sorghum and related species); beets: (sugar beet 
and fodder beet); ponies, stone fruit and soft fruit: (apples, pears, 
plums, peaches, almonds, cherries, strawberries, raspberries and 
blackberries); leguminous plants: (beans, lentils, peas and soybeans); oil 
plants: (rape, mustard, poppy, olives, sunflowers, coconut, castor oil 
plants, cocoa beans and groundnuts); cucumber plants: (marrows, cucumber 
and melons); fibre plants: (cotton, flax, hemp and jute); citrus fruit: 
(oranges, lemons, grapefruit and mandarins); vegetables: (spinach, 
lettuce, asparagus, cabbages, carrots, onions, tomatoes, potatoes and 
paprika); lauraceae: (avocados, cinnamon and camphor); or plants such as 
maize, tobacco, nuts, coffee, sugar cane, tea, vines, hops, bananas and 
natural rubber plants, as well as ornamentals (flowers, shrubs, 
broad-leaved trees and evergreens, such as conifers). That list does not 
represent any limitation. 
The compound mixtures according to the invention are especially 
advantageous for applications in cereals, especially in wheat and barley. 
The mixtures of compounds of formulae I and II are generally used in the 
form of compositions. The compounds of formulae I and II can be applied to 
the area or plant to be treated, either simultaneously or in succession on 
the same day, together with, where appropriate, further carriers, 
surfactants or other application-promoting adjuvants customarily employed 
in formulation technology. 
Suitable carriers and adjuvants may be solid or liquid and are substances 
ordinarily employed in formulation technology, for example natural or 
regenerated mineral substances, solvents, dispersants, wetting agents, 
tackifiers, thickeners, binders or fertilisers. 
A preferred method of applying a compound mixture comprising at least one 
of each of compounds I and II is application to the parts of the plants 
that are above the soil, especially to the leaves (foliar application). 
The frequency and rate of application depend on the biological and 
climatic living conditions of the pathogens. The compounds can, however, 
also penetrate the plants through the roots via the soil (systemic action) 
if the locus of the plant is impregnated with a liquid formulation (for 
example in rice culture), or if the compounds are introduced in solid form 
into the soil, e.g. in the form of granules (soil application). In order 
to treat the seed, the compounds of formulae I and II may also be applied 
to the seeds (coating) either by impregnating the tubers or grains with a 
liquid formulation of each of the compounds in succession or by coating 
them with an already combined wet or dry formulation. In addition, in 
special cases, other methods of application to plants are possible, e.g. 
treatment directed at the buds or the fruit. 
The compounds of the combination are used in unmodified form or preferably 
together with the adjuvants conventionally employed in formulation 
technology, and are therefore formulated in known manner, e.g. into 
emulsifiable concentrates, coatable pastes, directly sprayable or 
dilutable solutions, dilute emulsions, wettable powders, soluble powders, 
dusts or granules, or by encapsulation in e.g. polymer substances. As with 
the nature of the compositions, the methods of application, such as 
spraying, atomising, dusting, scattering, coating or pouring, are chosen 
in accordance with the intended objectives and the prevailing 
circumstances. Advantageous rates of application of the active ingredient 
mixture are generally from 50 g to 2 kg a.i./ha, preferably from 100 g to 
1000 g a.i./ha, especially from 400 g to 1000 g a.i./ha. In the case of 
the treatment of seed, the rates of application are from 0.5 g to 1000 g, 
preferably from 5 g to 100 g, a.i. per 100 kg of seed. 
The formulations are prepared in known manner, e.g. by homogeneously mixing 
and/or grinding the active ingredients with extenders, e.g. solvents, 
solid carriers and, where appropriate, surface-active compounds 
(surfactants). 
Suitable solvents are: aromatic hydrocarbons, preferably the fractions 
containing 8 to 12 carbon atoms, such as xylene mixtures or substituted 
naphthalenes, phthalates, such as dibutyl or dioctyl phthalate, aliphatic 
hydrocarbons, such as cyclohexane or paraffins, alcohols and glycols and 
their ethers and esters, such as ethanol, ethylene glycol, ethylene glycol 
monomethyl or monoethyl ether, ketones, such as cyclohexanone, strongly 
polar solvents, such as N-methyl-2-pyrrolidone, dimethyl sulfoxide or 
dimethylformamide, and vegetable oils or epoxidised vegetable oils, such 
as epoxidised coconut oil or soybean oil; and water. 
The solid carriers used, e.g. for dusts and dispersible powders, are 
normally natural mineral fillers, such as calcite, talcum, kaolin, 
montmorillonite or attapulgite. In order to improve the physical 
properties it is also possible to add highly dispersed silicic acid or 
highly dispersed absorbent polymers. Suitable granulated adsorptive 
carriers are porous types, for example pumice, broken brick, sepiolite or 
bentonire; and suitable nonsorbent carriers are e.g. calcite or sand. In 
addition, a great number of pregranulated materials of inorganic or 
organic nature can be used, such as especially dolomite or pulverised 
plant residues. 
Depending on the nature of the compounds of formulae I and II to be 
formulated, suitable surface-active compounds are non-ionic, cationic 
and/or anionic suffactants having good emulsifying, dispersing and wetting 
properties. The term "surfactants" will also be understood as comprising 
mixtures of surfactants. 
Especially advantageous application-promoting adjuvants are also natural or 
synthetic phospholipids from the series of cephalins and lecithins, such 
as phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol and 
lysolecithin. 
The agrochemical compositions generally comprise 0.1 to 99%, preferably 0.1 
to 95%, of compounds of formulae I and II, 99.9 to 1%, preferably 99.9 to 
5%, of a solid or liquid adjuvant and 0 to 25%, preferably 0.1 to 25%, of 
a surfactant. 
Whereas commercial products will preferably be formulated as concentrates, 
the end user will normally employ dilute formulations.