Note: Descriptions are shown in the official language in which they were submitted.
CA 02540292 2006-03-27
FUNGICIDAL MIXTURES FOR COMBATING RICE PATHOGENS
The present invention relates to fungicidal mixtures for controlling rice
pathogens,
which mixtures comprise, as active components,
1 ) the triazolopyrimidine derivative of the formula I,
CH3
JF F
N
i
N _N
~F
N N CI
and
2) fenhexamid of the formula II,
OH
HN \ CI
O CI
CH3
in a synergistically effective amount.
Moreover, the invention relates to a method for controlling rice pathogens
using mix-
tures of the compound I with the compound II and to the use of the compound I
with the
compound II for preparing such mixtures and compositions comprising these
mixtures.
The compound I, 5-chloro-7-(4-methylpiperidin-1-yl)-6-(2,4,6-trifluorophenyl)-
[1,2,4Jtri-
azolo[1,5-a]pyrimidine, its preparation and its action against harmful fungi
are known
from the literature (VllO 98146607).
The compound II, N-(2,3-dichloro-4-hydroxyphenyl)-1-
methylcyclohexanecarboxamide,
its preparation and its action against harmful fungi are likewise known from
the litera-
ture (Proc. Br. Crop Prot. Conf. - Pests Dis., 1998, Bd. 2, S. 327; common
name: fen-
hexamid). Commercially, fenhexamid is known mainly for the control of
Boyfritis infec-
tions in grapevines and specialty crops.
Mixtures of triazolopyrimidine derivatives with fenhexamid are known in a
general
manner from EP-A 988 790. The compound I is embraced by the general disclosure
of
PF 54953 CA 02540292 2006-03-27
2
this publication, but not explicitly mentioned. Accordingly, the combination
of compound
I with fenhexamid is novel.
The synergistic mixtures known from EP-A 988 790 are described as being
fungicidally
effective against various diseases of cereals, fruit and vegetables, for
example mildew
on wheat and barley or gray mold on apples.
Owing to the special cultivation conditions of rice plants, the requirements
that a rice
fungicide has to meet are considerably different from those that fungicides
used in
cereal or fruit growing have to meet. There are differences in the application
method: in
addition to foliar application, which is used in many places, the fungicide is
applied di-
rectly onto the soil during or shortly after sowing in modern rice
cultivation. The fungi-
cide is taken up into the plant via the roots and transported in the sap of
the plant to the
plant par a to be protected. in contrast, in cereal or fruit growing, the
fungicide is usu-
ally applied onto the leaves or the fruits; accordingly, in these crops the
systemic action
of the active compounds is considerably less important.
Moreover, rice pathogens are typically different from those in cereals or
fruit. Pyricu
laria oryzae, Cochliobolus miyabeanus and Corticium sasakii (syn. Rhizoctonia
solanr)
are the pathogens of the diseases most prevalent in rice plants. Rhizocfonia
solani is
the only pathogen of agricultural significance from the sub-class
Agaricomycetidae. In
contrast to most other fungi, this fungus attacks the plant not via spores but
via a myce-
lium infection.
For this reason, findings concerning the fungicidal activity in the
cultivation of cereals or
fruit cannot be transferred to rice crops.
Practical agricultural experience has shown that the repeated and exclusive
application
of an individual active compound in the control of harmful fungi leads in many
cases to
a rapid selection of such fungus strains which have developed natural or
adapted resis-
tance against the active compound in question. Effective control of these
fungi with the
active compound in question is then no longer possible.
To reduce the risk of selection of resistant fungus strains, mixtures of
different active
compounds are nowadays usually employed for controlling harmful fungi. By
combining
active compounds having different mechanisms of action, it is possible to
ensure suc-
cessful control over a relatively long period of time.
It was an object of the present invention to provide, with a view to effective
resistance
management and effective control of rice pathogens at application rates which
are as
PF 54953 CA 02540292 2006-03-27
3
low as possible, mixtures which, at a reduced total amount of active compounds
ap-
plied, have improved action against the harmful fungi.
We have found that this object is achieved by the mixtures defined at the
outset. More
over, we have found that simultaneous, that is joint or separate, application
of the com
pound I and the compound II or successive application of the compound I and
the
compound II allows better control of rice pathogens than is possible with the
individual
compounds.
When preparing the mixtures, it is preferred to employ the pure active
compounds I and
II, to which further active compounds against harmful fungi or other pests,
such as in-
sects, arachnids or nematodes, or else herbicidal or growth-regulating active
com-
pounds or fertilizers can be added as required.
Other suitable active compounds in the above sense are in particular
fungicides se-
lected from the following group:
~ acylalanines, such as benalaxyl, metalaxyl, ofurace, oxadixyl,
~ amine derivatives, such as aldimorph, dodemorph, fenpropidin, guazatine,
iminoc-
tadine, tridemorph,
~ antibiotics, such as cycloheximid, griseofulvin, kasugamycin, natamycin,
polyoxin or
streptomycin,
~ azoles, such as bitertanol, bromoconazole, cyproconazole, difenoconazole,
dinitro-
conazole, enilconazole, fenbuconazole, fluquinconazole, flusilazole,
flutriafol, hex-
aconazole, imazalil, ipconazole, myclobutanil, penconazole, propiconazole, pro-
chloraz, prothioconazole, simeconazole, tetraconazole, triadimefon,
triadimenol,
triflumizole, triticonazole,
~ dicarboximides, such as myclozolin, procymidone,
~ dithiocarbamates, such as ferbam, nabam, metam, propineb, polycarbamate, zi-
ram, zineb,
~ heterocyclic compounds, such as anilazine, boscalid, carbendazim, carboxin,
oxy-
carboxin, cyazofamid, dazomet, famoxadon, fenamidon, fuberidazole, flutolanil,
fu-
rametpyr, isoprothiolan, mepronil, nuarimol, probenazole, pyroquilon,
silthiofam,
thiabendazol, thifluzamide, tiadinil, tricyclazole, triforine,
~ nitrophenyl derivatives, such as binapacryl, dinocap, dinobuton, nitrophthal-
isopropyl,
~ phenylpyrroles, such as fenpiclonil or fludioxonil,
~ sulfur,
~ other fungicides, such as acibenzolar-S-methyl, carpropamid, chlorothalonil,
cy-
flufenamid, cymoxanil, diclomezin, diclocymet, diethofencarb, edifenphos, eth-
PF 54953 CA 02540292 2006-03-27
4
aboxam, fentin-acetate, fenoxanil, ferimzone, fluazinam, fosetyl,
hexachloroben-
zene, metrafenone, pencycuron, propamocarb, phthalide, toloclofos-methyl, quin-
tozene, zoxamide,
~ strobilurins, such as, fluoxastrobin, metominostrobin, orysastrobin or
pyraclostrobin,
~ sulfenic acid derivatives, such as captafol,
~ cinnamides and analogous compounds, such as flumetover.
In one embodiment of the mixtures according to the invention, a further
fungicide III or
two fungicides III and IV are added to the compounds I and II. Preference is
given to
mixtures of the compounds I and II with a component III. Particular preference
is given
to mixtures of the compounds I and II.
The mixtures of compounds I and II, or the compound I and the compound II used
si-
multaneously, that is jointly or separately, exhibit outstanding action
against rice patho-
gens from the classes of the Ascomycetes, Deuteromycetes and Basidiomycetes.
They
can be used for the treatment of seed and as foliar- and soil-acting
fungicides. The
compounds I and II are preferably applied by spraying the leaves. The
application of
the compounds can also be carried out by applying granules or by dusting the
soils.
They are especially important for controlling harmful fungi on rice plants and
their
seeds, such as Bipolaris and Drechslera species, and also Pyricularia oryzae.
They are
particularly suitable for controlling brown spot of rice, caused by
Cochliobolus miya-
beanus.
Moreover, the combination according to the invention of the compounds I and II
is also
suitable for controlling other pathogens, such as Septoria and Puccinia
species in ce-
reals and Alternaria and Botrytis species in vegetables, fruit and grapevines,
for exam-
ple.
The compound I and the compound II can be applied simultaneously, that is
jointly or
separately, or in succession, the sequence, in the case of separate
application, gener-
ally not having any effect on the result of the control measures.
The compound I and the compound II are usually applied in a weight ratio of
from
100:1 to 1:100, preferably from 20:1 to 1:50, in particular from 10:1 to 1:10.
The components III and if appropriate IV are, if desired, added to the
compound I in a
ratio of from 20:1 to 1:20.
PF 54953 CA 02540292 2006-03-27
Depending on the type of compound and on the desired effect, the application
rates of
the mixtures according to the invention are from 5 g/ha to 2000 glha,
preferably from
50 to 1500 g/ha, in particular from 50 to 750 g/ha.
Correspondingly, the application rates of the compound I are generally from 1
to
1000 g/ha, preferably from 10 to 750 g/ha, in particular from 20 to 500 glha.
Correspondingly, the application rates of the compound II are generally from 1
to
1000 g/ha, preferably from 10 to 750 glha, in particular from 20 to 500 g/ha.
In the treatment of seed, the application rates of the mixture are generally
from 1 to
1000 g/100 kg of seed, preferably from 1 to 750 gI100 kg, in particular from 5
to 500
g/100 kg.
In the control of harmful fungi pathogenic to rice plants, the separate or
joint application
of the compounds i and II or of the mixtures of the compounds I and II is
carried out by
spraying or dusting the seeds, the seedlings, the plants or the soils before
or after sow-
ing of the plants or before or after emergence of the plants.
The mixtures according to the invention or the compounds I and II can be
converted
into the customary formulations, for example solutions, emulsions,
suspensions, dusts,
powders, pastes and granules. The application form depends on the particular
pur-
pose; 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 extending the
active
compound with solvents and/or carriers, if desired using emulsifiers and
dispersants.
Solvents/auxiliaries which are suitable are essentially:
water, aromatic solvents (for example Solvesso products, xylene), paraffins
(for
example mineral fractions), alcohols (for example methanol, butanol, pentanol,
benzyl alcohol), ketones (for example cyclohexanone, gamma-butyrolactone),
pyrrolidones (NMP, NOP), acetates (glycol diacetate), glycols, fatty acid
dimethylamides, fatty acids and fatty acid esters. In principle, solvent
mixtures
may also be used.
- carriers such as ground natural minerals (for example kaolins, clays, talc,
chalk)
and ground synthetic minerals (for example highly disperse silica, silicates);
emulsifiers such as nonionic and anionic emulsifiers (for example
polyoxyethylene fatty alcohol ethers, alkylsulfonates and arylsulfonates) and
dispersants such as lignin-sulfite waste liquors and methylcellulose.
PF 54953 CA 02540292 2006-03-27
s
Suitable surfactants are alkali metal, alkaline earth metal and ammonium salts
of
lignosulfonic acid, naphthalenesulfonic acid, phenolsulfonic acid,
dibutylnaphthalenesulfonic acid, alkylarylsulfonates, alkyl sulfates,
alkylsulfonates, fatty
alcohol sulfates, fatty acids and sulfated fatty alcohol glycol ethers,
furthermore
condensates of sulfonated naphthalene and naphthalene derivatives with
formaldehyde, condensates of naphthalene or of naphthalenesulfonic acid with
phenol
and formaldehyde, polyoxyethylene octylphenyl ether, ethoxylated
isooctylphenol,
octylphenol, nonylphenol, alkylphenyl polyglycol ethers, tributylphenyl
polyglycol ether,
tristearylphenyl polyglycol ether, alkylaryl polyether alcohols, alcohol and
fatty
alcohol/ethylene oxide condensates, ethoxylated castor oil, polyoxyethylene
alkyl
ethers, ethoxylated polyoxypropylene, lauryl alcohol polyglycol ether acetal,
sorbitol
esters, lignin-sulfite waste liquors and methylcellulose.
Substances which are suitable for the preparation of directly sprayable
solutions,
emulsions, pastes or oil dispersions are mineral oil fractions of medium to
high boiling
point, such as kerosene or diesel oil, furthermore coal tar oils and oils of
vegetable or
animal origin, aliphatic, cyclic and aromatic hydrocarbons, for example
toluene, xylene,
paraffin, tetrahydronaphthalene, alkylated naphthalenes or their derivatives,
methanol,
ethanol, propanol, butanol, cyclohexanol, cyclohexanone, isophorone, strongly
polar
solvents, for example dimethyl sulfoxide, N-methylpyrrolidone and water.
Powders, materials for spreading and dustable products can be prepared by
mixing or
concomitantly grinding the active substances with a solid carrier.
Granules, for example 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 gels, silicates, talc,
kaolin, attaclay,
limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous earth,
calcium sulfate,
magnesium sulfate, magnesium oxide, ground synthetic materials, fertilizers,
such as,
for example, ammonium sulfate, ammonium phosphate, ammonium nitrate, ureas,
and
products of vegetable origin, such as cereal meal, tree bark meal, wood meal
and
nutshell meal, cellulose powders and other solid carriers.
In general, the formulations comprise from 0.01 to 95% by weight, preferably
from 0.1
to 90% by weight, of the active compounds. The active compounds are employed
in a
purity of from 90% to 100%, preferably 95% to 100% (according to NMR
spectrum).
PF 54953 CA 02540292 2006-03-27
7
The following are examples of formulations: 1. Products for dilution with
water
A) Water-soluble concentrates (SL)
parts by weight of the active compounds are dissolved in water or in a water-
soluble
5 solvent. As an alternative, wetters or other auxiliaries are added. The
active compound
dissolves upon dilution with water.
B) Dispersible concentrates (DC)
parts by weight of the active compounds are dissolved in cyclohexanone with
10 addition of a dispersant, for example polyvinylpyrrolidone. Dilution with
water gives a
dispersion.
C) Emulsifiable concentrates (EC)
15 parts by weight of the active compounds are dissolved in xylene with
addition of
15 calcium dodecylbenzenesulfonate and castor oil ethoxylate (in each case 5%
strength).
Dilution with water gives an emulsion.
D) Emulsions (EW, EO)
40 parts by weight of the active compounds are dissolved in xylene with
addition of
20 calcium dodecylbenzenesulfonate and castor oil ethoxylate (in each case 5%
strength).
This mixture is introduced into water by means of an emulsifying machine
(Ultraturrax)
and made into a homogeneous emulsion. Dilution with water gives an emulsion.
E) Suspensions (SC, OD)
In an agitated ball mill, 20 parts by weight of the active compounds are
comminuted
with addition of dispersants, wetters and water or an organic solvent to give
a fine
active compound suspension. Dilution with water gives a stable suspension of
the
active compound.
F) Water-dispersible granules and water-soluble granules (WG, SG)
50 parts by weight of the active compounds are ground finely with addition of
dispersants and wetters and made into water-dispersible or water-soluble
granules by
means of technical appliances (for example extrusion, spray tower, fluidized
bed).
Dilution with water gives a stable dispersion or solution of the active
compound.
G) Water-dispersible powders and water-soluble powders (WP, SP)
75 parts by weight of the active compounds are ground in a rotor-stator mill
with
addition of dispersants, wetters and silica gel. Dilution with water gives a
stable
dispersion or solution of the active compound.
PF 54953 CA 02540292 2006-03-27
2. Products to be applied undiluted
H) Dustable powders (DP)
parts by weight of the active compounds are ground finely and mixed intimately
with
5 95% of finely divided kaolin. This gives a dustable product.
I) Granules (GR, FG, GG, MG)
0.5 part by weight of the active compounds is ground finely and associated
with 95.5%
carriers. Current methods are extrusion, spray-drying or the fluidized bed.
This gives
granules to be applied undiluted.
J) ULV solutions (UL)
10 parts by weight of the active compounds are dissolved in an organic
solvent, for
exarripie xylene. T his gives a product to be applied undiluted.
The active compounds can be used as such, in the form of their formulations or
the use
forms prepared therefrom, for example in the form of directly sprayable
solutions,
powders, suspensions or dispersions, emulsions, oil dispersions, pastes,
dustable
products, materials for spreading, or granules, by means of spraying,
atomizing,
dusting, spreading or pouring. The use forms depend entirely on the intended
purposes; they are intended to ensure in each case the finest possible
distribution of
the active compounds according to the invention.
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, as such or dissolved in an oil or
solvent, can
be homogenized in water by means of a wetter, tackifier, dispersant or
emulsifier.
Alternatively, it is possible to prepare concentrates composed of active
substance,
wetter, tackifier, dispersant or emulsifier and, if appropriate, solvent or
oil, and such
concentrates are suitable for dilution with water.
The active compound concentrations in the ready-to-use preparations can be
varied
within relatively wide ranges. In general, they are from 0.0001 to 10%,
preferably from
0.01 to 1 %.
The active compounds may also be used successfully in the ultra-low-volume
process
(ULV), it being possible to apply formulations comprising over 95% by weight
of active
compound, or even to apply the active compound without additives.
PF 54953 CA 02540292 2006-03-27
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Various types of oils, wetters, adjuvants, herbicides, fungicides, other
pesticides, or
bactericides may be added to the active compounds, if appropriate just
immediately
prior to use (tank mix). These agents are typically admixed with the agents
according to
the invention in a weight ratio of 1:10 to 10:1.
The compounds I and II or the mixtures or the corresponding formulations are
applied
by treating the harmful fungi or the plants, seeds, soils, areas, materials or
spaces to
be kept free from them with a fungicidally effective amount of the mixture or,
in the
case of separate application, of the compounds I and II. Application can be
carried out
before or after infection by the harmful fungi.
The fungicidal action of the compound and the mixtures can be demonstrated by
the
experiments below:
The active compounds, separately or jointly, were prepared as a stock solution
with
0.25% by weight of active compound in acetone or DMSO. 1 % by weight of the
emulsi-
fier Uniperol~ EL (wetting agent having emulsifying and dispersing action
based on
ethoxylated alkylphenols) was added to this solution, and the solution was
diluted with
water to the desired concentration.
Use example - activity against brown spot of rice caused by Cochliobolus
miyabeanus,
protective application
Leaves of potted rice seedlings of the cultivar'Tai-Nong 67" were sprayed to
runoff point
with an aqueous suspension of the concentration of active compound stated
below. The
next day, the plants were inoculated with an aqueous spore suspension of
Cochiiobolus
miyabeanus. The test plants were then placed in climatized chambers at 22 -
24°C and
95 - 99 % relative atmospheric humidity for six days. The extent of the
development of the
infection on the leaves was then determined visually.
Evaluation is carried out by determining the percentage of infected plants.
These per-
centages were converted into efficacies.
The efficacy (E) is calculated as follows using Abbot's formula:
E = (1 - a/(3) - 100
a corresponds to the fungicidal infection of the treated plants in % and
(3 corresponds to the fungicidal infection of the untreated (control) plants
in
PF 54953 CA 02540292 2006-03-27
An efficacy of 0 means that the infection level of the treated plants
corresponds to that
of the untreated control plants; an efficacy of 100 means that the treated
plants are not
infected.
5 The expected efficacies of mixtures of active compounds are determined using
Colby's
formula (Colby, R.S., Weeds, 15, 20-22, 1967) and compared with the observed
efficacies.
Colby's formula:
E=x+y-x~y1100
E expected efficacy, expressed in % of the untreated control, when using the
mixture of the active compounds A and B at the concentrations a and b
x efficacy, expressed in % of the untreated control, when using the active
compound A at the concentration a
y efficacy, expressed in % of the untreated control, when using the active
compound B at the concentration b
The comparative compounds used were compounds A and B which are known from
the fenhexamid mixtures described in EP-A 988 790:
CH3
CF3
F
F H3C~NH ~ F
N ~ A I ~ B
N~N w
N~N ~ / ~~ ~ ~ \F
~N~ , CI N N CI
N CI
PF 54953 CA 02540292 2006-03-27
11
Table A - individual active compounds
Concentration of
active
Ex- Efficacy in % of
the
Active compound compound in the
ample spray untreated control
liquor [ppm]
1 control (untreated)- (85% infection)
16 17
2 I
4 5
16 0
3 II (fenhexamid)
4 0
comparative compound16 53
4 A 4 29
comparative compound16 41
B 4 5
Table B - mixtures according to the invention
Mixture of active compounds
Ex-
Concentration Observed efficacyCalculated efficacy*)
ample
Mixing ratio
I+II
6 16 + 4 ppm 76 17
4:1
I+II
7 16 + 16 ppm 88 17
1:1
I+II
8 4 + 16 ppm 70 5
1:4
*) efficacy calculated using Colby's formula
5
Table C - comparative tests
Mixture of active compounds
Ex-
Concentration Observed efficacyCalculated efficacy*)
ample
Mixing ratio
A+II
9 16 + 4 ppm 29 53
4:1
A+ II
16 + 16 ppm 17 53
1:1
PF 54953 CA 02540292 2006-03-27
12
Mixture of active compounds
Ex-
Concentration Observed efficacyCalculated efficacy*)
ample
Mixing ratio
A+II
11 4 + 16 ppm 17 29
1:4
B+II
12 16 + 4 ppm 53 41
4:1
B+II
13 16 + 16 ppm 53 41
1:1
B+II
i4 4+16ppm 41 5
1:4
*) efficacy calculated using Colby's formula
The test results show that the mixtures according to the invention, owing to
strong syn-
ergism, are considerably more effective than the fenhexamid mixtures known
from EP-
A 988 790, although the comparative compounds, as individual compounds, are,
at
comparable application rates, more effective than compound I.
