Note: Descriptions are shown in the official language in which they were submitted.
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Bayer CropScience GmbH
Bayer CropScience LP
Description
Aqueous crop protection formulations comprising asulam and synergistic
herbicidal
combinations thereof
The present invention relates to the field of the crop protectant
formulations. In
particular, the invention relates to formulations in the form of aqueous
solutions
which comprise the herbicidal active ingredient asulam and certain
surfactants. The
present invention also relates to a synergistic herbicidal combination and a
method
of controlling weed growth, comprising the aqueous formulation of asulam
according
to the invention and further herbicidal active ingredients, preferably from
the series of
the sulfonylureas (e.g. trifloxysulfuron).
In general, herbicidal active ingredients are not employed in pure form.
Depending
on the field and type of application and on physical, chemical and biological
parameters, the active ingredients are employed as active ingredient
formulation in
admixture with conventional auxiliaries and adjuvants. The combinations with
further
active ingredients for widening this spectrum of action and/or for protecting
the crop
plants (for example by safeners, antidotes) are also known.
Formulations of herbicidal active ingredients should generally have a high
chemical
and physical stability, good application qualities and user friendliness and a
broad
biological action combined with high selectivity. The herbicidal active
ingredient
asulam is generally employed as an aqueous solution, for example under the
trade
name Asulox . The disadvantage of this product is the high application rate in
which
it is applied to the areas to be treated.
It was an object of the present invention to provide an aqueous crop
protectant
formulation for the active ingredient asulam which has an improved herbicidal
activity.
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This object is achieved by aqueous herbicidal compositions comprising the
herbicidal
active ingredient asulam or its salts, such as the potassium salt or sodium
salt, and
at least one surfactant selected from among group B) consisting of the
surfactants
B1: mixtures of quaternary ammonium compounds,
B2: sodium lauryl ether sulfate,
B3: fatty alcohol polyglycerol esters and
B4: ethoxyiated fatty amines.
An example of a mixture of quaternary ammonium compounds is Geronol0
CF/AS30, see, for example, Material Safety Data Sheet of Rhodia Asia Pacific
Pte.
Ltd., Singapore.
An example of sodium lauryl ether sulfate is Rhodapex0 ESB 70/FEA, see, for
example, Material Safety Data Sheet of Rhodia Inc., USA.
An example of a fatty alcohol polyglycerol ester is Synergen0 B01, which
constitutes
a copolymer of giycerol, coconut fatty acid and phthalic anhydride and which
is
known under the CAS No. 67746-02-5.
An example of an ethoxylated fatty amine (with 15 ethylene oxide units) is
Rhodameen CF/15H0, see, for example, Safety Data Sheet of Rhodia Gerronazzo
S.p.A, Italy.
The aqueous herbicidal compositions according to the invention show a markedly
increased herbicidal activity in comparison with the asulam-comprising aqueous
compositions which are known to date.
The aqueous herbicidal compositions according to the invention can
additionally
comprise antifoams and conventional adjuvants and additives such as antifreeze
agents, colorants, fragrances and preservatives.
Suitable antifoams are for example silicone-based ones, preferably Rhodorsil0
481.
Suitable antifreeze agents are those from the group consisting of the ureas,
diols
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and polyols, such as ethylene glycol and propylene glycol. Suitable
preservatives,
colorants and fragrances are known to the skilled worker.
Depending on the intended purpose, i.e. depending on which harmful plants are
to
be controlled in the crop in question, the aqueous herbicidal compositions
according
to the invention additionally comprise a further herbicidal active ingredient,
preferably
from the series of the sulfonylureas, especially preferably trifloxysulfuron
(e.g. sold
as the herbicide brand name Envoker"').
The ratio of the aqueous herbicidal compositions according to the invention
(Component A) and a further herbicidal active ingredient (Component B), based
on
active ingredient, may vary greatly and is dependent from the efficacy of the
further
herbicidal active ingredient against different weeds in different crops.
Therefore
(A):(B) could be in the range from 1000:1 to 1:1000, preferably from 600:1 to
1:600,
particular from 400:1 to 1:400, very particular from 200:1 to 1:200.
In case that the further herbicidal active ingredient are from the series of
the
sulfonylureas, e.g. trifloxysulfuron, (A):(B) could be in the range from 1:1
and 1000:1,
preferably in the range of 80:1 and 380:1, particularly in the range from
110:1 to
120:1 based on active ingredient.
In case that the further herbicidal active ingredient (Component B) is
trifloxysulfuron,
e.g. in the formulation of EnvokeTM, the weight ratio of trifloxysulfuron is
in the range
of between 10 g and 20 g active ingredient, per hectare, preferably in the
range of
14.5 g to 17.5 g active ingredient per hectare and asulam (Component A), e.g.
according to formuiation example No. 2, is in a range from 1600 g to 3740 g
active
ingredient per hectare, preferably in the range of 1600 g to 1800 g active
ingredient
per hectare.
The further herbicidal active ingredient can both be present, in the aqueous
herbicidal composition according to the invention, as what is known as a ready
mix
or else be applied as what is known as a tank mix by joint dilution of the
separately,
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or partly separately, formulated components.
The aqueous herbicidal compositions according to the invention conventionally
comprise the herbicidal active ingredient asulam; a surfactant from among
group B);
water; if appropriate, an antifoam; if appropriate, auxiliaries and additives;
and, if
appropriate, a further herbicidal active ingredient.
In a preferred embodiment, the aqueous herbicidal compositions according to
the
invention comprise
a) 10 to 50% asulam, or its salts, such as the sodium salt,
b) 1 to 30% of a surfactant from among group B),
c) 0 to 1% of an antifoam,
d) 0 to 10% adjuvants and auxiliaries,
e) 0 to 5% of a further herbicidal active ingredient, and
f) 25 to 75% water.
Especially preferred are aqueous herbicidal compositions according to the
invention
comprising
a) 20 to 50% asulam, or its salts, such as the sodium salt,
b) 5 to 25% of a surfactant from among group B),
c) 0 to 1% of an antifoam,
d) 0 to 10% adjuvants and auxiliaries,
e) 0 to 5% of a further herbicidal active ingredient, and
f) 25 to 75% water.
Very especially preferred aqueous herbicidal compositions according to the
invention
are those comprising
a) 25 to 40% asulam, or its salts, such as the sodium salt,
b) 10 to 20% of a surfactant from among group B),
c) 0 to 1 /a of an antifoam,
d) 0 to 5% adjuvants and auxiliaries,
e) 0 to 3% of a further herbicidal active ingredient, and
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f) 40 to 65% water.
All percentages are by weight.
5 As a ruie, asulam and trifloxysulfuron are used in the form of their sodium
salt; in this
context, see also "The Pesticide Manual", 13th edition (2003), The British
Crop
Protection Council. Unless otherwise specified, the terms "asulam" and
"trifloxysulfuron" are in each case to be understood as meaning the free
compound
and its salts such as the potassium salt or sodium salt for the purpose of the
present
application.
The terms "solutions according to the invention" and "herbicidal compositions
according to the invention" or "herbicidal compositions" are used
interchangeably
hereinbelow.
The abovementioned formulation auxiliaries of groups c) and d) are known to
the
skilled worker and are described, for example, in: Watkins, "Handbook of
Insecticide
Dust Diluents and Carriers", 2nd Ed., Darland Books, Caldwell N.J., H.v.
Olphen,
"Introduction to Clay Colloid Chemistry"; 2nd Ed., J. Wiley & Sons, N.Y.; C.
Marsden,
"Solvents Guide"; 2nd Ed., Interscience, N.Y. 1963; McCutcheon's "Detergents
and
Emulsifiers Annual", MC Publ. Corp., Ridgewood N.J.; Sisley and Wood,
"Encyclopedia of Surface Active Agents", Chem. Publ. Co. Inc., N.Y. 1964;
Schonfeldt, "Grenzflachenaktive Athylenoxidaddukte [Surface-active ethylene
oxide
adducts]", Wiss. Verlagsgesell., Stuttgart 1976; Winnacker-Kuchler, "Chemische
Technologie [Chemical technology]", Volume 7, C. Hauser Verlag Munich, 4th Ed.
1986.
For use, the aqueous herbicidal compositions according to the invention can be
diluted in a customary manner, for example with water. It may be advantageous
to
add, to resulting spray mixtures, further agrochemical active ingredients (for
example
components for tank mixes in the form of suitable formulations) and/or
customary
auxiliaries and additives conventionally used for application and/or
fertilizers. It has
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proved advantageous to dilute the aqueous herbicidal compositions according to
the
invention with aqueous solutions of fertilizers, for example ammonium nitrate
and
ammonium sulfate.
The present invention therefore also relates to those aqueous herbicidal
compositions comprising the agrochemical active ingredients mentioned in the
above
section, auxiliaries and additives and/or fertilizers.
The aqueous herbicidal compositions according to the invention have an
outstanding
herbicidal activity against a broad spectrum of economically important
monocotyledonous and dicotyledonous harmful plants. They even affect good
control
of perennial problem weeds which emerge from rhizomes, root stocks or other
perennial organs. In this context, the according to the invention are usually
applied
post-emergence.
The aqueous herbicidal compositions according to the invention are
distinguished by
a prolonged herbicidal activity with prompt onset. The combination, according
to the
invention, of herbicidal active ingredients and surfactants makes it possible
to
substantially reduce the necessary application rate of the active ingredients.
The abovementioned properties and advantages are useful in the practical
control of
harmful plants in order to keep agricuitural crops free from undesired plant
competition and thus for ensuring and/or for increasing yields in terms of
quality and
quantity. With regard to the above-described properties, these novel
competitions
clearly outperform the prior art.
Although the aqueous herbicidal compositions according to the invention have
an
outstanding herbicidal activity against mono- and dicotyledonous harmful
plants,
crop plants of economically important crops, for example dicotyledonous crops
such
as soybeans, cotton, oilseed rape, sugar beet, or graminaceous crops such as
wheat, barley, rye, oats, sorghum and millet, sugarcane, coffee, tea, cacao,
coconut,
bananas or maize, only suffer a minor extent of damage, or none at all. This
is why
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the aqueous herbicidal compositions according to the invention are highly
suitable
for selectively controlling undesired vegetation in plantations of
agricultural useful
crops or in ornamental plantations.
Owing to their herbicidal properties, the aqueous herbicidal compositions
according
to the invention can also be employed for controlling harmful plants in crops
of
genetically modified plants which are known or yet to be developed. As a rule,
the
transgenic plants are distinguished by specific advantageous properties, for
example by
resistances to certain pesticides, especially certain herbicides, resistances
to plant
diseases or pathogens causing plant diseases, such as certain insects or
microorganisms such as fungi, bacteria or viruses. Other specific properties
concern for
example the crop with regard to quantity, quality, storability, composition
and specific
constituents. Thus, transgenic plants with an increased starch content or
modified starch
quality, or those with a different fatty acid composition of the crop, are
known.
Preferred is the use of the aqueous herbicidal compositions according to the
invention in
economically important transgenic cultures of useful plants and ornamentals,
for
example graminaceous crops such as wheat, barley, rye, oats, sorghum and
millet, rice
and maize, or else cultures of sugar beet, cotton, soybean, oilseed rape,
potato, tomato,
pea and other vegetables. The aqueous herbicidal compositions according to the
invention can preferably be employed as herbicides in crops of useful plants
which are
resistant, or which have been made resistant by means of genetic engineering,
to the
phytotoxic effects of the herbicidal active ingredients.
When the aqueous herbicidal compositions according to the invention are
applied in
transgenic crops, effects are frequently observed which are specific for the
application in the transgenic crop in question, for example a modified, or
specifically
widened, weed spectrum which can be controlled, modified application rates
which
can be employed for the application, preferably good combining ability with
the
herbicides to which the transgenic crop is resistant, and an effect on the
growth and
yield of the transgenic crop plants, in addition to the effects, against
harmful plants,
which can be observed in the other crops.
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The present invention furthermore also relates to a method for controlling
undesired
plant growth, preferably in crops of plants such as cereals (for example
wheat,
barley, rye, oats, rice, maize, sorghum and millet), sugar beet, sugarcane,
oilseed rape,
cotton and soybeans, especially preferably in monocotyledonous crops such as
cereals,
for example wheat, barley, rye, oats, their hybridization products such as
triticale, rice,
maize, sorghum and millet, one or more aqueous herbicidal compositions
according to
the invention being applied to the harmful plants, plant parts, plant seeds or
the area on
which the plants grow, for example the area under cultivation.
The plant crops can also have been genetically modified or have been obtained
by
mutation selection and are preferably tolerant to acetolactate synthase (ALS)
inhibitors.
The aqueous herbicidal compositions according to the invention are prepared in
the
manner with which the skilled worker is familiar, for example by mixing the
individual
constituents; see, in this context, Winnacker-Kochler, "Chemische
Technologie",
Volume 7, C. Hauser Verlag Munich, 4th Ed. 1986, Wade van Valkenburg,
"Pesticide
Formulations", Marcel Dekker, N.Y., 1973; K. Martens, "Spray Drying" Handbook,
3rd Ed. 1979, G. Goodwin Ltd. London.
The examples which follow illustrate the invention.
The surfactants and adjuvants used in this context mean:
Geronol CF/AS30 = mixture of quaternary ammonium compounds, supplier:
Rhodia
Rhodapex ESB 70/FEA = sodium lauryl ether sulfate (70% strength solution in
water), supplier: Rhodia
Synergen B01 = fatty alcohol polyglycerol ester (copolymer of glycerol,
coconut fatty acid and phthalic anhydride), supplier:
Clariant
Rhodorsil 481 = silicone-based antifoam, supplier: Rhodia
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Rhodameen CF/15H0 = ethoxylated fatty amines, manufacturer: Rhone-Poulenc
Geronazzo SpA, Div. of Rhone-Poulenc S.A
Formulation example No. 1:
34.30 g of asulam (in the form of a sodium salt),
13.57 g of Rhodapex ES B70,
0.03 g of Rhodorsil 481 and
52.10 g of water
are stirred to give a homogeneous solution.
Formulation example No. 2:
34.30 g of asulam (in the form of a sodium salt),
13.97 g of Geronol CF/AS30,
0.03 g of Rhodorsil 481 and
51.70 g of water
are stirred to give a homogeneous solution.
Formulation example No. 3:
34.30 g of asulam (in the form of a sodium salt),
13.57 g of Rhodameen CF/15H ,
0.03 g of Rhodorsil 481 and
52.10 g of water
are stirred to give a homogeneous solution.
A formulation example "V" which is known from the prior art was prepared for
comparison purposes:
43.80 g of asulam (in the form of a sodium salt) and
56.20 g of water
are stirred to give a homogeneous solution.
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Biological examples:
1. Post-emergence herbicidal action against harmful plants
5 Seeds of monocotyledonous and dicotyledonous harmful plants are placed in
cardboard pots containing sandy loam, covered with soil and grown in the
greenhouse under good growth conditions. Two to three weeks after sowing, the
test
plants, which are in the three-leaf stage, are treated with the aqueous
herbicidal
compositions according to the invention and, for comparison reasons, with a
prior-art
10 herbicidal composition. The herbicidal compositions are sprayed onto the
surface of
the green plant parts in various dosages at a water application rate of 600 to
800 I/ha
(converted). After the test plants have been left to stand in the greenhouse
for 3 to
4 weeks under optimal growth conditions, the effect of the aqueous herbicidal
compositions according to the invention is scored.
The abbreviations denote:
CYNDA Cynodon dactylon DIGSA Digitaria sanguinalis
PANDI Panicum dichotomiflorum PANRA Panicum ramosum
PESGL Pennisetum glaucum SORHA Sorghum halepense
a.i. active ingredient, in tables 3 in each case asulam
Table 1
Herbicidal Dosage rate Herbicidal activity against harmful plants
composition [g a.i./ha] DIGSA SORHA PANRA PESGL
[Example No.]
1 1400 73% 63% 63% 93%
2 1400 62% 57% 58% 92%
3 1400 53% 53% 63% 88%
U 1400 25% 30% 48% 73%
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Table 2
Herbicidal Dosage Herbicidal activity against harmful plants
composition [g a.i./ha] PANDI CYNDA
[Example No.]
1 2800 63% 89%
2 2800 62% 84%
3 2800 60% 83%
V 2800 40% 30%
The results of tables 1 and 2 show that, at the same application rate, the
aqueous
herbicidal compositions according to the invention have a better herbicidal
activity
against different harmful plants than the one known from the prior art.
In a further experiment, in each case 120 g of ammonium sulfate (AMS) per
hectare
were employed when applying the aqueous herbicidal compositions 1 and 2
according to the invention.
Table 3
Herbicidal Dosage Herbicidal activity against harmful plants
composition [g a.i./ha] PANDI CYNDA
Example No.
1 2800 63% 89%
1+ 120 g AMS 2800 68 / 91 %
2 2800 62% 84%
2+ 120 g AMS 2800 65% 88%
3 2800 60% 83%
3+ 120 g AMS 2800 63% 93%
The results of table 3 show that the aqueous herbicidal compositions according
to
the invention, which comprise the fertilizer ammonium sulfate, have a yet
higher
herbicidal activity.
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2. Synergistic herbicidal combination comprising the aqueous formulation of
asulam
according to the invention and further herbicidal active ingredients
A synergistic effect of herbicides is always present when the activity against
weeds
of the herbicide combination exceeds the total of the activities of the
herbicides when
applied individually. The expected activity for a given combination of two
active
compounds can be calculated according to S.R. Colby ("Calculating Synergistic
and
Antagonistic Responses of Herbicide Combinations", Weeds 15, (1967), 20-22) as
follows:
If X is the percent inhibition of growth by herbicide A at an
application rate of m g/ha,
Y is the percent inhibition of growth by herbicide B at an
application rate of n g/ha, and
E is the expected growth as a percent of control with herbicides
A+B when applying the active compounds A and B at application rates
of m and n g/ha,
then E = 100 - (X + Y - XY/100).
The efficacy is calculated in Percent of Control (%): 0% is an efficacy which
corresponds to that of the untreated control, while an efficacy of 100% means
that no
growth is observed.
If the actual activity against weeds of the herbicide combination exceeds the
calculated value, then the activity of the combination is super additive, i.e.
a
synergistic effect exists. In this case, the efficacy which was actually
observed must
be greater than the value for the expected efficacy (E) calculated from the
abovementioned formula.
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Table 4
Component Herbicidal efficacy against harmful plants (weeds) applied
post-emergence
Redroot Broadleaf Crabgrass Fall Prickly
Pigweed SignalGrass Panicum Sida
A+NIS 25 93 85 94 60
B+NIS 95 59 68 79 20
TM 100 99 99 99 78
TM-El 3.75 1.87 3.8 0.26 10
Abbreviations: Efficacy as Percent of Control; A + NIS = asulam plus nonionic
surfactant (NIS) as known to the skilled worker as in formulation example No.
2
applied with 4 pints/acre; B + NIS = trifloxysulfuron as EnvokeTM formulation
plus nonionic surfactant (NIS) as known to the skilled worker applied with 0.3
oz/acre; TM = Tank mix of asulam formulation example No. 2 plus
trifloxysulfuron EnvokeTM formulation (A+NIS+B) in above dosages; El = (B
efficacy + A efficacy - ((B efficacy X A efficacy)/100), where El = Expected
efficacy if tank mix components are additive; TM-El = Difference between
expected additive effect and actual tank mix effect (values greater than zero
indicate synergy).
The results of table 4 shows that an unexpected good synergistic effect
accured
against each of all tested weeds by using the tank mix (TM = A+B+NIS). In a
further
experiment, the formulations according to the invention as shown in example
No. 1
together with trifloxysulfuron were applied post-emergence to various harmful
plants.
Again it was shown that unexpectedly good synergistic effects are obtained.
Although the invention has been described with reference to preferred
embodiments
and examples thereof, the scope of the present invention is not limited only
to those
described embodiments. As will be apparent to those skilled in the art,
adaptations
and modifications to the invention described above can be made without
departing
from the spirit and scope of the invention, which is defined by the following
claims.
