Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~L(?5~5 9 0 - 2 -
The present invention relates to a method of combating weeds,herbicidal compositions a~d their preparation.
The invention provides a method of combating weeds at a locus
infested or liable to be infested with them, which method
comprises applying to the locus
~a) 2-ethoxy-2,3-d~hydro-3,3-dimethylbenzofuran-5-yl
methanesulphonate; and
Cb) 3-ethoxycarbonylaminophenyl N-phenylcarbamate and/or
3-methoxycarbonylaminophenyl N-(3,5-dimethylphenyl)
carbQmate.
In addition, the invention provides a herbicidal composition
comprising ta) and tb).
It has been found that (a) and (b) seem to render weeds more
susceptible to the action of the other, so that the present method
and composition are unexpectedly advantageous, especially when
used in the control of weeds in sugar beet. Components (a) and
Cb) are synergistic, being surprisingly effective against weeds.
The method and composition can be used to combat a wider range of
weed species than when either (a) or ~b) is used alcne. Components
(a) and Cb) are also effective at lower dDsage rates than those
at which (a) or (b) alone is effective. In addition they are safe
to crops such as sugar beet. Further, when (a) and ~b3 are applied
separately in the present method, the timing of the applications
is less critical than when Cb) is used alone,
Each of the 2 essential compcnents should be employed as
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~()S'~ 5 g _ 3 _
1-100 parts. Parts, proportions and percentages m this
specification are by weight unless otherwise indicated. Preferably
the proportions of (a) to ~b) are from 1:10 to 10:1, especially
from 1:4 to 4:1. Usually there is only a single Cb) component.
The essential herbicides ~a) and ~b~ can be applied together
in a composition comprising (a) and (b). The compositions can be
prepared by admixing the ingredients. Usually the compositions
are initially produc~d in the form of concentrates, e.g.
containing O.S-85% in toto of the essential components, and these
are diluted with water or a hydrocarbon, usually water, or
appli~ation, generally such that the concentration In toto o the
essential components is 0.05-4~, though it may be up to 50~ or
; more when spray~d from aircraft. Thus, the present compositions
usually contain 0.05-85% in toto of the essential components.
The com~ositions normally contain a su~face active agent
and/or a carrier.
The carrier may be a liquid, e.g. water (e.g. water used to
dilute a concentrate for appli~ation). A concentrate containing
water as carrier may advantageously also contain a surace
active agent. In one embodiment, (a) and (b) are ground with
water, a wetting agent and a suspending agent, usually in an
agitated ball mill containing grinding media e.g. ste~ti~e balls,
to a particle size for both (a) and (b) of preferably less than
5 microns, to form a ~lowable suspension concentrate.
The carrier may be a liquid other than water, for exa~ple an
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~L()5'~ 5 9 0
organic solvent, usually a water-immiscible solvent, e.g. a
hydrocarbon which boils within the range 130-270C, in which the
essential components are dissolved or suspended. A concentrate
containing an organic solvent suitably also contains a surface
active agent so that the concentrate acts as a self-emulsifiable
oil on admixture with water. In a particular method, an
emulsifiable concentrate is produced by stirrin~ together,
preferably with warm mg to aid dissolution, components (a) and (b),
one or more emulsifiers and a ~ater-immiscible solvent desirably
comprising mainly isophorone to form a solution9 and usually
fiitering or centrifuging to remove msoluble impurities.
The carrier may be a solid, which may be finely dividedO
Bxamples of suitable solids are clays, sand, mica, chalk,
attapulgite, diatomate, perlite and sepiolite, synthetic solid
carriers, eOg. sili5as, silicates and lignosulphonates, and
solid fertilizers.
Wettable powders rapidly dispersible in water can be formed
by admixing ~a) and ~b) in particulate form with a carrier or
spraying molten (a) and ~b) on to the carrier, admixing a wetting
agent and a dispersing agent therewith, and fluid energy milling
or pulverising the whole powder mixture to a particle size
sufficiently small that the wettable powder in use can form the
desired suspension.
The term 'surface active agent' is used in the broad sense
to include materials variously called emulsifying agents,
~OS'~590
dispersing agents and wetting agents. Such agents are well
kno~n in the herbicide art.
The surface active agents used may comprise anionic surface
active agents, for example soaps, fatty sulphate esters such
as dodecyl sodium sulphate, octadecyl sodium sulphate and
cetyl sodium sulphate~ fatty aromatic sulphonates such as
alkyl-benzene sulphonates or butyl-naphthalene sulphonates, mo~e
complex fatty sulphonates such as the amide condensation product
of oleic acid and N-methyl taurine or the sodium sulphonate of
dioctyl succ mate.
The surface active agents may also comprise non-ionic
agents, for example condensation products of fatty acids, fatty
alcohols or fatty substituted phenols with ethylene oxide, or
fatty esters and ethers of sugars or polyhydric alcohols, or
the products obtained from the latter by condensation with
ethylene oxide, or the products known as block polymers of
ethylene oxide and propylene oxide.
The surface active agents may also comprise cationic
; agents, for example cetyl trimethylammonium bromide.
Preferred surface active agents include fatty alkyl sul~ha~e~,~
alkyl aryl sulph~nates, fatty alkyl ethoxylates, sulphated fatty
alkyl ethoxylates, dialkyl sulphosuccinate esters, lignin sulphonate
salts, sulphona~ed naphthalene-formaldehyde condensates and
sulphonatedun~formaldehyde condensates.
(a) and (b) may be admixed with a non-phytoxic oil, e.g.
- lOS'~590
Agri-Oil Plus~or Sun Oil llE.~
(a) and (b) may be mixed immediately before use.
Desirably, however, they would already have been mixed.
The composition is usually employed post-emergence of the weeds.
For the control of weeds in a crop, e.g. sugar beet, it may be
applied before sowing the crop ~with or without incorporation
of the composition in the soil) but preferably it is applied
after emergence of th~ crop.
Instead o applying (a) and (b) together in a composition
such as is discussed above, they can be applied separately in
analogous compositions containing just (a) or ~b), particularly
as a chemical l~eed control programme or part of a chemical weed
control programme in a crop season. (b) is preferably applied
after emergence of the crop. It is particularly advantageous to
apply (a) before (b); the time of application of (b), e.g.
- post-emergence of a sugar beet crop, is then much less critical
than when (b) alone is used in a chemical weed control programme.
(a) is preferably applied after planting but before emergence of
the crop.
; 20 A combination of simultaneous application of (a) and (b) and
a sequential application of (a) and ~b) can be employed. Thus,
in one embodiment, (a) is applied after planting but before
emergence of the crop and (a) and (b) are applied together
after emergence of the cropO
A further herbicide can be used in the present method
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TrcdQ IYlc~ k
105~59 7
besides (a) and (b). Thus, the further herbicide can be applied
before planting a crop, (a) after planting but before emergence
of the crop and (b) after emergence of the crop. Alternatively,
a composition comprising a mixture of ta), (b) and the filrther
herbicide can be appliedO Usually the proportions of (a) to the
further herbicide are from 1:10 to 10:1 by weight, preferably
from 1:3 to 3:1 by weightO In a particular embodiment, (b) is
employed in admixture with phenmedipham e.g. in a ratio of (b):
phenmedipham of from 1:3 to 3:1, e.g. 1:1, by weight. Examples
of such furt}ler herbicides include pheno~yaliphatic acids~(eOgO2~4~D~
MCPA, 2,4,5-T, 2,4-DB, M~PB, and CMPP) including functional derivatives
thereof, substituted ureas (ecgO monuron, diuron, neburon,
monolinuron, linuro~, fenur~n and benzthiazuron), triazines (eOg.
simazine, atrazine, trietazine and prometryne), DNOC, PCP,
ioxynil, bromoxynil, dichlobenil, diquat, paraquat, 2,3,6-tri-
chlorobenzoic acid, endothal, dalapon, dicamba, TCA, chlorpropham,
barban, EPTC, butylate, diallate, allidochlor, propachlor, bromacil,
lenacil, maleic hydrazide, salts of methanearsonic acid, cacodylic
acid, aminotriazole, picloram, trifluralin, S,S,S-tributyl
phosph~rotrithioate, 3-~1- Cethoxyamino_7propylidene)-6-ethyl-2H-
pyran-2,4(3H)-dione, phenmedipham, azolamid, triallate, cycloate,
propamide, carbetamide, diphenamid, pebullate, ben nuralin,
metobromuron, pyrazon, N-(chloroacetyl)-N (2,6-diethylphenyl)
glycine ethyl ester or N-~phosphonpmethyl)glycine, especially
phenmedipham, lenacil, pyrazon, dalapon, TCA or cycloate. Preferred
lQ5ZS90 - 8 -
compositions comprise (a) and ~b) optionally with phenmedîpham,
lenacil, pyrazon or dalaponO
As preferred examples of use of other herbicides;
1. cycloate is applied before plantIng a crop, (a) after planting
but before emergence and (b) after emergence;
2. (a) is applied with TCA after planting but before emergence
of a crop and tb), optionally with phenmedipham or pyrazon, is
applied after emergence of the crop; and
3. cycloate is applied before planting a crop, and (a) and Cb)
are applied together a~ter planting but before emergence of the
cropO
cycloate with (a) is applied before planting, and ~b)
optionally with (a) is applied after emergence of the crop~
Fertilizers or pesticides other than herbicides can also be
employed with the present essential herbicides.
Plants, the soil, land or aquatic areas can be treated by the
present methodO The method and composition are preferably used
for selectively combating weeds, especially at a locus at which
a crop, eOg. beetroot (otherwise known as red beet, Beta vulgaris~
and especially sugar beet ~Beta vulgaris~ is growing or, less
preferably, is to growO
In the present method, usually 0.2-8 kg, preferably 005-4 kg,
especially 1-4 kg, in toto of (a) and (b~ are applied per hectareO
The invention is illustrated by the following ExamplesO
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~0525
Examples 1-4
In field trials, plots of sugar beet planted in a sandy
clay loam of organic matter content 3D3~ were subjected 46 days
after planting to the comparative post-emergence treatments
shown in the following table, the herbicides being applied as
aqueous sprays in a standard way and the mixtures of herbicides
being obtained by mixing formulations of each of the active
components in a tank with water immediately prior to spraying.
The table records the control of smartweed tPol~anum
pensylvanicum) achieved in the crop on a scale from 0.0 tindicating
no cGntrol~ to lOoO (indicating complete control), assessed
9 days after treatmentO
(a) is 2-ethoxy-2,3-dihydro-3,3-dimethylbenzofuran-5-yl
methanesulphonate; and
Cb) is 3-ethoxycarbonylaminophenyl N-phenylcarbamateO
Rate
Example Treatment pounds per acre (kg per hal Smartw_ed Control
1 (a) 2 (2~2) ) 8 0
l (b) ~ (008)
2 (a) 2 (202) ) 9 3
l tb) 1 (lol)
3 (a) 2 (202) 3.3
4 (a) 3 (304) 3.7
Examples 5-8
In field trials, plots of sugar beet planted in a sandy loam
of organic matter wntent 201% weTe sprayed post-emergence in a
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lO5Z590
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standard way 31 days after planting with aqueous sprays o the
herbicides as shQwn in the following table, the mixtures of
herbicides being obtained by mixing formulations of each of the
active components m a tank with water immediately prior to
spr~yingO The table records the control o lambsquarter
(Chenopodium album) achieved in the crop on a scale from 000
(indicating no control~ to lOoO (indicating complete control),
assessed 22 days afi.er ~reatmentO (a) and ~b) are as in
Examples 1-40
Rate Lambsquarter
Exa~ e Treatment pounds per acre (kg per ha? Control
. ~
( ~ I (b3 2 (oo28) 10.0
6 (a) ~b~ 12 (l13 lOoO
7 ~a) 2 (2,2) 803
8 ~a) 3 (304) 903
Examples 9 and 10
In a post-emergence herbicide screen, the plants indicated
in the following table were sprayed in a standard way with aqueous
sprays of the herbicides indicated, the mL~ture of herbicides
being obtained by mlxing formulations of each of the active
components with water immediately prior to sprayingO The table
reco~ds the herbid dal activity achieved on a scale from 0 (indicating
no effect) to 100 (indi~ting complete supression)~
(a~ and (b) are as in Examples 1-40
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~ ~ o~
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r~ ~
,_ ~ o
~ ~ 1
:~ ,~
a
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105'~S~0
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Example 11
In field trials, plots of sandy clay loam of organic matter content 3 3
l~ere treated with inco~poration with 1 1b per acre (4~5 kg per h~ctare)
of cycloate (S-ethyl-N-ethyl-cyclohexylthiolcarbamate), then sugar
beet was planted on the same day. 46 days later, when the sugar
beet had emerged, the plots were treated sinwltaneously with 2 lb
per acre t2.2 kg per hectare) of 2-ethoxy-2,3-dihydro-3,3-dimethyl
benzofuran-5-yl methanesulphonate and ~ lb per acre (0.8 kg per
hectare) of 3-ethoxycarbonylaminophenyl N-phenylcarbamate, applied
together with 1 US gallon per acre ~9.4 litres per hectare3 of the
non-phytotoxic oil ~un Oil llE~ 9 Days later, control of
smartweed in the crop was assessed on a scale from 0~0 (indicating
no control) to 10.0 (indicating complete control), and was ~ound
to be 10Ø
The herbicides weTe applied in a standard way as aqueous
sprays and the mixture of herbicides and oil was obtained by
mixing foTmulations of each of the herbicides with the oil and
water immediately prior to spraying.
Exam~le 12
In analogues experiments to those described in Example 11,
the plots were treated with incorporation with 4 lb per acre
(4.5 kg per hectare) of cycloate, then sugar beet was planted on
the same dayl The plots were then on the same day sprayed with
2 lb per acre tZ.2 kg per hectare) of 2-ethoxy-2,3-dihydro--~,3-
dimethylbenzofuran-5-yl methanesulphona~e. 46 Days later, when
1^rqdQ ~Ih~ 2-
11[)5'~S90
- 13 -
the sugar beet had em~rged, the plots were sprayed wlth ~ lb per
acre ~008 kg per hectare) of 3-ethoxycarbonylaminophenyl
N-phenylcarbamateO 9 Days later control of smartweed in the crop
was assessed on a scale from 0~0 (indicating no cont~ol) to lOoO
(indicating complete control). A score of lOoO was found,
The herbicides in each instance were applied in a standard
way as aqueous spraysO
Examples 13-18
In field trials, plots of sugar beet planted in a sandy loam
of organic matter content 201~ were sprayed, after planting but
on the same day as planting, with 2 lb per acre ~202 kg per
hectare) of 2-ethoxy-2,3-dihydro-3,3-dimethylbenzofuran-5-yl
methanesulphonate and 6 lb per acre (6~7 kg per hectare) of
TCA (trichloroacetic acid, in the form of its sodium salt)O The
: 15 herbicides were applied in a standard way as an aqueous spray
obtained by admixing formLlations of each of them with water in
a tank immediately prior to sprayingO 31 Days later, after
emergenre of the beet, the materials shown in the following
table were applied in a series of Examples at the rates indicated
in a standard way in an aqueous sprayO Where a mixture of
herbicides is indicated, their formulations were admixed with
water in a tank immediately prior to spray mg~
. ~ tb) is 3-ethoxycarbonylaminophenyl N-phenylcarbamate;
Oil is the non-phytotoxic oil Sun Oil llE;
Pyrazon is 5-amino-4-chloro-2-phenyl-3-pyridazone;
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105'~5~0
- 14 -
Endothall is 7-oxabicyclo(2,2,1)heptane-2,3-dicarboxylic
acid, dipotassium salt; and
Phenmedipham is 3-methoxycarbonylaminophen~l N-(3-methylphenyl)
carbamate.
Post-emergence Treatments
Example Material, rate
13 (b), ~ lb per acre (0.8 kg per hectare)
14 (b), ~ lb per acre (0056 kg per hectare~
Oil, 1 US gallon per acre (9.4 litres per hectare)
Pyrazon, 2 lb per acre (202 kg per hectare)
+
(b), ~ lb per acre ~0.8 kg per hectare)
Oil, 1 US gallon per acre (904 litres per hectare)
: 16 (b~, ~ lb per acre ~008 kg per hectare)
+
Endothall, ~ lb per acre ~0056 kg per hectare)
17 (b), ~ lb per acre ~008 kg per hectare)
t
Endothall, 1 lb per acre (0 56 kg per hectare)
+
Oil, 1 US gallon per acre (904 litres per hectare~
18 Phenmedipham, 1 lb per ac~e (0.56 kg per hectare)
(b), ~ lb per acre (0.56 kg per hectare)
- 15 - 105~590
The control of lambsquarter achieved in the crop was assessed
22 days later on a scale from 0,0 (indicating no control~ to lOoO
(indicating complete control)~ In each Example, a score of 10uO
l~as foundO
Exam~les 19-24
Examples 13-18 were followed except that the pre-emergence
treatment was with 3 lb per acre {304 kg per hectare) of 2-eth~xy-
2,3-dihydro-3,3-dime~hylbenzofuran-S-yl methanesulphonate and 6 lb
per acre ~6.7 kg per hectare) of TCA, and the post-emergence treatments
were with the materials and at the rates shown in the following
table.
Example Ma~erial, rate
.~
: 19 ~b), ~ lb per acre (008 kg per hectare) .
~ 20 (b), 1 lb per acre (0.56 kg per hectare)
+
Oil, 1 US gallon per acre (9.4 litres per hectare)
21 PyTazon, 2 lb per acre ~202 kg per hectare)
+
(b), ~ lb per acre (0~8 kg per hectare)
+
Oil, 1 US gallon per acre ~904 litres per hectare)
- 22 (b), ~ lb per acre ~0.8 kg per hectare)
+
Endothall, ~ lb per acre (0056 kg per hectare~
251
-
105Z~;90
- 16 -
ample Material rate
23 (b), ~ lb per acre (0,8 kg per hectare~
Endothall~ ~- lb per acre (0.56 kg per hectare)
*
Oil, l US gallon per acre ~g~4 litres per hectare)
24 Phenmedlpham, ~ lb per acre ~3oS6 kg per hectare)
~b), ~ lb pe~ acre (0056 kg per hectare) .
Again in each Example a score of lOoO was oundO
Examples 25 and 26
In field trials, plots of sandy loam of organic matter
conten~ 2~1~ were treated with incorporatlon with 3 lb per acIe
(3~3kg per hectare) of cyclcate ~S-ethyl-N-ethyl~N-cyclohexylthio-
lcarbamate~, then sugar beet was planted on the s~me dayO Afterplanting but still on the same day, some plots were treated with
2 lb per ac~e ~202 kg per hectare) of Z eth~xy-2,3-dlhyd~o-3,3-
dimethylbenzofuran-5-yl methanesulphcnate, ~ lb per acre (008 k~
per hectare~ of 3-ethoxycarbQnyl~minGpheny1 N-phenylcarbamate~
and l US gallon per acre (904 litres per hectare) of the non-
phytotoxic oil Sun Oil llE, ~nd other plots were treated just
with 2 lb per acre (202 kg per hectare) of 2-eth~xy-2,3-dihydro-
3,3-dimethylbenzofuran-5-yl methanesulphonateO 31 Days later,
afte~ emergence of the beet9 these other plots only were treatea
wi~h ~ lb per ac~e ~0~8 kg per hectare) of 3-ethoxycarbcny1amLno-
~ - 16 -
~dQ ~k
- 17 - ll)S;~S~O
phenyl N-phenylcarbamate. 22 Days iater, both sets o~ plots
were assessed for control of lambsquarter on a scale from 000
(indicating no control) to lOoO (indicating complete control30 On
ea.ch set, a score of 10~0 was foundO
The herbicides werc applied in a standard way as aqueous
sprays and the mixture of herbicid.es and oil was obtained by
mixing formulations of each of the herbicides with the oil ~nd
water immediately prlor to spraying.
