Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1:133L~3~
HERBICIDA~ 3 71/~ D F~RM~ ONS
The inventio~ relate.s to a method of controlling weeds in c2real
crops and to herbicidal fo~mulations useful inter alia in such method.
In order to control a broad ranye of weeds in cro~s, such as
cereal crops~ it is o~ten necessary to employ more than one herbicide.
Despite the use of such mixtures, weeds ~re still resistant to herbicide
traatment, causing damage to both winter and spring cereal crops such as,
for example, wheatr barley, oats and rye.
It ha~ now been found that speci~ic combinations of herbicides
not only give a broad spectrum of control but are also unexpectedly
effective against ~eeds, especially broadleaf weedæ, in cereal crops.
Accordingly, the invention provides a method of controlling
weed9, especially broadleaf w~eds, in a cereal crop loous, which method
comprise~ applying to ~aid locus, post emergence the crop, bifenox, being
- a compound of ~ormula I,
~2 ~ D ~ ~ - Cl
and one or more further active ingredient~ selec~ed from (l) a benzoic
acid herbicide which is dioamba or 2,3,6-TBA or a salt or ester thereof,
(2) a phenoxy a~id herbicide which is dichlorprop or 2,4-DB or a salt ox
ester thereo~, (3) a dinitrophenol herbicide which i~ DNOC/ dinoterb or
dinoseb or a salt or estex thereof~ (4) a ben~onitrile herbicide ~hich
~ is ioxynil or bromoxynil or a salt or ester thereof, (5) benazolin or a
salt or ester thereo~, (6) bentazone, and (7) 3,6-DCP or a salt or ester
thereof.
3~36
It will be appreciated that more than one of the acti~e
ingredients (1) to (7) may be employed in the method of the invention
and, indeed, that further or additional herbicidally active compounds may
be employed alongside such ingredients (1) to (7). Where the active
ingredient is acidic or phenolic, derivatives such as salts and esters
may be employed, provided, of course, that they are non-phytotoxic to the
cropl that is to say not substantially more phytotoxic than the Eree acid
or phenoI. The nature of such salts and esters is well-known to those
skilled in the art.
The preparation o~ bifenox, methyl 5~(2,4-dichlorophenoxy)-
2-nitrobenæoate, is described in United Ringdom Patent 1,232,368 and its
use as a herbicide in Proc. N.E. Weed Sci Con 1973, 27, 31.
Similarly, the benzoic acid herbicide dicamba, which is
3,6-dichloro~2-me~hoxybenzoic acid, is disclosed in U.S. Patent
3,013,054, and 2,3,6-TBA, which is 2,3,6-trichlorobenzoic acid, in U.S.
Patents 2,848,470 and 3,0~1,162. The phenoxy acid herbicides are a
well-knGwn group of compounds and have been widely available for some
considerable time. Dichlorprop is a common name for
2-(2,4-dichlorophenoxy) propionic acid, otherwise known as 2,4-DP; 2,4-DB
is the common name for 4-(2,4-dichlorophenoxy) butyric acid. The.
dinitrophenol herbicide, DNOC (chemical name 2-methyl-4,6-dinitrophenol3
was introduced under the protection of British Patent 425,295; dinoseb is
the common name for 2-sec-butyl-4,6-dinitrophenol, disclosed in U.S.
Patent 2,192,197; and dinoterb, 2-tert-butyl-4,6-dinitrophenol is
disclosed in, for example, British Patent 1,126,658. The benzonitrile
herbicides ioxynil (4-hydro~y-3,5-dl-iodoben2Onitrile) and bromoxynil
(3,5-dibromo-4-hydroxybenzonltrile) are both disclosed in, for example,
British Patent 977,755. Benazolin, having the chemical structure
4-chloro-2-oxo~3-benzothiazolineacetic acid, is disclosed in aritish
Patent 862,226 and bentazone, which is the common name ~or
3-isopropyl-(lH)-benzo-2,1,3-thiadiazin-4-one 2,2-dioxide, is described
in U.S. Patent 3,708,277. 3,6-DCP, which is 3,6-dichloropicolinic acid
is disclosed in U.S. Patent 3,317,549.
~3~3~
~3-
The cereal crop can be, for example, wheat, barley, oats or rye,
and the method of the invention finds its greatest potential in the
treatment of wheat and barley, particularly winter wheat and spring and
winter barley. Crop sensitivity and also the severity of the weed
problem determine the amount of active ingredients applied. In general,
however, the bi~enox is applied at a rate of 0.25 to 3.0 kilogram per
hectare, preferably from 0.5 ~o 1.5 kilogram per hectare and particularly
from 0.5 to 0.75 kilogram per hectare.
Set out below are the preferred application rates for the
further active ingredients (1) to ~7). Wh@re a component is derived from
an acid or phenol, the quantities are based on the free acid or phenol
equivalent.
Thu , where a benzoic acid herbicide, which is dicamba or
2,3,6-TBA, is e~ployed, such is preferably applied at a rate of ~rom 0.05
to 0.2 kilogram per hectare, the weight ratio cf the bifenox to the
benzoic acid herbicide suitably being in the ratio of 60:1 to 1:1,
preferably 30:1 to 4:1. The benzoic acid herbioide may be employed in
~he fcrm of a salt thereof, especially an alkali metal salt such as a
sodium or potassium salt, or in the form of an ester $hereof, e.g. a
Cl-C8 alkyl ester.
.
~here a phenoxy acid herbicide, which i5 dichloroprop or 2,4-DB,
Z5 i~ employed, such is preferably applied at a rate o~ 0.1 ~o 3.5 kilogram
per hectare, the weight ratio of the bifenox to the phenoxy acid
herbicide suitably being in the ratio of 30:1 to 1:15, especially from
8:1 to 1:6. In a particularly preferred embodiment, the bifenox is
applied at a rate of 0.5 to 0.75 kilogram per hectare, the phenoxy acid
herbicide at a rate of 1.5 to 3.0 kilogram per hectare. The phenoxy acid
herbicide is suitably employed in the ~orm of a salt thereof, for example
as an alkali metal salt, especially the sodium or potassium salt, or as
an amine or ammonium salt. AS examples of ester forms of the phenoxy
acid herbicide may be given those containing from 1 to 8 carbon atoms in
the ester grouping, for example the ethyl, isopropyl and butyl esters.
~3~ 6
--4--
Where a dinitrophenol herbicide, which is DNOC, dinoterb or
dinoseb is employed, such is preferably applied at a ra~e of from 0.5 to
5.0 kilogram per hectare, more preferably, particularly in the case of
dinoterb or dinoseb, at a rate of 0.5 to 2.0 kilogram per hectare. The
weight ra~io of bifenox to dinitrophenol herbicide is preferably from 6:1
to 1:20, more preferably from 3:1 to 1:6. As examples of suitable salt
forms of the dinitrophenol herbicide may be given those formed with both
inorganic and organic bases, especially the amine and ammonium salts. As
examples o~ esters may be given those formed with organic acids, e.g.
carboxylic acids, for example dinoseb acetate.
Where a benzonitrile herbicide, which is io~ynil or bromoxynil,
is employed, su~h is prePerably applied at a rate of from 0.05 to 0.5
kilogram per hectare, more preferably at a rate of from 0.1 ~o 0.35
kilogram per hectare. The weight ratio of bifenox to the benzonitrile
herbicide is preferably from 60:1 to 1:2, more preferably from 15:1 to
2:1. In a particular embodiment, both ioxynil and bromoxynil are
employed together with the bi~enox, in which case the preferred rates of
application and weight ratios given above are based on the total weight
of bo~h the ioxynil and brom~synil. Preferred salt forms of the ioxynil
and bromoxynil are the alkali metal, such as sodium and potassium, salt
forms. PrePerred esters include ioxynil octanoake a~d bromo~ynil
octanoate.
Where benazolin is employed, such is preferably applied at a
rate of from 0.05 to 0.25 kilogram per hectare. The ~eight ratio of
bifenox to benazolin is preferably from 60:1 to l:l, m~re preferably from
15:1 to 5:2. Suitable salt forms of the benazolin include the alkali
metal, especially the sodium and potassium, salt forms. The preferred
esters are those containing from l to 4 carbon atoms in the ester
grouping, especially the ethyl ester.
Where bentazone is employed, such is preferably applied at a
rate of from 0.1 to 1.5, more preferably 0.2 to 1.5 and most preferably
0.5 ~o 1.5 kilogram per hectare. A preferred weight ratio of bifenox to
bentazone is from 6:1 to 1:6, more preferably 3:1 to 1:2.
3~
--5--
Where 3,6 DCP is employed, such is preferably applied at a rate
of from 0.025 to 0.15 kilogram per hectare, more preferably at a rate of
from O.OS to 0.1 kilogram per hectare. A preferred weight ratio of
biEenox to 3,6 DCP is from 30:1 to 3:1, more preferably from 15:1 to
5:1. As examples of salt forms of the 3,6 DCP may be given the alkali
metal, e.g. sGdium and potassium, salt forms and ~he amine and ammonium
salt forms, e.g. the monoethanolamine salt form. As examples of esters
may be given those containing from 1 to 8 carbon atoms in the ester
grouping.
~;
The meth~d of the present inventicn is preferably carried out
when the cereal crop is between the one leaf stage and the appearance of
the second node.
Where the bifenox is employed together with the benzoic acid
herbicide, particularly good control of the weed species ~tellaria media,
Pol~on m spp, ~E~ arvensis, _ril~leuroapermum marit um, Viola sPP
and Veronica ~Ee is observed.
,: ~
Where the bienox is employe~ together with the phenoxy acid
herbicide, particularly good control of the weed species Galium aparine.
Stellaria media and Veronica spp is observ~d.
Where the bifenox is employed together with the dinitrophenol
herbicide, particularly good control of the weed specie~ Galeopsis
tetrahit, Fumaria officinalis, Polygonum convolvulus and Gal~um aparine
is observed.
Where the bifenox is employed together with the ben~onitrile
herbicide, particularly good control of the weed species Matricaria spp,
Polygonum ~e and Galium aparine is observed.
Where the bifanox is employed together with bena~olin,
particularly good control of the weed spe~ies Stellarla ~ L Galium
aearine and iola s~e is observed.
,~ ',
~L33L~3~
Where the bifenox is employed together with benta~one,
particularly good control of the weed species Viola ~, Veronica ~e and
Matricaria sPP is observed.
Where the bifenox is employed together with 3,6 DCP,
particularly good control of the weed species Veronica ~e and Matricaria
spp is observedO
AR e~amples of further or additional herbicidally active
compounds which may be employed together with the bife~ox and çomponent
(l) to (7), above, may be given MCPA, MCPB and mecoprop, all of which are
well kncwn herbicides, well documented in the literature and listed in
the "Pesticide Manualn, fifth editionl issued by the British Crop
Protection Council.
The bifenox and the active ingredient(s) ~l) to (7), abo~e,
optionally alcng with any further or additional herbicidally active
compound may be applied to the crop locus either simultaneously or
separa~ely. I~ the latter, the time period between applications is
preferably short, say one day or les;. It is b~ far preferred, however,
for the compounds W be applied 6imultaneou~ly as a single formulation.
In order to simplify manufacture, storage and transport, herbicidal
~ormulations will normally be produced in concentrate form intended for
dilution with water to the degree necessary to enable the above
application rates ~o be achieved, which dilution is generally such that
the formulation to be applied to the crop loc~s contains from 0.05 to 3.0
per cent by weight of the active herbicide ingredients. The concentrate
formulaticns generally contain from l to 90%, preferably 15 to 85% of
active ingredients assGciated with one or more non-phytotoxic carriers or
diluent
Concentrate formulations form part of the present invention.
Thus, there i5 provided a concentrated herbicidal ~ormulation which can
particularly, though by no means e~clusively, be employed in the method
of the present invention, which formulation comprises bifeno~, one or
~L~3~13~
--7--
more further active ingredients selected from (l) a benzoic acid
he}bicide which is dicamba or 2,3,6~TBA or a salt or ester thereof, (2)
a phenoxy acid herbicide which is dichlorprop or 2,4-DB or a salt or
ester thereof, (3) a dinitrophenol herbicide ~hich is DNOC, dinoterb or
dinoseb or a salt or ester thereof, (4) a benzonitrile herbicide which
i5 ioxynil or bromoxynil or a salt or ester thereof, (5) benazolin or a
salt or ester thereof, (6) bentazone and (7) 3,6-DCP or a salt or ester
thereof~ in association with one or more non-phytotoxic carriers or
diluents.
- In such formulation, the weight ratios of bifenox to each of the
ingredients (l) to (7) are preferably as set out a~ove in connection with
the method of the invention.
The concentrate formulations according to the invention will
usually be in the form of a wettable pcwder, an emulsifiable concentrate
or an aqueous s~spension. Aqueous suspension and wettable powder
formulations are preferred for use in the method of the invention, giving
significantly lower phytotoxlcity to ~he cereal crop ~han the
emulsifiable concentrate.
Wettable powders comprise an intimate mixture of the active
ingredients, one or more inert carriers and appropriate surfactants. The
inert carrier may, ~or example, be chos~n from the attapulgite clays, the
monbmorillonite clays, thç diatomaceous earths, kaolins, micas, talcs and
puriied silicates. Effective surfactants may be found among the
sulfonated lignins, the naphthalene sulfonates and condensed naphthalene
sulfonates, the alkyl succinates, the alkylbenzene sulfonates, the alkyl
sulfates and nonionic sur~a~tants such as ethylene oxide adducts o~
phenol.
Emulsifiable concentrates comprise the active ingredients
dissolved in a suitable solvent or suitable solvents, together with a
surfactant. Suitabie surfactants may, for example, be chosen from those
mentioned above in connection with wettable powders. Suitable solvents
include alkyl substituted benzenes, o-chlorotoluene, heavy aromatic
naphthalenes, glycol ethers and cyclic ketones.
36
--8--
Aqueous suspensions and solutions comprise the active
ingredients suspended or dissolved in water or suitable solvents
r&spectively together with any desired surfactants, thickening aqentsy
antifreezing agents or preservatives. Suitable surfactants may be chosen
from those mentioned a~o~e in connection with wettable powdersO
Thickening agents, if used, are no~mally chosen from appropriate
cellulose material~ and natural gums whilst glycols will generally be
used when an antifreezing agent is required. Preservatives may be chosen
- from a wide range of materials such as the ~arious paraben
antibacterials, phenol, o-chlorocresol, phenyl mercuric nitrate and
formaldehyde.
Alternatively, herbicidal formulations may be formed by mi~ing
tha two or more active ingredients with water in a spray tank just prior
to use, the water thus acting as a non-phytotoxic carrier. Such
formulations are called "tank mixes" and form a further aspect of the
invention. ID such tank mixes, the weight ratios of bifenox to the other
ingredient (1) to ~7) are again p~eferably those given for the method of
the invention.
The ~ollowing ~xa~ples illustriate concentrated herbicidal
for~ulations according to the invention. Where a herbicidal ingredient
is a aerivative of an asid or phenol the amount is based on the acid or
phenol equivalent.
EXAMPLBS 1 to lO
The ~ollo~ing wettable powders were prepared in each ase with
the ingredients shown.
% b;~ weight
~l) Bifeno~ 25
~entazone 25
Sodium alkyl ether sulphate 3
Sulphonated lignin 2
3~
9 .
Preclpitated silica 6
Talc tolO0
(2) Bifenox 50
Ioxynil 5
~odium salt of condensed naphthalene
Sulphonic aclds 2
Ethoxylat~d alkyl phenol 4
Fumed silica 5
Montmor illonite to100
(3) Bifenox 42
BrGmoxynil 6
Sodium lauryl sulphate 5
Sodium lignin sulphonate 3
Precipitated silica 8
Raolin tolO0
~43 Bi~enox 48
Benazolin (ethyl ester) 4
Ethoxylated nonyl phenol 4
Sulphite lye pawder 4
Fumed silica 5
Attapulgite ~olO0
(5) Bl~eno~ 4
3,6 DCP (monoethanolamine sal~) 4
Sodium lauryl sulphate 4
Sodium lignin sulphonate 3
Precipitated silica 8
Raolin ~olO0
.
: ., .
:
, ;
'
~3~
-10-
(6) Bifenox 20
2,4 DB (po~assi~n salt)30
Etboxylated alkyl phenol 2
Sulphite lye powder 4
Fu~ed silica 5
Attapulgite to.. 100
(7) ~3ifenox 20
Dichlorprop ~potag8i~n salt) 40
Sodium dialkylsulpho uccinate 3
Lignosulphonate 2
Micronised sllica 7
Dia'~o~ac~ls earth to 100
(8) Bifenox 45
Io~:yn il 2 . 5
Bro~o~nil 3
Sodium lauryl sulphate 2
Sodium llgnin sulphQnate 3
Preclpitated silica
Mon~morillonite to 100
~9) Bifeno~ 40
2,3~6~q~A (sodiUrQ ~alt1 5
Sodilm~ lauryl sulphate 3
Sodium lignin 3ulphonate 3
Precipitated ~illca 4
~aolin to 100
~10), 3i~enox 40
Dicamba ~ 50d iU~I sal~) 4
Ethoxylated alkyl phenol 4
Lignosulphonate 2
Fumed silica
Sod ium alumino silicate to 100
~$
, "
~3~3~k~ !
In each Example, the active ingre~ient6 were carefully blended
with the sp~cified exolpients in conventional mixing equipment. The
blend wa~ then fur~her milled in a fluid energy mill to a size range of
from 1 bD 10 microns.
EXAMP~ES 11 TO 2~
The following emulsi~iable concentrat~s were p~epared having ~he
con8tituents RhaWn below :
~ll) Bifenox 25
Io~ynil toctanoate~ 3
Cal~ium dodecylbenzene ~ulphonate 4
AlkylphenQxypolyD~yethylene ethanol~ 2
Cyclohexanone 35
Xylene tol00
~l2). Bifenox 20
Bromoxynil (octanoate3
Amine salt of d~decylbenzene ~ulphoic acid 3
Polyoxyethylene triglyceride 3
Cyclohexanona 30
Orthochlorotolu~ne tol00
25 ~13) Bi~enox 20
Benazolin ~ethyl e~ter) 2
Calciu~ dcdecylbenzene sulphonate 2
~thoxylatYd alkyl phenol 4
Isophorone 35
~eavy aro~atic naphtha tol00
~14) Bi~nox 6
DNCC 20
Calc~um dodecylbenzene sulphonate 3
EthoxylatPd alkyl pbenol 3
C~clohexanone 25
~eævy aromatic naphtha tol00
~' i' r '; ' ~'
~L3~3~
-12-
(15) Bifenox 20
Dinoterb 10
Al!cyl aryl sulphonate 2
Alkylphenoxypolyoxyethylene ethanol s
Isophorone 30
O}thochlorotoluene to 100
(1~) Bifenox 15
Dinoseb 15
1o Amine ~alt of dedecylbenzenesulphonic acid 4
Pol~oxyethylene triglyceride 3
Isophorone 20
Heavy aromatic naphtha to 100
~17) Bifenox 20
3,6 ncP 4
Calciu~ dodecylbenzene sulphonate
Ethoxyla~ed alkyl phenol 4
Isophorone 30
~eavy aro~atic naphtha to 100
(18) Bifenox lS
2,4-DB (isopropyl ester) 30
U kyl aryl sulphonate
Polyoxyethylene triglyceride
Cy~lohexanone 25
Xylene to 100
(19) Bifenox 15
Dichlorprop (butyl ester) 45
Amine salt of dodecylbenzene sulphonate 3
Alkylpheno~ypolyoxyethylene ethanols 3
Cyclohexanone 25
~eavy aromatic naphtha to 100
36
-13-
(20) Bifenox 20
Ioxynil ~o~tanoate) 1.5
Bromoxynil (octanoate) 2
Calcium dodecylbenzene sulphonate 3
Alkylphenoxypolyoxyethylene ethanols 4
Isophorone 30
Orthochlorotoluene to100
(21~ Bifenox 25
2~3,6-TBA (ester) 3
Calcium dodecylbenzene sulphonate 3
Ethoxylated alkyl phenol 3
Isophorone 30
Osthochlorotoluene to100
(22) Bifenox 20
Dica~ba 2
Alkyl aryl sulphonate 4
Alkylphenoxypoloxyethylene ethanols 2
Cyclohexanone 25
~ylene to100
The active ingredient~ were added to the appropriate solvent(s)
with stirxing and optional heating to facilitate solubilisation of the
active materials. ~he surfactants were then add~d. After solubilisation
the solu~ion was filtered to remove insoluble impuritie~.
~0 ~he following aqueous suspensions were prepared ~rom the
constituents hown below :
% by_w qht/b~ volume
(23) Bifeno~ 20
Bentazone 20
~3~
-14-
Alkyl aryl sulphonate 2
Phosphate ester of an ethoxylated
polyarylphenol neu~ralised with
triethanolamine~ 2
Xanthan gum 0.2
5ilicone antifoam 0.1
Formaldehyde 0.2
Water tolO0
(24) Bifenox 40
Ioaynil (sodium salt) 4
Ethoxylated nonyl phenol - 3
~ydro~ymethyl cellulose 2
Siliaone antifoam O.l
Water tolO0
(25) 8ifenox 35
Bromoxynil (potassium salt~ 3.5
Ethoxylated nonyl phenol 2.5
Hydroxymethyl cellulose l.7
Silicone antifoam O.l
Water tolO0
(26) Bifenox 48
Benazolin ~potassium salt) 8
Sodi~n lauryl ~ulphate 3
Attapulgite 1. 5
Silicone antifoam 0.15
Wa~er tolO0
The herbicide ingredients were mlxed with surfactants and
antifoaming agent, then vigorou~ly stirred in water to form a coarse
aqueous suspension. This was then wet-milled to reduce the particle si~e
of the active ingredients to 0.5 to 20 microns. To this wet milled
preparation was then added an aqueous suspension of the thickening or
suspending agent ~hydrated).
,~ ~
~3L31~33~
-15-
The following Example 2~ is of the test method employed to asses
the efficacy of the method and formula~ion o~ the invention
EX~MP~E 2? TEST M~T~OD
: 5
The appropriate quantity of formulated produc~ (for example of
one of the co~centrate formulations of the foregoing Examples 1 to 261 is
added to water in a micro-spra~er which i~ subsequently agitated ~o
ensure dispersion. The ~prayer is adjusted to deliver a volume
equivalent to 200 litres per hectare at a press~re of 40 p.s.i~ (ca 2.72
atm3. A standard nozzle (Allman No.-0) delive~ing a fan shaped jet is
fitted to the ~prayer~
Application is made post emergence to both crop and weeds, the
crop size for diff~rent applications varying from the 3 leaf stage to
beginning of stem extension. Weed ~ize at application can also be
variable, ranging from the cotyledon stage ~o the small plant stage.
2~ .
. . , ,~
,' :
, .. . .
,
