FR2579866A1 - Synergic herbicidal compositions containing a thiolcarbamate derivative and a diphenyl ether derivative - Google Patents

Abstract

Synergic herbicidal composition comprising a mixture: a. Of a herbicidal effective quantity of a thiolcarbamate of formula: in which: X represents a hydrogen, chlorine or bromine atom and R<1> and R<2> are independently chosen from the group consisting of a C1 to C6 alkyl radical and a C5 to C7 cycloalkyl radical; b. Of an effective quantity, as herbicide, of a substituted derivative of the diphenyl ether chosen from the group consisting of sodium 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate, methyl 5-(2,4-dichlorophenoxy)-2-nitrobenzoate, methyl 2-[2,4-(dichlorophenoxy)phenoxy]propionate, 2-chloro-2-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene, 5-[2-chloro-4-(trifluoromethyl)phenoxy]-N-(methylsulphonyl)-2- nitrobenzimide, 4-nitrophenyl alpha , alpha , alpha -trifluoro-2-nitro-p-tolyl ether, 2,4-dichlorophenyl 3-methoxy-4-nitrophenyl ether and 2,4-dichlorophenyl p-nitrophenyl ether, in a ratio by weight of a to b of approximately 0.25/1 to approximately 8/1.

Description

Protecting crops from weeds and other vegetation that inhibits plant growth is a constant problem in agriculture. To help solve this problem, synthetic chemistry researchers have developed a wide variety of chemicals and chemical formulations that are effective in controlling the growth of this unwanted vegetation. Chemical herbicides of many types have been described in the literature and a large number of them are on the market.

In a few cases, active herbicides have been shown to be more effective in combination than when applied alone. This phenomenon is often referred to as "synergy", since the combination exhibits a degree of effectiveness or activity which exceeds that which one would expect from knowledge of each of the activities of the components. The present invention is based on the finding that certain thiolcarbamates and certain substitution derivatives of diphe nylether, already known individually for their effective herbicide, develop this synergy when they are applied in combination.

The two classes of compounds forming the compositions according to the present invention are known independently in the state of the art for their effects on the growth of plants.

Thiolcarbamates are described as herbicides in U.S. Patents 3,185,720 (Tilles & al. May 25, 1965), No. 3,198,786 (Tilles et al., August 3, 1965) and No. 2,913,327 (Tilles et al., November 17, 1959).

The diphenyl ethers forming the second class of compounds in the compositions according to the present invention represent a separate group, but each is currently commercially available from different manufacturers as will be seen herein.

A synergistic effect has now been found in controlling the development of undesirable vegetation with compositions comprising a mixture of the following two components:
(a) an effective amount, as a herbicide, of a thiolcarbamate
of formula:

in which:
X represents a hydrogen, chlorine or bromine atom; and
R1 and R2 are independently selected from the group consisting of
with a C1 to C6 alkyl radical and a cycloalkyl radical in
C5 to C7; and
(b) an effective amount, as a herbicide, of a derivative substitute
diphenyl ether selected from the group consisting of 5-f2-chlo-
sodium ro-4- (trifluoromethyl) phenoxy} -2-nitrobenzoate, the
Methyl 5- (2,4-dichlorophenoxy) -2-nitrobenzoate, 2- (2,4- (di-
methyl chlorophenoxy) phenoxy} -proplonate, 2-chloro-2- (3
ethoxy-4-nitrophEnoxy) -4-trifluoromethyl) benzene, 5- (2-chloro- 4- (trifluoromethyl) -phenoxy} -N- (methylsulfonyl) -2-nitrobenzamide,
4-nitrophenol-a, a, a-trifluoro-2-nitro-p-tolylether, 2, 4-di -
chlorophenyl-3-methoxy-4-nitrophenyleth and 2,4-dichlorophenyl -p-nitrophenyl ether.

The term "alkyl" is used herein to denote both straight chain and branched chain groups. Examples of alkyl groups include methyl, methyl, n-propyl, isopropyl, n-butyl, butyl-secondary, isobutyl, etc. All the intervals of number of carbon atoms must be understood as the upper and lower limits included.

The thiolcarbamates useful in the present invention are, for example:
1.- S-benzyl-dipropylthiolcarbamate;
2.- S-benzylethyl, 1,2-dimethylpropylthiolcarbamate;
3.- S- (2-chlorobenzyl) -N, N-diethylthiolcarbamate;
4.- S- (4-chlorobenzyl) -N, N-dibthylthiolcarbamate.

These and other thiolcarbamates within the scope of the present invention can be prepared by the procedures described in U.S. Patent Nos. 2,913,327, 3,185,720 and 3,198,786 mentioned above. above and state patents
States of America Nos. 3,144,475, 2,992,091 and 3,207,775.

The preferred thiolcarbamate for use in the present invention is S-benzyl-dipropyl-thiolcarbamate.

The preferred diphenyl ether for use in the compositions according to the present invention is 2,4-dichlorophenyl-p-nitrophenyl-ether.

Each of the other compounds listed in subparagraph (b) lines 16 to 25 above can be found commercially.

The terms “synergy” and “synergistic” are used here to qualify the result observed when a combination of herbicides shows an effectiveness higher than that ellu &commat; that one would expect from said combination on the basis of the effectiveness of each herbicide applied individually.

The term "herbicide" is used herein to denote a compound which controls the development or modifies the growth of plants. The term "herbicide effective amount" is used to indicate the amount of that compound or combination of these compounds which is capable of producing an effect on the development or growth of plants. Effects on development or growth of plants include all abnormalities to natural development, e.g. extermination, retardation, leaf scorch, dwarfism, etc. The term "plant" is used to denote any post-emergence vegetation from young shoots to well-established vegetation.

In the composition according to the present invention, the thiolcarbamate / diphGnylether weight ratio for which the herbicidal response is synergistic is in the range of about 0.125 / 1 to about 8/1. The synergy is observed, in particular, when the composition is used against Fumaria officinalis, Galium aparium and Papaver spp.

Application rates depend on the weeds being treated and the degree of development control desired. In general, the compositions of the present invention work most effectively at a rate of 0.011 to 56 kg / ha (0.01 to 50 lb / ac) of the active ingredients, preferably 0.11 to 28 kg / ha. (0.1 to 25 lbs / acre). These compositions are particularly effective in controlling weeds which grow in sugar beets and in small seed crops such as, for example, wheat, barley and rapeseed.

le 2,4-dichlorophényl -p-nitrophényléther.Example 1
Synergy in weed control using S-benzyl-thiol carbamates and nitrofen
The herbicidal effects corresponding to the simultaneous use of
S-benzyl-dipropylthiolcarbamate (compound 1) and nitrogen (compound 2) are investigated by means of a greenhouse experiment. Nitrofen is:

2,4-dichlorophenyl -p-nitrophenylether.

Aluminum basins (planks) measuring 19 x 8 x 6 cm are filled with a loamy sand soil, and six furrows are drawn across the width of each plank. The following plant species are sown in the furrows: - Alopecurus myosuroides (BKGR), - Avena fatua (WO), - Beta vulgaris (SBTM), - Brassica napus (RAJN), - Bromus sterilis (PBRO), - Fumaria officinalis ( FUM), - Galium aparine (BDSW), - Hordeum vulgare (BAIG), - Lolium perenne PRGR), - Matricaria recutita (MARE), - Papaver spp. (POP), - Phalaris arundinaceae (REED), - Poa annua (ABG), - Sinapis arvensis (MD), - Triticum aestivum (WHFL).

The solutions of chemicals that are sprayed on the day of sowing are prepared as follows: water is used to dilute both compound 1 (emulsifiable concentrate at 80X) and compound 2 (emulsifiable concentrate at 25X).

Chemical solutions are distributed to the soil surface for pre-emergence applications using a linear spray table. The table is qualified for a spray volume of 235 L / ha (25 gallons / acre). Each compound is applied alone at the following application rates:
kg / ha
compound 1 ..................... 0.25 - 0.50 - 1.00 and 2.00
compound 2 ...................... 0.25 - 0.50 - 1.00 and 2.00
Compound 1 is applied with compound 2 at all rates corresponding to the possibilities of combination of application. Each test is squared 5 x 5 (including zero application rate) and is referred to as a full random block with two replicates.

The planks are placed in a greenhouse in the shade after spraying and sprayed over them. The air temperatures range from 15 to 17 C, the boards are wet during each experiment.

Nineteen days after treatment, the degree of growth in each row of young shoots is visually estimated on the basis of all the adverse factors. Planks of untreated young shoots are used for comparison. A zero percent damage or change in growth rate corresponds to the growth in the control boards. A one hundred percent damage rate is equivalent to a complete extermination.

The herbicidal interaction effects are evaluated using the Limpel's formula (Limpel L.E. et al., 1962, "Weed Control by Dimethyltetrachloroterephthalate Alone and in Certain Combinations", Proc.

NEWCC 16, 48-53):
E = X + y-XY
100 in which:
E = expected effect (E);
X = observed value (O) of the rate of change in growth in%
when the first herbicide is applied alone; and
Y = observed value (0) of the rate of change in growth in%
when the second herbicide is applied alone.

The effect or interaction (R) corresponding to a treatment with a herbicide combination is synergistic (S) when the observed value of the effect is greater than the expected value. It is understood that an effect is synergistic if the interaction effect is greater than the sum of the effects of each of the individual chemical treatments. An antagonistic effect (A) represents the opposite situation. An effect is additive (AD) when the observed effect is equal to the expected effect.

The following table shows the average of the data and the results of the experiments. It can be concluded that the joint applications of compound 1 and of compound 2 lead to various synergistic herbicidal effects.

TABLE 2
Compound 1 = S-benzyl -dipropyl thiolcarbamate
Compound 2 = 2,4-dichlorophenyl -p-nitrophenyl ester
Pre-emergence: study of compound 1 + compound 2
Growth change rate in%
kg / ha BDSW SBTM FUM POP MARE
OER OER OER OER OER
0 + 0 0 0 0 0 0
0 + 1/4 0 0 0 10 0
0 + 1/2 0 O 0 O 0
0 + 1 20 18 0 0 0
0 + 2 35 43 15 0 45 1/4 + 0 0 0 0 0 0 1/4 + 1/4 8 0 S 10 0 S 15 0 S 23 10 S 0 O AD 1/4 + 1/2 18 0 S 43 0 SOOSOO AD OO AD 1/4 + 1 25 20 S 50 18 S 30 0 SOO AD OO AD 1/4 + 2 30 35 A 73 43 S 68 15 S 10 0 S 35 45 A 1/2 + 0 0 13 20 0 0 1/2 + 1/4 10 0 S 25 13 S 0 20 A 0 10 AOO AD 1/2 + 1/2 10 0 S 45 13 S 0 20 AOO AD OO AD 1/2 + 1 0 20 A 58 29 S 38 20 SOO AD OO AD 1/2 + S 40 35 S 85 50 S 73 32 S 48 0 S 65 45 S
1 + 0 20 28 13 10 0
1 + 1/4 25 20 S 53 28 S 43 13 S 75 19 SOO AD
1 + 1/2 28 20 S 48 28 S 10 13 A 0 10 AOO AD
1 + 1 35 36 A 68 41 S 65 13 S 0 10 AOO AD
1 + 2 55 48 S 93 59 S 85 26 S 43 10 S 78 45 S
2 + 0 33 50 0 0 0
2 + 1/4 43 33 S 58 50 S 33 0 S 23 10 SOO AD
2 + 1/2 30 33 A 70 50 S 70 0 S 60 0 S 45 0 S
2 + 1 43 46 A 85 62 S 65 0 S 25 0 S 80 0 S
2 + 2 48 57 A 93 72 S 88 15 S 75 0 S 83 45 S
TABLE 2 (continued)
Pre-emergence :: study of compound 1 + compound 2
Growth change rate in%
kg / ha WO PBRO REED BKGR PRGR
OER OER OER OER OER
o + 0 0 0 0 0 0
0 + 1/4 45 25 73 68 35
O + 1/2 70 45 88 80 55
0 + 1 70 58 98 98 78
0 + 2 85 73 100 100 80 1/4 + 0 75 5 30 50 -0 1/4 + 1/4 70 86 A 30 29 S 80 81 A 83 84 A 40 35 S 1/4 + 1/2 83 93 A 63 48 S 98 92 S 95 90 S 60 55 S 1/4 + 1 80 93 A 78 60 S 100 99 S 98 99 A 70 78 A 1/4 + 2 93 96 A 90 74 S 100 100 AD 95 100 A 85 80 S 1/2 + 0 80 10 63 75 0 1/2 + 1/4 78 89 A 10 33 A 68 90 A 78 92 A 20 25 A 1/2 + 1/2 88 94 A 38 51 A 88 96 A 88 95 A 58 55 S 1/2 + 1 90 94 A 90 62 S 85 99 A 83 100 A 70 78 A 1/2 + S 93 97 A 100 76 S 100 100 AD 100 100 AD 93 80 S
1 + 0 83 78 95 90 55
1 + 1/4 88 91 A 70 85 A 95 99 A 90 97 A 73 71 S
1 + 1/2 88 95 A 88 88 AD 100 99 S 100 98 S 75 80 A
1 + 1 93 95 A 93 91 S 100 100 AD 100 100 AD 80 80 A
1 + 2 9398 A 9394 A 100 100 AD 100 100 AD 93 91 S
2 + 0 95 93 98 95 85
2 + 1/4 93 97 A 90 95 A 100 100 AD -98 98 AD 88 90 A
2 + 1/2 93 99 A 95 96 A 100 100 AD 100 99 S 95 93 S
2 + 1 95 99 A 95 97 A 100 100 AD 100 100 AD 95 97 A
2 + 2 95 99 A 98 98 AD 100 100 AD 100 100 AD 88 97 A
TABLE 2 (continued)
Pre-emergence :: study of compound 1 + compound 2
Growth change rate in%
kg / ha ABG WHFL BAIG RAJN MD
OER OER OER OER OER
0 + 0 0 0 0 0 0
0 + 1/4 40 0 O 0 10
0 + 1 / 2- 65 5 90 0 0
0 + 1 78 25 28 15 15
0 + 2 85 35 40 0 10 [/ 4 + 0 0 0 0 0 0 1/4 + 1/4 55 40 SO 0 AD OO AD 0 0 AD 0 10 A 1/4 + 1/2 60 65 A 10 5 S 10 0 SO 0 AD 15 0 SL / 4 + 1 58 78 A 28 25 S 15 28 A 15 28 A 0 15 AL / 4 + 2 85 85 AD 45 35 S 55 40 SO 0 AD OOAL / 2 + 0 0 0 0 5 10 L / 2 + 1/4 20 40 AO 0 AD OO AD 0 5 A 0 19 AL / 2 + 1/2 48 65 A 5 5 AD 10 0 S 0 5 A 8 10 AL / 2 + 1 70 78 A 20 25 A 10 28 A 0 19 A 0 24 AL / 2 + S 95 85 S 40 35 S 50 40 S 0 5 A 23 19 S
1 + 0 40 18 0 40 33
1 + 1/4 65 64 S 43 18 S 15 0 S 40 40 AD 38 40 A
1 + 1/2 73 79 A 43 22 S 25 0 S 30 40 A 10 33 A
1 + 1 83 97 A 33 39 A 28 28 AD 23 49 A 23 43 A
1 + 2 90 91 A 40 47 A 45 40 S 35 40 A 40 40 AD
2 + 0 - 45 30 55 30
2 + 1/4 90 - - 55 45 S 43 30 S 48 55 A 50 37 S
2 + 1/2 90 - - 45 48 A 48 30 S 48 55 A 43 30 S
2 + 1 95 - - 48 59 A 53 50 S 43 62 A 43 41 A
2 + 2 98 - - 68 64 S 65 58 S 45 55 A 45 37 S
The rates are shown respectively.

O = observed response.

E = expected response derived from Limpel's formula.

R = relation which can be: A: antagonist, S: synergistic- or AD: additive.

The compositions according to the present invention exhibit synergistic herbicidal activity in controlling the modification of the growth of undesirable vegetation when applied to such vegetation as a pre-emergence or post-emergence application. The compositions are, generally, incorporated into formulations which include inert or, occasionally, active ingredients or diluent carriers in addition to the active compounds. These ingredients or carriers are, for example, water, organic solvents, surfactants, oil, water-in-oil emulsions, wetting agents, dispersing agents and emulsifying agents. Herbicidal formulations generally take the form of wettable powders, emulsifiable solutions or concentrates.

Wettable powders are finely divided compositions comprising a particular carrier impregnated with the herbicidal agent and additionally containing one or more surfactants. The surfactant allows rapid dispersion of the powder in the aqueous medium and results in stable suspensions which can be sprayed.

A wide variety of surfactants can be used, for example long chain fatty alcohols and alkali metal salts of sulfated fatty alcohols; salts of sulfonic acid; long chain fatty acid esters; and polyhydric alcohols, in which the alcohol groups are free, polyethylene glycols having a relatively long chain length, substituted in omega.

The herbicidal compositions can also be applied to the foliage as a solution in a suitable solvent. Solvents commonly used in herbicidal formulations include kerogen, fuel oil, xylene, petroleum fractions with higher boiling points than xylene, and petroleum aromatics rich in methylated naphthalenes.

Preferred formulations are emulsifiable concentrates which consist of an oil solution of the herbicide and an emulsifying agent. Before use, the concentrate is diluted with water to form an emulsion containing, in suspension, drops of oil.

The emulsifying agents used are, in general, a mixture of anionic and nonionic surfactants. Other additives, such as spreading and sizing agents can be included in the emulsifiable concentrate.

The carefully described formulations can be applied to vegetation whose growth is to be controlled in any conventional manner before or after emergence from the soil.

Vegetation can be found at any stage of its development after emergence, from the young shoot stage to the stage of the plant having reached full size. The application can be carried out by any conventional technique using, for example, a device for spraying the ground or sprayers mounted on airplanes.

Various other application techniques will occur to those skilled in the art of pesticides.

Claims (10)

1.- Synergistic herbicidal composition comprising a mixture (a) of a herbicidal effective amount, of a thiolcarbamate of formula:

from about 0.25 / 1 to about 8/1. nyl-p-nitrophenylether, in a weight ratio of (a) to (b) chlorophenyl -3-methoxy-4-nitrophenyl ether and 2,4-dichl orophen 4-nitrophEnol-a, a, -trifluoro-2-nitro-p = tolylether, 2,4-di 4- (trifluoromethyl) -phenoxy} -N- (methylsulfonyl) -2-nitrobenzamide, ethoxy-4-nitrophenoxy) -4-trifluoromethyl) benzene, 5-f2-chl oro- methyl chlorophenoxy) phenoxyl-propionate, 2-chl oro-2- (3- Methyl 5- (2,4-dichlorophenoxy) -2-nitrobenzoate, 2-f2,4- (di- sodium ro-4- (trifluoromethylphenoxy} -2-nitrobenzoate, diphenyl ether selected from the group consisting of 5- {2-chlo (b) a herbicidally effective amount, a substituted derivative of C5 to C7; and with a C1 to C6 alkyl radical and a cycloalkyl radical in R1 and R2 are independently selected from the group consisting of X represents a hydrogen, chlorine or bromine atom; and in which: 2. A composition according to claim 1, wherein (a) is S-benzyl-dipropyl-thiolcarbamate and (b) is 2,4-dichlorophenyl-p-ni trophenyl ether. 3. A composition according to claim 1, wherein (a) is S-benzylethyl, 1,2-dimethylpropyl-thiolcarbamate and (b) is 2,4-di chl orophenyl -p-nitrophenyl ether. 4. A composition according to claim 1, wherein (a) is 5- (2-chlorobenzyl) -N, N-diethyl-thiolcarbamate and (b) is 2,4-dichlo rophenyl -p-ni trophenyl ether. 5.- Method of controlling the growth of undesirable vegetation which consists in the pre-emergence application or the post-emergence application to this vegetation of a herbicidal composition comprising a mange: (a) d 'a herbicidally effective amount of a thiolcarbamate of the formula:

chlorophenyl-3-methoxy-4-nitrophenylether and 2,4-dichlorophe-nyl -p-nitrophenyl ether. 4-nitrophenol-a,, -trifluoro-2-nitro-p-tolylether, 2,4-di 4- (trifluoromethyl) -phenoxy} -N- (methylsulfonyl) -2-nitrobenzamide, ethoxy-4-nitrophenoxy) -4-trifluoromethyl) benzene, 5-f2-chl oro- methyl chlorophenoxy) phenoxyl-propionate, 2-chloro-2- (3 Methyl 5- (2,4-dichlorophbnoxy) -2-nitrobenzoate, 2-12,4- (di- sodium ro-4- (trifl uoromethyl) phenoxyl-2-nltrobenzoate, the diphenylether selected from the group consisting of 5-f2-chlo- (b) a herbicidally effective amount, a substituted derivative of C5 to C7; and with a C1 to C6 alkyl radical and a cycloalkyl radical in R1 and R2 are independently selected from the group consisting of X represents a hydrogen, chlorine or bromine atom; and in which: 6. A method according to claim 5, wherein (a) is S-benzyl-dipropyl-thiolcarbamate and (b) is 2,4-dichlorophenyl-p-ni-trophenylether. 7. A method according to claim 5, wherein (a) is S-benzyl-ethyl, 1,2-dimEthylpropyl-thiolcarbamate and (b) is 2,4-dichlorophenyl-p-nitrophenyl ether. 8. A method according to claim 5, wherein (a) is S- (2-chlorobenzyl) -N, N-diethyl-thiolcarbamate and (b) is 2,4-dichlo rophenyl-p-nitrophenylether. 9.- Method of controlling undesirable vegetation which comprises the application in pre-emergence or the application in post-emergence to this vegetation of a herbicidal composition comprising a mixture: (a) an effective amount, as a herbicide, of a thiolcarbamate of the formula:

(b) from about 0.25 / 1 to about 8/1. thyl) phenoxy) -2-nitrobenzoate in a weight ratio of (a) to (b) a herbicidally effective amount of 5-i2-chloro-4- (trifluorome- C7; and with a C1 to C6 alkyl radical and a C1 to C6 alkyl radical R1 and R2 are independently selected from the group consisting of X represents a hydrogen, chlorine or bromine atom; and in which: 10.- Method of controlling the development of weed species chosen from Beta vulgaris, Fumaria officinalis, Papaver spp. or Matricaria recutita which comprises the application in pre-emergence or the application in post-emergence to these weed species of a herbicidal composition comprising a mixture (a) of S-benzyl-dipropylthiolcarbamate and (b) of 2, 4-dichlorophenyl-p-nitrophenylether, in a ratio of (a) to (b) of between about 8/1 and about 1/1.