NO126458B - - Google Patents

Description

Herbicide mixture containing

carbamoyloxyphenyl carbamates.

The present invention relates to herbicidal mixtures containing at least two compounds from the group of carbamoyloxyphenylcarbamates.

Herbicide mixtures with different active ingredients are often used. They earn, e.g. the purpose of destroying more completely a greater number of plant species with a single treatment than is possible using the individual components. Most herbicides, however, only produce the effect in mixtures that they would exhibit when used alone. An effect that goes beyond or is different from the effect of the individual components in such mixtures is, on the other hand, rather rare, and due to the as-yet lack of knowledge of the mechanism of action underlying such an effect, it cannot be foreseen.

Carbamoyloxyphenylcarbamates with herbicidal action are previously known (German specification 1,567-151 and French patent specification 1,498-834), but specific mixtures of these active substances have not yet been described.

It has now been found that mixtures containing at least two compounds of the general formula:

where

R^ is a phenyl group which is optionally substituted with lower alkyl, lower alkoxy or halogen,

R 2 is hydrogen or lower alkyl, and

R 1 is lower alkyl,

exhibits a herbicidal effect that is higher than the effect of the individual components at the same application concentration. Surprisingly, this effect also extends to weeds of the species Galium aparine, Amarantus retroflexus and Matricaria chamomilla, which are known to be very difficult to control.

Such an effect is particularly surprising as a mutual increase in effect between connections that are so closely related in constitution was the least to be expected.

The preferred combinations of agents are: methyl-N-(3-[N'-(3'-methylphenyl)-carbamoyloxy]-phenyl)-carbamate with respectively ethyl N-(3-[N * -(3-methylphenyl)-carbamoyloxy]-phenyl)-carbamate, methyl-N-[3-(N-phenylcarbamoyloxy)-phenyl]-carbamate or ethyl-N-[3- (N'-phenylcarbamoyloxy)-phenyl]-carbamate.

The mixtures according to the invention show when used post-emergence, e.g. at application amounts that lie at the minimum effective limit for the individual components, a sufficient herbicidal effect against weeds, which can only be combated to a lesser extent or not at all with corresponding application amounts of the individual components for the present mixtures. In addition to this broad effect against a wide variety of weeds, even with small amounts of application from approx. 0.5 kg/ha, the mixtures have the advantage that they have a high selectivity towards cultivated plants, e.g. sugar beet, beetroot, beetroot, rice and grain, which are not damaged by the use of the mixtures in post-emergence application.

The mixing ratio between the individual components in the mixtures can be varied within wide limits and is always dependent on the desired control result, on the type of weed to be controlled, or the unwanted plants, the age of the weeds or the plants, the prevailing atmospheric conditions as well as the method of application. It is therefore not possible to specify in advance a specific mixing ratio that would satisfy all possibilities in the same way, although on the other hand it has been shown that the effects found are not strictly dependent on specific mixing ratios.

In general, the mixing ratio for a two-component mixture can be from approx. 4:1 to approx. l:4i preferably from approx. 1:2

to approx. 2:1, while the mixing ratio for a three-component mixture can be roughly the same, i.e. approx. 1:1:1.

The total amount of the two components in a ready-to-use combination preparation can suitably amount to approx. 2 - 8% by weight, preferably 15 - 50% by weight of the agent. The most favorable content of total active ingredient in such combination preparations mainly depends on the amount and the type of application in which the agent is to be used for weed control. In addition, the preparations contain approx. 98 - 20% by weight of liquid or solid carriers and, if necessary, up to approx.

20% by weight surfactants, as discussed in more detail below.

The preferred quantities of active substances are for weed control

in sugar beet, beetroot, beetroot, strawberry, rice and grain approx. 0.5 -

4 kg/ha, but can be exceeded in special cases. The herbicidal effect of the mixtures, as well as that of the individual components, is particularly apparent in their emulsion preparations. This applies to a particular extent also to the mixing effect.

The use of the mixtures therefore preferably takes place as emulsions or in a preparation form other than that usual for herbicides, such as e.g. powder, flow agent, grains, solutions, emulsions or suspensions, with the addition of liquid/or solid carriers, respectively diluents and possibly surfactants, such as wetting, binding, emulsifying and/or dispersing aids as well as fertilizers or other substances. Suitable liquid carriers are water, mineral oils or other organic solvents, such as e.g. xylene, cyclohexanol, cyclohexanone, isophorone, chloroform, carbon tetrachloride, dimethylformamide, dimethylsulfoxide and others. As permanent carriers, e.g. namely lime, kaolin, chalk, talcum, attaclay and other clays.

As surfactants, e.g. in terms of anion-active, cation-active and non-ionic products, such as e.g. ethoxylated isooctylphenol, ethoxylated octylphenol, ethoxylated nonylphenol, alkylphenol polyglycol ether, tributylphenyl polyglycol ether, alkaryl polyether alcohols, isotridecyl alcohol, alkyl sulfates, lauryl ether sulfate, fatty alcohol-ethylene oxide condensates, ethoxylated castor oil> polyoxyethylene alkyl ether, ethoxylated polyoxypropylene, sorbitol esters and lauryl alcohol-polyglycoletheracetal.

Other herbicides can also be added, whereby it can be achieved that the spectrum of action becomes wider, or the herbicidal effect is increased. The selectivity will naturally not always be maintained. Mixture partners suitable as herbicides are e.g. active substances from the group of carbamic acid and thiocarbamic acid esters, the substituted anilines and anilides, triazines, amino-triazoles, diazines, such as uracils, e.g. 3-cyclohexyl-5,6-trimethyleneuracil, 1-phenyl-4-amino-5-chloropyridazone(6), aliphatic carboxylic acids and halocarboxylic acids, halogenated benzoic acids and phenylacetic acids, aryloxycarboxylic acids, hydrazides, amides, nitriles, halocarboxylic acids, e.g.0 2,2-dichloropropionic acid or its salts, tetrafluoropropionic acid or its salts, esters of such carboxylic acids, ureas, 2,3,6-trichlorobenzyloxypropanol and rhodan containing agents, and others.

As a further addition, e.g. also non-phyto-toxic additives, which in the case of herbicides can give a synergistic increase in effectiveness, such as wetting agents, emulsifiers, solvents and oily additives and others.

The production of these preparations can be carried out in a manner and manner known per se, e.g. by mixing or grinding processes. If desired, the individual components can also first be mixed just before their use, as it e.g. is done in the so-called tank mixing method in practice.

Considerable advantages are associated with the use of the present mixtures, since in order to achieve the same or, surprisingly, even better effect against many weeds, smaller amounts of active substance are required than when using the individual components alone.

The fight against weeds or unwanted plants can therefore be carried out more economically, safer and less dangerous and with the greatest possible sparing of the cultivated plants.

Weeds that can be combated particularly well with the present mixtures are seed weeds, such as e.g. Stellaria medda, Lamium amplexicaule, Chenopodium album, Amaranthus retroflexus, Galium aparine, Matricaria chamomilla and Setaria italica.

In the following, some carbamates are listed which are used in the mixtures according to the invention, which can be produced by methods known per se.

The above-mentioned carbamates also individually have a herbicidal effect, although the described increase in effect occurs first in the mixture according to the invention. \

The following examples will illustrate the invention.

Example 1

In greenhouses, the plants indicated below at a growth height of 5 - 10 cm were treated with the 3-carbamoyloxyphenylcarbamates: Methyl-N-(3-[N'-(3'-methylphenyl)-carbamoyloxy]-phenyl)-carbamate (I)

Ethy1-N-(3-[N'-(3'-methylphenyl)-carbamoyloxy]-phenyl)-carbamate (H)

Methyl N-[3-(N'-phenylearbamoyloxy)-phenyl]-carbamate

(III)

Ethyl-N-[3-(N'-phenylcarbamoyloxy)-phenyl]-

carbamate (IV)

Methyl N-(3-[N *-(3*-chlorophenyl)-carbamoyloxy]-phenyl)-carbamate (V)

Ethyl N-(3-[N * -(3'-chlorophenyl)-carbamoyloxy]-phenyl)-carbamate (VI)

Methyl N-(3-[N'-(4'-methylphenyl)-carbamoyloxy]-phenyl)-carbamate (VII)

in a dosage of 0.5 kg of active substance per hectares. In addition, other plants were treated with the mixtures indicated in the table. The amount used was also here 0.5 kg of total active substance per hectares.

The agents were sprayed evenly on the plants as aqueous emulsions with 600 l of water per hectares. 10 days after the treatment, the mixtures for the listed weed species showed a clearly better effect than the individual components. A special test showed full compatibility with Beta turnips.

Example 2

In greenhouses, the plants listed below at a growth height of 5 - 10 cm were treated with methyl-N-(3-[N'-(3'-methylphenyl)-carba-moyloxy ]-phenyl)-carbamate (I) in a dosage amount of 0.5 kg of active ingredient per hectares. The following active substances were also applied with the same amount of application: Methyl-N-(3_[N'-(3'-methoxyphenyl)-carbamoyloxy]-phenyl)-carbamate (VIII)

Methyl N-(3-[N'-(3',5'-dimethylphenyl)-carbamoyloxy]-phenyl)-carbamate (IX)

Methyl N-[3-(N'-methyl-N'-phenyl-carbamoyloxy)-phenyl]-carbamate (X)

In addition, the plants were treated with the following mixtures: Active substance I 0.25 kg/ha + active substance VIII 0.25 kg/ha Active substance I 0.25 kg/ha + active substance IX 0.25 kg/ha Active substance I 0.25 kg/ha + active substance X 0.25 kg/ha The agents were sprayed evenly on the plants as aqueous emulsions with 600 1 water per hectares. 10 days after the treatment, the mixtures showed a clearly better effect on many weed species than the individual components. This included full compatibility with Beta-beets and/or rice, wheat and barley.

Claims (2)

1. Herbicidal mixture, characterized in that it contains at least two compounds of the general formula: where R^ is a phenyl group optionally substituted with lower alkyl, lower alkoxy or halogen, R^ is hydrogen or lower alkyl, and R^ is lower alkyl. 2. Herbicidal mixture according to claim 1, characterized in that it contains methyl-N-(3-[N'-(3'-methylphenyl)-carbamoyloxy]-phenyl)-carbamate and ethyl-N-(3_ [N'-(3'-methylphenyl)-carbamoyloxy] -phenyl)-carbamate . 3- Herbicide mixture according to claim 1, characterized in that it contains methyl-N-(3-[ N'-(3'-methylphenyl)-carbamoyloxy]-phenyl)-carbamate and methyl-N-[3-(N'-phenylcarbamoyloxy)-phenyl ]-carbamate. 4- Herbicide mixture according to claim 1, characterized in that it contains methyl-N-(3-[N'-(3'-methylphenyl)-carbamoyloxy]-phenyl)-carbamate and ethyl-N-[3-(N'-phenylcarbamoyloxy)-phenyl]- about rbamate.