DE3444860A1 - Selective herbicide - Google Patents

Abstract

The novel active substance combination of (a) (trimethylsilyl)methyl 2-[4-(3,5-dichloropyridin-2-oxy)-phenoxy]propionate, of the formula <IMAGE> and (b) 4-amino-6-tert-butyl-3-ethylthio-1,2,4-triazin-5(4H)-one, of the formula <IMAGE> is distinguished by a very good selective herbicidal activity.

Description

Selective weed control agents

The present invention relates to a new combination of active ingredients from a known pyridoxyphenoxypropionic acid derivative on the one hand and from a well-known triazinon on the other hand and particularly good for selective Weed control in crops of useful plants is suitable.

It is already known that 2- / 4- (3,5-dichloropyridin-2-oxy) -phenoxy7-propionic acid (trimethylsilyl) methyl ester has herbicidal activity (see EP-OS 0 096 354). It is also known that weeds with the help of Let 4-amino-6-tert-butyl-3-ethylthio-1,2,4-triazin-5 (4H) -one be combated selectively (See U.S. Patent 3,671,523). The substances mentioned are characterized by a good selective herbicidal activity, but leaves the tolerance to crop plants in some cases much to be desired.

It has now been found that the new active ingredient combination of (a) 2- [4- (3,5-dichloro-pyridin-2-oxy) -phenoxy] -propionic acid (trimethylsilyl? -Methyl ester of the formula and (b) 4-amino-6-tert-butyl-3-ethylthio-1,2,4-triazin-5 (4H) -one of the formula has a particularly good selective herbicidal effectiveness.

Surprisingly, the compatibility of the invention The combination of active ingredients compared to crop plants is significantly higher than the sum of the tolerances of the individual active ingredients. So there is an unpredictable antagonistic Effect and not just a supplement.

The compound of the formula (I) contains an asymmetrically substituted one Carbon atom in the propionic acid unit and can therefore be in two enantiomers to shape are present. The invention relates to both an active ingredient combination, which contains the racemate of the compound of formula (I), as well as a combination of active ingredients, which contains the R enantiomer *) of the compound of the formula (I).

The active ingredients contained in the active ingredient combination according to the invention are already known (cf. EP-OS 0 096 354 and US-PS 3,671,523).

The antagonistic effect of the active ingredient combination according to the invention shows up especially when the active ingredients of formulas (I) and (II) in certain Weight ratios are available. However, the weight ratios in the combination of active ingredients can be varied over a relatively wide range. In general allotted to 1 part by weight of active ingredient of the formula (II) 0.01 to 0.6 parts by weight, preferably 0.05 to 0.5 parts by weight of active ingredient of the formula (I).

The active ingredient combination according to the invention shows a very good effect against weeds and grass weeds in crops of useful plants, in particular in cereals. Weeds and grass weeds in the broadest sense are all plants that grow in places where they are undesirable.

*) In the present case, the R enantiomer is optical active compound of formula (I) to understand the most asymmetrically substituted Carbon atom of the propionic acid unit has the R configuration.

The active ingredient combination according to the invention can e.g.

be used in the following plants: dicot weeds the Genera: Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio, Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Solanum, Rorippa, Rotala, Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis, Papaver, Centaurea.

Dicot cultures of the genera: Gossypium, Glycine, Beta, Daucus, Phaseolus, Pisum, Solanum, Linum, Ipomoea, Vicia, Nicotiana, Lycopersicon, Arachis, Brassica, Lactuca, Cucumis, Cucurbita.

Monocot weeds of the genera. Echinochloa, Setaria, Panicum, Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus, Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristylis, Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea, Dactyloctenium, Agrostis e Alopecurus, Apera.

Monocot cultures of the genera: Oryza, Zea, Triticum, Hordeum, Avena, Secale, Sorghum, Panicum, Saccharum, Ananas, Asparagus, Allium.

However, the use of the active ingredients according to the invention is by no means limited to these genera, but extends in the same way to other plants.

The use of the active ingredient combination according to the invention for selective Weed control is preferably possible in cereal crops, such as Wheat and barley.

The combination of active ingredients can be converted into the usual formulations such as solutions, emulsions, wettable powders, suspensions, powders, dusts, Pastes, soluble powders, granules, suspension-emulsion concentrates, active ingredient-impregnated Natural and synthetic materials, finest encapsulation in polymer materials.

These formulations are prepared in a known manner, e.g. Mixing the active ingredients with extenders, i.e. liquid solvents, under Liquefied gases under pressure and / or solid carriers, if appropriate using surface-active agents, i.e. emulsifiers and / or dispersants and / or foam-generating agents.

In the case of using water as an extender, e.g. organic solvents can be used as auxiliary solvents. As a liquid solvent are essentially: aromatics, such as xylene, toluene or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons, such as chlorobenzenes, Chlorethylene or methylene chloride, aliphatic hydrocarbons such as cyclohexane or paraffins, e.g. petroleum fractions, alcohols such as butanol or glycol and their Ethers and esters, ketones, such as Acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents such as dimethylformamide and dimethyl sulfoxide, as well as water.

The following can be used as solid carriers: e.g. natural rock flour, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth and synthetic minerals such as fumed silica, alumina and Silicates; Solid carriers for granulates are: e.g. broken ones and fractionated natural rocks such as calcite, marble, pumice, sepiolite, dolomite as well as synthetic granules made from inorganic and organic flours and granules made of organic material such as sawdust, coconut shells, corn on the cob, and tobacco stalks; as emulsifying and / or foam-generating agents come into question: e.g. non-ionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, e.g. alkylaryl polyglycol ethers, alkyl sulfonates, alkyl sulfates, aryl sulfonates and Protein hydrolysates; Possible dispersants are: e.g. lignin sulphite waste liquors and methyl cellulose.

Surface-active substances come into consideration as further additives. Preferably lecithins, phospholipids, isopropyl myristate and those under the names can be used Agridex, Azone, Surfactant WK and Emulsifier OX are known substances.

Adhesives such as carboxymethyl cellulose, natural and synthetic powdery granular or latex-shaped Polymers are used, such as gum arabic, polyvinyl alcohol, polyvinyl acetate.

Dyes such as inorganic pigments, e.g. iron oxide, titanium oxide, Ferrocyan blue and organic dyes such as alizarin, azo and metal phthalocyanine dyes and trace nutrients such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc can be used.

The formulations generally contain between 0.1 and 95% by weight Active ingredient, preferably between 0.5 and 90%.

The active ingredient combination according to the invention can be used as such or in their formulations also mixed with known herbicides for weed control Find use, finished formulation or tank mixing is possible. Even a mixture with other known active ingredients, such as fungicides, insecticides, acaricides, Nematicides, bird repellants, growth substances, plant nutrients and Soil structure improvers is possible.

The active ingredient combination can be used as such, in the form of their formulations or the use forms prepared therefrom by further dilution, such as ready-to-use Solutions, suspensions, emulsions, powders, pastes and granulates can be used. It is used in the usual way, e.g. by watering, squirting, atomizing, Sprinkle.

The active ingredient combination according to the invention can both before and be applied after the plants emerge. It can also be pre-sown in be incorporated into the floor.

The amount of active ingredient used can fluctuate over a wide range. It essentially depends on the type of effect you want. In general the application rates are between 0.1 and 5 kg of active ingredient per hectare, preferably between 0.5 and 2.5 kg / ha.

The good herbicidal effect and the excellent plant tolerance The following example shows the effectiveness of the active ingredient combination according to the invention emerged.

While the individual active ingredients have weaknesses in plant tolerance have, the combination shows a plant tolerance that is higher than a simple Effect summation goes beyond.

With herbicides, there is always an antagonistic effect when the plant tolerance of the active ingredient combination is better than that of the individual applied active ingredients and at the same time the herbicidal potency is not impaired will.

The expected effect for a given combination of two herbicides can (cf. Colby, S. R., 'tCalculating synergistic and antagonistic responses of herbicide combinations ", Weeds 15, pages 20-22, 1967) can be calculated as follows: if X =% damage by herbicide A at p kg / ha application rate and Y =% damage by herbicide B at q kg / ha application rate and E = the expected damage to the herbicides A and B at p and q mean the application rate, then E = X + Y - X. Y 100 If the actual damage to the cultivated plants is less than calculated, then the effect of the combination is not additive; i.e. there is an antagonistic one Effect before.

As can be seen from the example below, the is damaging The effect of the active compound combination according to the invention on the crop plants is smaller than the calculated. So there is a real antagonistic effect.

Example A Post-emergence test / field solvent: 5 parts by weight Acetone emulsifier: 1 part by weight of alkylaryl polyglycol ether Active ingredient preparation is mixed with 1 part by weight of active ingredient or active ingredient mixture the specified amount of solvent, adds the specified amount of emulsifier and dilutes the concentrate with water to the desired concentration.

In the field, test plants that are 3 to 10 cm in height are used have, sprayed with the respective active ingredient preparation so that the particular desired Amount of active ingredient per unit area is applied. The concentration of the spray liquid is chosen so that the particular amount of active compound desired is applied in 2,000 l of water / ha will.

After three weeks, the degree of damage to the plants is rated in % Damage compared to the development of the untreated control. It means: 0% no effect (like untreated control) 100% total destruction.

In this test, the active ingredient combination according to the invention shows a Plant tolerance that is better than the plant tolerance of the individual Active ingredients.

Active ingredients, active ingredient concentrations and test results go from the following table.

Table A Post-emergence test / field Active ingredient active ingredient Alopercus barley wheat kg / ha collected *) calculated *) collected *) calculated **) collected *) calculated **) (II) 1.25 100 0 15 (I) 0.18 100 10 5 (R enantiomer) (II) 1.25 + # + # 100 100 0 10 0 19.25 (I) 0.18 (R enantiomer) *) found. = damage found **) calc. = damage calculated using the Colby formula given above

Claims (5)

Claims: 1. Herbicidal agents for selective weed control, characterized by a content of an active ingredient combination consisting of (a) 2- [4- (3,5-dichloro-pyridin-2-oxy) -phenoxy] -propionic acid- (trimethylsilyl) - methyl ester of the formula and (b) 4-amino-6-tert-butyl-3-ethylthio-1,2,4-triazin-5 (4H) -one of the formula 2. Agent according to claim 1, characterized in that the weight ratio of active ingredient of formula (II) to active ingredient of formula (I) in the active ingredient combination is between 1: 0.01 and 1: 0.6. 3. Methods for selective weed control in crops of useful plants, characterized in that an active ingredient combination of the active ingredients of the Formulas (I) and (II) apply to the plants or their habitat. 4. Use of an active ingredient combination from the active ingredients of the formulas (I) and (II) for selective weed control in crops of useful plants. 5. Process for the preparation of herbicidal agents for selective Weed control in crops of useful plants, characterized in that one Combination of active ingredients from the active ingredients of formulas (I) and (II) with extenders and / or surfactants mixed.