WO1998002043A1

WO1998002043A1 - Synergistic herbicides

Info

Publication number: WO1998002043A1
Application number: PCT/EP1997/003474
Authority: WO
Inventors: Hernando Pabon
Original assignee: Hoechst Schering Agrevo Gmbh
Priority date: 1996-07-11
Filing date: 1997-07-02
Publication date: 1998-01-22
Also published as: CO4750595A1; AR007736A1; AU3345797A; DE19627900A1; PA8433801A1; PE90298A1; BR9703950A

Abstract

Combinations of propanyl and anilofos have a synergistic effect and are useful as herbicides for controlling harmful plants in cultures of useful plants such as rice.

Description

Synergistic herbicidal agents

The invention relates to combinations of herbicides which can be used to control harmful plants in crops

A large number of herbicide active ingredients are available today for combating a spectrum of harmful plants in crops. However, the effect of individually applied herbicide active ingredients is often not sufficient in practice.So the herbicidal action of individual active ingredients generally varies from harmful plant to harmful plant and there are naturally differences in flora depending on the climatic zone and soil conditions.Resistance is sometimes observed in some harmful plants after long-term use of an active ingredient.However, increasing the application rate of a single active ingredient to adequately combat less sensitive harmful plants means that there are limits due to cost reasons and ineffectiveness.An increase in the application rate then helps, for example not if this results in increased undesirable herbicidal side effects on the useful plants. It is also frequently observed that resistance to em active ingredient can only be compensated for a short time by increasing the application rate and after some time the resistance occurs even with the higher application rate

Combinations of herbicides with different mechanisms of action may be suitable for solving the above-mentioned problems.However, the search for suitable combination partners, with which the ineffectiveness of the individual active compound in some harmful plants or resistant harmful plants is to be compensated for, is increased by physical or physiological intolerance of the combination active compounds Side effects in crops are more difficult Combination active substances that have an over-additive effect, ie synergistic effect in pest plants, were ideal. However, due to the relatively low application rate of the individual active ingredients in the combination, they can be used without giving rise to any significant harmful effects on crop plants. However, such beneficial synergistic effects can practically never be predicted for combination active ingredients.

It is known that the herbicide Propanil, i. H. N- (3,4-dichloropheπyl) propanoic acid amide, for controlling monocotyledonous and dicotyledonous harmful plants in cereals such as, for. B. rice and wheat, preferably in rice at a rate of 2.5 to 5 kg / ha of active substance in the post-emergence method, in particular harmful plants of the type Amaranthus retroflexus, Digitaria spp., Echinochloa spp., Panicum spp. and Setaria spp. can be fought (see "The Pesticide Manual", British Crop Protection Council & The Royal Society of Chemistry, UK, 10th edition 1994; hereinafter referred to as "The Pesticide Manual")

In addition, the herbicide Anilofos, d. H. S-4-Ch! Or-N-isopropylcarbaniloylmethyl-dithiophosphoric acid dimethyl ester, for combating grasses such as Echinochloa, Cyperus, Fimbristylis and Scirpus spp. used in rice crops (see "The Pesticide Manual", 10th edition 1994).

Surprisingly, it has now been found that combinations of propanil and anilofos give superadditive (synergistic) effects in a number of harmful plants and are very suitable for controlling some harmful plants in which resistance to one or both of the individual active compounds occurs.

The invention therefore relates to herbicidal compositions, characterized by an effective content of a combination of A) a compound of formula (A)

O— lj— NHÜOCH ₂ ÜM _{3 (A)}

cι

(Propanil) and

B) a compound of formula (B)

(Anilofos)

The combination of the active ingredients can be used in a conventional manner, either by spray application of a spray broth prepared from individual formulations of the active substances in the tank mix or a spray broth prepared by dilution with water from a mixed formulation of the active substances are common for the application of the individual active ingredients and enable a common application. Because propanil is absorbed and acted less by the roots than by the green parts of the plant, propanil is primarily suitable for application in the post-emergence process. Anilofos, on the other hand, is both leaf and soil-effective.Because of the properties of propanil, however, the combination according to the invention is preferably applied by spraying a spray booth Post-emergence method applied to the plants

In principle, the application can also be carried out by successive applications of the individual active ingredients (A) and (B), the possible time interval in Preliminary tests can be determined The active ingredients (A) and (B) can optionally also be used in combination with other active pesticide ingredients

With the same herbicidal action on harmful plants, the application rate of a single active ingredient in the combination is significantly reduced in comparison with the application rate of the individual active ingredient in question when used alone. The optimal choice of the weight ratio and the application rates depends, for example, on the stage of development of the weeds or weeds, weed spectrum, environmental factors and climatic conditions or also depending on the type of additional crop protection agents used

The weight ratios of the combined herbicides (A) and (B) can therefore vary within wide limits, they are generally between 20 1 and 1 1, preferably 12 1 and 3 1, in particular 10 1 and 4 1, based on the ratio ( A) (B) The application rate for the herbicide (A) (propanil) in the combination is generally in the range from 0.5 to 4.5 kg, preferably 1 to 3.5 kg, in particular 1.5 to 3 kg of active substance per hectare The application rate for the herbicide (B) (anilofos) in the combination is generally in the range from 50 to 1000 g, preferably 100 to 800 g, in particular 200 to 500 g of active substance per hectare

The combinations of the compounds of the formulas (A) and (B) according to the invention have excellent herbicidal activity against a broad spectrum of economically important mono- and dicotyledonous harmful plants. In part, perennial weeds which are difficult to control and which sprout from rhizomes, rhizomes or other permanent organs are also found the active substances are usually applied in the post-emergence process, preferably in the early post-emergence process.For example, some representatives of the monocotyledonous and dicotyledonous weed flora can be mentioned, which can be controlled by the compounds according to the invention, without being restricted to certain species by the name should be done On the monocotyledon weed species, for example, species from the Echinochloa, Panicum, Digitaπa, Setaπa, Ischaemum species and Cyperus species from the annual group are well recorded. In the case of dicotyledon weed species, species such as Amaranthus should be emphasized

Weeds which occur especially in rice under the specific culture conditions, such as, for example, Echinochloa, Eleusme, Leptochloa, Digitaπa, Sagittaπa, Ahsma, Eleochaπs, Scirpus and Cyperus, are combated by the active compounds according to the invention Harmful plants of the Echinochloa spp type, such as Echinochloa colona, tend to develop resistance, which can be found in rice cultivation areas, especially in the case of transplanted rice

When the active ingredient combinations are applied to the green plant parts in the early post-emergence process, a drastic growth stop occurs very quickly after the treatment and the weed plants remain in the growth stage at the time of application or die completely after a certain time, so that one for the crop plants harmful weed competition is eliminated very early and sustainably

Although the active compound combinations have excellent herbicidal activity against monocotyledonous and dicotyledon weeds, rice crops from sown or transplanted rice are only insignificantly damaged or not at all harmed. Other useful plants, preferably cereal plants, are not very badly damaged during application good for selective control of undesired plant growth in the corresponding agricultural crops The invention also relates to herbicidal compositions which contain combinations of active compounds (A) and (B) and customary formulation auxiliaries

The combinations according to the invention and their individual active substances can be formulated in various ways, depending on which biological and / or chemical-physical parameters are specified. Possibility of formation include, for example, powdered powders (WP), water-soluble powders (SP), water-soluble concentrates, emulsifiable concentrates ( EC), emulsions (EW), such as oil-in-water and water-in-oil emulsions, sprayable solutions, suspension concentrates (SC), dispersions based on oil or water, oil-miscible solutions, capsule suspensions (CS), dusting agents (DP ), Pickling agents, granules for litter and soil application, granules (GR) in the form of micro, spray, elevator and adsorption granules, water-dispersible granules (WG), water-soluble granules (SG), ULV formulations, microcapsules and waxes

These individual formulation types are known in principle and are described, for example, in Wmnacker-Kuchler, "Chemische Technologie", Volume 7, C Hauser Verlag Munich, 4 ed. 1986, Wade van Valkenburg, "Pesticide Formulations", Marcel Dekker, NY, 1973, K Martens "Spray Drymg" Handbook, 3rd Ed 1979, G Goodwin Ltd London

The necessary formulation aids such as inert materials, surfactants, solvents and other additives are also known and are described, for example, in Watkins, "Handbook of Insecticide Dust Diluents and Carπers", 2nd Ed, Darland Books, Caldwell NJ, H v Olphen "Introduction to Clay Colloid Chemistry ", 2nd Ed, J Wiley & Sons, NY, C Marsden," Solvents Guide ", 2nd Ed, Inters ence, NY 1963, McCutcheon's" Detergents and Emulsifiers Annual ", MC Publ Corp, Ridgewood NJ, Sisley and Wood," Encyclopedia of Surface Active Agents ", Chem Publ Co Ine, NY 1964, Schonfeldt," Grenzflächenaktiv Athyienoxidaddukte ", Wiss Verlagsgesellschaft, Stuttgart 1976, Wmnacker-Kuchler," Chemische Technologie ", Volume 7, C Hauser Verlag Munich, 4 ed. 1986 On the basis of these formulations, combinations with other pesticidally active substances, such as, for example, insecticides, acacids, other herbicides, fungicides, safeners, growth regulators and / or fertilizers, can also be prepared, for example in the form of a finished formulation or as a tank mix

Spray powders are preparations which are uniformly dispersible in water and, in addition to the active ingredient, in addition to a diluent or inert substance, also surfactants of an ionic and / or nonionic type (wetting agents, dispersants), for example polyoxyethylated alkylphenols, polyoxethylated fatty alcohols, polyoxethylated fatty amines, fatty alcohol polyglycol ether sulfates, alkanesulfonates, alkylbenzene sulfonates, alkylbenzene sulfonates , 2,2'-dιnaphthylmethane-6,6'-dιsulfonsauresodium, dibutylnaphthalenesulfonsauresodium or oleoylmethyltaunnsauresodium contain For the preparation of the wettable powders, the herbicidal active ingredients are finely ground, for example, in conventional equipment such as hammer mills, blower mills and air jet mills and simultaneously or subsequently Formulation aids mixed

Emulsifiable concentrates are prepared by dissolving the active ingredients in an organic solvent, e.g. butanol, cyclohexanone, dimethylformamide, xylene or higher-boiling aromatics or hydrocarbons or mixtures of the organic solvents with the addition of one or more ionic and / or nonionic surfactants (emulsifiers). As emulsifiers can be used, for example, alkylarylsulfonic acid calcium salts such as Ca-dodecylbenzenesulfonate or nonionic emulsifiers such as fatty acid polyglycol esters, alkylaryl polyglycol ethers, fatty alcohol polyglycol ethers, propylene oxide-ethylene oxide condensation products, alkyl polyethers, sorbitan esters such as, for example, sorbitan oxyethyl fatty acid ester esters, polyphenol fatty acid sorbitan fatty acid such as borbitan fatty acid polybutyl ester or polybutyl sorbitol such as borbitan fatty acid polybutyl sorbetate

Dusting agents are obtained by grinding the active ingredients with finely divided solid substances, e.g. talc, natural clays such as kaolin bentonite and pyrophyllite or diatomaceous earth Suspension concentrates can be water- or oil-based. They can be prepared, for example, by wet grinding using commercially available pearl mills and, if appropriate, addition of surfactants, such as those already listed above for the other types of formulation

Emulsions e.g. B OI-in water emulsions (EW) can be prepared, for example, by means of stirrers, colloid mills and / or static mixers using aqueous organic solvents and optionally surfactants, such as those already listed above for the other types of formulation

Granules can either be produced by spraying the active ingredients onto adsorbable, granulated inert material or by applying active ingredient concentrates using adhesives, e.g. polyvinyl alcohol, polyacrylic acid sodium or mineral oils, on the surface of carriers such as sand, kaolinites or granulated inert material granulated in the usual way for the production of fertilizer granules - if desired in a mixture with fertilizers

Water-dispersible granules are usually produced by the usual methods such as spray drying, fluidized bed granulation, plate granulation, mixing with high-speed mixers and extrusion without solid inert material

The agrochemical preparations generally contain 0.1 to 99% by weight, in particular 0.1 to 95% by weight, of active compounds of the formula (A) and / or (B)

The active ingredient concentration in wettable powders is, for example, about 10 to 90% by weight, the remainder to 100% by weight consists of customary formulation constituents. In the case of emulsifiable concentrates, the active ingredient concentration can be about 1 to 90% by weight. Dust-like formulations contain, for example, 1 to 30, mostly 5 to 20% by weight of active ingredient. Sprayable solutions, for example 0.05 to 80, mostly 2 to 50% by weight of active ingredient. In the case of water-dispersible granules, the active ingredient content depends in part on whether the active compound is liquid or solid and which granulation aids, fillers, etc. are used in water-dispersible granules the active substance content is, for example, between 1 and 95% by weight, mostly between 10 and 80% by weight

In addition, the active ingredient formulations mentioned may contain the customary adhesives, wetting agents, dispersants, emulsifiers, penetrants, preservatives, antifreeze agents and solvents, fillers, carriers and dyes, defoamers, evaporation inhibitors and agents which influence the pH and viscosity

Known active ingredients, such as those described, for example, in Weed Research 26, 441-445 (1986) or "The Pesticide Manual", 10th edition, 1994 and cited there, can also be used as combination partners for the active ingredients according to the invention in mixture formulations or in the tank mix Literature are preferably described for use in rice crops

For use, the formulations available in commercial form are optionally diluted in the customary manner, for example in the case of wettable powders, emulsifiable concentrates, dispersions and water-dispersible granules by means of water, and then onto the plants, parts of plants or the agricultural or industrial soil or the area under cultivation on which the plants stand or in which they grow or are present as seeds, this also includes special application variants as are customary in rice cultivation, for example the watering application, in which the herbicidal compositions are applied to the backwater of the irrigated area, dust-like preparations, Soil or scatter granules and sprayable solutions are usually no longer diluted with other inert substances before use

Surprisingly, it has been found that when herbicide (A) is used together with herbicide (B) under otherwise customary conditions, superadditive (= synergistic) herbicidal effects occur in harmful plants, the selectivity being retained in the case of cereals such as rice. These effects allow a reduction in the application rate Control of a broader spectrum of weeds and grass weeds, faster use of herbicidal effects, longer lasting effects, better control of harmful plants with only one or Few applications and an extension of the possible application period These properties are required in practical weed control in order to keep agricultural crops free of undesired competing plants and thus to ensure and / or increase the yield qualitatively and quantitatively. The technical standard is due to the new combination with regard to the properties described clearly surpassed

In the following examples, quantities and percentages relate to the weight, unless otherwise defined

A Examples of formulation

a) A dusting agent is obtained by mixing 10 parts by weight of an active ingredient combination according to the invention and 90 parts by weight of talc as an inert substance and comminuting them in a hammer mill

b) A wettable powder which is readily dispersible in water is obtained by adding 25 parts by weight of active compounds (A) + (B), 64 parts by weight of kaolin-containing quartz as an inert substance, 10 parts by weight of lignosulfonic acid potassium and 1 part by weight of oleoylmethyltaunic acid sodium mixes as a wetting and dispersing agent and grinds in a pin mill

c) A dispersion concentrate which is readily dispersible in water is obtained by mixing 20 parts by weight of active compounds (A) + (B) with 6 parts by weight of alkylphenol polyglycol ether (© Triton X 207), 3 parts by weight of isotecdecanol polyglycol ether (8 EO) and 71 parts by weight Parts of paraffinic mineral oil (boiling range e.g. approx. 255 to 277 ° C) and ground in a friction ball mill to a fineness of less than 5 microns

d) An emulsifiable concentrate is obtained from 15 parts by weight of cyclohexanone as solvent and 10 parts by weight of oxyethylated nonylphenol as emulsifier e) A water-dispersible granulate is obtained by adding 75 parts by weight of active ingredients (A) + (B), 0 parts by weight of calcium lignosulfonic acid,

5 parts by weight of sodium lauryl sulfate,

3 parts by weight of polyvinyl alcohol and

Mix 7 parts by weight of kaolin, grind on a pin mill and granulate the powder in a fluidized bed by spraying water as granulating liquid

f) Water-dispersible granules are also obtained by adding 25 parts by weight of active ingredients (A) + (B),

5 parts by weight of 2,2'-naphthylmethane-6,6'-disulfonic acid sodium,

2 parts by weight of sodium oleoylmethyltaunn acid,

1 part by weight of polyvinyl alcohol,

17 parts by weight of calcium carbonate and

50 parts by weight of water are homogenized and pre-comminuted on a colloid mill, then ground on a bead mill and the suspension obtained is dusted and dried in a spray tower using a single-component nozzle

B Biological examples

1 Assessment of harmful effects and evaluation of synergism

The harmful effect on the plants is assessed according to the dry weight of the harvested plant material on a scale from 0 to 100% (standard method according to Abbott) 0% = no recognizable effect compared to the untreated one

Plant, i.e. the dry matter is 100% = treated plant dies, the dry weight is in

This is negligible compared to that of the untreated plant

In some cases, the assessment was also made visually compared to untreated controls and also given on a rating scale from 0 to 100% (0% = no difference to the control, 100% = plant completely dead)

An assessment of the synergism with the active ingredients used here must take into account the greatly different application rates of the individual active ingredients.Therefore, it does not make sense to compare the effects of the active ingredient combinations and those of the individual active ingredients in each case at the same application rates Application rates or by reducing the application rates of the two individual active ingredients in the case of combined use in comparison to the application rates of the active ingredients in the case of individual application with the same effect in each case

In all cases, a distinction is made in the combinations between the calculated and the found efficiency. In the majority of the cases, the synergistic increase in activity is so high that the effect of the combination clearly exceeds the formal (numerical) sum of the effects of the individual substances known effects of the individual active ingredients were not to be expected The theoretically expected efficiency of a combination can be estimated approximately according to the formula by SR Colby (see "Calculation of synergistic and antagonistic responses of herbicide combinations", Weeds 15 (1967), pages 20-22)

This formula is for combinations of two

Y

E = X + Y

100 where

X =% damage by herbicide A at an application rate of x kg / ha, Y =% damage by herbicide B at an application rate of y kg / ha, E = damage to be expected from herbicides A + B at x + y kg / ha

If the actual damage is greater than the expected damage, the effect of the combination is more than additive, i.e. there is a synergistic effect

Weed action in the post-emergence

2 1 General procedure (greenhouse trial)

Seeds or rhizome pieces of monocotyledonous and dicotyledonous weeds are placed in pots with sandy loam soil, covered with soil and grown in the greenhouse under good growth conditions. For some tests under conditions in rice cultivation, the weeds are grown in pots with water-saturated soil or in pots with soil, in whose water is up to 2 cm above the surface of the soil and cultivated during the test phase Three to four weeks after sowing, the test plants are treated in the two- or three-leaf stage, with any existing accumulation water being drained off beforehand, if necessary. For application, they are used as emulsion concentrates formulated active ingredient combinations according to the invention and, in parallel tests, the correspondingly formulated individual active ingredients in various dosages with a water application rate of 300 l / ha sprayed onto the green plant parts. After 2 weeks of standing of the test plants in the greenhouse under optimal growth conditions, the effect of the preparations is assessed in comparison with untreated controls The compositions according to the invention have good herbicidal activity against a broad spectrum of economically important grass weeds and weeds

2.2 Control of Echinochloa colona and selectivity in rice (greenhouse trial)

a) Control of Echinochloa colona

Echinochloa colona seeds from fields for the cultivation of transplanted rice were grown in plastic soil with sandy soil (see Section 2 1). Propanil and anilofos, each formulated as emulsifiable concentrates, were mixed in a tank mix and applied with a water application rate of 300 l / ha Harmful plants spread in the 2- or 3-leaf stage After two weeks of standing of the test plants in the greenhouse under optimal growth conditions, the effect of the preparations was rated in comparison to untreated controls in accordance with Section 1. The results of the ratings are summarized in Table 1

The effect of the combinations according to the invention in each case far exceeded the expected value according to Colby and was accordingly synergistic Table 1 Effect on Echinochloa colona (post-emergence test)

Product dose effect in% effect in% ga I / ha application stage 2-leaf application stage ^* 3-leaf

Propanil 1920 57.5 28.6

Propanil 2880 74.5 33.9

Anilofos 300 63.9 65.9

Anilofos 450 73.2 67.0

Propanil 1920 + 300 94.3 94.4 + Anilofos (84.6) (75.7)

Propanil 1920 + 450 96.2 97.5 + Anilofos (88.6) (76.4)

Propanil 2880 + 300 99 97.4 + anilofos (90.8) (77.6)

Propanil 2880 + 450 99.0 98.6 + Anilofos (93.2) (78.3)

Abbreviations.

1. The effect values in brackets are expected values according to Colby (see Section 1)

2. a.i. = active ingredient = based on 100% active ingredient

3rd stage of application = stage of application of Echinochloa colona

b) Selectivity in rice crops

The effect of the herbicidal compositions on transplanted rice was investigated in analogous experiments. In all cases, the effect on rice was about the same and was usually less than 10% harmful compared to untreated rice 3.2 Effect on Echinochloa colona (field trial)

Echinochloa colona seeds from fields for the cultivation of transplanted rice were grown on field plots in sandy soil. Propanil and anilofos, each formulated as emulsifiable concentrates, were mixed in a tank mix and applied to the harmful plants at the two-leaf stage with a water application rate of 300 l / ha. After two The test plants were rated for weeks after the test plants had been compared to untreated controls in accordance with Section 1. The results of the ratings are summarized in Table 2.

Table 2. Post-emergence trial (field trial)

Active substance (s) dose effect in% g ai / ha application stage ^* 2-leaf

Propanil 1920 38.5

Propanil 2880 44.7

Anilofos 300 12.6

Anilofos 450 15.9

Propanil 1920 + 300 77.3 + Anilofos (46.2)

Propanil 1920 + 450 93.3 + Anilofos (48.3)

Propanil 2880 + 300 93.5 + anilofos (51, 6)

Propanil 2880 + 450 96.7 + anilofos (53.5)

Abbreviations: see table 1 3 3 Effect on other rice pests (field trial)

Seeds of harmful plants from fields for the cultivation of transplanted rice were grown on field plots in sandy soil. Propanil and anilofos, each formulated as emulsifiable concentrates, were mixed in the tank mix and applied to the harmful plants at a water application rate of 300 l / ha three weeks after sowing After the test plants had been left to stand for two weeks, the effect of the preparations was assessed visually in comparison with untreated controls (see section 1). The results of the evaluations are summarized in Table 3

Table 3 Post-emergence trial (field trial)

Drug (s) dose effect in% effect in% effect in% g a i / ha at ISCRU at DIGSA at ELEIN

Propanil 1920 85 80 83

Anilofos 300 35 38 30

Anilofos 450 43 45 38

Anilofos 900 50 50 48

Propanil 1920 + 300 93 93 92 + Anιlofos (90.3) (87.6) (88.1)

Propanil 1920 + 450 95 95 95

+ Anιlofos (91, 5) (89.0) (89.5)

Propanil 1920 + 900 95 95 95 + Anιlofos (92.5) (90) (91.2)

Abbreviations See table 1 as well

ISCRU = Ischaemum rugosum (Grammaceae)

DIGSA = Digitana sangumalis and ELEIN = Eleusιne indica

Claims

claims

1 Herbicidal agent, characterized by an effective content of one

combination of

A) a compound of formula (A)

B) a compound of formula (B)

(Anilofos)

Herbicidal compositions according to claim 1, characterized in that the herbicides (A) and (B) are contained in a weight ratio of 20 1 to 1 1

Herbicidal compositions according to claim 1 or 2, characterized in that the herbicides (A) and (B) are contained in a weight ratio of 12 1 to 3 1

Herbicidal compositions according to one of claims 1 to 3, characterized in that they contain 0.1 to 99% by weight of active ingredients (A) and (B) and 99.1 to 1% by weight of customary formulation auxiliaries 5 A method for controlling unwanted harmful plants, if appropriate in crops, characterized in that an effective amount of a combination of a herbicide (A) and a herbicide (B) on the harmful plants, parts of plants thereof or the area of the soil on which they grow or the cultivated area is applied, the herbicides (A) and (B) as defined in claim 1

6 The method according to claim 5, characterized in that harmful plants are selectively controlled in rice crops in the post-emergence process

7. The method according to claim 5 or 6, characterized in that the harmful plant is Echinochloa colona

8 Use of a combination of a compound of formula (A) and a compound of formula (B) as a herbicide, wherein the compounds (A) and (B) are as defined in claim 1

9. Use according to claim 8 for combating harmful plants in rice crops

10 Use according to claim 8 or 9 for combating Echinochloa colona