The invention relates also to a method of controlling weeds in crops of useful plants, comprising the herbicidal composition, and to the use of the novel composition for that purpose.

Compound a) 7- [ (4, 6-dimethoxypyrimidin-2-yl) thiol]-3-methylphthalide of formula I exhibits herbicidal action, as described, for example, in EP-A-0 447 506 and EP-A-0 768 034.

It has now surprisingly been found that a combination of variable amounts of active ingredients, that is to say of an active ingredient of formula I under a) with one or more of the herbicidal active ingredients listed under b), all of which are known and some of which are also available commercially, exhibits a synergistic action that is capable of controlling, both pre-emergence and post-emergence, the majority of the weeds and grasses occurring especially in crops of useful plants, without causing any appreciable damage to the useful plants.

There is therefore proposed in accordance with the present invention a novel synergistic composition for the selective control of weeds that, in addition to comprising customary inert formulation adjuvants, comprises as active ingredient a mixture of a) a herbicidally effective amount of the compound of formula I b) a synergistically effective amount of one or more compounds selected from the group consisting of the co-herbicides: paraquat (592), pyrazogyl, mesotrione (500), sulcotrione (710), clomazone (159), prosulfocarb (656), pretilachlor (632), cinosulfuron (154), molinate (542) and trifloxysulfuron, with the two active ingredient combinations consisting of compound of formula I + pretilachlor, and compound of formula I + cinosulfuron, being excluded.

The compound of formula I is known as a herbicide under the common name"pyriftalid" (ISO 1750) and is registered under CAS Reg. No. [135186-78-6].

The herbicidal active ingredients above under b) are known and are described, for example, in"The Pesticide Manual", Editor C. D. S. Tomlin, 12th Edition, British Crop Protection Council, 2000, under the entry numbers added in brackets; for example mesotrione (500) is described therein under entry number 500.

The compound of formula 2.1 is known as a herbicide under the common name"pyrazogyl" (Aventis; Code No. AEB 172391) and is registered under CAS Reg. No. [158353-15-2].

The compound of formula 2.2 is known as a herbicide under the common name"trifloxysulfuron" (ISO, 1750), registered under CAS Reg. No. [145099-21-4] and published in WO 00/52006.

The following specific active ingredient combinations have proved especially effective synergistic compositions: compound of formula I + paraquat; compound of formula I + pyrazogyl ; compound of formula I + mesotrione; compound of formula I + sulcotrione ; compound of formula I + clomazone ; compound of formula I + prosulfocarb ; compound of formula I + trifloxysulfuron ; and compound of formula I + molinate.

The following specific active ingredient combinations have likewise proved especially effective active ingredient combinations: compound of formula I + molinate + mesotrione; compound of formula I + molinate + pretilachlor ; compound of formula I + molinate + cinosulfuron ; compound of formula I + molinate + trifloxysulfuron ; compound of formula I + cinosulfuron + trifloxysulfuron ; compound of formula I + mesotrione + cinosulfuron + pretilachlor ; compound of formula I + molinate + cinosulfuron + pretilachlor ; and compound of formula I + cinosulfuron + pretilachlor + trifloxysulfuron.

It is extremely surprising that the combination of the active ingredient of formula I under a) with one or more-active ingredients selected from the co-herbicides under b) exceeds the additive action on the weeds to be controlled that is to be expected in principle and thus broadens the range of action of the individual active ingredients especially in two respects: firstly, the rates of application of the individual compounds of formula I under a) and co- herbicides under b) are reduced while a good level of action is maintained. Secondly, the composition according to the invention achieves a high level of weed control also in those cases where the individual substances, in the range of low rates of application, have become useless from the agronomic standpoint. The result is a substantial broadening of the spectrum of weeds and an additional increase in selectivity in respect of the crops of useful plants, as is necessary and desirable in the event of an unintentional overdose of active ingredient. The composition according to the invention, while retaining excellent control of weeds in crops of useful plants, also allows greater flexibility in succeeding crops.

The composition according to the invention can be used against a large number of agronomically important weeds, such as Eleocaris, Nasturtium, Ludwigia spp. , Digitaria, Lindernia spp. , Setaria, Fimbristylis, Leptochloa, Solanum, Phaseolus, Echinochloa, Scirpus, Monochoria, Sagittaria, Alopecurus, Sorghum halepense, Rottboellia, Cyperus, Abutilon, Sida, Xanthium, Ipomoea and Chrysanthemum. The composition according to the invention is suitable for all methods of application conventionally used in agriculture, for example pre- emergence application, post-emergence application and seed dressing. The composition according to the invention is suitable especially for controlling weeds in crops of useful plants, such as rice.

"Crops"are to be understood to mean also those crops which have been rendered tolerant to herbicides or classes of herbicides as a result of conventional methods of breeding or genetic engineering.

The composition according to the invention comprises the active ingredient of formula I under a) and the co-herbicide under b) in any desired mixing ratio, but usually has an excess of one of the components over the other (s). Generally, the mixing ratios (ratios by weight) of the active ingredient of formula I and the co-herbicides under b) is from 1: 2000 to 2000 : 1, especially from 200: 1 to 1: 200.

The rate of application may vary within wide limits and depends on the nature of the soil, the method of application (pre-or post-emergence; seed dressing; application to the seed furrow; no tillage application etc. ), the crop plant, the weed to be controlled, the prevailing climatic conditions and other factors governed by the method of application, the time of application and the target crop. The active ingredient mixture according to the invention can generally be applied at a rate of from 1 to 5000 g of active ingredient mixture/ha, especially from 1 to 2000 g of active ingredient mixture/ha.

The invention relates also to a method for the selective control of weeds and grasses in crops of useful plants, which comprises treating the useful plants, seeds or cuttings thereof, or the area of cultivation thereof, simultaneously or separately with an amount, effective for herbicide synergy, of the herbicide a) and at least one further co-herbicide b).

Preference is given to a method in which the herbicide a) is applied to the useful plants or to the area of cultivation of those useful plants and, together with the herbicide a) or at a later time, a further co-herbicide b) or, optionally, a mixture of such substances, is applied. The compounds that come into consideration as herbicide a) and co-herbicides b) are the same active ingredients as those mentioned hereinabove.

The mixtures of the compound of formula I under a) with the co-herbicides under b) may be used in unmodified form, that is to say as obtained in synthesis. Preferably, however, they are formulated in customary manner, together with the adjuvants conventionally used in formulation technology, such as solvents, solid carriers or surfactants, for example into emulsifiable concentrates, directly sprayable or dilutable solutions, dilute emulsions, wettable powders, soluble powders, dusts, granules or microcapsules, as described in WO 97/34483, pages 9 to 13. As with the nature of the compositions, the methods of application, such as spraying, atomising, dusting, wetting, scattering or pouring, are chosen in accordance with the intended objectives and the prevailing circumstances.

The formulations, i. e. the compositions, preparations or mixtures comprising the compound of formula I under a) and the co-herbicides under b), and also, where appropriate, one or more solid or liquid formulation adjuvants, are prepared in a manner known perse, e. g. by intimately mixing and/or grinding the active ingredients with the formulation adjuvants, e. g. solvents or solid carriers. In addition, surface-active compounds (surfactants) may also be used in the preparation of the formulations.

Examples of solvents and solid carriers are given, for example, in WO 97/34485, page 6.

Depending on the nature of the compound of formula I and of the co-herbicides under b) to be formulated, suitable surface-active compounds are non-ionic, cationic and/or anionic surfactants and surfactant mixtures having good emulsifying, dispersing and wetting properties.

Examples of suitable anionic, non-ionic and cationic surfactants are listed, for example, in WO 97/34485, pages 7 and 8.

Also suitable for the preparation of the herbicidal compositions according to the invention are the surfactants conventionally employed in formulation technology, which are described, inter alia, in"McCutcheon's Detergents and Emulsifiers Annual"MC Publishing Corp. , Ridgewood New Jersey, 1981, Stache, H.,"Tensid-Taschenbuch", Carl Hanser Verlag, MunichNienna, 1981 and M. and J. Ash,"Encyclopedia of Surfactants", Vol 1-111, Chemical Publishing Co. , New York, 1980-81.

The herbicidal formulations usually contain from 0.1 to 99 % by weight, especially from 0.1 to 95 % by weight, of active ingredient mixture comprising the compound of formula I together with the co-herbicides under b), from 1 to 99.9 % by weight of a solid or liquid formulation adjuvant, and from 0 to 25 % by weight, especially from 0.1 to 25 % by weight, of a surfactant.

Whereas commercial products are usually formulated as concentrates, the end user will normally employ dilute formulations. The compositions may also comprise further ingredients, such as stabilisers, e. g. vegetable oils or epoxidised vegetable oils (epoxidised coconut oil, rapeseed oil or soybean oil), antifoams, e. g. silicone oil, preservatives, viscosity regulators, binders, tackifiers, and also fertilisers or other active ingredients. Preferred formulations have especially the following compositions: (% = percent by weight) Emulsifiable concentrates: active ingredient mixture: 1 to 90 %, preferably 5 to 20 % surfactant : 1 to 30 %, preferably 10 to 20 % liquid carrier: 5 to 94 %, preferably 70 to 85 % Dusts: active ingredient mixture: 0.1 to 10 %, preferably 0.1 to 5 % solid carrier: 99.9 to 90 %, preferably 99.9 to 99 % Suspension concentrates: active ingredient mixture: 5 to 75 %, preferably 10 to 50 % water: 94 to 24 %, preferably 88 to 30 % surfactant: 1 to 40 %, preferably 2 to 30 % Wettable powders: active ingredient mixture: 0.5 to 90 %, preferably 1 to 80 % surfactant: 0.5 to 20 %, preferably 1 to 15 % solid carrier: 5 to 95 %, preferably 15 to 90 % Granules: active ingredient mixture: 0.1 to 30 %, preferably 0.1 to 15 % solid carrier: 99.5 to 70 %, preferably 97 to 85 % The following Examples illustrate the invention further, but do not limit the invention.

F1. Emulsifiable concentrates a) b) c) d) active ingredient mixture 5 % 10 % 25 % 50 % calcium dodecylbenzenesulfonate 6% 8% 6% 8% castor oil polyglycol ether 4 %-4 % 4 % (36 mol of ethylene oxide) octylphenol polyglycol ether-4 %-2 % (7-8 mol of ethylene oxide) cyclohexanone--10 % 20 % arom. hydrocarbon mixture 85 % 78 % 55 % 16 % C9-C12 Emulsions of any desired concentration can be obtained from such concentrates by dilution with water.

F2. Solutions a) b) c) d) active ingredient mixture 5% 10% 50% 90% 1-methoxy-3- (3-methoxy- propoxy)-propane-20 % 20 % polyethylene lycol MW 400 20 % 10 % - - <BR> <BR> <BR> N-methyl-2-pyrrolidone--30 % 10 % arom. hydrocarbon mixture 75 % 60 % Cg-C12 The solutions are suitable for use in the form of microdrops.

F3. Wettable powders a) b) c) d) active ingredient mixture 5 % 25 % 50 % 80 % sodium lignosulfonate 4 % - 3 % - sodium lauryl sulfate 2 % 3 % - 4 % sodium diisobutylnaphthalene- sulfonate - 6 % 5 % 6 % octylphenol polyglycol ether-1 % 2 % (7-8 mol of ethylene oxide) highly dispersed silicic acid 1 % 3 % 5 % 10 % kaolin 88 % 6 % 35 % - The active ingredients are (or the active ingredient mixture is) mixed thoroughly with the adjuvants and the mixture is thoroughly ground in a suitable mill, affording wettable powders which can be diluted with water to give suspensions of any desired concentration.

F4. Coated granules a) b) c) active ingredient mixture 0. 1 % 5 % 15 % highly dispersed silicic acid 0. 9 % 2 % 2 % inorganic carrier 99. 0 % 93 % 83 % (diameter 0.1-1 mm) e. g. CaCO3 or Si02 The active ingredients are (or the active ingredient mixture is) dissolved in methylene chloride and applied to the carrier by spraying, and the solvent is then evaporated off in vacuo.

F5. Coated granules a) b) c) active ingredient mixture 0. 1 % 5 % 15 % polyethylene glycol MW 200 1. 0% 2% 3% highly dispersed silicic acid 0. 9 % 1 % 2 % inorganic carrier 98. 0 % 92 % 80 % (diameter 0.1-1 mm) e. g. CaCO3 or SiO2 The finely ground active ingredients are (or the finely ground active ingredient mixture is) uniformly applied, in a mixer, to the carrier moistened with polyethylene glycol. Non-dusty coated granules are obtained in this manner.

F6. Extruder granules a) b) c) d) active ingredient mixture 0. 1 % 3 % 5 % 15 % sodium lignosulfonate 1. 5% 2% 3% 4% carboxymethylcellulose 1. 4% 2% 2% 2% kaolin 97. 0 % 93 % 90 % 79 % The active ingredients are (or the active ingredient mixture is) mixed and ground with the adjuvants, and the mixture is moistened with water. The mixture is extruded and then dried in a stream of air.

F7. Dusts a) b) c) active ingredient mixture 0. 1 % 1 % 5 % talcum 39.9 % 49 % 35 % kaolin 60. 0 % 50 % 60 % Ready-to-use dusts are obtained by mixing the active ingredients (or the active ingredient mixture) with the carriers and grinding the mixture in a suitable mill.

F8. Suspension concentrates a) b) c) d) active ingredient mixture 3 % 10 % 25 % 50 % ethylene glycol 5 % 5 % 5 % 5 % nonylphenol polyglycol ether-1 % 2 % - (15 mol of ethylene oxide) sodium lignosulfonate 3% 3% 4% 5% carboxymethylcellulose 1 % 1 % 1 % 1 % 37 % aqueous formaldehyde 0. 2 % 0. 2% 0. 2 % 0. 2 % solution silicone oil emulsion 0. 8 % 0. 8 % 0. 8 % 0. 8 % water 87 % 79 % 62 % 38 % The finely ground active ingredients are (or the finely ground active ingredient mixture is) intimately mixed with the adjuvants, giving a suspension concentrate from which suspensions of any desired concentration can be obtained by dilution with water.

It is often more practical for the compound of formula I and the mixing partner or partners under b) to be formulated separately and to be brought together in the desired mixing ratio in the applicator in the form of a"tank mixture"in water shortly before application.

Biotoaica) Exampies : A synergistic effect exists whenever the action of the active ingredient combination of compound of formula I and co-herbicides under b) is greater than the sum of the actions of the active ingredients applied separately.

The herbicidal action to be expected We for a given combination of two herbicides can be calculated as follows (see COLBY, S. R.,"Calculating synergistic and antagonistic response of herbicide combinations", Weeds 15, pages 20-22,1967) : We=X+ [Y (100-X)/100] wherein: X = percentage herbicidal action on treatment with the compound of formula I at a rate of application of p kg per hectare, compared with the untreated control (= 0 %).

Y = percentage herbicidal action on treatment with a co-herbicide under b) at a rate of application of q kg per hectare, compared with the untreated control.

We = expected herbicidal action (percentage herbicidal action compared with the untreated control) following treatment with the compound of formula I under a) and co-herbicide under b) at a rate of application of p + q kg of active ingredient per hectare.

When the action actually observed is greater than the value to be expected We, there is a synergistic effect.

The synergistic effect of the combinations of the compound of formula I under a) with the co- herbicides under b) is demonstrated in the following Examples.

Example B1 : Experiment description-pre-emergence test Monocotyledonous and dicotyledonous test plants are sown in standard soil in plastics pots.

Directly after sowing, the test compounds are applied alone and in the form of a mixture to the soil surface. The application is carried out using an aqueous suspension of the test compounds prepared from a 25 % suspension concentrate (Example F8, c) ), using 500 litres of water/ha. The rates of application depend on the optimum concentrations ascertained under field conditions or greenhouse conditions. The test plants are then grown on in the greenhouse under optimum conditions. The tests are evaluated after from 1 to 4 weeks (% action, 100 % = plant has died, 0 % = no phytotoxic action).

The mixtures used in this test exhibit good synergistic effects.

Example B2: Experiment description-post-emergence test The test plants are grown to the 1-to 3-leaf stage in plastics pots under greenhouse conditions. A standard soil is used as cultivation substrate. At the 1-to 3-leaf stage, the herbicides are applied to the test plants on their own and as a mixture. The application is carried out using an aqueous suspension of the test compounds prepared from a 25 % suspension concentrate (Example F8, c) ), using 500 litres of water/ha. The rates of application depend on the optimum doses ascertained under field conditions or greenhouse conditions. The tests are evaluated after from 1 to 4 weeks (% action, 100 % = plant has died, 0 % = no phytotoxic action).

Test plants : Useful plant : rice (Arborio) ; weeds: Echinochloa crus galli (1-to 2-leaf stage) and Sagittaria pygmaea or Sagittaria sp..

Examples of the synergistic activity of the combinations of the compound of formula I with at least one co-herbicide under b), molinate or trifloxysulfuron, are given in Tables B2.1 to B2.6.

Table B2.1 : Tests with compound of formula I (pyriftalid) and molinate (2000 g/ha), alone and in admixture, post-emergence, in the presence of rice (3-leaf stage) and 2 weeds.

Herbicidal activity in [%] 7 days after application by spraying. Compound Rate of Useful plant : Echinochloa Echinochloa Sagittaria application rice (Arborio) crus galli (1-crus gaffai (2-pygmaea [g of active leaf stage) leaf stage) ingredient/ha] pyriftalid 180 40 90 95 60 molinate 2000 10 40 10 30 pyriftalid + 180+2000 20 (We=46) 95 (We=94) 98 (We=95.5) 90 (We=72) molinate Table B2.2 : Tests with compound of formula I (pyriftalid) and molinate (1000 g/ha) alone and in admixture, post-emergence, in the presence of rice (3-leaf stage) and 2 weeds.

Herbicidal activity in [%] 7 days after application by spraying. Compound Rate of Useful plant : Echinochloa Echinochloa Sagittaria application rice (Arborio) crus galli (1-crus galli (2-pygmaea [g of active leaf stage) leaf stage) ingredient/ha] pyriftalid 180 40 90 95 molinate 1000 0 20 0-- pyriftalid + 180+1000 10 (We=40) 95 (We=92) 98 (We=95) molinate Table B2.3 : Tests with compound of formula I (pyriftalid) and molinate (2000 g/ha) alone and in admixture, post-emergence, on Sagittaria pygmaea. Herbicidal activity in [%] 7 days after application by injection of the active ingredients or of the mixture directly into the paddy water. Compound Days after application Rate of application Sagittaria pygmaea by injection into paddy [g of active ingredient/ha] water pyriftalid 7 180 20 molinate 7 2000 0 pyriftalid 180 + 7 + 80 (We=20) molinate 2000 Table B2.4 : Tests with compound of formula I (pyriftalid) and molinate (2000 g/ha) alone and in admixture, post-emergence, on Sagittaria pygmaea. Herbicidal activity in [%] 14 days after application by injection of the active ingredients or mixture directly into the paddy water. Compound Days after Rate of application Sagittaria pygmaea application by [g of active injection into paddy ingredient/ha] water pyriftalid 14 180 20 molinate 14 2000 0 pyriftalid 180 + 14 + 95 (We=20) molinate 2000 Table B2.5 : Tests with compound of formula I (pyriftalid) and molinate (2000 g/ha) alone and in admixture, post-emergence, on Sagittaria pygmaea. Herbicidal activity in [%] 21 days after application by injection of the active ingredients or mixture directly into the paddy water. Compound Days after Rate of application Sagittaria pygmaea application by [g of active injection into paddy ingredient/ha] water pyriftalid 21 180 40 molinate 21 2000 0 pyriftalid 180 + 21 + 98 (We=40) molinate 2000 Table B2.6 : Tests with compound of formula I (pyriftalid) and trifloxysulfuron alone and in admixture, post-emergence, in the presence of rice (3-leaf stage) and Sagittaria sp..

Herbicidal activity in [%] 15 days in the case of rice, and 29 days in the case of Sagittaria, after application of the active ingredients or mixture by spraying. Compound Rate of application Useful plant : Sagittaria sp. [g of active rice (Arborio) ingredient/ha] pyriftalid 150 11 13 trifloxysulfuron 5 31 73 pyriftalid 150 + + 18 (We=39) 88 (We=77) trifloxysulfuron 5 pyriftalid 150 11 13 trifloxysulfuron 7. 5 36 83 pyriftalid 150 + + 26 (We=43) 93 (We=85) trifluoxysulfuron 7.5 The same results are obtained when the test compound of formula I and molinate are formulated in accordance with Examples F1 to F7.

It has been shown, surprisingly, that particular safeners are suitable for mixing with the synergistic composition according to the invention. The present invention accordingly relates also to a selectively herbicidal composition for controlling grasses and weeds in crops of useful plants, especially in crops of rice, that comprises a compound of formula I under a), one or more compounds selected from the co-herbicides under b), and a safener (counter- agent, antidote) and that protects the useful plants, but not the weeds, against the phytotoxic action of the herbicide, as well as to the use of such a composition in the control of weeds in crops of useful plants.

There is accordingly also proposed in accordance with the invention a selectively herbicidal composition that, in addition to comprising customary inert formulation adjuvants, such as carriers, solvents and wetting agents, comprises as active ingredient a mixture of ab) an amount, effective for herbicide synergy, of the compound of formula I under a) and one or more compounds selected from the co-herbicides under b), and c) an amount, effective for herbicide antagonism, of a compound selected from the group consisting of the compound of formula 3.1 and the compound of formula 3.2 and the compound of formula 3.3 (3.3), and the free acid and salts thereof, and the compound of formula 3.4 (3.4), and the free acid and salts thereof, and the compound of formula 3.5 and the compound of formula 3. 6 and the compound of formula 3.7 Cl2CHCoN (CH2CH=CH2) 2 (3 7)- The compounds of formulae 3.1 to 3.7 are known and are described, for example, in"The Pesticide Manual", 12th Edition, British Crop Protection Council, 2000, under entry numbers 65 (formula 3.1, benoxacor), 325 (formula 3.2, fenclorim), 163 (formula 3.3, cloquintocet- mexyl), 492 (formula 3.4, mefenpyr-diethyl), 324 (formula 3.6, fenchlorazole-ethyl) and 225 (formula 3.7, dichlormid).

The free acid and salts of cloquintocet-mexyl (formula 3.3) are known, for example, from the Swiss Application No. 2000 2066/00, and the free acid and salts of mefenpyr-diethyl (formula 3.4) are known, for example, from WO 01/17353.

The compounds of formula 3.5 are known under the common name"isoxadifen"and "isoxadifen-ethyl", are described in DE-A-4 331 448 and registered under the CAS Reg. Nos.

[209866-92-2] and [163520-33-0], and. the compound of formula 3.6 is described in DE-A-3 525 205.

Preferred selective compositions according to the invention comprise as safener a compound selected from the compounds of formulae 3.1 to 3.7 in combination with the above-mentioned especially effective synergistic compositions that comprise the compound of formula I and one or more compounds selected from the group consisting of the co- herbicides under b).

Especially preferred selective compositions according to the invention comprise as safenrer a compound selected from the compounds of formulae 3.1, 3.2, 3.4, 3.5 and 3.7 in combination with the above-mentioned especially effective synergistic compositions that comprise the compound of formula I and one or more compounds selected from the group consisting of the co-herbicides under b).

The invention relates also to a method for the selective control of weeds in crops of useful plants, which comprises treating the useful plants, seeds or cuttings thereof, or the area of cultivation thereof, with a herbicidally effective amount ab) of the herbicide of formula I and one or more herbicides selected from the co-herbicides under b), and an amount, effective for herbicide antagonism, of a safener of formulae 3. 1 to 3.7 under c).

As crop plants that can be protected by the safeners of formulae 3.1 to 3.7 against the damaging effect of the above-mentioned herbicides there comes into consideration especially rice. "Crops"are to be understood to mean also those crops which have been made tolerant to herbicides or classes of herbicides as a result of conventional methods of breeding or genetic engineering.

The weeds to be controlled may be both monocotyledonous and dicotyledonous weeds, e. g.

Eleocaris, Nasturtium, Ludwigia spp. , Digitaria, Lindernia spp. , Setaria, Fimbristylis, Leptochloa, Solanum, Phaseolus, Echinochloa, Scirpus, Monochoria, Sagittaria, Alopecurus, Sorghum halepense, Rottboellia, Cyperus, Abutilon, Sida, Xanthium, Ipomoea and Chrysanthemum.

Areas of cultivation include the areas of ground on which the crop plants are already growing or which have already been sown with the seeds of those crop plants, as well as ground intended for cultivation with such crop plants.

Depending on the intended use, a safener of formula 3.1 to 3.7 can be used in the pretreatment of the seed of the crop plant (dressing of the seeds or cuttings) or can be introduced into the soil before or after sowing. It can, however, also be applied, either alone or together with the herbicide, after emergence of the plants. The treatment of the plants or seeds with the safener can therefore in principle be carried out independently of the time at which the herbicide is applied. The plants can, however, also be treated by simultaneous application of herbicide and safener (e. g. in the form of a tank mixture). The ratio of the rate of application of safener to the rate of application of herbicide depends largely on the method of application. In the case of field treatment, which is carried out either using a tank mixture comprising a combination of safener and herbicide or by separate application of safener and herbicide, the ratio of herbicides to safener is generally from 100: 1 to 1: 10, preferably from 20: 1 to 1: 1. In the case of field treatment it is usual to apply from 1 to 1000 g of safener/ha, preferably from 1 to 250 g of safener/ha.

The rate of application of herbicides is generally from 1 to 5000 g/ha, but preferably from 1 to 2000 g/ha.

The compositions according to the invention are suitable for all methods of application conventionally used in agriculture, e. g. pre-emergence application, post-emergence application and seed dressing.

In the case of seed dressing, generally from 0.001 to 10 g of safener/kg of seed, preferably from 0.05 to 2 g of safener/kg of seed, are applied. When the safener is applied in liquid form shortly before sowing, with soaking of the seeds ; then advantageously the safener solutions used contain the active ingredient in a concentration of from 1 to 10 000 ppm, preferably from 100 to 1000 ppm.

For the purpose of application, the safeners of formulae 3.1 to 3.7 or combinations of those safeners with ab) the herbicide of formula I and one or more herbicides selected from the co- herbicides under b) are advantageously formulated together with adjuvants customary in formulation technology, e. g. into emulsifiable concentrates, coatable pastes, directly sprayable or dilutable solutions, dilute emulsions, wettable powders, soluble powders, dusts, granules or microcapsules.

Such formulations are described, for example, in WO 97/34485, pages 9 to 13. The formulations are prepared in known manner, e. g. by intimately mixing and/or grinding the active ingredients with liquid or solid formulation adjuvants, e. g. solvents or solid carriers. In addition, surface-active compounds (surfactants) can also be used in the preparation of the formulations. Solvents and solid carriers suitable for that purpose are mentioned, for example, in WO 97/34485, page 6.

Depending on the nature of the compound ab) of formula I and co-herbicides under b) and safener under c) of formulae 3.1 to 3.7 to be formulated, there come into consideration as surface-active compounds non-ionic, cationic and/or anionic surfactants and surfactant mixtures having good emulsifying, dispersing and wetting properties. Examples of suitable anionic, non-ionic and cationic surfactants are listed, for example, on pages 7 and 8 of WO 97/34485. Also suitable for the preparation of the herbicidal compositions according to the invention are the surfactants conventionally employed in formulation technology, which are described, inter alia, in"McCutcheon's Detergents and Emulsifiers Annual" MC Publishing Corp. , Ridgewood New Jersey, 1981, Stache, H.,"Tensid-Taschenbuch", Carl HanserVerlag, MunichNienna, 1981 and M. and J. Ash,"Encyclopedia of Surfactants", Vol. 1-111, Chemical Publishing Co., New York, 1980-81.

The herbicidal formulations usually contain from 0.1 to 99 % by weight, especially from 0.1 to 95 % by weight, of active ingredient mixture comprising ab) the compound of formula I and at least one compound selected from the co-herbicides under b), and the safeners under c) of formulae 3.1 to 3.7, from 1 to 99.9 % by weight of a solid or liquid formulation adjuvant and from 0 to 25 % by weight, especially from 0.1 to 25 % by weight, of a surfactant.

Whereas commercial products are usually formulated as concentrates, the end user will normally employ dilute formulations.

The compositions may also comprise further ingredients, such as stabilisers, e. g. vegetable oils or epoxidised vegetable oils (epoxidised coconut oil, rapeseed oil or soybean oil), anti- foams, e. g. silicone oil, preservatives, viscosity regulators, binders, tackifiers, and also fertilisers or other active ingredients. For the use of safeners under c) of formulae 3.1 to 3.7, or of compositions comprising them, in the protection of crop plants against the damaging effects of ab) herbicides of formula I and co-herbicides under b), various methods and techniques come into consideration, such as, for example, the following : i) Seed dressing a) Dressing of the seeds with a wettable powder formulation of a compound of formulae 3.1 to 3.7 by shaking in a vessel until uniformly distributed over the seed surface (dry dressing).

In that procedure approximately from 1 to 500 g of compound of formulae 3. 1 to 3.7 (4 g to 2 kg of wettable powder) are used per 100 kg of seed. b) Dressing of the seeds with an emulsifiable concentrate of a compound of formulae 3.1 to 3.7 according to method a) (wet dressing). c) Dressing by immersing the seeds for from 1 to 72 hours in a liquor comprising from 100 to 1000 ppm of a compound of formulae 3.1 to 3.7 and optionally subsequently drying the seeds (immersion dressing).

Dressing the seed or treating the germinated seedling are naturally the preferred methods of application, because treatment with the active ingredients is directed entirely at the target crop. Generally from 1 to 1000 g of antidote, preferably from 5 to 250 g of antidote, are used per 100 kg of seed, but depending on the methodology, which also allows other active ingredients or micronutrients to be added, concentrations above or below the limits indicated may be employed (repeat dressing). ii) Application as a tank mixture A liquid formulation of a mixture of antidote and herbicide is used (ratio by weight of the one to the other from 10: 1 to 1: 100), the rate of application of herbicide being from 0.005 to 5.0 kg per hectare. Such tank mixtures are applied before or after sowing. iii) Application to the seed furrow The compounds of formulae 3.1 to 3.7 are introduced into the open, sown seed furrow in the form of an emulsifiable concentrate, wettable powder or granules. Once the seed furrow has been covered over, the herbicide is applied in the usual manner pre-emergence. iv) Controlled release of active ingredient The compounds of formulae 3. 1 to 3.7 are applied in solution to mineral granule carriers or polymerised granules (urea/formaldehyde) and dried. If desired, it is also possible to apply a coating that allows the active ingredient to be released in metered amounts over a specific period of time (coated granules).

Preferred formulations have especially the following compositions: (% = percent by weight) Emulsifiable concentrates: active ingredient mixture : 1 to 90 %, preferably 5 to 20 % surfactant: 1 to 30 %, preferably 10 to 20 % liquid carrier: 5 to 94 %, preferably 70 to 85 % Dusts: active ingredient mixture: 0.1 to 10 %, preferably 0.1 to 5 % solid carrier: 99.9 to 90 %, preferably 99.9 to 99 % Suspension concentrates: active ingredient mixture: 5 to 75 %, preferably 10 to 50 % water: 94 to 24 %, preferably 88 to 30 % surfactant: 1 to 40 %, preferably 2 to 30 % Wettable powders: active ingredient mixture: 0.5 to 90 %, preferably 1 to 80 % surfactant: 0.5 to 20 %, preferably 1 to 15 % solid carrier: 5 to 95 %, preferably 15 to 90 % Granules : active ingredient mixture: 0.1 to 30 %, preferably 0.1 to 15 % solid carrier: 99.5 to 70 %, preferably 97 to 85 % The following Examples illustrate the invention further, but do not limit the invention.

Formulation Examples for mixtures of ab) herbicide of formula I and co-herbicides under b), and safeners of formulae 3. 1 to 3.7 (% = percent by weight) F1. Emulsifiable concentrates a) b) c) d) active ingredient mixture 5 % 10 % 25 % 50 % calcium dodecylbenzenesufonate 6 % 8 % 6 % 8 % castor oil polyglycol ether 4 %-4 % 4 % (36 mol of ethylene oxide) octylphenol polyglycol ether-4 %-2 % (7-8 mol of ethylene oxide) <BR> <BR> <BR> <BR> cyclohexanone--10 % 20 % arom. hydrocarbon mixture 85 % 78 % 55 % 16 % Cg~Ct2 Emulsions of any desired concentration can be obtained from such concentrates by dilution with water.

F2. Solutions a) b) c) d) active ingredient mixture 5% 10% 50% 90% 1-methoxy-3- (3-methoxy- propoxy)-propane-20 % 20 % polyethylene glycol MW 040 20 % 10 % - - N-methyl-2-pyrrolidone - - 30 % 10 % arom. hydrocarbon mixture 75 % 60 % - - Cg-C12 The solutions are suitable for use in the form of microdrops.

F3. Wettable powders a) b) c) d) active ingredient mixture 5 % 25 % 50 % 80 % sodium lignosulfonate 4 %-3 % sodium lauryl sulfate 2 % 3 % - 4 % sodium diisobutylnaphthalene- sulfonate - 6 % 5 % 6 % octylphenol polyglycol ether-1 % 2 % (7-8 mol of ethylene oxide) highly dispersed silicic acid 1 % 3 % 5 % 10 % kaolin 88 % 62 % 35 % - The active ingredients are (or the active ingredient mixture is) mixed thoroughly with the adjuvants and the mixture is thoroughly ground in a suitable mill, affording wettable powders which can be diluted with water to give suspensions of any desired concentration.

F4. Coated granules a) b) c) active ingredient mixture 0. 1 % 5 % 15 % highly dispersed silicic acid 0. 9 % 2 % 2 % inorganic carrier 99. 0 % 93 % 83 % (diameter 0.1-1 mm) e. g. CaCO3 or SiO2 The active ingredients are (or the active ingredient mixture is) dissolved in methylene chloride and applied to the carrier by spraying, and the solvent is then evaporated off in vacuo.

F5. Coated granules a) b) c) active ingredient mixture 0. 1 % 5 % 15 % polyethylene glycol MW 200 1. 0% 2% 3% highly dispersed silicic acid 0. 9 % 1 % 2 % inorganic carrier 98. 0 % 92 % 80 % (diameter 0.1-1 mm) e. g. CaCO3 or SiO2 The finely ground active ingredients are (or the finely ground active ingredient mixture is) uniformly applied, in a mixer, to the carrier moistened with polyethylene glycol. Non-dusty coated granules are obtained in this manner.

F6. Extruder granules a) b) c) d) active ingredient mixture 0. 1 % 3 % 5 % 15 % sodium lignosulfonate 1. 5% 2% 3% 4% carboxymethylcellulose 1. 4% 2% 2% 2% kaolin 97. 0 % 93 % 90 % 79 % The active ingredients are (or the active ingredient mixture is) mixed and ground with the adjuvants, and the mixture is moistened with water. The mixture is extruded and then dried in a stream of air.

F7. Dusts a) b) c) active ingredient mixture 0.1 % 1 % 5 % talcum 39. 9 % 49 % 35 % kaolin 60. 0% 50% 60% Ready-to-use dusts are obtained by mixing the active ingredients (or the active ingredient mixture) with the carriers and grinding the mixture in a suitable mill.

F8. Suspension concentrates a) b) c) d) active ingredient mixture 3 % 10 % 25 % 50 % ethylene glycol 5 % 5 % 5 % 5 % nonylphenol polyglycol ether-1 % 2 % (15 mol of ethylene oxide) sodium lignosulfonate 3 % 3 % 4 % 5 % carboxymethylcellulose 1 % 1 % 1 % 1 % 37 % aqueous formaldehyde 0. 2 % 0. 2 % 0. 2 % 0. 2 % solution silicone oil emulsion 0. 8 % 0. 8 % 0. 8 % 0. 8 % water 87 % 79 % 62 % 38 % The finely ground active ingredients are (or the finely ground active ingredient mixture is) intimately mixed with the adjuvants, giving a suspension concentrate from which suspensions of any desired concentration can be obtained by dilution with water.

It is often more practical for the compound ab) of formula I and the co-herbicides under b), and safeners under c) of formulae 3.1 to 3.7 to be formulated separately and then to be brought together in the desired mixing ratio in the applicator in the form of a"tank mixture"in water shortly before application.

The ability of the safeners of formulae 3.1 to 3.7 to protect crop plants against the phytotoxic action of ab) the herbicide of formula I and the co-herbicides under b) is illustrated in the following Examples.

Biotoaica) Examp) e : safening action The test plants are grown in plastics pots under greenhouse conditions to the 1-to 4-leaf stage. At that stage, either the herbicides alone or the mixtures of the herbicides with the test compounds being tested as safeners are applied to the test plants. The test compounds are applied in the form of an aqueous suspension prepared from a 25 % suspension concentrate (Example F8, c) ), using 500 litres of water/ha. From 1 to 4 weeks after application, the phytotoxic action of the herbicides on the crop plants, e. g. rice, is evaluated using a percentage scale. 100 % indicates that the test plant has died, 0 % indicates no phytotoxic action. The mixtures according to the invention exhibit a good selectively herbicidal action in this test.