FR3037480A1 - HERBICIDE MIX - Google Patents

Abstract

The present invention provides a synergistic herbicidal mixture comprising iodosulfuron-methyl (compound I) or salts thereof, florasulam (compound II) or salts thereof and diflufenican (compound III). The present invention also relates to a method for controlling weeds in winter and spring cereal crops by applying said mixture.

Description

HERBICIDE MIXTURE [0001] This invention belongs to the field of crop protection, and specifically relates to a synergistic herbicidal mixture comprising iodosulfuron-methyl or its salts, florasulam or salts thereof and diflufenican, and to the preparation and using said mixture to control weeds in winter and spring cereal crops. In the field of crop protection, the use of an active substance to control weeds can become increasingly difficult over time, because of the emergence of a resistance related to the herbicide used. This leads to a loss of effectiveness in the control of weeds and, consequently, to a loss of yield and profitability of the crops. A very well known and widely used form to address this problem is the use of a combination of different active substances with different biochemical mechanisms of action. However, the combination of a plurality of active substances frequently poses problems of physical or biological incompatibility, which may result, for example, in a lack of physical stability of the formulation, the degradation of one or more several time-active substances, antagonism in terms of biological efficacy and phytotoxicity effects in the harvest. [0005] Compound (I), iodosulfuron-methyl (IUPAC: 4-iodo-2 - [(4-methoxy-6-methyl-1,3,5-triazin-2-yl) carbamoyl-sulfamoyl] benzoate of methyl) whose structural formula is: is a herbicidal active substance described in European Patent EP 0574418. [0006] Iodosulfuron-methyl is preferably used in the form of its sodium salt (iodosulfuron-methyl-sodium), which has the formula (Ia): ## STR2 ## wherein N, OH, Na + CH 3 (Ia) iodosulfuron-methyl-sodium is a sulfonylurea which acts by inhibiting the biosynthesis of essential amino acids of susceptible plants through the inhibition of the enzyme acetolactate synthase (ALS). [0008] Its use in early post-emergence treatments (with regard to both cultivation and weeds) of wheat is well known. The 10 weeds controlled were darnel (Lolium rigidium), wild oats (Avena spp), annual Phalaris (Phalaris paradoxa) and several dicotyledons. [0009] Compound (II), florasulam (IUPAC: 2 ', 6', 8-trifluoro-5-methoxy [1,2,4] triazolo [1,5-c] pyrimidine-2-sulfonanilide), disclosed in European Patent EP 0343752 has the following structural formula: O. [0009] Florasulam is a triazolopyrinidine sulfonanilide used in post-emergence cereal treatments for the control of broadleaf weeds, which acts by inhibiting acetolactate synthase. (ALS). [00011] Compound (III), diflufenican, (IUPAC: 2 ', 4'-difluoro-2- (α, α, α-trifluoromethyl-tolyloxy) nicotinanilide), disclosed in European Patent EP 053011, The following structural formula: diflufenican is a pyridinecarboxamide which can be used in pre- or post-emergence cereal treatments for broadleaf weed control and which acts by inhibiting phytoene dehydrogenase, a key enzyme in the biosynthesis of carotenoids, which are pigments responsible for the absorption of light for photosynthesis. [00013] There are patent documents relating to the use of the aforementioned active substances in the composition of herbicidal mixtures: [00014] European Patent EP 0831707 B1 relates to combinations of esters of acid 4- iodo-2 - [(4-methoxy-6-methyl-1,3,5-triazin-2-yl) carbamoylsulfamoyl] benzoic acid, in particular iodosulfuron-methyl and its salts, with another active substance selected from a group that includes diflufenican. The patent discloses an example of a synergistic action against Lolium multiflorum, in which the addition of 13 g / ha diflufenican (which up to a dose of 25 g / ha showed no herbicidal activity) to 10 g / ha. iodosulfuron-methyl has produced an increase in the effectiveness of weed control from 60 ° to 98 ° / o, which could only be achieved by the use of 20 g / ha of iodosulfuron. -methyl. [00015] European Patent EP 2033521 B1 relates to mixtures of iodosulfuron-methyl and its salts with florasulam. The patent discloses an example of a synergistic action against Veronica hederifolia, in which the addition of 2.5 g / ha of iodosulfuron-methyl-sodium (which alone showed no herbicidal activity) at 4 g / ha florasulam produced an increase in efficacy from 60% to 65%. [00016] European patent application EP 2095712 A1 relates to combinations of diflufenican with florasulam. The patent shows an example of synergistic action against Lolium nnultiflorum, in which neither the use of 9 g / ha of diflufenican nor the use of 0.5 g / ha of florasulam showed any herbicidal activity 3037480 but the combination of 9 g / ha of diflufenican with 0.5 g / ha of florasulam produced an efficiency of 30%. [00017] WO 2003/07] 854 relates to ternary combinations of herbicides comprising mesosulfuron, iodosulfuron-methyl and a third component selected from a list of 57 active substances including florasulam and diflufenican. [00018] None of the documents of the prior art discloses the mixture of the active substances (I), (II) and (III). [00019] There is a need for mixtures allowing broader control of weeds, especially for less sensitive ones, with a rate of application as low as possible in order to optimize their toxicological, ecotoxicological and environmental impact, and with a number of applications producing an economical solution for the user. The invention relates to a new synergistic herbicidal mixture comprising iodosulfuron-methyl or its salts, florasulam or its salts and diflufenican. In one embodiment of the invention, the range of concentrations of iodosulfuron is 4.0% to 6.3% w / w, the concentration range of florasulam is 1.6% w / w at 2.5% w / w, and the concentration range of diflufenican is 32. In a preferred embodiment of the invention, the herbicidal mixture comprises 5% w / w iodosulfuron, 2% w / w florasulam and 40% w / w diflufenican. The mixture according to the invention may further comprise a safener, cloquintocet-mexyl (IUPAC: (5-chloroquinolin-8-yloxy) 1-methylhexyl acetate). In one embodiment of the invention, the concentration range of cloquintocet-mexyl is 8.0% w / w at 12.5% w / w. The invention also relates to the use of said mixture for controlling weeds in winter and spring cereals 3037480 5 (durum and soft wheat, barley, oats, triticale and rye) chosen in the group comprising Anagallis arvensis, Anthemis spp., Galium aparine, Lolium multiflorum, Lolium rigidum, Matricaria chamomilla, Papaver rheas, Picris echioides, Poa annua, Rumex crispus, Sinapis arvensis, Stellaria media and Veronica spp. The invention further relates to a method for controlling weeds in winter and spring cereal crops (durum and soft wheat, barley, oats, triticale and rye), characterized in that it comprises a step of applying to the weeds or the soil on which they develop a mixture of iodosulfuron-methyl or its salts, florasulam or its salts and diflufenican. In one aspect of the invention, the process is characterized by applying 7.5 g / ha to 10 g / ha of iodosulfuron; of] g / ha to 4 g / ha florasulam and 60 g / ha to 80 g / ha diflufenican. The object of the present invention is to provide a mixture of herbicidal active substances having a high effectiveness in controlling weeds in winter and spring cereals (durum wheat and barley, oats, triticale and rye) selected from the group consisting of Anagallis arvensis, Anthemis spp., Galium aparine, Lolium multiflorum, Lolium rigidum, Matricaria chamomilla, Papaver rheas, Picris echioides, Poa annua, Rumex crispus, Sinapis arvensis, Stellaria media and Veronica spp. [00029] Surprisingly, it has been discovered that by combining iodosulfuron-methyl (compound I) or its sodium salt (compound Ia) with florasulam (compound II) and diflufenican (compound III), it is found that A synergistic effect is observed in the biological efficiency resulting in an unexpected increase in efficacy compared to the effectiveness of each of the active components. [000] 0] This synergistic effect allows lower application rates or an increase in the herbicidal action with the same application rates, which results in an economically advantageous process for the user, and which is also more favorable from an ecological point of view. Unless otherwise indicated, all concentrations of the active substances referred to in this application are expressed as percentages by weight (0/0 m / m). In order to specify the concentration of the active substance in the mixture and the rate to be used per hectare, the active substance iodosulfuron-methyl (I) or its sodium salt (Ia) is expressed as iodosulfuron, taking into account that 5.00 g of iodosulfuron corresponds to 5.14 g of iodosulfuron-methyl or 5.36 g of iodosulfuron-methyl-sodium. In one embodiment of the invention, the range of concentrations of iodosulfuron is 4.0% at 6.3 ° h, the concentration range of florasulann is 1.6% to 2%. 5%, and the concentration range of diflufenican is 32% to 50%. In a preferred embodiment of the invention, the herbicidal mixture comprises 5% of iodosulfuron, 2% of florasulam and 40% of diflufenican. The mixture according to the invention may further comprise a safener 15 to prevent the phytotoxic effect on the crops to be protected, without significant influence on the herbicidal action on the weeds to be chemically combated. In the present invention, the antidote used is 1-methyl-hexyl cloquintocet-mexyl (IUPAC: (5-chloroquinolin-8-yloxy) acetate). [00036] In one embodiment of the invention, the concentration range of cloquintocet-mexyl is 8.0 ° / 0 to 12.5 ° h. The mixture according to the invention may be in the form of a wettable powder (WP), water-dispersible granules (WG), an aqueous suspension (SC) or a suspension in the oil (OD). The formulations are prepared in known manner, for example, by mixing the active substances with the other co-formulants selected from dispersants, wetting agents, disintegrants, stabilizers, pH and viscosity modifiers. , filler and their combinations. The preferred dispersants are, for example, sodium or calcium lignosulfonates (Borresperse® Ca, Borresperse® Na or Ufoxane® 3A, commercially available from Borregaard), sodium-formaldehyde naphthalenesulphonate condensates (Supragil®). MNS / 90 commercially available from Rhodia), sodium phenylsulfonates (Supragil® GN, commercially available from Rhodia), ethoxylated and / or propoxylated tristyrylphenols (Soprophor® BSU, Soprophor® S / 40, Soprophor® TSP, Soprophor® 4D384, commercially available 3037480 7 from Rhodia) and polycarboxylates (Geropon® T36, commercially available from Rhodia). Preferred wetting agents are, for example, sulfosuccinates (Geropon® SOS, commercially available from Rhodia) and alkyl naphthalenesulfonate salts (Supragil® WP, commercially available from Rhodia, or Morwet® IP). , commercially available from AkzoNobel). The disintegrating agents are, for example, ammonium sulphate and anhydrous sodium acetate. The formulations may further contain pH modifiers (such as, for example, citric acid) and bulking agents (e.g., kaolin or silica). The application rates of the mixture according to the invention are 7.5 g / ha to 10 g / ha iodosulfuron, 3 g / ha to 4 g / ha florasulam and 60 g / ha at 80 g / ha diflufenican.

Formulation Example [00044] As an example, a formulation in the form of water-dispersible granules (WG) is made using the following composition and procedure: _Geropon® T36 (sodium polycarboxylate) Ufoxane® 3A (lignosulfonate) sodium) Sipernat® 22S (silica) Sodium acetate anhydrous Citric acid 6 0 2.0 I 15.0 1.5 I Up to 100 cY0 Kaolin 5 Compounds I, II, III, and cloquintocet- mexyl are mixed and then milled in a jet mill, until a sufficiently fine particle size (about 95 ° to) of particles smaller than 10 μm) is obtained. The above mixture is added to the remaining components listed in the table above, and all components are mixed in a suitable mixer (e.g., Nautamix mixer). [00047] Water (5 to 20% of the solid mass) is added to the above mixture in order to form a homogeneous "paste", which is then loaded into a "basket" type extruder, where the material is forced through a perforated sieve (diameter from 0.7 mm to 1 mm) by extrusion blades. [00048] The wet granules from the extruder are loaded into the spheronizer, where a rotating plate promotes the collisions of the granules against the walls of the instrument and against the other granules, causing their plastic deformation, forming spheres. Component 96 m Iodosulfuron-N-ethyl-Sodium (Compound Ia), equivalent to 5.0% iodosulfuron Florasulam (Compound II) Diflufenican (Compound III) Cloquintocet-mexyl Morwet® IP (Sodium isopropylnaphthalenesulfonate) Supragil® MNS / 90 (Condensate The resultant product is dried with a hot air stream in a fluidized bed drier. The resulting product is dried with a stream of hot air in a fluidized bed drier. As a variant, the combination of the active substances according to the invention can be, for example, in the form of wettable powders, suspensions in water or oil or emulsions, applied by spraying. after dilution with water. The formulation is applied by diluting it in water and spraying a volume of 200 to 400 liters of the resulting suspension or emulsion per hectare. [00052] To quantify the synergistic effect resulting from the combination of the active substances, the method described by Colby (Colby, SR, "Calculating synergistic and antagonistic response of herbicide compositions", Weeds 15, pp 20-22, 1967) was used, according to which the expected efficiency (EE) for the mixture of the active components, determined by the Colby formula: EE = x + y - (xy) / 100 in which: EE represents the expected% efficiency using the mixture of active substances A and B at concentrations a and b; x represents the 0/0 of effectiveness using the active substance A at the concentration a; Y is 0% of efficacy using active substance B at concentration b; is compared with the efficiency observed experimentally. [0005] For a mixture of three active substances A, B and C, the aforementioned reference shows a modification of the Colby formula according to which the expected efficiency (EE) is determined by: EE = x + y + z - (xy + xz + yz) / 100 + (xyz) / 10,000 wherein: - x and y are as previously defined; z represents the 0/0 of effectiveness using the active substance C at the concentration c; EE represents the expected% efficiency using the mixture of active substances A, B and C at concentrations a, b and c. If the observed efficiency (E) exceeds that expected (calculated) (EE), the mixture displays a synergistic effect. [00055] The applicant conducted tests under controlled conditions in which the results of the application of each of the active substances and the ternary mixture obtained according to the formulation example on Galium aparine and Papaver rhoeas were evaluated. [00056] The tests were carried out in a greenhouse under controlled temperature, humidity and illumination, in order to simulate days with 16 hours of light. Weeds germinated in randomly placed 15 cm diameter pots in the greenhouse, repositioned 14 days after application to minimize variations in weed growth conditions. The treatments were carried out by diluting the formulations in water and applying the aqueous suspensions thus obtained by spraying at a rate of 2001 / ha. The efficacy results were evaluated 28 days after the application of the 20 treatments. The results of the tests were worked using the formulas above and are presented in Tables A and B (for reasons of mathematical treatment, the efficiencies of 0% were converted into 0.1%).

Table A Table B [00060] Twenty-eight days after the treatment, the efficacy observed was, in both cases, greater than the expected efficiency of about 8%. Thus, it can be concluded that the mixture according to the invention displays a synergistic effect which results in an unexpected increase in the effectiveness in controlling weeds in winter and spring cereal crops. Diflufenican (III) I + II + III Efficacy (%) Observed Rate of active substance, g / ha Expected Efficacy against Gallum apipine after 28 bursts 5.0 + 2.0 + 40 0 Active substance 5 [7.-coryl efficacy: r ... Papayer laughed? oe at 5 after 28 s Efficiency (%) Observed 35 0/0 52 0/0 10 0/0 77 0/0 7 1 9 0/0 Active substance level, q / ha 1.0 2.S 20.0 2.5 + 1.0 + 20 0 Expected Active substance Florasulam II Iodosulfuron-meth II Diflufenican (III) I + II + III

Claims (8)

REVENDICATIONS1. Synergistic herbicidal mixture characterized in that it comprises iodosulfuron methyl or its salts, florasulam or its salts and diflufenican. 2. Herbicidal mixture according to claim 1 characterized in that: the concentration range of iodosulfuron is from 4% m / m to 6.3% the concentration range of florasulam is 1.6% m / m to 2%. 5% w / w; the concentration range of diflufenican is 32% w / w to 50% w / w. 3. herbicidal mixture according to claims 1 or 2, characterized in that it further comprises cloquintocet-mexyl. 4. A herbicidal mixture according to claim 3, characterized in that the concentration range of cloquintocet-mexyl is from 8.0% w / w to 12.5% w / w. 5. Herbicidal mixture according to claim 2, characterized in that it comprises 5.0% w / w of iodosulfuron, 2% w / w of florasulam and 40% w / w of diflufenican. 20 6. Use of the herbicide mixture according to any one of claims 1 to 5 for controlling weeds in winter and spring cereal crops (durum and soft wheat, barley, oats, triticale and rye) chosen from the group comprising Anagallis arvensis, Anthemis spp., Galium aparine, Lolium multiflorum, Lolium rigidum, Matricaria chamomilla, Papaver rheas, Picris echioides, Poa annua, Rumex crispus, Sinapis arvensis, Stellaria media and Veronica spp. 7. A method for controlling weeds in winter and spring cereals (durum wheat, barley, oats, triticale and rye), characterized in that it comprises a step of application on the weeds or on the soil on which they develop a mixture of iodosulfuron-methyl or its salts, florasulam or its salts and diflufenican. 8. A process according to claim 7 characterized by applying 7.5 g / ha to 10 g / ha iodosulfuron; from 3 g / ha to 4 g / ha florasulam and from 60 g / ha to 80 g / ha diflufenican. 10