PT109118B - HERBICIDE MIXTURE UNDERSTANDING METILO IODOSSULFURÃO OR ITS SAIS AND FLASASSULFURÃO - Google Patents

Abstract

The present invention relates to a herbicidal mixture comprising methyl-isosulfuron or its salts and flasksulfuron and to a process for the control of the insects in the olival or vine cultures.

Description

DESCRIPTION

HERBICIDE MIX UNDERSTANDING METHODSULFURON OR ITS SALTS AND FLAZASSULFURON

FIELD OF THE INVENTION

The present invention relates to a herbicidal mixture comprising iodosulfuron-methyl or its salts and flazasulfuron, and its use in crop protection.

BACKGROUND OF

INVENTION compound (I), methyl iodosulfuron (IUPAC: 4-iodo-2- [3- (4-methoxy-6-methyl-1,2,5-triazin-2-yl) ureidosulfonyl] benzoate), structural formula is:

is a herbicidal substance described in European Patent EP 057441.

Preferably the sodium salt of iodosulfuron methyl (iodosulfuron methyl sodium) having the formula (Ia) is used:

Ο

Ο

Na +

Iodosulfuron-methyl-sodium is a sulfonylurea that acts by inhibiting the biosynthesis of the essential amino acids of susceptible plants by inhibiting the enzyme acetolactate synthase (ALS).

In this application, the dose of the active substance methyl iodosulfuron (I) or its sodium salt (Ia) is expressed for the purpose of calculating the proportions of the active substances in the mixture and for the amount to be used per hectare as iodosulfuron (Ib ),

O

O (Ib) bearing in mind that 493.2 g of iodosulfuron corresponds to 507.2 g of iodosulfuron methyl or 529.2 g of iodosulfuromethyl sodium.

The compound (II), Flazasulfuron [IUPAC: (1- (4,6-dimethoxypyrimidin-2-yl) -3- (3-trifluoromethyl-2-pyridyl sulfonyl) urea], has the following structural formula:

(II)

CH ₃ flazasulfuron is also a sulphonylurea which acts by inhibiting the biosynthesis of the essential amino acids of susceptible plants by inhibiting the enzyme acetolactate synthase (ALS), which is involved in the synthesis of the amino acids leucine, isoleucine and valine. It was first described by Ishihara Sangyo Kaisha, Ltd. in 19 5 (EP01 43 5).

There are some patents regarding sulfonylurea formulations.

WO200201771 relates to a method of producing a solid formulation containing a sulfonylurea or salt thereof, optionally another herbicide and at least one adjuvant, comprising the steps of forming a suspension in water containing the formulants, adjusting the pH of that suspension. at a value between 6.5 and drying the suspension to obtain the solid formulation.

WO200609 156 discloses a suspension comprising a sulfonylurea or a salt thereof, at least one surfactant selected from alkoxylated fatty acid sorbitol esters and alkoxylated fatty acid sorbitan esters and a water immiscible inert.

W02007027 63 relates to liquid formulations comprising 0.1 to 20 sulfonylureas, 0 to 40 other

active agents that not sulfonylureas, 0.1 to 10 in lignosulfonates, 0 to 99, of esters of fat acids in C1-C4 alcohols and 0 to 20 of other formulants.

WO2007119435 relates to the incorporation of a polyalkoxy alkyl phosphate or salt thereof to improve the biological efficacy and to reduce the dose of sulfonylurea to be used.

However, none of the prior art documents contain any reference or suggestion concerning the mixture of iodosulfuron with flazasulfuron.

DETAILED DESCRIPTION OF THE INVENTION

It is common practice in the field of crop protection to develop formulations containing various active substances for very different purposes such as managing phenotypes for the development of resistant biotypes, broadening the spectrum of biological action, avoiding successive applications of plant protection products, etc. Liquid formulations are generally preferred by users because of the ease of measuring, mixing, diluting and spraying operations.

Surprisingly, it was found that by applying in the early postemergence to olive or vine crops a mixture of iodosulfuron-methyl-sodium and flazasulfuron, weed control efficacy was higher than would be expected given the efficacy observed for each one of the active substances, which indicates a synergistic behavior of the mixture with respect to each of the active substances.

Early postemergence application means herbicide application on permanent crops after weed germination up to 2 to 3 leaves.

The weeds referred to in the present invention are, for example:

Amaranthaceae as turkey monk (Amaranthus retroflexus L.), red bredo (Amaranthus hybridus L.);

Caryophyllaceae as white morugem (Stellaria media (L.) Will.);

Compositae as ivory avocado (Conyza albida Sprengel), hairy avocado (Conyza bonariensis (L.) Cronq), cow herb (Calendula arvensis L.), margaça (Matricaria chamomilla L.), soft milkweed (Sonchus oleraceus L.);

Cruciferae as a shepherd's purse (Capsella bursa-pastoris

L.), grizandra (Diplotaxis cathotica (L.) DC.), Field mustard (Sinapis arvensis L.), saramago (Raphanus raphanistrum L.);

Chenopodiaceae as sunflower (Chenopodium album L.);

Geraniaceae as Maria fia (Erodium malacoides (L.) L'Her.);

Labiatae as purple lamium (Lamium purpureum L.);

Leguminosae as lucerne brava (Medicago lupulina L.);

Malvaceae as mallow (Malva parviflora L.), Mallow (Malva silvestris L.);

Papaveraceaea as poppy (Papaver rhoeas L.);

Polygonaceae as always bride (Polygonum aviculare L.), peach herb (Polygonum persicaria L.);

Rubiaceae as a mint love (Galium aparine L.);

Gramineae as ryegrass (Lollium spp.), Tick (Setaria verticillata (L.) P. eauv.), Million typed (Digitaria sanguinalis (L.) Scop), million rooster (Echinochloa crus galli (L.) P.) .

The mixture according to the invention is particularly useful in the control of ivory (Conyza albida Sprengel), hairy (Conyza bonariensis (L.) Cronq) and ryegrass (Lollium spp.) Weeds.

An object of the present invention is to provide a novel synergistic herbicidal mixture comprising the iodosulfuron-methyl (I) active substances or their salts and flazasulfuron (II).

In a preferred embodiment of the invention, the mass ratio of flazasulfuron to iodosulfuron in the mixture is in the range 2: 1 to 7: 1.

In a more preferred embodiment of the invention, the mass ratio of flazasulfuron to iodosulfuron in the mixture is in the range 3: 1 to 4: 1.

In an even more preferred embodiment of the invention, the mass ratio of flazasulfuron to iodosulfuron in the mixture is 4: 1.

The mixture according to the invention may be obtained by mixing in the tank immediately prior to application of commercially available formulations of both active substances or, alternatively, a formulation comprising both active substances and the usual adjuvants may be used. in the form of water dispersible granules (hereinafter referred to as the internationally adopted designation: WG formulation) or as an oil particle suspension (hereinafter referred to as the internationally adopted designation: OD formulation).

WG formulations are prepared according to procedures known to the person skilled in the art and may be obtained, for example, by an extrusion process comprising the steps of:

-mix the active substances (I) or (Ia) and (II) and subsequently grind the mixture in an air jet mill to a sufficiently fine particle size (about 95 of the particles below 10 pm) ;

adding the above mixture to the other components of the formulation (dispersants, wetting agents, antifoam agents, disintegrants, stabilizers, pH regulators and inert) and mixing in a suitable mixer (eg Nautamix Mixer);

- adding water to the above mixture to form a homogeneous paste, which is then fed to an extruder (for example of the basket type), where the material is forced through a perforated mesh (0 mm to 1 mm in diameter). due to the action of extrusion blades;

feed the wet granules from the extruder to a

Spheronizer, in which a rotating plate promotes the collisions of the granules against the equipment walls and against other granules, resulting in their plastic deformation, providing the formation of spheres, and

drying the resulting product with a hot air flow in a fluid bed dryer.

OD formulations are prepared according to procedures known to one skilled in the art and may be obtained, for example, by a wet milling process comprising the steps of:

adding, under stirring, to a vegetable or mineral oil a set of additives (dispersants, wetting agents, stabilizers, pH regulators);

adding to the solution obtained in the previous step the active substances (I) or (Ia) and (II) until a homogeneous oil dispersion is obtained;

pump the oil dispersion from the previous step through a refrigerated ball mill to obtain a particle size distribution of Do.95 pm;

and,

adding a structuring agent to the above suspension and stirring until a homogeneous oil dispersion is obtained.

Preferably the formulation containing the active substances according to the invention is presented as an OD formulation.

Another object of the present invention is to provide a process for controlling weeds in olive or vine crops which comprises applying, in early post-emergence, the mixture according to the invention diluted in a sufficient amount of water (typically 150 to 600 per hectare terrestrial application per tractor) to ensure homogeneous application to the soil or weeds of 25 to 35g of flazasulfuron and 5 to 12,5 g of iodosulfuron per hectare.

In a preferred embodiment, the treatment process comprises applying 30 g of flazasulfuron and 7.5 to 10 g of iodosulfuron per hectare.

More preferably, the treatment process comprises applying 30 g of flasulfuron and 7.5 g of iodosulfuron per hectare.

BIOLOGICAL EFFICIENCY

A mixture comprising iodosulfuron-methyl sodium and flazasulfuron was applied in early postemergence to olive grove using a dose of 30 g / ha of flazasulfuron and 7.5 g / ha of iodosulfuron (as iodosulfuron methyl sodium).

In parallel were also applied:

- a formulation containing flazasulfuron, in which the applied dose was 50 g / ha;

- a formulation containing iodosulfuron and diflufenicon, where the applied dose was 10 g / ha iodosulfuron (as methyl sodium iodosulfuron) and 150 g / ha diflufenicon.

The tests were performed in Portugal, and were conducted according to the Experimental Practices defined by Regulation 1107/2009 of the European Union.

The assays were performed in randomized blocks, with 4 repetitions, with an untreated strip next to each treated area.

An efficacy evaluation was made 2 days after application of the mixture according to the invention and the following results were obtained:

Culture: Olive Grove grams of efficiency Weeder: Conyza spp. substance 2 days after active / ha the app Iodosulfuron + 10 + 39.9 diflufenicão 150 Flazasulfuron 50 29.5 Iodosulfuron + 7.5 + 5, 9 Flazasulfuron 30

Table 1. Efficacy Results

It can be seen that the efficacy value obtained for the mixture is much higher than that of any of the active ingredients applied alone, even when the doses of the active ingredients applied alone are significantly higher than the doses in the mixture.

To quantify the synergistic effect resulting from the association of active substances, the methodology described by Colby (Colby, SR, Calculating synergistic and antagonistic response of herbicide compositions, Weeds 15, pp. 20-22, 1967), according to which it is compared, is used. the expected efficacy (EE) for the active ingredient mixture determined using Colby's formula:

EE = x + y - (xy) / 100 where:

-EE is the expected efficacy in using the active compound mixture A and at concentrations a and b.

-X and the effectiveness, in using the compound active Ana concentration The; -y is the effectiveness, in using the compound active at concentration B;

with the experimentally observed efficacy (E).

If the observed efficacy (E) exceeds the calculated (EE), there is a synergistic effect.

Although the results in Table 1 do not allow the Colby formula to be used accurately, since the doses of the active substances applied individually are not the same as the doses in the mixture and because iodosulfuron was not tested alone but mixed with diflufenicon, We can use Colby's formula to obtain an estimate of the expected effectiveness of the mixture according to the invention.

This estimate will correspond to an approximation by excess of the theoretical value, since the dose of flazasulfuron on its own is higher than that of flazasulfuron in the binary mixture and also because when using a mixture of iodosulfuron with diflufenition instead of iodosulfuron alone of iodosulfuron is higher than the dose in the mixture as we are still considering the effectiveness of diflufenition to be zero.

Substituting the values of table 1 in Colby's formula gives an expected value for efficacy of 57.6, lower than that observed experimentally (5, 9).

Given that the calculations were performed considering a very unfavorable case for the mixture according to the invention, it is clear that there is a surprising synergistic effect arising from the mixture of the two active substances.

Claims (7)

A synergistic herbicidal mixture characterized by comprising a set of active substances consisting of iodosulfuron-methyl or its salts and flazasulfuron. Mixture according to claim 1, characterized in that the ratio by weight of flasassulfuron and iodosulfuron in the mixture is in the range of 2: 1 to 7: 1. Mixture according to claim 2, characterized in that the ratio by weight of flasassulfuron and iodosulfuron in the mixture is in the range of 3: 1 to 4: 1. Mixture according to claim 3, characterized in that the ratio by weight of flasassulfuron and iodosulfuron in the mixture is 4: 1. Process for controlling weeds from olive or vineyard crops characterized in that it comprises a step of applying, in an early post-emergence, the mixture according to any of claims 1 to 4, in order to apply 25 to 35 g of f lazassulfuron and 5 to 12.5 g of iodosulfuron per hectare. A process according to claim 5, characterized in that 30 g of flasassulfuron and 7.5 to 10 g of iodosulfuron per hectare are applied. A process according to claim 6, in that 30 g of flasassulfuron iodosulfuron per hectare are applied. characterized and 7.5 g of