BE1021447B1 - Method and fungicidal product based on propamocarb, cymoxanil and acid - Google Patents

Abstract

The present invention relates to a concentrated aqueous suspension formulation for the protection of a plant, comprising as active substances, a propamocarb and cymoxanil and an acid, characterized in that the acid is chosen from the list of phosphoric acid, boric acid, acetic acid, propionic acid, citric acid, fumaric acid, tartaric acid, oxalic acid, succinic acid, and combinations thereof. The present invention also relates to a process for controlling Plasmopara viticola or Phytophthora spp., In a place which is infested or is likely to be infested.

Description

Method and fungicidal product based on propamocarb, cymoxanil and acid

The present invention relates to the fungicidal activity of a mixture containing, as active substances, propamocarb-HCl and cymoxanil and the use of the mixture to control Plasmopara spp., Especially Plasmopara viticola, or Phytophthora spp. especially Phytophthora infestans.

The fungus Plasmopara viticola is the cause of downy mildew. This disease infects most species of the genus Vitis (vine, for example Vitis vinifera). Cultivars of the vinifera species are very sensitive, while wild species are relatively resistant. Downy mildew can cause direct damage to the vine by deforming shoots, tendrils and bunches or causing premature leaf drop, delaying fruit ripening and increasing vine vulnerability to low-level injury. temperatures and rain for example.

The fungus responsible for late blight winters as an oospore mainly within the fallen leaves in and around the vineyard. As soon as temperatures reach 11 ° C, the oospores germinate in the water to form sporangia. Sporangia contain zoospores (motile spores) that are scattered on host vine tissues through splashing rain. Zoospores penetrate the undersides of the leaves, tendrils and soft shoots by stomata (small openings in the tissues, which make possible gas exchange). Once inside the host tissue, the fungus spreads into the tissue. Downy mildew can contaminate the vine between bud burst and pre-bloom, during pre-bloom, after bloom or at the end of the season, thereby destroying fruit.

Downy mildew is a disease that is difficult to treat in an effective way. To fight against these fungal diseases that attack the vines at the time of the appearance of the leaves, the flowering or the development of the bunches of grapes, the vine growers were brought to appeal to a certain number of fungicidal products.

Potato late blight (Solanum tuberosum) is a fungal disease caused by an oomycete of the family Pythiaceae, Phytophthora infestans. This disease, which is widespread throughout the world, is the main enemy of potato crops, and was responsible for the great famine of the 1840s, particularly in Ireland and the Scottish region.

Highlands. This species also affects tomato crops (Solanum lycopersicum) and other species of the family Solanaceae. For example, in tomato growing it is the most severe disease because the leaves, stems and fruits are attacked, which can destroy the plant in a few days.

Propamocarb chlorohydrate (propamocarb-HCl) alone is used to control downy mildew and potato late blight (Harris RI, Brighton Crop Protection Conference, Pests & Diseases, Volume 1, pp. 281-286). 1996). The results showed that the absorption of propamocarb-HCI in grapevine foliage is lower, slower and less pronounced, than that observed in the foliage of the potato. In addition, in the vineyard, the redistribution of propamocarb-HCI was absent beyond the tissues of the area of application. The study concluded that the activity of propamocarb-HCI in the fight against downy mildew is not satisfactory. The study also concluded that the marketing of propamocarb-HCI as an agent to control downy mildew is not interesting.

Other products used are derivatives of the dicarboximide type, such as folpel and captafol, which are respectively trichloromethylthio-2-isoindoline-1,3-dione and N- (1,1,2,2-tetrachloroethylthio) ) -tetrahydro-3a, 4,7,7a-iso-indoline-1,3-dione, as well as acetamide derivatives, such as cymoxanil, which is 2-cyano-N- (ethylaminocarbonyl) -2- (methoxyimino) acetamide. The latter, however, is not used alone but only in combination with many conventional fungicides.

Cymoxanil is a multi-metabolic anti-mildew that penetrates rapidly in the vine, has a preventive action on the spore germination and curative on the growth of mycelium in the leaf, within the limit of 25% of the period. mushroom incubation (1 to 2 days in practice). Farmers avoid the use of cymoxanil because of its short persistence. Remanence is the time during which a treatment product continues to exert its action.

In addition, cymoxanil is known to be unstable and rapidly degradable in the presence of water. Therefore, the formulations available on the market today are often dry powders. However, it is necessary to provide a liquid formulation for ease of use and to avoid the disadvantages of handling powders. Unfortunately, products that can be mixed with cymoxanil, such as ethylenebisdithiocarbamates, are also known to be unstable in many aqueous solutions, particularly under acidic conditions.

However, these different formulations of fungicidal agents can become biologically ineffective due to the appearance of resistant fungi strains.

Another problem is represented by the phytotoxicity of the treated plants. The phenomena of phytotoxicity result in the formation of roughness (russetting) on the grains and a decrease in the size of the grapes, thus rendering them unfit for use. Therefore, the farmer is always looking for new combinations and treatments that are both effective at fighting diseases and non-toxic to the plant. FR2761577A1 discloses a synergistic fungicidal composition based on propamocarb and phosphorous acid derivatives and a method for controlling, curative or preventive, against phytopathogenic fungi by using such a composition. However, FR2761577A1 does not reveal the combination of propamocarb-HCI and cymoxanil. The object of the invention is to provide a solution for at least one of the problems described above. Specifically, provide a method for controlling Plasmopara viticola or Phytophthora spp .. The method should be effective, non-toxic to plants, easy to apply, with a persistence on leaves that is longer compared to cymoxanil alone. The invention also aims to provide a ready-to-use product and / or easy to reconstitute, cheap, easy to apply, for use in the method of the invention. Another object of the invention is the use of the product of the invention for controlling Plasmopara viticola or Phytophthora spp. The subject of the invention is a stable aqueous mixture containing, as active substances, propamocarb-HCl and cymoxanil.

Propamocarb is preferably present in an agronomically acceptable form, more preferably in the form of a hydrochloride. The preferred mixture of the invention comprises 400 g / L propamocarb-HCl and 50 g / L cymoxanil. The propamocarb-HCl + cymoxanil combination of the present invention is very advantageous since the two active ingredients exhibit a synergistic effect in comparison with the effect of each active ingredient alone, in the fight against Phytophthora spp and downy mildew.

Preferably, both active ingredients are included in a single product. In a preferred embodiment, said product is in the form of a concentrated suspension in water (SC). An SC formulation has the advantage of being easier to use than the formulation of wettable powders (WP) or wettable granular formulations (WG). The use of a formulation SC does not give off any dust contrary to a formulation WP or WG. The subject of the invention is a product in the form of a concentrated suspension in water comprising, as active substances, propamocarb and cymoxanil. Propamocarb is preferably present as the hydrochloride. Propamocarb-HCl can be pure propamocarb-HCl or propamocarb-technical HCl (92% min) or a pre-mix of propamocarb in water. Similarly, cymoxanil may be pure cymoxanil or technical cymoxanil (min 97% min)

In a preferred embodiment, said product contains propamocarb, cymoxanil, water and at least one auxiliary selected from the list comprising: a stabilizing agent, a dispersing agent, an antifreeze agent, a rheological agent, an antimicrobial agent , an antifoaming agent, or any combination thereof.

In a preferred embodiment, said product contains a stabilizing agent. Preferably, the stabilizing agent used has an acid character and is soluble in water. The water-soluble acid is a weak acid, preferably citric acid, fumaric acid, acetic acid. More preferably, the stabilizing agent is citric acid, either hydrated or anhydrous. Preferably, the stabilizing agent used is citric acid monohydrate. The stabilizing agent is preferably used at a concentration of between 1 and 100 g / l, more preferably between 5 and 90 g / l, still more preferably between 10 and 80 g / l.

In a preferred embodiment of the invention, said mixture contains at least one dispersing agent. The dispersing agent is preferably selected from the list of compounds comprising alkali metal, alkaline earth metal and ammonium salts of aromatic sulfonic acids, for example lignin (Borresperse® types Borregaard, Norway), the acids phenol-, naphthalene- (Morwet® types, Akzo Nobel, USA) and dibutylnaphthalene sulphonic acid (Nekal® types, BASF, Germany), and fatty acids, alcohols ether phosphates, polyarylphenyl ether phosphate alkyls and alkylarylsulfonates, alkyl, lauryl ether and sulphates of fatty alcohols, and sulfated hexa, hepta- and octadecanols salts, as well as glycol ethers of alcohols, condensation products of naphthalenesulfonated and its derivatives with the condensation products of formaldehyde, naphthalene or naphthalene sulfonic acids with phenol and formaldehyde, polyoxyethyleneoctylphenol ethoxylated ethers, isooctyl-, octyl-polyglycol ethers or nonylphenol, alkylphenyl or tributylphenyl, alkylaryl polyether alcohols, isotridecyl alcohol, fatty alcohol-ethylene oxide condensates, ethylene oxide block copolymer and propylene oxide, Ricinethoxylated oil, polyoxyethylene or polyoxypropylenealkyl ethers, lauryl polyglycolacetate alcohol, sorbitol esters, esters of (meth) acrylic acid, waste liquor lignin and proteins, denatured proteins, polysaccharides (eg methylcellulose), hydrophobic modified starches, polyvinyl alcohol (Mowiol® types, Clariant, Switzerland), polycarboxylates (Sokolan® types, BASF, Germany), polyalkoxylates, alkoxylated alcohol polyvinylamine (Lupamin® types, BASF, Germany), polyethyleneimine (Lupasol® BASF types, Germany), poly (methoxyPEG750), polyvinylpyrrolidone (PVP) and copolymers thereof. The dispersing agent is used at a concentration of between 1 and 30 g / l, more preferably between 2 and 25 g / l, even more preferably between 4 and 20 g / l.

In a preferred embodiment, said product contains a dispersing agent and a stabilizing agent. Preferably the ratio of stabilizer to dispersant is 2: 1 to 10: 1; more preferably from 3: 1 to 8: 1.

In a preferred embodiment of the invention, said product contains an antifreeze agent. Antifreezes are known to those skilled in the art. Preferably, the antifreeze agent used is propylene glycol. The antifreeze agent is preferably used at a concentration of between 5 and 20 g / l, more preferably between 7 and 15 g / l.

In a preferred embodiment of the invention, said product contains a rheological agent. The rheological agent is preferably selected from the list of compounds comprising xanthan gum, attapulgite, magnesium and / or aluminum silicate or any combination thereof. Preferably, the rheological agent used is xanthan gum. The rheological agent is used at a concentration of between 1 and 20 g / l, preferably between 1 and 15 g / l, more preferably between 2 and 12 g / l, even more preferably between 3 and 10 g / l.

In a preferred embodiment of the invention, said product contains an antimicrobial agent. Preferably, the antimicrobial agent used is an isothiazolinone. The antimicrobial agent is preferably used at a concentration of between 0.05 g / L and 5 g / L, more preferably between 0.1 g / L and 2 g / L. The most preferred concentration of the antimicrobial agent is between 0.2 g / L and 1 g / L.

In a preferred embodiment of the process of the invention, said product contains an antifoaming agent. The anti-foaming agent is preferably used at a concentration of between 1 and 10 g / l.

Another advantage of the compositions of this invention, besides being stable themselves, is that they form a stable aqueous mixture when diluted in water, for example, in a spray tank. This is important because many fungicidal formulations do not form stable mixtures when diluted in water. Instead, they form gels, insoluble solids, sticky masses, and / or foams that make it impossible to apply the diluted mixture due to clogging of the spray device. The invention also relates to the use of a mixture containing propamocarb-HCl and cymoxanil. It has been found that the combination of the active substances propamocarb and cymoxanil is useful for controlling Plasmopara viticola or Phytophthora spp. The invention also relates to the use of a mixture containing, as active substances, propamocarb-HCl and cymoxanil to control Plasmopara viticola or Phytophthora spp. The subject of the invention is a method for controlling Plasmopara viticola or Phytophthora spp., In a place which is infested with or susceptible to infestation thereof, characterized in that a mixture containing, as active substances, propamocarb and cymoxanil on the said site.

The mixture of the present invention can be used by applying it to the vines. It is usually in the agrochemical concentrate state which is diluted with water to the desired concentration before application.

In a preferred embodiment, said mixture contains 1-100 g / L of a stabilizing agent, preferably said stabilizing agent is citric acid.

In a preferred embodiment, said mixture is in the form of a concentrated suspension in water; preferably corresponding to the product described above.

In one embodiment of the invention, said mixture is obtained by the addition in water of a formulation containing as active substance propamocarb, preferably in the form of a hydrochloride and a formulation containing as active substance the cymoxanil.

In one embodiment of the invention, said mixture contains between 200 and 600 g / L, preferably between 300 and 500 g / L, more preferably about 400 g / L propamocarb-HCl and between 10 and 100, preferably between 20 and 80 g / l, more preferably about 50 g / l cymoxanil, expressed by weight per L of formulated product. In a preferred embodiment of the invention, said mixture contains 400 g / L propamocarb-HCl and 50 g / L cymoxanil.

In a preferred embodiment of the invention, said mixture is in the form of a concentrated suspension in water. The advantage of this type of formulation is that it is ready for use and only requires addition to the water tank to obtain a spray tank for application of the product to the plants. Preferably, an SC product as described above is used.

The mixture of the present invention may be in the form of a concentrated suspension in water. The application rate is between 1.5 and 3 liters of product per hectare (ha) of field to be treated. Preferably, the application rate is between 2 and 2.5 L / ha, more preferably the application rate is about 2.25 L / ha.

For the treatment of one hectare of vines, preferably between 400 and 1000 liters of water are used, preferably 800 liters.

In a preferred embodiment of the invention, the rate between two applications is 5 to 8 days. The tested product has a persistence of 7 days. The invention is illustrated by the following non-limiting examples.

Example 1

A finished product based on propamocarb-HCl + cymoxanil is prepared with the following composition:

propamocarb-HCI 400 g / L

cymoxanil 50 g / L

adjuvant incl. citric acid until IL 250 ml of this finished product is added to 100 L of water to obtain a preparation (A) containing propamocarb-HCl + cymoxanil (250 ml finished product per 100 L of water).

The preparation (A) was sprayed on plots of vines before the period of infection of the vines by Plasmopara viticola. The experiment was performed according to a randomized block device and in five repetitions. The vineyard plots, Chardonnay grape, were sprayed 4 times using the preparation (A). Another plot was not sprayed and was used as a control. The area of each plot is 14 m2 (4m x 3.5m).

In addition to the preparation (A) containing propamocarb-HCl + cymoxanil, propamocarb alone, cymoxanil alone, Acrobat SC + Dithane M-45, Dimethomorph 500 SC + Dithane M-45 and Kocide Blue Xtra have been tested.

Acrobat SC is a product with dimethomorph as the active ingredient. Dithane M-45 is a product having the active substance mancozeb. Kocide Blue Xtra is a product whose active ingredient is copper. The preparations of dimethomorph + mancozeb are the most used products for the treatment of Plasmopara viticola.

The sprays were run at a pressure of 750 kPa and the applications were separated from each other by a period of 10 days. The experiment was performed over a period of two months. The dates of the 4 applications are shown in Table 1 along with other parameters such as temperature, relative humidity, cloud cover, wind speed and direction, and BBCH scale vine growth stage. . The appearance and development of the infection were evaluated 10 days after each spraying.

Table 1: dates and parameters recorded during spraying

N = north; 0 = west; E = is Table 2: evaluation dates

Rainfall during the study was recorded (Table 3).

Table 3: Precipitation recorded.

The recorded rainfall corresponds to the averages observed in the region and are ideal for the development of downy mildew in the absence of any preventive treatment.

The results recorded assessed (i) the spread of downy mildew on leaves and bunches and evaluated (ii) the phytotoxicity of the sprayed (A) preparation on the vines. The statistical analysis of the results was performed using the "GenStat Release 11.1" software. The least significant variance and difference analysis (Least Significant Difference) was calculated.

Per parcel, 100 leaves were examined and the frequency of attack (percentage of infected leaves) was determined and recorded (incidence). The intensity of the infection (percentage of leaf area reached on each leaf) was also assessed (severity).

Similarly, per plot, 100 clusters were examined and the attack frequencies and the intensity of the infection were measured.

The plots used were inspected for signs or symptoms of phytotoxicity on the leaves, flowers and / or fruits of the vines. The presence of phytotoxicity symptoms was recorded according to an arithmetic scale ranging from 0 to 100 in which 0 indicates the absence of phytotoxicity and 100 indicates the death of the crop.

The observed results are as follows (Tables 4-7):

The treatments are expressed in volume of finished products in 100 liters of water.

Table 4: Frequency of attack on leaves (incidence)

If similar letters (a, b, ab or c) = results not significantly different at 95% confidence level

Table 5: Intensity of infection on leaves (severity)

If similar letters (a, b, ab or c) = results not significantly different at 95% confidence level

Table 6: Cluster Attack Frequency (Incidence)

Table 7: Intensity of cluster infection (severity)

Statistical analysis has shown that the results obtained for treated plots are significantly different from the results recorded in the untreated plot. In each treated plot and after each application of propamocarb-HCl + cymoxanil, the leaves and clusters of vines were examined for the presence of, for example, yellowing, necrosis and / or deformities. The result of these observations was negative.

The results obtained show that treatment with propamocarb-HCl + cymoxanil leads to a much lower frequency of attack and infection intensity than those observed on untreated vines. In addition, no symptoms of phytotoxicity were observed on clusters or leaves of vines treated with propamocarb-HCI + cymoxanil.

Eight days after application 4, the propamocarb-HCl + cymoxanil mixture (250 ml / 100 L) exhibited the lowest attack frequency and infection intensity on the leaves compared with the other treatments tested as only propamocarb-HCI or cymoxanil alone. The results obtained for the propamocarb-HCl + cymoxanil mixture (250 ml / 100 L) are significantly different from the results obtained for the other treatments tested (Tables 4 and 5). The experiment described shows that propamocarb-HCl + cymoxanil is effective against Plasmopara viticola. This efficiency is all the more advantageous since the treatment of vines with propamocarb-HCl + cymoxanil induces no phytotoxicity and thus reduces the losses due to the treatment.

EXAMPLE 2 The object of this experiment is to evaluate the activity of the propamocarb-HCl + cymoxanil mixture, of propamocarb-HCl alone and of cymoxanil alone in the context of the fight against grapevine mildew (Plasmopara viticola). The composition of the preparation containing propamocarb-HCl and cymoxanil is as follows:

propamocarb-HCI 400 g / L

cymoxanil 50 g / L

adjuvant incl. acid up to IL

The composition of propamocarb-HCI alone is that of a product that is sold commercially (Proplant) with 722 g propamocarb-HCl / L. The study was conducted under controlled conditions on an experimental model of whole Cabernet Sauvignon plants produced in a greenhouse. Homogeneous batches of 6 plants were formed for the study of each modality. The plants were contaminated with a monosporocyst strain of Plasmopara viticola.

The applications were carried out on the basis of a slurry volume of 800 L / ha. The slurry is obtained by dissolving 2 liters of the propamocarb-HCl + cymoxanil mixture in 800 liters of water.

The treatments were performed at different dates: • 2 days before artificial contamination (preventive) (I - 2) • 3 days after artificial contamination (curative) (I + 3) • 5 days after artificial contamination (anti-sporulant) (I + 5)

All plants were incubated after inoculation in an air conditioned room at 21 ° C ± 2 ° C and lit 14 hours per day. Each condition of the test has been perfectly isolated from the others by closed mini-enclosures or isolation cages that ensure high permanent moisture favorable to the development of mildew. When necessary, water misting was carried out on the batches of plants.

The plants remained in these conditions for 7 days. At the end of this period, a notation of the damage of the fungus was carried out on each plant and for each leaf stage.

The notation is based on a visual observation of the damage intensity of the decomposed fungus in two parts: the surface colonized by the fungus and the intensity of sporulation. A scale from 0 to 100% is used.

Each leaf is observed individually. For each plant, an average attack is calculated from the percentages noted on each leaf level. The average N of the plants in the same batch gave the damage rate for each condition of the test. The efficiency E of each test modality is then calculated with reference to the batch of untreated test plants according to the formula:

Where T is the average attack score on untreated plants, and D is observed on plants treated with the dose.

An analysis of variance made it possible to compare the results and to give, where appropriate, the differences between the conditions studied.

Quantification of the number of sporocysts produced, a log of sporocyst release and zoospore germination were also performed on foliar levels of the 5 day curative treatment.

Table 8: Attack intensity of grapevine mildew and efficacy calculated after fungicidal treatments with propamocarb, cymoxanil and propamocarb-HCl + cymoxanil mixture at 1-2, 1 + 3 and 1 + 5.

The results expressed as a percentage of efficacy indicate that cymoxanil alone and the propamocarb-HCI + cymoxanil mixture have excellent preventive activity (100%) when the fungicide treatments were carried out two days before the artificial infestation. Propamocarb-HCI alone has a limited preventive activity and is statistically inferior to the other two products.

The curative treatment applied 3 days after artificial contamination also shows us an excellent efficiency of cymoxanil and propamocarb-HCI + cymoxanil mixture. The efficiency of propamocarb-HCI remains statistically lower than the other two products. The curative activity of cymoxanil applied 5 days after artificial contamination is significantly reduced (29.2%) and insufficient. The activity of propamocarb-HCl in curative treatment carried out 5 days after the artificial contamination is slightly reduced compared to the curative treatment carried out 3 days after the artificial contamination. The effectiveness of propamocarb-HCl is statistically superior to the curative activity of cymoxanil 5 days after artificial contamination. The curative efficacy of the propamocarb-HCl + cymoxanil mixture 5 days after the artificial contamination gives satisfactory and statistically superior results to those obtained with the two active substances used alone. The combination of the two products gives more favorable results in comparison with those obtained with the two products tested in isolation.

Table 9: Evaluation and calculated efficiency of the release, germination and the capacity of infection of the spores after fungicidal treatments with propamocarb, cymoxanil and propamocarb-HCl + cymoxanil mixture at 1 + 5.

Observations and notations on released spores also suggest an advantage of the combination of the two active ingredients compared to the two products used alone. The combination of propamocarb-HCI + cymoxanil completely blocks the release of spores. Cymoxanil partially blocks spore release whereas propamocarb-HCl alone has no effect.

With respect to the germination of liberated zoospores, the propamocarb-HCl + cymoxanil mixture and cymoxanil completely inhibit germination. Propamocarb-HCI alone partially prevents germination of zoospores.

EXAMPLE 3 The object of this experiment is the study of the system of propamocarb-HCI + cymoxanil mixture, propamocarb-HCl and cymoxanil in the context of the fight against the downy mildew (Plasmopara viticola).

The composition of the preparation containing propamocarb-HCl and cymoxanil is as follows:

propamocarb-HCI 400 g / L

cymoxanil 50 g / L

adjuvant incl. acid up to IL

The composition of propamocarb-HCI alone is from a product that is sold commercially (Proplant) with 722 g propamocarb-HCl / L. The study was conducted under controlled conditions on an experimental model of whole Cabernet Sauvignon plants produced in a greenhouse. Homogeneous batches of 6 plants were formed for the study of each modality. The plants were contaminated with a monosporocyst strain of Plasmopara viticola.

The applications were carried out on the basis of a slurry volume of 800 L / ha. The slurry is obtained by dissolving 2 liters of the propamocarb-HCl + cymoxanil mixture in 800 liters of water.

The treatments were carried out 24 hours before the date of the plant contamination. The application was carried out either on the whole plant, or on the lower part of the plants. In this case, a plastic sleeve will be applied to the leaves F1, F2 and F3 of the plant.

All plants were incubated after inoculation in an air conditioned room at 21 ° C ± 2 ° C and lit 14 hours per day. Each condition of the test has been perfectly isolated from the others by closed mini-enclosures or isolation cages that ensure high permanent moisture favorable to the development of mildew. When necessary, water misting was carried out on the batches of plants.

The plants remained in these conditions for 7 days. At the end of this period, a notation of the damage of the fungus was carried out on each plant and for each leaf stage.

The notation is based on a visual observation of the damage intensity of the decomposed fungus in two parts: the surface colonized by the fungus and the intensity of sporulation. A scale from 0 to 100% is used.

Each leaf is observed individually.

For each plant, an average attack is calculated from the percentages noted on each leaf level. The average of N plants in the same batch gave the damage rate for each condition of the test. The efficiency E of each test modality is then calculated with reference to the batch of untreated test plants according to the formula:

Where T is the average attack score on untreated plants, and D is observed on plants treated with the dose.

An analysis of variance made it possible to compare the results and to give, where appropriate, the differences between the conditions studied.

Table 10: Attack intensity of grapevine mildew and efficiency calculated after fungicidal treatments with propamocarb-HCl, cymoxanil and propamocarb-HCI + cymoxanil mixture 24 hours after artificial contamination.

The results of this study (Table 10) indicate that propamocarb-HCl is not systemic in vines and proves to be a contact-only active substance affecting downy mildew. Cymoxanil has an efficacy of 87.4% on the protected leaves at the time of treatment and suggests a systemicity of the active substance. The propamocarb-HCl + cymoxanil mixture provides excellent efficacy on the protected leaves (95.6%) and its efficacy is statistically superior to that obtained with cymoxanil alone. The combination of the two products gives more favorable results in comparison with those obtained with the two products tested alone on the protected leaves and suggests an increased system.

Moreover, cymoxanil and the propamocarb-HCl + cymoxanil mixture gives a 100% efficiency on the treated plants in their entirety. Propamocarb-HCl alone provides good efficacy and its efficacy is statistically lower than cymoxanil alone and propamocarb-HCI + cymoxanil.

The propamocarb-HCl + cymoxanil mixture gives results superior to the systemic active substance of reference fosethyl aluminum.

EXAMPLE 4 The object of this experiment is the study of the effect of the mixture propamocarb-HCl + cymoxanil, in the context of the fight against potato late blight CPhytophthora infestans).

In the following photos (Fig 1), the potatoes in field (a) are not treated at all, and (b) are effectively treated against mildew by a typical mixture of propamocarb-HCI and cymoxanil with the citric acid.

Also, in the following graph (Fig 2), the treatment effect with a mixture of propamocarb-HCl and cymoxanil is visible, applied curative after 33 hours after being infected with P. infestans, and applied as eradicant after 5 days after the infection.

The propamocarb-HCl / cymoxanil mixture is curative against P. infestans during the immediate post-infection phase, but before symptoms become visible, ie during the latent phase. The mixture has antisporulent activity, so that P. infestans lesions are affected by decreasing the formation of sporangiophores and / or by decreasing the viability of sporangia formed.

Claims (13)

claims 1. Concentrated aqueous suspension formulation for the protection of a plant, comprising as active substances, a propamocarb and cymoxanil and an acid, characterized in that the acid is selected from the list of phosphoric acid, the acid boric acid, acetic acid, propionic acid, citric acid, fumaric acid, tartaric acid, oxalic acid, succinic acid, and combinations thereof, and comprising at least one auxiliary selected from list: a stabilizing agent, a dispersing agent, an antifreeze agent, a rheological agent, an antimicrobial agent, an antifoam agent, or any combination thereof. 2. Formulation according to claim 1, wherein said plant is selected from the list of potatoes, tomatoes and vine. 3. Formulation according to claim 2 for controlling Plasmopara viticola or Phytophthora spp. 4. Formulation according to any one of claims 1 to 3, comprising 1100 g / L of said acid. The formulation of any one of claims 1 to 4, wherein said acid is citric acid. The formulation of any one of claims 1 to 5, comprising from 200 to 600 g / L of propamocarb and from 10 to 100 g / L of cymoxanil. The formulation of claim 6 comprising 400 g / L propamocarb-HCl and 50 g / L cymoxanil. 8. A method for controlling Plasmopara viticola or Phytophthora spp., In a place which is infested with or susceptible to infestation thereof, characterized in that propamocarb is applied to said place as active substances, preferably in the form of chlorohydrate, and cymoxanil, in combination with an acid selected from the list of phosphoric acid, boric acid, acetic acid, propionic acid, citric acid, fumaric acid, acid tartaric acid, oxalic acid, succinic acid, and combinations thereof, characterized in that 400-1200 g propamocarb, 50-150 g cymoxanil, and 1-300 g / L of said acid per hectare are applied. 9. The method of claim 8, characterized by a rate of 5-8 days between two applications. 10. Use of a formulation according to claims 1 to 7 as a fungicide. 11. Use according to claim 10, wherein said plant is selected from the list of potatoes, tomatoes and vine. 12. Use according to claim 11 for controlling Plasmopara viticola or Phytophthora spp. 13. Use according to any one of claims 10-12, wherein the acid is citric acid.