EP3941202A1 - Magnesium hydroxide for use as a contact fungicide in agriculture - Google Patents

Magnesium hydroxide for use as a contact fungicide in agriculture

Info

Publication number
EP3941202A1
EP3941202A1 EP20731160.6A EP20731160A EP3941202A1 EP 3941202 A1 EP3941202 A1 EP 3941202A1 EP 20731160 A EP20731160 A EP 20731160A EP 3941202 A1 EP3941202 A1 EP 3941202A1
Authority
EP
European Patent Office
Prior art keywords
particles
magnesium
product
fungicide
magnesium hydroxide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP20731160.6A
Other languages
German (de)
French (fr)
Inventor
Nicolas MACAIGNE
Julie DUCLOS
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Timab Magnesium
Original Assignee
Timab Magnesium
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Timab Magnesium filed Critical Timab Magnesium
Publication of EP3941202A1 publication Critical patent/EP3941202A1/en
Pending legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
    • A01N59/00—Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
    • A01N59/06—Aluminium; Calcium; Magnesium; Compounds thereof
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
    • A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
    • A01N25/02—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests containing liquids as carriers, diluents or solvents
    • A01N25/04—Dispersions, emulsions, suspoemulsions, suspension concentrates or gels
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
    • A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
    • A01N25/12—Powders or granules
    • A01N25/14—Powders or granules wettable
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01P—BIOCIDAL, PEST REPELLANT, PEST ATTRACTANT OR PLANT GROWTH REGULATORY ACTIVITY OF CHEMICAL COMPOUNDS OR PREPARATIONS
    • A01P3/00—Fungicides

Definitions

  • the invention relates to a fungicide based on a magnesium product comprising magnesium hydroxide.
  • This fungicide can be used in organic farming.
  • the invention also relates to a method for controlling a fungal pathogen and for treating a fungal disease of a crop, in particular by the foliar route.
  • nanoparticles comprising magnesium oxide and magnesium hydroxide exhibit improved biocidal properties. Nanomaterials remain expensive to produce, however, and special filtration equipment is needed to limit loss of yield and inhalation risks during manufacture. In addition, the regulatory constraints linked to the use of nanoparticles are very high in agriculture.
  • the inventors of application WO 2015/100468 proposed to agglomerate magnesium hydroxide nanocrystals in the form of a composite.
  • This document teaches that the biocidal activity depends on the size of the crystals of magnesium hydroxide, and not on the size of the particles.
  • the composite is obtained by calcining a rock comprising magnesium carbonate and / or magnesium hydroxide to obtain magnesium oxide which is then hydrated to give magnesium hydroxide.
  • the calcination process known as the “flash” calcination process is particular because it is carried out at low temperature for a very short time. Flash calcination, however, requires very high investment costs, and consumes a lot of energy.
  • magnesium hydroxide is obtained from particles of magnesium oxide having a degree of calcination greater than 90%, a particle size between 10 and 100 microns, a very high porosity (greater than 0.5), a specific surface area (SSA) greater than 150 m2 / g and comprising crystal domains of size less than 20 nm.
  • the invention relates to a contact fungicide for agriculture comprising particles of a magnesium product comprising magnesium hydroxide, said particles having a magnesium hydroxide purity greater than or equal to 86% by mass relative to the mass of the magnesium product on a dry basis, and having a particle size characterized by a D50 of between 1 and 10 microns.
  • the fungicide has the advantage of having a fungicidal activity superior to the magnesian biocides of the prior art supplemented or not with oxygen peroxide.
  • a fungicide according to the invention makes it possible to protect crops against pathogenic fungi.
  • the fungicide of the invention when in the form of a suspension, has the advantage of being in liquid form, which facilitates its use.
  • plants can only receive a limited amount of solid particles of magnesium product on the surface of their leaves. Beyond a certain threshold, there is a risk of phytotoxicity (burning, facilitated penetration of pathogens).
  • the fungicide of the invention has no phytotoxicity at the doses at which it is effective.
  • the fungicide of the invention has the advantage of creating a dense network of particles on the surface of the plant while applying a small amount of product. Without being bound by any theory, it is believed that the very high purity of the magnesium product results in a greater number of active links in the network, and in increased fungicidal efficacy.
  • the inventors have in fact found that a product with a higher D50 forms agglomerates preventing a homogeneous distribution of the fungicide on the plant.
  • Figure 1 shows the fungicidal efficacy of two magnesium products used in the context of the invention and a reference magnesium product, against the pathogenic fungus of downy mildew of the vine.
  • Figure 2 shows the bacteriostatic activity of three fungicides according to the invention.
  • Figure 3 illustrates the bactericidal activity of a prior art magnesium product at three different doses.
  • the magnesium hydroxide purity of the particles of a magnesium product comprising magnesium hydroxide is expressed as a percentage by mass relative to the mass of the magnesium product on a dry basis.
  • the "purity of the magnesium product on a dry basis” is understood to mean the content of magnesium hydroxide in the magnesium product in this specification.
  • the magnesium product used in the context of the invention may be pure (contain only magnesium hydroxide) or comprise, in addition to the magnesium hydroxide, other magnesium compounds in the form of silicate, carbonate , chloride or sulfate, these impurities possibly coming from the raw material used to prepare the particles of magnesian product.
  • the raw material can be a rock or a synthetic product comprising magnesium hydroxide.
  • Purity within the meaning of the invention is defined as being the purity of the particles of the magnesium product on a dry basis, that is to say the mass of magnesium hydroxide relative to the mass of the particles of magnesium product which have been dried to remove all or part of the free water it contains, for example after steaming the product at 105 ° C for 2 hours.
  • the dried palicles preferably contain less than 1% by weight of free water. The amount of water can be measured by any method known to those skilled in the art.
  • the purity of the magnesium product on a dry basis can be determined by any method known to those skilled in the art.
  • a first method uses the X-ray diffraction technique.
  • a second method comprises a chemical analysis of the magnesium product to measure its content of impurities, and a measurement of the loss on ignition of the magnesium product.
  • the loss on ignition can consist in measuring the loss of mass of the magnesium product between 250 ° C and 550 ° C.
  • the mass of the product at the end of this heat treatment is equal to the sum of the mass of MgO and the mass of the impurities.
  • the amount of magnesium hydroxide in the particles of magnesium product is greater than or equal to 86% by mass on a dry basis.
  • Impurities that the product may contain are, for example, calcium oxide, ferric oxide, silica, magnesium carbonate, magnesium silicate, magnesium sulfate.
  • the silica content is preferably less than or equal to 2%, more preferably less than or equal to 1.5% by mass on a dry basis of particles.
  • the purity of the particles of magnesium product can be expressed as the difference between the mass of the magnesium product and the mass of all the impurities (any compound other than magnesium hydroxide) that it contains, relative to the mass of magnesian product on a dry basis.
  • the amount of magnesium hydroxide in the particles of magnesium product is greater than or equal to 86% and less than or equal to 100% by mass relative to the mass of the dried magnesium product. It is for example greater than or equal to a value chosen from the group consisting of 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97% and 98 %, and less than or equal to the value of 99%.
  • the particle size of the particles of the magnesium product comprising magnesium hydroxide within the meaning of the invention is the particle size of the particles of the magnesium product on a dry basis.
  • the particle size distribution of the particles can be characterized by a D50 of between 1 and 10 microns.
  • the expression “between ... and ....” excludes the limits of the range of values, while the expression “ranging from ... to ....” includes the limits of the value range.
  • the D50 of particles containing magnesium hydroxide is less than 10 microns, preferably less than 6 microns, or even less than 5 microns and greater than 1 micron.
  • the D50 can be measured using any conventional method known to those skilled in the art.
  • the particle size can also be characterized by a D90 ranging from 1 micron to 30 microns, preferably ranging from 1 micron to 12 microns.
  • the specific surface area (SSA) of the particles of the dried magnesium product preferably ranges from 10 m2 / g to 100 m2 / g, for example from 10 m2 / g to 50 m2 / g.
  • the specific surface area of the particles of the dried magnesium product is for example less than a value chosen from the group consisting of 100, 90, 80, 70, 60, 50, 40, 30, 25 and 20 m2 / g.
  • the specific surface area of the dried magnesium product particles is more preferably from 10 m2 / g to 18 m2 / g.
  • the specific surface area (SSA) defined in this description is measured on dried particles (before their possible suspension in water), and not on hydrated particles or on particles which are suspended in water.
  • the particles of the magnesium product comprising magnesium hydroxide can be obtained by chemical synthesis, by calcination or by mining from a rock containing it.
  • the particles of the magnesium product comprising magnesium hydroxide are obtained by mining of brucite, followed by grinding of the rock.
  • the process for preparing the particles does not include a calcination step.
  • a formula based on brucite naturally magnesium hydroxide
  • the fungicide is a foliar fungicide for organic farming.
  • organic farming means a cultivation method in accordance with Regulation (EC) No. 203/2012 of March 8, 2012 amending Regulation (EC) No. 889/2008 laying down detailed rules for the application of Regulation (EC) No. 834 / 2007 of the Council for organic wine, and complies with Regulation (EC) 889/2008.
  • the particles of the magnesium product comprising magnesium hydroxide are obtained by calcination in an oven, followed by hydration.
  • the calcination furnace is preferably a rotary furnace, a vertical furnace or a furnace on a fluidized bed allowing slow calcination.
  • the calcination process is a slow calcination process as opposed to a rapid calcination process, called “flash" calcination.
  • flash calcination process means a process in which the calcination chamber is in the form of a vertical tube in which the mineral particles to be calcined are injected at the top of the tube. A stream of steam can be used to entrain the particles in the oven; in this case the steam and the mineral particles are injected simultaneously.
  • the heat required for calcination is unique in that it is generated outside the calcination chamber. The heat is transferred by diffusion into the chamber through the wall by a flow of hot air.
  • the hot air flow can be set up against the flow of particles to even out the calcination temperature throughout the tube.
  • the particles undergo a sudden increase in temperature for a very short time (a few seconds at most), the thermal shock produced having the effect of considerably increasing the specific surface area and the porosity of the particles.
  • a fine grinding of the rock ⁇ 100 ⁇ m must first be carried out.
  • the temperature is chosen to be as low as possible, preferably from 550 ° C to 750 ° C.
  • the specific surface of the particles of magnesium oxide obtained by flash calcination is typically greater than 150 m2 / g, or even greater than 200 m2 / g.
  • the furnace can be a vertical furnace, a multi-hearth furnace (Multy Hearth Furnance) or a horizontal rotary furnace.
  • Vertical ovens and multi-hearth ovens are particularly suitable for producing reactive and caustic products.
  • a vertical furnace is a cylindrical or elliptical tube in which ore is introduced to the top of the tube along with a fuel (coal, gas or oil). The ore-fuel mixture then falls into a combustion zone before exiting the furnace.
  • the coal can also be pyrolyzed in a boiler before injection into the chamber in the form of carbonaceous gas.
  • the calcination temperature of this oven is 800 ° C-950 ° C with a long residence time, between 7 to 8 hours.
  • a multi-hearth oven is a vertical cylinder containing a certain number of stages equipped with a burner (hearth) whose temperature is between 750 and 1000 ° C.
  • the ore is driven from the top of the cylinder by a rotating blade in successive foci. There may be between 10 to 14 fireplaces in these ovens.
  • the residence time of the ore in the furnace is variable according to the number of hearths and the speed of rotation of the mechanism, it is generally calculated in hours.
  • Horizontal rotary kilns are more versatile: they can produce reactive, caustic or refractory products thanks to a temperature range that can go from 600 ° C to 1600 ° C.
  • the residence time is 3h to 6h. It is an inclined horizontal tube (approximately 3 ° -4 °).
  • the ore is introduced from the highest side and combustion takes place from the lowest side, against the current.
  • the ore is driven by a slow rotating movement of the tube. The latter consumes more energy but accepts larger particles at the furnace inlet.
  • a magnesium hydroxide obtained by a calcination process is obtained by a slow calcination process, according to which the residence time of the magnesium hydroxide used as material first is greater than 1 minute, preferably greater than 30 minutes, and more preferably greater than 1 hour.
  • the residence time is preferably less than 12 hours or less than 10 hours.
  • the fungicide of the invention may contain, in addition to the particles of the magnesium product comprising magnesium hydroxide, other additives. These additives, when they are present, are preferably bio-sourced so that the fungicide can be advantageously used as a contact fungicide in organic farming, preferably as a foliar fungicide in organic farming.
  • the fungicide of the invention may contain additives such as an anti-leaching agent in order to avoid losses of efficiency during rains.
  • the fungicide may be in the form of a powder of the particles or of a suspension obtained by dispersing the particles in water.
  • the fungicide of the invention is in the form of a suspension and preferably comprises at least one dispersing agent and / or at least one surfactant to obtain a stable suspension during for preserving the product, or to resuspend the magnesium hydroxide after stirring the product, while it is applied to the plants.
  • the particles of the magnesium product preferably represent from 40% to 65% by mass, for example from 50% to 55% by mass of the mass of the suspension.
  • Another object of the invention is a liquid composition for foliar biocidal treatment of a crop, characterized in that it consists of 90% by mass:
  • a crop treatment product chosen from the group comprising fertilizers, in particular fertilizers, bio stimulants, natural defense stimulators (SDN) and their mixtures, and
  • biocide within the meaning of the invention is meant a fungicide, herbicide, pesticide, bactericide, insecticide and / or virucide.
  • a proportion of the particles preferably has a D50 of between 1 and 10 microns before being put into the water.
  • the proportion of particles is preferably the majority proportion: it is preferably greater than 50%, more preferably greater than 90% and more preferably greater than 95% by mass of the total mass of the particles which are suspended in water.
  • Another object of the invention is a method of fungal treatment of a crop which consists in applying the fungicide or the composition described above, by foliar route.
  • the method aims in particular to improve the growth and development of crops, to improve crop yields, to stimulate and strengthen crops, in particular by improving their resistance to pathogens, and / or to improve the yield of crops. sanitary quality of crops.
  • the fungicide and the composition of the invention are advantageously free of a pesticide obtained by chemical synthesis chosen from the group comprising fungicides, herbicides, insecticides and mixtures thereof. It is preferred to use elicitors which stimulate the plant's defense system systemically, as an alternative to phytosanitary products.
  • the fungicide or the composition of the invention can be used for its foliar application on crops, said foliar application can be carried out at the time of the appearance of the first leaves and / or at any other time until harvest. of the culture. This application is on the order of 3 to 15 L per hectare.
  • the culture can in particular be chosen from the group comprising:
  • - field crops such as cereals, oilseeds, protein crops, fodder legumes, fodder grasses or sugar crops,
  • - fruit crops such as stone fruits, pome fruits, almond fruits, cluster fruits, small fruits or fruits from hot regions,
  • the fungicide of the invention in the form of a suspension can achieve an efficiency greater than 85%.
  • Another object of the invention relates to a method for controlling a fungal pathogen and treating a fungal disease of a crop, which consists in applying the fungicide or the composition described above, preferably by foliar route.
  • the fungal pathogen can be chosen from the group consisting of Mycosphaerella fijiensis, Phytophthora megakarya, Phytophthora palmivora, Fusicladium oleagineum or Cycloconium oleaginum, Colletotrichum acutatum, Phytophthora infestans, Bremia lactucclerii, Sasmotryscleria nunclerardii, Saswellotryscleria n, Sclerotrysclerae n, Sclerotrysclerae n, Sclerotryscleraii, Sclerotinia n, Sclerotinia n, Sclerotinia n, Sclerotinia n, Magnaporthe grisea, Sphaerotheca pannosa and Septoria tritici (also called Zymoseptoria tritici).
  • the fungal disease can be chosen from the group consisting of Sigatoka disease of bananas, brown rot of cocoa pods, olive peacock eye, apple burp bitter, apple downy mildew. of earth, tomato, lettuce and grapevine, powdery mildew of grapevine and rosebush, black rot of grapevine, septoria of wheat, sclerotinia of rapeseed, and blast of rice.
  • Example 1 Preparation of the fungicide of the invention
  • a first suspension (Suspension A) is prepared from particles obtained by grinding and sieving a brucite having a purity of magnesium hydroxide on a dry basis equal to 92%.
  • the D50 of the particles after sieving ranges from 3 to 4 ⁇ m.
  • the D90 ranges from 12 to 13 microns.
  • the particles contain less than 1.3% by mass of SiO2, and their specific surface area is of the order of 13 m2 / g after being suspended in water.
  • the particles are suspended as follows
  • a second suspension (Suspension B) is prepared from particles obtained by chemical synthesis, more precisely by precipitation from a brine of MgCl2 and lime.
  • the D50 of the magnesium hydroxide particles after sieving ranges from 2 to 3 ⁇ m.
  • the D90 is 5 to 6 microns.
  • the purity of magnesium hydroxide on a dry basis is 97.5%.
  • the particles contain less than 1.5% by mass of SiO 2, and their specific surface area is of the order of 17 m2 / g after being suspended in water.
  • the particles are suspended as follows:
  • the fungicide of the invention has been shown to have no phytotoxicity at the doses at which it is effective, on field crops. Each of the tests were carried out according to "Good experimental practices”.
  • Suspension A made in Example 1 was applied weekly or bimonthly during the period of plant susceptibility to the pathogen. The same test is carried out on the same crop the following year.
  • Suspension A was applied to the leaves of the plant. The aspect of these is then studied. The phytotoxicity is checked visually and gives rise to a score of 0 to 10 (0 encoding an absence of phytotoxicity). A score of 0 was assigned in each of the tests performed. The results are shown in Table 2 below.
  • Comparative Example 4 Comparison between a product of the invention and a product of the prior art
  • the study is carried out in the laboratory.
  • the solutions are applied on a plant (vine leaf). These are then inoculated with the pathogenic organism Guignardia bidwellii responsible for black rot of the vine. After 12 days of incubation, a notation of the colonization and the sporulation of the fungus is carried out under a binocular magnifying glass. An average of the damage over the ten repetitions is calculated and makes it possible to obtain the effectiveness of the modality compared to the untreated control.
  • the product comprising magnesium hydroxide used in the context of the invention has a fungicidal efficacy greater than that of a product of the prior art comprising a composite of magnesium hydroxide nanocrystals, obtained by flash calcination according to l teaching of patent application WO 2015/100468.
  • Table 3 The results are shown in Table 3 below
  • Three magnesian products are studied here having a D50 of between 4 and 8 microns, with respective purities of 98% magnesia (comprising 2% calcite), 94% (comprising 3% periclase and 3% calcite) and 84% (comprising 14% akermanite and 2% calcite).
  • the loss of purity of the magnesium product induces a sharp decrease in its fungicidal efficacy despite a high total magnesium content.
  • the purity of magnesium hydroxide on a dry basis is a key point of its effectiveness.
  • Particle size has a role in the effectiveness of the fungicide.
  • a D50 greater than 10 microns does not make it possible to have a product of sufficient efficiency, contrary to what is suggested in the prior art.
  • Comparative Example 7 Bacteriostatic activity of the products of the invention and bactericidal activity of the products of the prior art
  • the first magnesium hydroxide results from chemical synthesis: it complies with that used in Example 1 to prepare suspension B. Its activity is measured relative to Control 1.
  • the second magnesium hydroxide comes from calcination then hydration; it has for characteristics an D50 of 10 ⁇ m, an MgO content of 61.9% after hydration, and an Mg (OH) 2 purity of 87%. Its activity is measured relative to Control 2.
  • the third magnesium hydroxide is obtained from brucite: it is consistent with that used to prepare suspension A of Example 1. Its activity is measured relative to Control 3.
  • the bactericidal activity of a magnesium product of the prior art was measured at three different doses (25 g MgO / L equivalent to 36.2 g Mg (OH) 2 / L- Control 3, 50 g MgO / L equivalent to 72.5 g Mg (OH) 2 / L - Control 2 and 75 g MgO / L equivalent to 108.7 g Mg (OH) 2 / L - Control 1).
  • the prior art product comprises a composite of nanocrystals of magnesium hydroxide; it is obtained by flash calcination according to the teaching of patent application WO 2015/100468.
  • Each growth control of the strain consists of sterile distilled water.
  • FIG. 3 illustrates the bactericidal effect of the suspension of the prior art: the bacteria are completely decimated after several hours.
  • the present invention does not claim a bactericidal effect but only fungicidal.
  • FIG. 2 shows that the product of the invention has a bacteriostatic effect (stabilization of the bacterial population over time).
  • we claim a more interesting effect on fungi Table 3).
  • the product of the invention is the best product for use as a fungicide in agriculture and the product of the prior art the best product with regard to the invention for use as a bactericide.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Zoology (AREA)
  • Plant Pathology (AREA)
  • Environmental Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Pest Control & Pesticides (AREA)
  • Dentistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Agronomy & Crop Science (AREA)
  • Toxicology (AREA)
  • Inorganic Chemistry (AREA)
  • Microbiology (AREA)
  • Mycology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Agricultural Chemicals And Associated Chemicals (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Fertilizers (AREA)

Abstract

The invention relates to a contact fungicide used in agriculture, comprising particles of a magnesium-containing product which contains magnesium hydroxide, the purity of which is greater than 86% by mass on a dry basis, and the particle size of which is characterised by a d50 value of between 1 micron and 10 microns.

Description

Hydroxyde de magnésium comme fongicide de contact en agriculture Magnesium hydroxide as a contact fungicide in agriculture
DOMAINE TECHNIQUE TECHNICAL AREA
[0001 ] L’invention concerne un fongicide à base d’un produit magnésien comprenant de l’hydroxyde de magnésium. Ce fongicide peut être utilisé en agriculture biologique. L’invention concerne également une méthode pour contrôler un pathogène fongique et pour traiter une maladie fongique d’une culture, notamment par voie foliaire. [0001] The invention relates to a fungicide based on a magnesium product comprising magnesium hydroxide. This fungicide can be used in organic farming. The invention also relates to a method for controlling a fungal pathogen and for treating a fungal disease of a crop, in particular by the foliar route.
ART ANTERIEUR PRIOR ART
[0002] Il a été suggéré dans l’art antérieur et notamment dans le brevet US 6 827 766, que des nanoparticules comprenant de l’oxyde de magnésium et de l’hydroxyde de magnésium présentent des propriétés biocides améliorées. Les nanomatériaux restent cependant coûteux à produire, et des équipements de filtration particuliers sont nécessaires pour limiter la perte de rendement et les risques d’inhalation pendant la fabrication. Au surplus, les contraintes réglementaires liées à l’usage de nanoparticules sont très élevées en agriculture. [0002] It has been suggested in the prior art and in particular in US Pat. No. 6,827,766, that nanoparticles comprising magnesium oxide and magnesium hydroxide exhibit improved biocidal properties. Nanomaterials remain expensive to produce, however, and special filtration equipment is needed to limit loss of yield and inhalation risks during manufacture. In addition, the regulatory constraints linked to the use of nanoparticles are very high in agriculture.
[0003] Pour pallier à ces inconvénients, les inventeurs de la demande WO 2015/100468 ont proposé d’agglomérer des nanocristaux d’hydroxyde de magnésium sous la forme d’un composite. Ce document enseigne que l’activité biocide dépend de la taille des cristaux d’hydroxyde de magnésium, et non de la taille des particules. Le composite est obtenu par calcination d’une roche comprenant du carbonate de magnésium et/ou de l’hydroxyde de magnésium pour obtenir de l’oxyde de magnésium qui est ensuite hydraté pour donner l’hydroxyde de magnésium. Le procédé de calcination dit procédé de calcination « flash » est particulier car il est réalisé à basse température pendant une durée très courte,. La calcination flash nécessite cependant des coûts d’investissement très élevés, et consomme beaucoup d’énergie. Par ailleurs, la réglementation européenne n’autorise pas l’usage de produits obtenus par calcination en agriculture biologique. Dans la demande WO 2015/100468, l’hydroxyde de magnésium est obtenu à partir de particules d’oxyde de magnésium ayant un degré de calcination supérieure à 90%, une granulométrie comprise entre 10 et 100 microns, une porosité très élevée (supérieure à 0.5), une surface spécifique supérieure (SSA) à 150 m2/g et comprenant des domaines cristallins de taille inférieure à 20 nm. [0003] To overcome these drawbacks, the inventors of application WO 2015/100468 proposed to agglomerate magnesium hydroxide nanocrystals in the form of a composite. This document teaches that the biocidal activity depends on the size of the crystals of magnesium hydroxide, and not on the size of the particles. The composite is obtained by calcining a rock comprising magnesium carbonate and / or magnesium hydroxide to obtain magnesium oxide which is then hydrated to give magnesium hydroxide. The calcination process known as the “flash” calcination process is particular because it is carried out at low temperature for a very short time. Flash calcination, however, requires very high investment costs, and consumes a lot of energy. Moreover, European regulations do not authorize the use of products obtained by calcination in organic farming. In application WO 2015/100468, magnesium hydroxide is obtained from particles of magnesium oxide having a degree of calcination greater than 90%, a particle size between 10 and 100 microns, a very high porosity (greater than 0.5), a specific surface area (SSA) greater than 150 m2 / g and comprising crystal domains of size less than 20 nm.
[0004] Le besoin subsiste par conséquent de proposer un biocide à base d’hydroxyde de magnésium dont le coût de fabrication est compatible avec un usage agricole à grande échelle, et qui peut être autorisé en agriculture biologique. [0004] The need therefore remains to provide a biocide based on magnesium hydroxide whose manufacturing cost is compatible with large-scale agricultural use, and which can be authorized in organic farming.
[0005] Il est également souhaitable de disposer d’un produit biocide à base d’hydroxyde de magnésium qui possède une activité biologique comparable à celle des nanomatériaux sans présenter de problèmes de manipulation et de réglementation. [0005] It is also desirable to have a biocidal product based on magnesium hydroxide which has a biological activity comparable to that of nanomaterials without presenting handling and regulatory problems.
[0006] Or les inventeurs ont découvert, contrairement à ce que suggère l’art antérieur, que l’activité biocide de particules d’hydroxyde de magnésium, plus précisément leur activité fongicide, peut être améliorée indépendamment de leur cristallinité et sans devoir passer par un procédé de calcination flash. However, the inventors have discovered, contrary to what the prior art suggests, that the biocidal activity of magnesium hydroxide particles, more precisely their fungicidal activity, can be improved independently of their crystallinity and without having to go through a flash calcination process.
DESCRIPTION DE L’INVENTION DESCRIPTION OF THE INVENTION
[0007] Aussi, l’invention a pour objet un fongicide de contact pour l’agriculture comprenant des particules d’un produit magnésien comprenant de l’hydroxyde de magnésium, lesdites particules ayant une pureté en hydroxyde de magnésium supérieure ou égale à 86% en masse par rapport à la masse du produit magnésien sur base sèche, et ayant une granulométrie caractérisée par une D50 comprise entre 1 et 10 microns. [0007] Also, the invention relates to a contact fungicide for agriculture comprising particles of a magnesium product comprising magnesium hydroxide, said particles having a magnesium hydroxide purity greater than or equal to 86% by mass relative to the mass of the magnesium product on a dry basis, and having a particle size characterized by a D50 of between 1 and 10 microns.
[0008] Le fongicide présente l’avantage d’avoir une activité fongicide supérieure aux biocides magnésiens de l’art antérieur supplémentés ou non en peroxyde d’oxygène. Un fongicide selon l’invention permet de protéger des cultures contre les champignons pathogènes. The fungicide has the advantage of having a fungicidal activity superior to the magnesian biocides of the prior art supplemented or not with oxygen peroxide. A fungicide according to the invention makes it possible to protect crops against pathogenic fungi.
[0009] Le fongicide de l’invention, lorsqu’il est sous la forme d’une suspension, présente l’avantage d’être sous forme liquide, ce qui facilite son utilisation. [0009] The fungicide of the invention, when in the form of a suspension, has the advantage of being in liquid form, which facilitates its use.
[0010] D’une manière générale, les plantes ne peuvent recevoir qu’une quantité limitée de particules solides de produit magnésien à la surface de leurs feuilles. Au- delà d’un certain seuil, il risque en effet de se produire une phytotoxicité (brûlure, pénétration facilitée des pathogènes). Le fongicide de l’invention n’a pas de phytotoxicité aux doses auxquelles il est efficace. [0011 ] Le fongicide de l’invention présente l’avantage de créer un réseau de particules dense à la surface de la plante tout en appliquant une faible quantité de produit. Sans être lié par aucune théorie, on pense que la très haute pureté du produit magnésien se traduit par un plus grand nombre de maillons actifs dans le réseau, et par une efficacité fongicide accrue. Les inventeurs ont en effet trouvé qu’un produit de D50 plus élevée forme des agglomérats empêchant une répartition homogène du fongicide sur la plante. In general, plants can only receive a limited amount of solid particles of magnesium product on the surface of their leaves. Beyond a certain threshold, there is a risk of phytotoxicity (burning, facilitated penetration of pathogens). The fungicide of the invention has no phytotoxicity at the doses at which it is effective. The fungicide of the invention has the advantage of creating a dense network of particles on the surface of the plant while applying a small amount of product. Without being bound by any theory, it is believed that the very high purity of the magnesium product results in a greater number of active links in the network, and in increased fungicidal efficacy. The inventors have in fact found that a product with a higher D50 forms agglomerates preventing a homogeneous distribution of the fungicide on the plant.
DESCRIPTION DES FIGURES DESCRIPTION OF FIGURES
[0012] La Figure 1 présente l’efficacité fongicide de deux produits magnésiens utilisés dans le cadre de l’invention et d’un produit magnésien de référence, contre le champignon pathogène du mildiou de la vigne. [0012] Figure 1 shows the fungicidal efficacy of two magnesium products used in the context of the invention and a reference magnesium product, against the pathogenic fungus of downy mildew of the vine.
[0013] La Figure 2 représente l’activité bactériostatique de trois fongicides selon l’invention. [0013] Figure 2 shows the bacteriostatic activity of three fungicides according to the invention.
[0014] La Figure 3 illustre l’activité bactéricide d’un produit magnésien de l’art antérieur à trois doses différentes. [0014] Figure 3 illustrates the bactericidal activity of a prior art magnesium product at three different doses.
DESCRIPTION DETAILLEE DETAILED DESCRIPTION
[0015] Au sens de l’invention, la pureté en hydroxyde de magnésium des particules d’un produit magnésien comprenant de l’hydroxyde de magnésium est exprimée en pourcentage en masse par rapport à la masse du produit magnésien sur base sèche. La « pureté du produit magnésien sur base sèche » s’entend de la teneur en hydroxyde de magnésium du produit magnésien dans la présente description. [0015] Within the meaning of the invention, the magnesium hydroxide purity of the particles of a magnesium product comprising magnesium hydroxide is expressed as a percentage by mass relative to the mass of the magnesium product on a dry basis. The "purity of the magnesium product on a dry basis" is understood to mean the content of magnesium hydroxide in the magnesium product in this specification.
[0016] Le produit magnésien utilisé dans le cadre de l’invention peut être pur (ne contenir que de l’hydroxyde de magnésium) ou comprendre outre de l’hydroxyde de magnésium d’autres composés du magnésium sous forme de silicate, de carbonate, de chlorure ou de sulfate, ces impuretés pouvant provenir de la matière première utilisée pour préparer les particules de produit magnésien. La matière première peut être une roche ou un produit de synthèse comprenant de l’hydroxyde de magnésium. The magnesium product used in the context of the invention may be pure (contain only magnesium hydroxide) or comprise, in addition to the magnesium hydroxide, other magnesium compounds in the form of silicate, carbonate , chloride or sulfate, these impurities possibly coming from the raw material used to prepare the particles of magnesian product. The raw material can be a rock or a synthetic product comprising magnesium hydroxide.
[0017] La pureté au sens de l’invention est définie comme étant la pureté des particules du produit magnésien sur base sèche, c’est-à-dire la masse en hydroxyde de magnésium par rapport à la masse des particules de produit magnésien qui ont été séchées pour éliminer en tout ou partie de l’eau libre qu’il contient, par exemple après étuvage du produit à 105°C pendant 2h. Les palicules séchées contiennent de préférence moins de 1 % en masse d’eau libre. La quantité d’eau peut être mesurée par toute méthode connue de l’homme du métier. Purity within the meaning of the invention is defined as being the purity of the particles of the magnesium product on a dry basis, that is to say the mass of magnesium hydroxide relative to the mass of the particles of magnesium product which have been dried to remove all or part of the free water it contains, for example after steaming the product at 105 ° C for 2 hours. The dried palicles preferably contain less than 1% by weight of free water. The amount of water can be measured by any method known to those skilled in the art.
[0018] La pureté du produit magnésien sur base sèche peut être déterminée par toute méthode connue de l’homme du métier. Une première méthode utilise la technique de diffraction des rayons X. Une deuxième méthode comprend une analyse chimique du produit magnésien pour mesurer sa teneur en impuretés, et une mesure de perte au feu du produit magnésien. La perte au feu peut consister à mesurer la perte de masse du produit magnésien entre 250 °C et 550 °C. La masse du produit à l’issue de ce traitement thermique est égale à la somme de la masse de MgO et la masse des impuretés. La pureté des particules de produit magnésien comprenant de l’hydroxyde de magnésium au sens de l’invention est ensuite calculée à partir de la teneur en MgO mesurée, selon la formule suivante : % Mg(OH)2 = % MgO * 58.3/40.3. The purity of the magnesium product on a dry basis can be determined by any method known to those skilled in the art. A first method uses the X-ray diffraction technique. A second method comprises a chemical analysis of the magnesium product to measure its content of impurities, and a measurement of the loss on ignition of the magnesium product. The loss on ignition can consist in measuring the loss of mass of the magnesium product between 250 ° C and 550 ° C. The mass of the product at the end of this heat treatment is equal to the sum of the mass of MgO and the mass of the impurities. The purity of the particles of magnesium product comprising magnesium hydroxide within the meaning of the invention is then calculated from the measured MgO content, according to the following formula:% Mg (OH) 2 =% MgO * 58.3 / 40.3 .
[0019] La quantité d’hydroxyde de magnésium dans les particules de produit magnésien est supérieure ou égale à 86% en masse sur base sèche. Les impuretés que le produit peut contenir sont par exemple l’oxyde de calcium, l’oxyde ferrique, la silice, le carbonate de magnésium, le silicate de magnésium, le sulfate de magnésium. La teneur en silice est de préférence inférieure ou égale à 2%, de préférence encore inférieure ou égale à 1 ,5% en masse sur base sèche de particules. [0019] The amount of magnesium hydroxide in the particles of magnesium product is greater than or equal to 86% by mass on a dry basis. Impurities that the product may contain are, for example, calcium oxide, ferric oxide, silica, magnesium carbonate, magnesium silicate, magnesium sulfate. The silica content is preferably less than or equal to 2%, more preferably less than or equal to 1.5% by mass on a dry basis of particles.
[0020] La pureté des particules de produit magnésien peut être exprimée comme la différence entre la masse du produit magnésien et la masse de la totalité des impuretés (tout composé autre que l’hydroxyde de magnésium) qu’il contient, rapportée à la masse de produit magnésien sur base sèche. The purity of the particles of magnesium product can be expressed as the difference between the mass of the magnesium product and the mass of all the impurities (any compound other than magnesium hydroxide) that it contains, relative to the mass of magnesian product on a dry basis.
[0021 ] La quantité d’hydroxyde de magnésium dans les particules de produit magnésien est supérieure ou égale à 86% et inférieure ou égale à 100% en masse par rapport à la masse du produit magnésien séché. Elle est par exemple supérieure ou égale à une valeur choisie dans le groupe constitué de 87%, 88%, 89%, 90%, 91 %, 92%, 93%, 94%, 95%, 96%, 97% et 98%, et inférieure ou égale à la valeur de 99%. [0022] La granulométrie des particules du produit magnésien comprenant de l’hydroxyde de magnésium au sens de l’invention est la granulométrie des particules du produit magnésien sur base sèche. The amount of magnesium hydroxide in the particles of magnesium product is greater than or equal to 86% and less than or equal to 100% by mass relative to the mass of the dried magnesium product. It is for example greater than or equal to a value chosen from the group consisting of 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97% and 98 %, and less than or equal to the value of 99%. The particle size of the particles of the magnesium product comprising magnesium hydroxide within the meaning of the invention is the particle size of the particles of the magnesium product on a dry basis.
[0023] La granulométrie des particules peut être caractérisée par une D50 comprise entre 1 et 10 microns. Dans le cadre de la présente description, l’expression « compris entre ... et .... » exclut les bornes de la gamme de valeur, tandis que l’expression « allant de ...à .... » inclut les bornes de la gamme de valeur. La D50 des particules contenant de l’hydroxyde de magnésium est inférieure à 10 microns, de préférence inférieure à 6 microns, ou même inférieure à 5 microns et supérieure à 1 micron. La D50 pourra être mesurée selon toute méthode classique connue de l’homme du métier. La granulométrie peut également être caractérisée par une D90 allant de 1 micron à 30 microns, de préférence allant de 1 micron à 12 microns. [0023] The particle size distribution of the particles can be characterized by a D50 of between 1 and 10 microns. In the context of the present description, the expression “between ... and ....” excludes the limits of the range of values, while the expression “ranging from ... to ....” includes the limits of the value range. The D50 of particles containing magnesium hydroxide is less than 10 microns, preferably less than 6 microns, or even less than 5 microns and greater than 1 micron. The D50 can be measured using any conventional method known to those skilled in the art. The particle size can also be characterized by a D90 ranging from 1 micron to 30 microns, preferably ranging from 1 micron to 12 microns.
[0024] La surface spécifique (SSA) des particules du produit magnésien séchées (c’est-à-dire les particules avant hydratation ou avant mise en suspension éventuelle dans l’eau) va de préférence de 10 m2/g à 100 m2/g, par exemple de 10 m2/g à 50 m2/g. La surface spécifique des particules du produit magnésien séchées est par exemple inférieure à une valeur choisie dans le groupe constitué par 100, 90, 80, 70, 60, 50, 40, 30, 25 et 20 m2/g. La surface spécifique des particules de produit magnésien séchées va de préférence encore de 10 m2/g à 18 m2/g. La surface spécifique (SSA) définie dans la présente description est mesurée sur des particules séchées (avant leur éventuelle mise en suspension dans l’eau), et non sur des particules hydratées ou sur des particules qui sont en suspension dans l’eau. The specific surface area (SSA) of the particles of the dried magnesium product (that is to say the particles before hydration or before possible suspension in water) preferably ranges from 10 m2 / g to 100 m2 / g, for example from 10 m2 / g to 50 m2 / g. The specific surface area of the particles of the dried magnesium product is for example less than a value chosen from the group consisting of 100, 90, 80, 70, 60, 50, 40, 30, 25 and 20 m2 / g. The specific surface area of the dried magnesium product particles is more preferably from 10 m2 / g to 18 m2 / g. The specific surface area (SSA) defined in this description is measured on dried particles (before their possible suspension in water), and not on hydrated particles or on particles which are suspended in water.
[0025] Les particules du produit magnésien comprenant de l’hydroxyde de magnésium peuvent être obtenues par synthèse chimique, par calcination ou par extraction minière d’une roche en contenant. [0025] The particles of the magnesium product comprising magnesium hydroxide can be obtained by chemical synthesis, by calcination or by mining from a rock containing it.
[0026] Dans un mode de réalisation particulier, les particules du produit magnésien comprenant de l’hydroxyde de magnésium sont obtenues par extraction minière de brucite, suivie d’un broyage de la roche. Dans ce mode de réalisation, le procédé de préparation des particules ne comprend pas d’étape de calcination. Une formule à base de brucite (hydroxyde de magnésium naturel) permet de proposer une formule utilisable en agriculture biologique. Dans un mode de réalisation préféré de l’invention, le fongicide est un fongicide foliaire pour l’agriculture biologique. On entend par «agriculture biologique » une méthode de culture conforme aux règlements (CE) n° 203/2012 du 8 mars 2012 modifiant le règlement (CE) n°889/2008 portant modalités d’application du règlement (CE) n°834/2007 du Conseil en ce qui concerne le vin biologique, et conforme au règlement (CE) 889/2008. In a particular embodiment, the particles of the magnesium product comprising magnesium hydroxide are obtained by mining of brucite, followed by grinding of the rock. In this embodiment, the process for preparing the particles does not include a calcination step. A formula based on brucite (natural magnesium hydroxide) makes it possible to offer a formula that can be used in organic farming. In a preferred embodiment of the invention, the fungicide is a foliar fungicide for organic farming. We By "organic farming" means a cultivation method in accordance with Regulation (EC) No. 203/2012 of March 8, 2012 amending Regulation (EC) No. 889/2008 laying down detailed rules for the application of Regulation (EC) No. 834 / 2007 of the Council for organic wine, and complies with Regulation (EC) 889/2008.
[0027] Dans un autre mode de réalisation les particules du produit magnésien comprenant de l’hydroxyde de magnésium sont obtenues par calcination dans un four, suivie d’une hydratation. Le four de calcination est de préférence un four rotatif, un four vertical ou un four sur lit fluidisé permettant une calcination lente. [0027] In another embodiment, the particles of the magnesium product comprising magnesium hydroxide are obtained by calcination in an oven, followed by hydration. The calcination furnace is preferably a rotary furnace, a vertical furnace or a furnace on a fluidized bed allowing slow calcination.
[0028] Lorsque l’hydroxyde de magnésium de l’invention est obtenu par calcination, on préfère que le procédé de calcination soit un procédé de calcination lente par opposition à un procédé de calcination rapide, dite calcination « flash ». On entend par « procédé de calcination flash » au sens de l’invention, un procédé dans lequel la chambre de calcination est sous la forme d’un tube vertical dans lequel les particules minérales à calciner sont injectés au sommet du tube. Un flux de vapeur peut être utilisé pour entraîner les particules dans le four ; dans ce cas la vapeur et les particules minérales sont injectées simultanément. La chaleur nécessaire à la calcination a pour particularité d’être générée à l’extérieur de la chambre de calcination. La chaleur est transférée par diffusion dans la chambre à travers la paroi grâce à un flux d’air chaud. Le flux d’air chaud peut être mis en place à contre- courant du flux de particules pour uniformiser la température de calcination dans l’ensemble du tube. Selon ce procédé, les particules subissent une augmentation brutale de la température pendant une durée très courte (quelques secondes tout au plus), le choc thermique produit ayant pour effet d’augmenter considérablement la surface spécifique et la porosité des particules. Pour maximiser la surface spécifique des particules en sortie de four, il faut réaliser au préalable un broyage fin de la roche (<100pm). La température est choisie pour être la plus basse possible, préférentiellement de 550 °C à 750 °C. La surface pécifique des particules de l’oxyde de magnésium obtenues par calcination flash est typiquement supérieure à 150 m2/g, voire même supérieure à 200 m2/g. When the magnesium hydroxide of the invention is obtained by calcination, it is preferred that the calcination process is a slow calcination process as opposed to a rapid calcination process, called "flash" calcination. For the purposes of the invention, the term "flash calcination process" means a process in which the calcination chamber is in the form of a vertical tube in which the mineral particles to be calcined are injected at the top of the tube. A stream of steam can be used to entrain the particles in the oven; in this case the steam and the mineral particles are injected simultaneously. The heat required for calcination is unique in that it is generated outside the calcination chamber. The heat is transferred by diffusion into the chamber through the wall by a flow of hot air. The hot air flow can be set up against the flow of particles to even out the calcination temperature throughout the tube. According to this process, the particles undergo a sudden increase in temperature for a very short time (a few seconds at most), the thermal shock produced having the effect of considerably increasing the specific surface area and the porosity of the particles. To maximize the specific surface of the particles at the outlet of the furnace, a fine grinding of the rock (<100 μm) must first be carried out. The temperature is chosen to be as low as possible, preferably from 550 ° C to 750 ° C. The specific surface of the particles of magnesium oxide obtained by flash calcination is typically greater than 150 m2 / g, or even greater than 200 m2 / g.
[0029] Dans un procédé de calcination lente classique utilisé dans le cadre de l’invention, le four peut être un four vertical, un four multi-foyer (Multy Hearth Furnance) ou un four rotatif horizontal. Les fours verticaux et les fours multi-foyers sont particulièrement adaptés pour réaliser des produits réactifs et caustiques. Un four vertical est un tube cylindrique ou en forme d’ellipse dans lequel le minerai est introduit au sommet du tube avec un combustible (charbon, gaz ou pétrole). Le mélange minerai-combustible tombe ensuite dans une zone de combustion avant de sortir du four. Le charbon peut être également pyrolysé dans une chaudière avant injection dans la chambre sous forme de gaz charbonneux. La température de calcination de ce four est de 800°C-950°C avec un èmps de séjour long, entre 7 à 8h. Un four multi-foyers est un cylindre vertical contenant un certain nombre d’étages équipés d’un bruleur (foyer) dont la température est comprise entre 750 et 1000°C. Le minerai est entraîné depuis le sommet du cylindre par une lame en rotation dans les foyers successifs. Il peut y avoir entre 10 à 14 foyers dans ces fours. Le temps de séjour du minerai dans le four est variable selon le nombre de foyer et la vitesse de rotation du mécanisme, il se compte généralement en heures. Les fours rotatifs horizontaux sont plus versatiles : ils peuvent réaliser des produits réactifs, caustiques ou réfractaires grâce à une gamme de température pouvant aller de 600 ° C à 1600 ° C. Le temps de séjour est de 3h à6h. Il s’agit d’un tube horizontal incliné (environ 3°-4°). Le minerai est introduit di coté le plus haut et la combustion a lieu du côté le plus bas, à contre-courant. Le minerai est entraîné par un mouvement lent de rotation du tube. Ce dernier consomme plus d’énergie mais accepte des particules plus grosses en entrée de four. In a conventional slow calcination process used in the context of the invention, the furnace can be a vertical furnace, a multi-hearth furnace (Multy Hearth Furnance) or a horizontal rotary furnace. Vertical ovens and multi-hearth ovens are particularly suitable for producing reactive and caustic products. A vertical furnace is a cylindrical or elliptical tube in which ore is introduced to the top of the tube along with a fuel (coal, gas or oil). The ore-fuel mixture then falls into a combustion zone before exiting the furnace. The coal can also be pyrolyzed in a boiler before injection into the chamber in the form of carbonaceous gas. The calcination temperature of this oven is 800 ° C-950 ° C with a long residence time, between 7 to 8 hours. A multi-hearth oven is a vertical cylinder containing a certain number of stages equipped with a burner (hearth) whose temperature is between 750 and 1000 ° C. The ore is driven from the top of the cylinder by a rotating blade in successive foci. There may be between 10 to 14 fireplaces in these ovens. The residence time of the ore in the furnace is variable according to the number of hearths and the speed of rotation of the mechanism, it is generally calculated in hours. Horizontal rotary kilns are more versatile: they can produce reactive, caustic or refractory products thanks to a temperature range that can go from 600 ° C to 1600 ° C. The residence time is 3h to 6h. It is an inclined horizontal tube (approximately 3 ° -4 °). The ore is introduced from the highest side and combustion takes place from the lowest side, against the current. The ore is driven by a slow rotating movement of the tube. The latter consumes more energy but accepts larger particles at the furnace inlet.
[0030] Dans le cadre de la présente invention, on préfère qu’un hydroxyde de magnésium obtenu par un procédé de calcination, soit obtenu par un procédé de calcination lente, selon lequel le temps de séjour de l’hydroxyde de magnésium utilisé comme matière première soit supérieur à 1 minute, de préférence supérieur à 30 minutes, et de préférence encore supérieur à 1 heure. Le temps de séjour est de préférence inférieur à 12 heures ou inférieur à 10 heures. In the context of the present invention, it is preferred that a magnesium hydroxide obtained by a calcination process, is obtained by a slow calcination process, according to which the residence time of the magnesium hydroxide used as material first is greater than 1 minute, preferably greater than 30 minutes, and more preferably greater than 1 hour. The residence time is preferably less than 12 hours or less than 10 hours.
[0031 ] Le fongicide de l’invention peut contenir, outre les particules du produit magnésien comprenant de l’hydroxyde de magnésium, d’autres additifs. Ces additifs, lorsqu’ils sont présents, sont de préférence bio-sourcés de manière à ce que le fongicide puisse être avantageusement utilisé comme fongicide de contact en agriculture biologique, de préférence comme fongicide foliaire en agriculture biologique. [0032] Le fongicide de l’invention peut contenir des additifs tels qu’un agent anti lessivage afin d’éviter les pertes d’efficacité lors des pluies. [0031] The fungicide of the invention may contain, in addition to the particles of the magnesium product comprising magnesium hydroxide, other additives. These additives, when they are present, are preferably bio-sourced so that the fungicide can be advantageously used as a contact fungicide in organic farming, preferably as a foliar fungicide in organic farming. The fungicide of the invention may contain additives such as an anti-leaching agent in order to avoid losses of efficiency during rains.
[0033] Le fongicide peut être sous la forme d’une poudre des particules ou d’une suspension obtenue par dispersion dans l’eau des particules. [0033] The fungicide may be in the form of a powder of the particles or of a suspension obtained by dispersing the particles in water.
[0034] Dans un mode de réalisation particulier, le fongicide de l’invention est sous la forme d’une suspension et comprend de préférence au moins un agent de dispersion et/ou au moins un tensio-actif pour obtenir une suspension stable au cours de la conservation du produit, ou pour remettre l’hydroxyde de magnésium en suspension après agitation du produit, le temps de l’appliquer sur les plantes. Les particules du produit magnésien représentent de préférence de 40% à 65% en masse, par exemple de 50% à 55% en masse de la masse de la suspension. In a particular embodiment, the fungicide of the invention is in the form of a suspension and preferably comprises at least one dispersing agent and / or at least one surfactant to obtain a stable suspension during for preserving the product, or to resuspend the magnesium hydroxide after stirring the product, while it is applied to the plants. The particles of the magnesium product preferably represent from 40% to 65% by mass, for example from 50% to 55% by mass of the mass of the suspension.
[0035] Un autre objet de l’invention est une composition liquide de traitement biocide foliaire d’une culture caractérisée en ce qu'elle est constituée à 90% en masse: Another object of the invention is a liquid composition for foliar biocidal treatment of a crop, characterized in that it consists of 90% by mass:
- d’eau - water
- de particules d’un produit magnésien ayant une pureté en hydroxyde de magnésium supérieure ou égale à 86% en masse par rapport à la masse du produit magnésien sur base sèche, et ayant une D50 comprise entre 1 et 30 microns, - particles of a magnesium product having a magnesium hydroxide purity greater than or equal to 86% by mass relative to the mass of the magnesian product on a dry basis, and having an D50 of between 1 and 30 microns,
- d'un produit de traitement de culture choisi dans le groupe comprenant les fertilisants, notamment les engrais, les bio stimulants, les stimulateurs de défense naturelle (SDN) et leurs mélanges, et - a crop treatment product chosen from the group comprising fertilizers, in particular fertilizers, bio stimulants, natural defense stimulators (SDN) and their mixtures, and
- d'un agent de formulation et/ou d'un agent adjuvant choisi dans le groupe comprenant les agents conservateurs, les agents émulsifiants, les agents tensioactifs, les agents dispersants, les agents antigels, les agents anti mousses, les agents humectants, les agents pénétrants, les agents mouillants et étalants, les agents alourdisseurs de goutte, les agents anti dérives, les agents collants et rétenteurs, et leurs mélanges. - a formulation agent and / or an adjuvant agent chosen from the group comprising preservatives, emulsifying agents, surfactants, dispersing agents, antifreeze agents, anti-foaming agents, humectants, penetrating agents, wetting and spreading agents, drop-weighting agents, anti-drift agents, sticky and retention agents, and mixtures thereof.
[0036] Par biocide au sens de l’invention, on entend un produit fongicide, herbicide, pesticide, bactéricide, insecticide et/ou virucide. By biocide within the meaning of the invention is meant a fungicide, herbicide, pesticide, bactericide, insecticide and / or virucide.
[0037] Dans cette composition liquide, une proportion des particules a de préférence une D50 comprise entre 1 et 10 microns avant d’être mises dans l’eau. La proportion des particules est de préférence la proportion majoritaire : elle est de préférence supérieure à 50%, de préférence encore supérieure à 90% et de préférence encore supérieure à 95% en masse de la masse totale des particules qui sont mises en suspension dans l’eau. In this liquid composition, a proportion of the particles preferably has a D50 of between 1 and 10 microns before being put into the water. The proportion of particles is preferably the majority proportion: it is preferably greater than 50%, more preferably greater than 90% and more preferably greater than 95% by mass of the total mass of the particles which are suspended in water.
[0038] Un autre objet de l’invention est un procédé de traitement fongique d’une culture qui consiste à appliquer le fongicide ou la composition décrits précédemment, par voie foliaire. Another object of the invention is a method of fungal treatment of a crop which consists in applying the fungicide or the composition described above, by foliar route.
[0039] Le procédé a notamment pour objectifs d’améliorer la croissance et le développement des cultures, d’améliorer le rendement des cultures, de stimuler et renforcer les cultures, notamment en améliorant leur résistance aux pathogènes, et/ou d’améliorer la qualité sanitaire des cultures. The method aims in particular to improve the growth and development of crops, to improve crop yields, to stimulate and strengthen crops, in particular by improving their resistance to pathogens, and / or to improve the yield of crops. sanitary quality of crops.
[0040] Le fongicide et la composition de l’invention sont avantageusement dépourvus d'un pesticide obtenu par synthèse chimique choisi dans le groupe comprenant les fongicides, les herbicides, les insecticides et leurs mélanges. On préfère utiliser des éliciteurs qui stimulent le système de défense du végétal de façon systémique, comme alternative aux produits phytosanitaires. The fungicide and the composition of the invention are advantageously free of a pesticide obtained by chemical synthesis chosen from the group comprising fungicides, herbicides, insecticides and mixtures thereof. It is preferred to use elicitors which stimulate the plant's defense system systemically, as an alternative to phytosanitary products.
[0041 ] Le fongicide ou la composition de l’invention peuvent être utilisés pour son application foliaire sur les cultures, ladite application foliaire pouvant être effectuée au moment de l'apparition des premières feuilles et/ou à tout autre moment jusqu'à la récolte de la culture. Cette application est de l’ordre de 3 à 15 L par hectare. The fungicide or the composition of the invention can be used for its foliar application on crops, said foliar application can be carried out at the time of the appearance of the first leaves and / or at any other time until harvest. of the culture. This application is on the order of 3 to 15 L per hectare.
[0042] La culture peut être notamment choisie dans le groupe comprenant : The culture can in particular be chosen from the group comprising:
- les grandes cultures, comme les céréales, les oléagineux, les protéagineux, les légumineuses fourragères, les graminées fourragères ou les cultures sucrières, - field crops, such as cereals, oilseeds, protein crops, fodder legumes, fodder grasses or sugar crops,
- les cultures légumières ou maraîchères, notamment les légumes frais, - vegetable or market gardening crops, in particular fresh vegetables,
- les cultures fruitières, comme les fruits à noyaux, les fruits à pépins, les fruits à amandes, les fruits en grappe, les petits fruits ou les fruits des régions chaudes, - fruit crops, such as stone fruits, pome fruits, almond fruits, cluster fruits, small fruits or fruits from hot regions,
- les plantes aromatiques et médicinales, - aromatic and medicinal plants,
- les cultures florales et ornementales. - floral and ornamental crops.
[0043] Appliquée à une dose allant de 0,5% v/v (c’est-à-dire de 0.5 L de suspension pour 100 litres d’eau d’arrosage de la culture) à 5% v/v (c’est-à-dire de 5 L de suspension pour 100 litres d’eau d’arrosage de la culture), le fongicide de l’invention sous la forme d’une suspension peut atteindre une efficacité supérieure à 85%. Applied at a dose ranging from 0.5% v / v (that is to say from 0.5 L of suspension per 100 liters of water for irrigating the culture) to 5% v / v (c 'that is to say 5 L of suspension per 100 liters of water for irrigating the crop), the fungicide of the invention in the form of a suspension can achieve an efficiency greater than 85%.
[0044] Un autre objet de l’invention porte sur une méthode pour contrôler un pathogène fongique et traiter une maladie fongique d’une culture, qui consiste à appliquer le fongicide ou la composition décrits précédemment, de préférence par voie foliaire. [0044] Another object of the invention relates to a method for controlling a fungal pathogen and treating a fungal disease of a crop, which consists in applying the fungicide or the composition described above, preferably by foliar route.
[0045] Le pathogène fongique peut être choisi dans le groupe constitué par Mycosphaerella fijiensis, Phytophthora megakarya, Phytophthora palmivora, Fusicladium oleagineum ou Cycloconium oleaginum, Colletotrichum acutatum, Phytophthora infestans, Bremia lactucae, Plasmopara viticola, Erysiphe necator, Guignardia bidwellii, Sclerotinia sclerotiorum, Magnaporthe grisea, Sphaerotheca pannosa et Septoria tritici (encore appelé Zymoseptoria tritici). [0045] The fungal pathogen can be chosen from the group consisting of Mycosphaerella fijiensis, Phytophthora megakarya, Phytophthora palmivora, Fusicladium oleagineum or Cycloconium oleaginum, Colletotrichum acutatum, Phytophthora infestans, Bremia lactucclerii, Sasmotryscleria nunclerardii, Saswellotryscleria n, Sclerotrysclerae n, Sclerotrysclerae n, Sclerotryscleraii, Sclerotinia n, Sclerotinia n, Sclerotinia n, Sclerotinia n, Magnaporthe grisea, Sphaerotheca pannosa and Septoria tritici (also called Zymoseptoria tritici).
[0046] La maladie fongique peut être choisie dans le groupe constitué par la cercosporiose de la banane, la pourriture brune des cabosses de cacaoyer, l’œil de paon de l’olivier, le bitter rot de la pomme, le mildiou de la pomme de terre, de la tomate, de la salade et de la vigne, l’oïdium de la vigne et du rosier, le black rot de la vigne, la septoriose du blé, le sclérotinia du colza, et la pyriculariose du riz. The fungal disease can be chosen from the group consisting of Sigatoka disease of bananas, brown rot of cocoa pods, olive peacock eye, apple burp bitter, apple downy mildew. of earth, tomato, lettuce and grapevine, powdery mildew of grapevine and rosebush, black rot of grapevine, septoria of wheat, sclerotinia of rapeseed, and blast of rice.
[0047] L’invention est illustrée plus en détail par les exemples de réalisation suivants. The invention is illustrated in more detail by the following embodiments.
Exemple 1 : Préparation du fongicide de l’invention Example 1: Preparation of the fungicide of the invention
Une première suspension (Suspension A) est préparée à partir de particules obtenues par broyage et tamisage d’une brucite ayant une pureté en hydroxyde de magnésium sur base sèche égale à 92%. La D50 des particules après tamisage va de 3 à 4 pm. La D90 va de 12 à 13 microns. Les particules contiennent moins de 1.3% en masse de Si02, et leur surface spécifique est de l’ordre de 13 m2/g après leur mise en suspension dans l’eau. A first suspension (Suspension A) is prepared from particles obtained by grinding and sieving a brucite having a purity of magnesium hydroxide on a dry basis equal to 92%. The D50 of the particles after sieving ranges from 3 to 4 µm. The D90 ranges from 12 to 13 microns. The particles contain less than 1.3% by mass of SiO2, and their specific surface area is of the order of 13 m2 / g after being suspended in water.
Les particules sont mises en suspension comme suit The particles are suspended as follows
- 45% en masse d’eau - 45% by mass of water
- 55% en masse de particules de produit magnésien comprenant de l’hydroxyde de magnésium. Une deuxième suspension (Suspension B) est préparée à partir de particules obtenues par synthèse chimique, plus précisément par précipitation à partir d’une saumure de MgCI2 et de chaux. La D50 des particules d’hydroxyde de magnésium après tamisage va de 2 à 3 pm. La D90 est de 5 à 6 microns. La pureté en hydroxyde de magnésium sur base sèche est de 97.5%. Les particules contiennent moins de 1.5% en masse de Si02, et leur surface spécifique est de l’ordre de 17 m2/g après leur mise en suspension dans l’eau. - 55% by mass of particles of magnesium product comprising magnesium hydroxide. A second suspension (Suspension B) is prepared from particles obtained by chemical synthesis, more precisely by precipitation from a brine of MgCl2 and lime. The D50 of the magnesium hydroxide particles after sieving ranges from 2 to 3 µm. The D90 is 5 to 6 microns. The purity of magnesium hydroxide on a dry basis is 97.5%. The particles contain less than 1.5% by mass of SiO 2, and their specific surface area is of the order of 17 m2 / g after being suspended in water.
Les particules sont mises en suspension comme suit : The particles are suspended as follows:
- 47% en masse d’eau - 47% by mass of water
- 53% en masse de particules de produit magnésien comprenant de l’hydroxyde de magnésium. - 53% by mass of particles of magnesium product comprising magnesium hydroxide.
Exemple 2: Evaluation de l’efficacité antifongique Example 2: Evaluation of antifungal efficacy
[0048] Des tests d’efficacité ont été effectués avec les suspensions A et B préparées à l’Exemple 1 au cours du traitement de différentes maladies, en laboratoire, en serre ou en champ selon les cas. Les résultats sont présentés dans le tableau 1 ci- dessous Efficacy tests were carried out with suspensions A and B prepared in Example 1 during the treatment of various diseases, in the laboratory, in the greenhouse or in the field as appropriate. The results are shown in Table 1 below
[0049] [Tableau 1] [0049] [Table 1]
Exemple 3 : Evaluation de la phytotoxicité Example 3: Evaluation of phytotoxicity
[0050] Il a été démontré que le fongicide de l’invention n’a pas de phytotoxicité aux doses auxquelles il est efficace, sur des cultures en champ. Chacun des tests ont été réalisés selon les « Bonnes pratiques d’expérimentation ». [0050] The fungicide of the invention has been shown to have no phytotoxicity at the doses at which it is effective, on field crops. Each of the tests were carried out according to "Good experimental practices".
La suspension A fabriquée à l’Exemple 1 a été appliquée à une fréquence hebdomadaire ou bimensuelle durant la période de sensibilité de la plante au pathogène. Le même essai est réalisé sur la même culture l’année suivante. Suspension A made in Example 1 was applied weekly or bimonthly during the period of plant susceptibility to the pathogen. The same test is carried out on the same crop the following year.
La suspension A a été appliquée sur les feuilles de la plante. L’aspect de celles-ci est ensuite étudié. La phytotoxicité est contrôlée visuellement et donne lieu à une note de 0 à 10 (0 codant pour une absence de phytotoxicité). La note de 0 a été attribuée dans chacun des tests réalisés. Les résultats sont présentés dans le Tableau 2 ci-dessous. Suspension A was applied to the leaves of the plant. The aspect of these is then studied. The phytotoxicity is checked visually and gives rise to a score of 0 to 10 (0 encoding an absence of phytotoxicity). A score of 0 was assigned in each of the tests performed. The results are shown in Table 2 below.
[0051 ] [Tableau 2] [0051] [Table 2]
Exemple 4 comparatif : Comparaison entre un produit de l’invention et d’un produit de l’art antérieur Comparative Example 4: Comparison between a product of the invention and a product of the prior art
On a évalué l’activité fongicide d’un produit de l’invention et d’un produit de l’art antérieur. Leurs caractéristiques sont données au Tableau 3. The fungicidal activity of a product of the invention and a product of the prior art was evaluated. Their characteristics are given in Table 3.
[0052] Conditions de réalisation de l’étude [0052] Conditions for carrying out the study
L’étude est réalisée en laboratoire. L’application des solutions est faite sur végétal (feuille de vigne). Celles-ci sont ensuite inoculées avec l’organisme pathogène Guignardia bidwellii responsable du black rot de la vigne. Après 12 jours d’incubation, une notation de la colonisation et de la sporulation du champignon est réalisée sous une loupe binoculaire. Une moyenne des dégâts sur les dix répétitions est calculée et permet d’obtenir l’efficacité de la modalité par rapport au témoin non traité. The study is carried out in the laboratory. The solutions are applied on a plant (vine leaf). These are then inoculated with the pathogenic organism Guignardia bidwellii responsible for black rot of the vine. After 12 days of incubation, a notation of the colonization and the sporulation of the fungus is carried out under a binocular magnifying glass. An average of the damage over the ten repetitions is calculated and makes it possible to obtain the effectiveness of the modality compared to the untreated control.
[0053] Résultats [0053] Results
Le produit comprenant de l’hydroxyde de magnésium utilisé dans le cadre de l’invention présente une efficacité fongicide supérieure à celle d’un produit de l’art antérieur comprenant un composite de nanocristaux d’hydroxyde de magnésium, obtenu par calcination flash selon l’enseignement de la demande de brevet WO 2015/100468. Les résultats sont présentés dans le Tableau 3 ci-dessous The product comprising magnesium hydroxide used in the context of the invention has a fungicidal efficacy greater than that of a product of the prior art comprising a composite of magnesium hydroxide nanocrystals, obtained by flash calcination according to l teaching of patent application WO 2015/100468. The results are shown in Table 3 below
[0054] [Tableau 3] [0054] [Table 3]
Exemple 5 comparatif : Comparaison avec un hydroxyde de magnésium de pureté différente Comparative Example 5: Comparison with a magnesium hydroxide of different purity
[0055] Trois produits magnésiens ont été analysés par diffraction aux rayons X afin de déterminer leur pureté en MgO et leur composition.Three magnesian products were analyzed by X-ray diffraction in order to determine their MgO purity and their composition.
Sont étudiés ici trois produits magnésiens ayant une D50 compris entre 4 et 8 microns, de puretés respectives en magnésie 98% (comprenant 2% de calcite), 94% (comprenant 3% de périclase et 3% de calcite) et 84% (comprenant 14% d’akermanite et 2% de calcite). Three magnesian products are studied here having a D50 of between 4 and 8 microns, with respective purities of 98% magnesia (comprising 2% calcite), 94% (comprising 3% periclase and 3% calcite) and 84% (comprising 14% akermanite and 2% calcite).
L’efficacité de ces trois produits magnésiens dans la lutte contre le champignon pathogène du mildiou de la vigne (Plasmopara viticola) à la dose de 1 % : est présentée dans le Tableau 4 et à la Figure 1. [0056] [Tableau 4] The effectiveness of these three magnesium products in the fight against the pathogenic fungus of downy mildew of grapevine (Plasmopara viticola) at a dose of 1%: is presented in Table 4 and in Figure 1. [0056] [Table 4]
La perte de pureté du produit magnésien induit une forte diminution de son efficacité fongicide malgré une teneur en magnésium totale élevée. Ainsi, la pureté de l’hydroxyde de magnésium sur base sèche est un point clé de son efficacité. The loss of purity of the magnesium product induces a sharp decrease in its fungicidal efficacy despite a high total magnesium content. Thus, the purity of magnesium hydroxide on a dry basis is a key point of its effectiveness.
Exemple 6 comparatif : Comparaison avec des hydroxydes de magnésium non conformes à l’invention Comparative Example 6: Comparison with magnesium hydroxides not in accordance with the invention
[0057] L’efficacité de trois produits magnésiens de granulométries différentes, contre le mildiou de la vigne a été étudiée. Le test a été effectué en laboratoire afin de déterminer l’impact de la granulométrie sur l’efficacité fongicide du magnésium. On a utilisé la suspension A de l’Exemple 1 puis on l’a comparée à une suspension identique, à la différence près que l’hydroxyde de magnésium était remplacé par un produit d’une autre source : produit de référence A ou produit de référence B. Les résultats sont présentés dans le Tableau 5 ci-dessous : [0057] The effectiveness of three magnesium products of different grain sizes, against downy mildew of grapevine was studied. The test was performed in the laboratory to determine the impact of particle size on the fungicidal efficacy of magnesium. Suspension A of Example 1 was used and then compared with an identical suspension, with the difference that the magnesium hydroxide was replaced by a product from another source: reference product A or product of reference B. The results are shown in Table 5 below:
[0058] [Tableau 5] [0058] [Table 5]
[0059] Le produit de référence A présente les spécificités suivantes : D50 = 17 pm, obtenu par calcination, teneur en MgO de 67.4% et pureté en Mg(OH)2 = 92%. Le produit de référence B présente les spécificités suivantes : D50 = 23,9 pm, obtenu par calcination, teneur en MgO de 66.7% et pureté en Mg(OH)2 = 62%. La granulométrie a un rôle sur l’efficacité du fongicide. Une D50 supérieure à 10 microns ne permet pas d’avoir un produit d’une efficacité suffisante contrairement à ce qui est suggéré dans l’art antérieur. The reference product A has the following specificities: D50 = 17 μm, obtained by calcination, MgO content of 67.4% and Mg (OH) 2 purity = 92%. Reference product B has the following specificities: D50 = 23.9 μm, obtained by calcination, MgO content of 66.7% and Mg (OH) 2 purity = 62%. Particle size has a role in the effectiveness of the fungicide. A D50 greater than 10 microns does not make it possible to have a product of sufficient efficiency, contrary to what is suggested in the prior art.
Exemple 7 comparatif : Activité bactériostatique des produits de l’invention et activité bactéricide des produits de l’art antérieur Comparative Example 7: Bacteriostatic activity of the products of the invention and bactericidal activity of the products of the prior art
[0060] L’objectif de cette étude est de montrer que le procédé de fabrication de l’hydroxyde de magnésium a bien un impact sur son activité fongicide et que les produits issus du brevet WO2015/100468 et de la présente invention sont différents. Le produit obtenu selon le brevet WO2015/100468 qui fait partie de l’art antérieur possède un effet bactéricide supérieur à celui de l’invention. The objective of this study is to show that the manufacturing process of magnesium hydroxide does indeed have an impact on its fungicidal activity and that the products from patent WO2015 / 100468 and from the present invention are different. The product obtained according to patent WO2015 / 100468 which is part of the prior art has a bactericidal effect greater than that of the invention.
[0061 ] Les propriétés antimicrobiennes de différents produits magnésiens comprenant de l’hydroxyde de magnésium vis-à-vis du microorganisme modèle Pseudomonas aeruginosa DSM 939 ont été évaluées. La méthode utilisée suit les normes européennes de tests d’efficacité antibactérienne. Le test démontre l’activité bactériostatique (et non bactéricide) de trois hydroxydes conformes à l’invention et l’activité bactéricide d’un hydroxyde de l’art antérieur ; Les trois hydroxydes de l’invention sont mis en suspension à la dose de 72.5 g d’hydroxyde de magnésium par litre de solution nutritive (soit un équivalent de de 50 g de MgO par litre de solution nutritive). [0061] The antimicrobial properties of various magnesium products comprising magnesium hydroxide against the model microorganism Pseudomonas aeruginosa DSM 939 were evaluated. The method used follows European standards for antibacterial efficacy testing. The test demonstrates the bacteriostatic (and non-bactericidal) activity of three hydroxides according to the invention and the bactericidal activity of one hydroxide of the prior art; The three hydroxides of the invention are suspended at a dose of 72.5 g of magnesium hydroxide per liter of nutrient solution (equivalent to 50 g of MgO per liter of nutrient solution).
[0062] Le premier hydroxyde de magnésium est issu de synthèse chimique : il est conforme à celui utilisé dans l’Exemple 1 pour préparer la suspension B. Son activité est mesurée par rapport au Témoin 1. The first magnesium hydroxide results from chemical synthesis: it complies with that used in Example 1 to prepare suspension B. Its activity is measured relative to Control 1.
Le deuxième hydroxyde de magnésium est issu de calcination puis hydratation ; il a pour caractéristiques une D50 de 10 pm, une teneur en MgO de 61.9 % après hydratation, et une pureté en Mg(OH)2 de 87%. Son activité est mesurée par rapport au Témoin 2. Le troisième hydroxyde de magnésium est issu de brucite : il est conforme à celui utilisé pour préparer la suspension A de l’Exemple 1. Son activité est mesurée par rapport au Témoin 3. The second magnesium hydroxide comes from calcination then hydration; it has for characteristics an D50 of 10 μm, an MgO content of 61.9% after hydration, and an Mg (OH) 2 purity of 87%. Its activity is measured relative to Control 2. The third magnesium hydroxide is obtained from brucite: it is consistent with that used to prepare suspension A of Example 1. Its activity is measured relative to Control 3.
[0063] L’activité bactéricide d’un produit magnésien de l’art antérieur a été mesurée à trois doses différentes (25 g MgO/L équivalent à 36.2 g Mg(OH)2/L- Témoin 3, 50 g MgO/L équivalent à 72.5 g Mg(OH)2/L - Témoin 2 et 75 g MgO/L équivalent à 108.7 g Mg(OH)2/L - Témoin 1 ). The bactericidal activity of a magnesium product of the prior art was measured at three different doses (25 g MgO / L equivalent to 36.2 g Mg (OH) 2 / L- Control 3, 50 g MgO / L equivalent to 72.5 g Mg (OH) 2 / L - Control 2 and 75 g MgO / L equivalent to 108.7 g Mg (OH) 2 / L - Control 1).
[0064] Le produit de l’art antérieur comprend un composite de nanocristaux d’hydroxyde de magnésium ; il est obtenu par calcination flash selon l’enseignement de la demande de brevet WO 2015/100468. [0064] The prior art product comprises a composite of nanocrystals of magnesium hydroxide; it is obtained by flash calcination according to the teaching of patent application WO 2015/100468.
[0065] Chaque témoin de croissance de la souche est constitué d’eau distillée stérile. [0065] Each growth control of the strain consists of sterile distilled water.
Tableau récapitulatif des hydroxydes testés dans les figures 2 et 3. Summary table of the hydroxides tested in Figures 2 and 3.
Le produit obtenu selon le brevet WO2015/100468 qui fait partie de l’art antérieur possède un effet supérieur à celui de la demande de l’invention au niveau des bactéries (et non des champignons comme démontré dans les exemples précédents). La figure 3 illustre l'effet bactéricide de la suspension de l'art antérieur : les bactéries sont totalement décimées après plusieurs heures. La présente invention ne revendique pas un effet bactéricide mais seulement fongicide. La figure 2 montre que le produit de l’invention a un effet bactériostatique (stabilisation de la population en bactérie au cours du temps). Nous revendiquons au contraire un effet plus intéressant sur les champignons (Tableau 3). Ainsi, le produit de l’invention est le meilleur produit pour une utilisation comme fongicide en agriculture et le produit de l’art antérieur le meilleur produit au regard de l’invention pour une utilisation en bactéricide. The product obtained according to patent WO2015 / 100468, which forms part of the prior art, has an effect greater than that of the application of the invention on bacteria (and not on fungi as demonstrated in the preceding examples). FIG. 3 illustrates the bactericidal effect of the suspension of the prior art: the bacteria are completely decimated after several hours. The present invention does not claim a bactericidal effect but only fungicidal. FIG. 2 shows that the product of the invention has a bacteriostatic effect (stabilization of the bacterial population over time). On the contrary, we claim a more interesting effect on fungi (Table 3). Thus, the product of the invention is the best product for use as a fungicide in agriculture and the product of the prior art the best product with regard to the invention for use as a bactericide.

Claims

Revendications Claims
[Revendication 1] Fongicide de contact pour l'agriculture comprenant des particules d'un produit magnésien comprenant de l'hydroxyde de magnésium, lesdites particules comprenant une quantité d'hydroxyde de magnésium supérieure ou égale à 86% en masse par rapport à la masse du produit magnésien sur base sèche, et ayant une granulométrie caractérisée par une D50 comprise entre 1 micron et 10 microns. [Claim 1] Contact fungicide for agriculture comprising particles of a magnesium product comprising magnesium hydroxide, said particles comprising an amount of magnesium hydroxide greater than or equal to 86% by mass relative to the mass magnesium product on a dry basis, and having a particle size characterized by a D50 of between 1 micron and 10 microns.
[Revendication 2] Fongicide selon la revendication 1, caractérisé en ce que les particules du produit magnésien comprenant de l'hydroxyde de magnésium sont obtenues par extraction minière de brucite, suivie d'un broyage de la roche. [Claim 2] Fungicide according to claim 1, characterized in that the particles of the magnesium product comprising magnesium hydroxide are obtained by mining of brucite, followed by grinding of the rock.
[Revendication 3] Fongicide selon la revendication 1, caractérisé en ce que les particules du produit magnésien comprenant de l'hydroxyde de magnésium sont obtenues par synthèse chimique. [Claim 3] Fungicide according to claim 1, characterized in that the particles of the magnesium product comprising magnesium hydroxide are obtained by chemical synthesis.
[Revendication 4] Fongicide selon la revendication 1, caractérisé en ce que les particules du produit magnésien comprenant de l'hydroxyde de magnésium sont obtenues par calcination puis hydratation. [Claim 4] Fungicide according to claim 1, characterized in that the particles of the magnesium product comprising magnesium hydroxide are obtained by calcination then hydration.
[Revendication 5] Fongicide selon l'une des revendications précédentes, caractérisé en ce que la surface spécifique des particules du produit magnésien séchées est comprise entre 10 m2/g à 100 m2/g. [Claim 5] Fungicide according to one of the preceding claims, characterized in that the specific surface area of the particles of the dried magnesium product is between 10 m2 / g to 100 m2 / g.
[Revendication 6] Fongicide selon la revendication 1, caractérisé en ce qu'il est sous la forme d'une poudre des particules ou d'une suspension obtenue par dispersion dans l'eau des particules. [Claim 6] A fungicide according to claim 1, characterized in that it is in the form of a powder of the particles or of a suspension obtained by dispersing the particles in water.
[Revendication 7] Fongicide selon la revendication 6, caractérisé en ce que les particules représentent de 40 % à 65% en masse de la suspension. [Claim 7] Fungicide according to claim 6, characterized in that the particles represent from 40% to 65% by mass of the suspension.
[Revendication 8] Fongicide selon la revendication 1, caractérisé en ce que le fongicide est un fongicide foliaire pour l'agriculture biologique. [Claim 8] Fungicide according to claim 1, characterized in that the fungicide is a foliar fungicide for organic farming.
[Revendication 9]Composition liquide de traitement biocide foliaire d'une culture caractérisée en ce qu’elle est constituée à 90% en masse: [Claim 9] Liquid composition for foliar biocidal treatment of a crop, characterized in that it consists of 90% by mass:
- d'eau - de particules d'un produit magnésien ayant une pureté en hydroxyde de magnésium supérieure ou égale à 86% en masse par rapport à la masse du produit magnésien sur base sèche, et ayant une D50 comprise entre 1 et 10 microns, - water - particles of a magnesium product having a magnesium hydroxide purity greater than or equal to 86% by mass relative to the mass of the magnesium product on a dry basis, and having an D50 of between 1 and 10 microns,
- d’un produit de traitement de culture choisi dans le groupe comprenant les fertilisants, notamment les engrais, les bio stimulants, les stimulateurs de défense naturelle (SDN) et leurs mélanges, et - a crop treatment product chosen from the group comprising fertilizers, in particular fertilizers, bio stimulants, natural defense stimulators (SDN) and their mixtures, and
- d’un agent de formulation et/ou d’un agent adjuvant choisi dans le groupe comprenant les agents conservateurs, les agents émulsifiants, les agents tensioactifs, les agents dispersants, les agents antigels, les agents anti¬ mousses, les agents humectants, les agents pénétrants, les agents mouillants et étalants, les agents alourdisseurs de goutte, les agents anti¬ dérives, les agents collants et rétenteurs, et leurs mélanges. - a formulation of agent and / or an adjuvant chosen from the group comprising agent preservatives, emulsifying agents, surfactants, dispersants, antifreeze agents, agents for anti ¬ foams, humectants, penetrating agents, wetting agents and étalants the agents drop Weighting compounds, agents anti ¬ drifts, sticking agents and retainers, and mixtures thereof.
[Revendication 10] Procédé de traitement fongique d'une culture qui consiste à appliquer par voie foliaire le fongicide selon l'une des revendications 1 à 8 ou une composition selon la revendication 9. [Claim 10] A method of fungal treatment of a crop which consists in applying by foliar route the fungicide according to one of claims 1 to 8 or a composition according to claim 9.
[Revendication 11] Méthode pour contrôler un pathogène fongique et traiter une maladie fongique d'une culture, qui consiste à appliquer le fongicide selon l'une des revendications 1 à 8 ou une composition selon la revendication 9. [Claim 11] A method for controlling a fungal pathogen and treating a fungal disease of a crop, which comprises applying the fungicide according to one of claims 1 to 8 or a composition according to claim 9.
[Revendication 12] Méthode selon la revendication 11, caractérisée en ce que le pathogène fongique est choisi dans le groupe constitué par Mycosphaerella fijiensis, Phytophthora megakarya, Fusicladium oleagineum ou Cycloconium oleaginum, Colletotrichum acutatum, Phytophthora infestans, Bremia lactucae, Plasmopara viticola, Erysiphe necator, Guignardia bidwellii, Sclerotinia sderotiorum et Septoria tritici. [Claim 12] Method according to claim 11, characterized in that the fungal pathogen is selected from the group consisting of Mycosphaerella fijiensis, Phytophthora megakarya, Fusicladium oleagineum or Cycloconium oleaginum, Colletotrichum acutatum, Phytophthora infestans, Bremia lactucheicola, Plasmopatoria , Guignardia bidwellii, Sclerotinia sderotiorum and Septoria tritici.
[Revendication 13] Méthode selon la revendication 11 ou 12, caractérisée en ce que la maladie fongique est choisie dans le groupe constitué par la cercosporiose de la banane, la pourriture brune des cabosses de cacaoyer, l'œil de paon de l'olivier, le bitter rot de la pomme, le mildiou de la pomme de terre, de la salade et de la vigne, l'oïdium de la vigne, le black rot de la vigne, la septoriose du blé, le sclérotinia du colza et du blé. [Claim 13] Method according to claim 11 or 12, characterized in that the fungal disease is chosen from the group consisting of Sigatoka disease of bananas, brown rot of cocoa pods, peacock eye of the olive tree, apple bitter rot, potato, salad and vine mildew, vine powdery mildew, grapevine black rot, wheat septoria, sclerotinia in rapeseed and wheat.
EP20731160.6A 2019-03-21 2020-03-19 Magnesium hydroxide for use as a contact fungicide in agriculture Pending EP3941202A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1902955A FR3093893B1 (en) 2019-03-21 2019-03-21 Magnesium hydroxide as a contact fungicide in agriculture
PCT/FR2020/050601 WO2020188225A1 (en) 2019-03-21 2020-03-19 Magnesium hydroxide for use as a contact fungicide in agriculture

Publications (1)

Publication Number Publication Date
EP3941202A1 true EP3941202A1 (en) 2022-01-26

Family

ID=67185431

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20731160.6A Pending EP3941202A1 (en) 2019-03-21 2020-03-19 Magnesium hydroxide for use as a contact fungicide in agriculture

Country Status (6)

Country Link
US (1) US20220183298A1 (en)
EP (1) EP3941202A1 (en)
AR (1) AR118462A1 (en)
BR (1) BR112021017850A2 (en)
FR (1) FR3093893B1 (en)
WO (1) WO2020188225A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
MX2023012872A (en) * 2021-05-06 2024-01-19 Dead Sea Bromine Co Ltd Aqueous dispersions of magnesium compounds for use in preservation of harvested products.
FR3138264A1 (en) * 2022-07-27 2024-02-02 Gaiago SPRAYABLE ANTIFUNGAL COMPOSITION FOR USE IN AGRICULTURE - ASSOCIATED METHOD AND USE
WO2024157266A1 (en) * 2023-01-29 2024-08-02 Bromine Compounds Ltd. Method of controlling soilborne plant diseases

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IN183464B (en) * 1994-07-25 2000-01-15 Orica Australia Pty Ltd
JP2002173404A (en) * 2000-12-07 2002-06-21 Tokiwa Electric Co Ltd Antibacterial and antifungal inorganic structural material
US6827766B2 (en) 2002-10-08 2004-12-07 United States Air Force Decontaminating systems containing reactive nanoparticles and biocides
US9913475B2 (en) 2014-01-02 2018-03-13 Calix Ltd Oxide products formed from calcined carbonate powder for use as biocide, chemical detoxifier and catalyst support products
US11026428B2 (en) * 2016-06-20 2021-06-08 Calix Ltd Bioactive material

Also Published As

Publication number Publication date
BR112021017850A2 (en) 2021-11-30
FR3093893B1 (en) 2021-09-17
US20220183298A1 (en) 2022-06-16
WO2020188225A1 (en) 2020-09-24
AR118462A1 (en) 2021-10-06
FR3093893A1 (en) 2020-09-25

Similar Documents

Publication Publication Date Title
EP3941202A1 (en) Magnesium hydroxide for use as a contact fungicide in agriculture
Fouda et al. In-Vitro cytotoxicity, antibacterial, and UV protection properties of the biosynthesized Zinc oxide nanoparticles for medical textile applications
AU2003209070B2 (en) Method of weed control
CN110372617B (en) Medicinal composition, prothioconazole crystal form, preparation method and application thereof
Mahmoodzadeh et al. Effect on germination and early growth characteristics in wheat plants (Triticumaestivum L.) seeds exposed to TiO2 nanoparticles
KR101990714B1 (en) Calcium carbonate for plant protection
CN102696622B (en) Pesticide composition capable of preventing and controlling plant disease
JP5987672B2 (en) Plant disease control agent and plant disease control method using the same
OA20738A (en) Magnesium hydroxide as a contact fungicide in agriculture.
CN101258853B (en) Carbamate and azoles fungicide composition and use
KR20200140041A (en) Producing method for plant nutrients containing metal nano particles
KR101298112B1 (en) Agricultural pesticide against plant disease containing solution typed thiamine di-lauryl sulfate
JP6629670B2 (en) Algae control agent
KR20150031114A (en) Bacillus Subtilis strain KP04 and its use
Hamza et al. Spirulina platensis synthesized gold nanoparticles (AuNPs) as an antibacterial and antioxidant agent
Le Wee et al. Magnesium Oxide Nanoparticles: A Dual-action Solution for Combating Fusarium Oxysporum and Enhancing Plant Growth
AU2017384002B2 (en) Heavy metal-free calcium hydroxide-based active substance
RU2448460C1 (en) Method to control pests in vineyards
Pereș et al. Yield and physiological parameters of Siriana F1 under conventional and unconventional stimulants
KR20080112697A (en) Control agents for powdery mildew
Singh et al. Allelopathic effect of organic extract of green algal weed Pithophora oedogonia (Mont.) Wittrock on growth promotion of Nostoc sp. towards agricultural sustainability in rice field.
Al-Zuhairi et al. The effect of adding zinc oxide sol-gel Nano on the chemical characteristics of growing Capsicum frutescens plant in hydroponic system.
IT202100021014A1 (en) PRODUCTION PROCEDURE, METHOD OF USE AND ANTIFUNGAL COMPOSITION BASED ON COPPER-TANNIN NANO COMPLEXES
WO2021220281A1 (en) Composition comprising novel fungal strain and methods of using same for promoting plant growth and suppressing pathogens
CN118303426A (en) V (V)2C nano material and application thereof in bacterial wilt resistance

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20210910

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20240103