Process for preparing a concentrated algae extract for use in agriculture

Abstract

The present invention relates to a concentrated algae extract, containing between 6 and 100% dry matter, to its production method and its uses, whether isolated or associated with other nutritional, biostimulant or phytosanitary technologies, in particular, to stimulate the emergence, growth, development and reproduction of plants and to prevent birds from eating seeds. The invention also relates to a method for applying the concentrated algae extract of the invention, as well as to a seed coated with said extract.

Description

1 / 13 “PROCESS FOR PREPARING CONCENTRATED ALGAE EXTRACT AND USE IN AGRICULTURE FIELD OF THE INVENTION

[001] The present invention relates to a concentrated algae extract having a dry matter percentage between 6 and 100%, its method of preparation and its use alone or in combination with other nutritional, biostimulant or plant technologies, in particular, to promote the emergence, growth, development, improvement of plants and to prevent birds from eating the seeds. The invention also provides a method for applying the concentrated algae extract of the present invention and a seed coated with said extract. BACKGROUND OF THE INVENTION

[002] Increasing income is at the heart of farmers' concerns. However, performance depends heavily on proper plant development and therefore on growth and good health.

[003] Plant growth is directly related to the absorption and assimilation of minerals, as well as the hormonal flow that regulates the elongation and differentiation of plant tissue. Nutrients and hormones, therefore, play an essential role in plant growth. Because of their inability to move plants, they have established active and activated mechanisms to make the best use of these resources to promote growth. In order to increase growth, fertilizers are used.

[004] Algae have been used for many years as a modifier for organic and different types of soils. Petition 870220047210, dated 05 / 30 / 2022, page 16 / 48 2 / 13 Horticultural crops and cereals. Seaweed extracts are used as a biostimulant, typically sprayed onto plant leaves. Many benefits associated with the use of seaweed extract have been observed in agriculture and include increased productivity, nutrient uptake, resistance to frost and stress conditions, improved fruit preservation, and a decrease in fungal and insect attacks.

[005] Seaweed extracts are also known to allow for better seed germination, especially favoring plant emergence. In fact, as they emerge, seedlings are susceptible to pathogenic microorganisms, such as fungal species like common Rhizoctonia, Pythium, or bacteria that cause a disease called damping-off. Affected young shoots are found lying on their side, as if the base of the stem were pinched. Humidity and low temperatures favor the appearance of damping-off.

[006] Many algae extracts are marketed for use in agriculture. For example, applicants describe in EP 0538091 a composition derived from seaweed obtained through a method comprising the steps of: a) Basic hydrolysis of at least one brown alga in the presence of a reducing agent, at a temperature between 50 and 100 °C for a period of between 4 and 8 h b) neutralization of the hydrolysate thus obtained with a strong acid, until a pH between 6 and 8 is reached; c) filtration; d) optionally, diafiltration or electrodialysis of the permeate obtained at the end of step c) and Petition 870220047210, dated 05 / 30 / 2022, page 17 / 48 3 / 13 (e) optionally, reduction of the permeate to its powder obtained at the end of step c), or of the retentate obtained at the end of step d).

[007] However, due to the basic hydrolysis of the algae upon heating in the presence of a reducing agent, certain compounds of the algae's intracellular fluid are not preserved, in particular, polysaccharides, lipids, proteins and polyphenols, which reduces the biostimulant properties of the composition obtained with the method described above.

[008] The present inventors have found that an algae extract, in which the compounds of the algae's intracellular fluid are preserved, exhibits excellent bio-stimulating activity when concentrated to achieve a certain percentage of dry matter. Surprisingly, the Applicant has found that, following an application for comparable quantities, the concentrated algae extract of the invention is more effective than a diluted extract in stimulating plant emergence and growth. Furthermore, when the concentrated algae extract is used to coat seeds, they are less attacked by birds than uncoated seeds. SUMMARY OF THE INVENTION

[009] The present invention relates to a concentrated algae extract exhibiting a solids content of between 6 and 100%, preferably between 9 and 70%, more preferably between 12 and 50%, and containing 0 to 5%, in particular 1 to 4%, more particularly 2 to 3% by weight of alginate and / or cellulose based on the weight of said extract. Petition 870220047210, dated 05 / 30 / 2022, page 18 / 48 4 / 13

[0010] A second objective of the present invention is a process for preparing a concentrated algae extract of the invention, comprising the steps of: - Grind the algae until the cells rupture; - Homogenize the algae-based material in an aqueous solution. - remove alginate and cellulose by flocculation and filtration; Optionally, adjust the pH of the filtrate. - Concentrate the filtrate to obtain a dry matter percentage of between 6 and 100%, preferably between 9 and 70%, more preferably between 12 and 50%.

[0011] Another object of the present invention is a method for promoting the appearance, growth, development and / or reproduction of a plant characterized in that the extract of the present invention or preparations according to the method of the invention are applied by infiltration into the soil, sprayed onto the leaves of the plant, applied to a seed before planting, or applied to the roots of a seedling, including granulation, before planting.

[0012] Yet another objective of the present invention is the use of an extract according to the invention or preparations according to the method of the invention to promote plant growth.

[0013] The present invention also relates to the use of an extract according to the invention or prepared according to the method of the invention, to stimulate plant emergence.

[0014] A sixth objective of the present invention is the use of an extract according to the invention or Petition 870220047210, dated 05 / 30 / 2022, p. 19 / 48 5 / 13 prepared according to the method of the invention, as bird repellents.

[0015] Finally, the invention also relates to a seed coated with an extract according to the invention or prepared according to the method of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] The concentrated algae extract of the present invention is, in particular, an aqueous extract or a dry extract, with a dry matter percentage of between 6 and 100%, preferably between 9 and 70%, more preferably between 12 and 50%.

[0017] The percentage of dry matter, within the meaning of the present invention, is calculated using the following formula: msecaX 100mhidratada where mseca is the mass of material remaining after drying; and mhidratada is the mass of the seaweed extract before drying.

[0018] The concentrated algae extract of the present invention is devoid of alginate and / or cellulose. Thus, the algae extract according to the invention comprises intracellular fluid algae obtained after the rupture of the algal cell walls and their removal by flocculation. According to a particular embodiment, the concentrated algae extract of the present invention contains 0 to 5%, especially 1 to 4%, particularly 2 to 3% by weight of alginate and / or cellulose relative to the weight of said extract.

[0019] The algae from which the concentrated extract of the present invention is obtained can Petition 870220047210, dated 05 / 30 / 2022, p. 20 / 48 6 / 13 particular to be selected from Ascophyllum nodosum, Fucus vesiculosus, Laminaria digitata, Laminaria hyperborea, Laminaria saccharina, Eklonia maxima, Sargassum spp. and mixtures thereof. In a particular embodiment, the said alga is Ascophyllum nodosum.

[0020] The concentrated algae extract of the invention, in particular, has a pH between 1.5 and 9, preferably between 2 and 7, more preferably between 2.5 and 3.

[0021] The concentrated algae extract of the present invention comprises intracellular algae fluid. In particular, it may comprise one or more compounds selected from polysaccharides such as laminarin and fucans; free and conjugated sugars; polyphenols; mannitol; growth hormone; lipids; proteins; amino acids; vitamins; betaines; sterols; glucuronic acid and mineral salts. According to a particular embodiment, the concentrated algae extract of the present invention comprises laminarin; fucans; lipids; proteins and polyphenols.

[0022] According to a particular embodiment, the concentrated algae extract of the present invention may be formulated in a composition comprising said extract and at least one compound selected from a gelling agent, a thickener, a plant protection product, a second plant and / or algae extract, minerals, a surfactant, an oil, a preservative, and mixtures thereof.

[0023] The concentrated algae extract of the present invention can especially be obtained by the method described below.

[0024] The method of preparing an extract Petition 870220047210, dated 05 / 30 / 2022, page 21 / 48 7 / 13 algae concentrate according to the invention comprises the following steps: - crush the alga until cell rupture; - homogenize the algae-based material in aqueous solution; - remove alginate and cellulose by flocculation and filtration; - optionally, adjust the pH of the filtrate; — concentrate the filtrate until it reaches a solids percentage of between 6 and 100%, preferably between 9 and 70%, more preferably between 12 and 50%.

[0025] Advantageously, the method of the present invention does not include a hydrolysis step in the presence of a reducing agent, for example, at a temperature between 50 and 100°C for a period of between 4 and 8 hours. This makes it possible to preserve the compounds of the algal intracellular fluid, including polysaccharides.

[0026] The grinding step serves, in particular, to break the cell walls of algae, thus releasing intracellular fluid from the algae. The grinding step is preferably carried out on fresh algae, that is, algae harvested less than 24 hours ago.

[0027] The step of homogenizing the algae-based material can, in particular, be carried out by adding water at a rate of 1 to 2 liters of water per kg to the algae-based material.

[0028] The flocculation and filtration stage serves, in particular, to remove residues from the cell walls of algae in order to collect the intracellular fluid of the algae. Residues from algal cell walls can especially precipitate by flocculation with the addition of acid, Petition 870220047210, dated 05 / 30 / 2022, page 22 / 48 8 / 13 especially hydrochloric acid, to the algae-based material. According to a particular embodiment of the present invention, the acid is added so as to obtain a pH of between 1.5 and 4, preferably between 2 and 3.5, more preferably between 2.5 and 3.

[0029] The acidified mixture is then filtered to remove alginate and cellulose flakes larger than 40 microns.

[0030] The pH of the filtrate can optionally be adjusted by adding an acid or a base to obtain a pH between 1.5 and 9, preferably between 2 and 7, more preferably between 2.5 and 3.

[0031] The filtration from the concentration stage can be carried out in several ways, such as, in particular, by reverse osmosis, water evaporation, algae enrichment or centrifugation.

[0032] Reverse osmosis is a membrane separation technique based on a selective diffusion process. Two algae extracts of varying concentrations are placed on either side of a water-permeable membrane. When pressure is applied to the more concentrated algae extract, some of the water contained in the more concentrated extract migrates to the less concentrated extract.

[0033] The evaporation of water can, in particular, be carried out by heating the seaweed extract under reduced pressure, for example, with a rotary evaporator. The heating can be carried out between 40 and 90°C, preferably between 60 and 80°C.

[0034] Algae enrichment can, in particular, be produced by substitution in the algae homogenate of the homogenization step of the process. Petition 870220047210, dated 05 / 30 / 2022, p. 23 / 48 9 / 13 according to the invention, the algae suspension water obtained by the process according to the invention.

[0035] Centrifugation can, in particular, be carried out by subjecting the seaweed extract to centrifugal force in a high-speed rotary machine.

[0036] Preferably, the filtrate concentration step is carried out by evaporation of the water.

[0037] The concentrated algae extract according to the invention is advantageously used in agriculture, where it has many applications, depending on the type of plant to which it is applied and the period of the plant's cycle where it is used.

[0038] The concentrated algae extract of the present invention can especially be used alone or in combination with a composition of nutrients, biostimulants or phytosanitary products.

[0039] Plants in which the concentrated seaweed extract of the present invention can be used are agronomically useful plants, for example, vegetable crops, fruits and cereals, and ornamental plants. Agronomically useful plants are angiosperms selected from the groups Apiaceae, Asteraceae, Brassicaceae, Chenopodiaceae, Convolvulaceae, Cucurbitaceae, Fabaceae, Gramineae, Liliaceae, Polygonaceae, Rosaceae, Solanaceae, Poaceae and Vitaceae. In a particular embodiment, the concentrated seaweed extract of the invention is used on tomatoes, soybeans, rice, fruit trees, vines, wheat or corn.

[0040] Thus, when the concentrated algae extract of the present invention is used to promote the Petition 870220047210, dated 05 / 30 / 2022, p. 24 / 48 During plant growth, the extract can be applied via foliar application, soil application, or root infiltration. Applications can be made throughout the plant's growth, once or more times per week. Very interesting results were demonstrated in tomato and corn seedlings.

[0041] When the concentrated seaweed extract of the present invention is used to stimulate plant emergence and / or to provide a bird-repellent effect, said extract can, in particular, be applied to seeds before planting, or to young seedlings soon after emergence. The seed can, in particular, be coated with the concentrated seaweed extract of the present invention. The coating can, for example, be achieved by wetting the seed with said sample and allowing it to dry, preferably at room temperature. The application can be carried out at 10 to 120 g, preferably 20 to 110 g, more preferably 30 - 105 g of concentrated seaweed extract per 100 kg of seed. Quite interesting results have been demonstrated in maize seeds.

[0042] The coated seed, which is an object of the present invention, can be specially prepared as described in the preceding paragraph. Coating the seed with concentrated seaweed extract of the present invention allows the plant to emerge more quickly and makes it more resistant to damping-off compared to uncoated seed. In addition, the coated seeds of the present invention are much less attacked by birds, such as chickens, pigeons, larks, partridges and pheasants, compared to uncoated seeds.

[0043] The invention will be described in more detail at Petition 870220047210, dated 05 / 30 / 2022, p. 25 / 48 11 / 13 continue using the following examples, which are given for illustrative purposes only. BRIEF DESCRIPTION OF THE FIGURES

[0044] Figure 1 is a schematic representation of the number of corn plants obtained 3 weeks after sowing uncoated corn seeds, coated with an algae extract of the invention, or coated with a conventional fungicide, as described in Example 4.

[0045] Figure 2 is a schematic representation of the number of corn plants obtained 3 weeks after sowing uncoated corn seeds, seeds coated with an algae extract of the invention, or seeds coated with a conventional fungicide, as described in Example 5. EXAMPLES Example 1: Preparation of a concentrated algae extract

[0046] An extract of Ascophyllum nodosum algae having a dry matter percentage of 5.1%, referred to as GOACTIV by the applicant company, is concentrated by water evaporation by heating the extract to 50 °C in a rotary evaporator under vacuum (water pump), until the dry matter percentage reaches 13%. Example 2: Application of concentrated seaweed extract to tomato seeds.

[0047] An amount of extract per plant, as indicated in the table below, is sprayed once a week onto the leaves of tomato seed plants at the 3-leaf stage (3 weeks). Algae Extract Comparison: GOACTIV According to the invention (example 1) Petition 870220047210, dated 05 / 30 / 2022, page 26 / 48 12 / 13 % dry matter 5.1% 13% Amount of extract sprayed per seed 0.03 mg 0.01 mg

[0048] Tomato plants are treated with comparable amounts of each extract.

[0049] After 5 weeks of treatment, tomato plants treated with concentrated seaweed extract of the present invention (Example 1) are taller and thicker than plants treated with non-concentrated seaweed extract (GOACTIV).

[0050] For comparable quantities of applicable extract, the concentrated algae extract of the present invention is more effective in promoting the growth of tomato plants than a more diluted extract. Example 3: Coating corn seeds with the concentrated algae extract

[0051] 100 kg of corn seeds are moistened with 100 g of concentrated seaweed extract obtained in Example 1 in a rotary mixer. The seeds were then left to dry at 20–25 °C for 24 hours. Example 4: Effect of seed coating on corn plant emergence

[0052] The coated maize seeds prepared in Example 3 were sown in 20 m2 plots. Verification is performed with untreated maize seeds. A comparative test is performed with maize seeds coated with a conventional fungicide containing 25 g / l of fludioxonil and 9.7 g / l of metalaxyl.

[0053] Three weeks after sowing, the number of corn plants is counted. The results are shown in Petition 870220047210, dated 05 / 30 / 2022, page 27 / 48 13 / 13 Figure 1. It is noteworthy that the emergence of maize plants is promoted when seeds are coated with the concentrated algae extract prepared according to Example 1 compared with uncoated seeds or seeds coated with fungicide.

[0054] Example 4 was reproduced and gave similar results. Example 5: Effect of the bird repellent on seed coating.

[0055] In an experiment similar to Example 4, the field suffered an attack by particularly aggressive crows. The birds attack the seed in the soil, which causes a decrease in the number of healthy corn plants compared to the number of seeds planted.

[0056] The results are shown in Figure 2, the values ​​on the y-axis are expressed as a percentage of healthy corn plants in relation to the theoretical number of plants.

[0057] A clear difference in the level of attack between the control plots or those treated with fungicide and plots whose seeds were coated with concentrated seaweed extract from Example 1 was observed. Thus, the plots that were sown with seeds treated with concentrated seaweed extract from Example 1 were relatively spared by the birds.

[0058] The concentrated algae extract of the present invention, therefore, has a bird-repellent effect.

[0059] Example 5 was reproduced and gave similar results. Petition 870220047210, dated 05 / 30 / 2022, pp. 28 / 48

Claims

1 / 2 CLAIMS 1. Process for the preparation of a concentrated seaweed extract having a dry matter percentage between 6 and 100%, preferably between 9 and 70%, more preferably between 12 and 50%, and containing 0 to 5%, especially 1 to 4%, particularly 2 to 3% by weight of alginate and cellulose based on the weight of said extract, characterized by comprising the following steps: - grinding the seaweed until its cell rupture; - homogenizing the seaweed-based material in aqueous solution; - removing the alginate and cellulose by flocculation and filtration; - optionally, adjusting the pH of the filtrate; - concentrating the filtrate until it reaches a dry matter percentage of between 6 and 100%, preferably between 9 and 70%, more preferably between 12 and 50%.

2. Process, according to claim 1, characterized in that the step of concentrating the filtrate is carried out by reverse osmosis, by means of water evaporation, by means of enrichment in algae or by centrifugation.

3. Process for promoting the appearance, growth, development and / or reproduction of a plant, characterized in that the concentrated algae extract prepared by the process as defined by any one of claims 1 to 2 is applied by infiltration into the soil, sprayed onto the leaves of the plant, applied to a seed before planting, or applied to the roots of a plant, especially by immersion treatment, before planting. Petition 870220047210, dated 05 / 30 / 2022, p. 29 / 48 2 / 2 4. Use of an extract such as that prepared by the process defined in any one of claims 1 to 2, characterized in that it is for promoting plant growth.

5. Use of an extract such as that prepared by the process defined in any one of claims 1 to 2, characterized in that it is for stimulating plant emergence.

6. Use of an extract such as that prepared by the process defined in any one of claims 1 to 2, characterized in that it acts as a bird repellent. Petition 870220047210, dated 05 / 30 / 2022, pp. 30 / 48

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