CONCENTRATED EXTRACT OF ALGAE, PRODUCTION METHOD THEREOF AND USE OF SAME lN AGRICULTURE

Abstract

The present invention relates to a concentrated extract of algae, containing between 6 and 100% dry matter, to the production method thereof, and to the uses of same either alone or associated with another nutritional, biostimulating or phytosanitary technology, 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 extract of algae of the invention, as well as to a seed coating with said extract.

Claims

1-10. (canceled)

11. A concentrated algal extract having a percentage dry matter of between 6 and 100%, and containing 0 to 5%, by weight of alginate or of cellulose relative to the weight of said extract.

12. The extract as claimed in claim 11, wherein the alga is chosen from Ascophyllum nodosum, Fucus vesiculosus, Laminaria digitate, Laminaria hyperborea, Laminaria saccharine, Eklonia maxima, Sargassum spp. and mixtures thereof.

13. The extract as claimed in claim 12, having a pH of between 1.5 and 9.

14. A process for preparing a concentrated algal extract as defined in claim 11, comprising the following steps: grinding the algae until the cells rupture; homogenizing the ground algal material in aqueous solution; removing the alginate and the cellulose by flocculation and filtration; concentrating the filtrate to reach a percentage dry matter of between 6 and 100%, preferably between 9 and 70%, more preferentially between 12 and 50%.

15. The process as claimed in claim 14, wherein the step of concentrating the filtrate is performed by reverse osmosis, by water evaporation, by algae enrichment or by centrifugation.

16. A process for promoting the emergence, growth, development and/or reproduction of a plant, wherein the extract is as defined in claim 11, and is applied by infiltration into the soil, sprayed onto the leaves of the plant, applied to a seed before sowing, or applied to the roots of a seedling, before the planting thereof.

17. A seed coated with an extract as defined in claim 11.

18. The extract as claimed in claim 11, having a percentage dry matter of between 9 and 70%, and containing 1 to 4%, by weight of alginate or of cellulose relative to the weight of said extract.

19. The extract as claimed in claim 11, having a percentage dry matter of between 12 and 50%, and containing 2 to 3%, by weight of alginate or of cellulose relative to the weight of said extract.

20. The extract as claimed in claim 11, having a pH of between 2 and 7.

21. The extract as claimed in claim 11, having a pH of between 2.5 and 3.

22. The process as claimed in claim 14, comprising the step of adjusting the pH of the filtrate.

23. The process as claimed in claim 16, wherein the extract is applied to the roots of a seedling by dip treatment, before the planting thereof.

24. A method for promoting plant growth, wherein an extract as defined in claim 11 is applied by infiltration into the soil, sprayed onto the leaves of the plant, applied to a seed before sowing, or applied to the roots of a seedling, before the planting thereof.

25. A method for stimulating plant emergence, wherein an extract as defined in claim 11 is applied by infiltration into the soil, sprayed onto the leaves of the plant, applied to a seed before sowing, or applied to the roots of a seedling, before the planting thereof.

26. A method for repelling bird, wherein an extract as defined in claim 11 is applied by infiltration into the soil, sprayed onto the leaves of the plant, applied to a seed before sowing, or applied to the roots of a seedling, before the planting thereof.

27. A process for promoting the emergence, growth, development and/or reproduction of a plant, wherein an extract prepared by the process defined in claim 14 is applied by infiltration into the soil, sprayed onto the leaves of the plant, applied to a seed before sowing, or applied to the roots of a seedling, before the planting thereof.

28. A seed coated with an extract prepared by the process defined in claim 14.

29. The process as claimed in claim 16, wherein the extract is applied to the roots of a seedling by dip treatment, before the planting thereof, and wherein the extract is produced by a process comprising grinding the algae until the cells rupture; homogenizing the ground algal material in aqueous solution; removing the alginate and the cellulose by flocculation and filtration; concentrating the filtrate to reach a percentage dry matter of between 6 and 100%, preferably between 9 and 70%, more preferentially between 12 and 50%.

30. A method for promoting plant growth, wherein an extract prepared by the process defined in claim 14 is applied by infiltration into the soil, sprayed onto the leaves of the plant, applied to a seed before sowing, or applied to the roots of a seedling, before the planting thereof.

31. A method for stimulating plant emergence, wherein an extract prepared by the process defined in claim 14 is applied by infiltration into the soil, sprayed onto the leaves of the plant, applied to a seed before sowing, or applied to the roots of a seedling, before the planting thereof.

32. A method for repelling bird, wherein an extract prepared by the process defined in claim 14 is applied by infiltration into the soil, sprayed onto the leaves of the plant, applied to a seed before sowing, or applied to the roots of a seedling, before the planting thereof.

Description

FIGURES

[0060] FIG. 1 is a schematic representation of the number of corn seedlings obtained 3 weeks after sewing uncoated corn seeds, corn seeds coated with an algal extract of the present invention or corn seeds coated with a conventional fungicide as described in example 4.

[0061] FIG. 2 is a schematic representation of the number of corn seedlings obtained 3 weeks after sewing uncoated corn seeds, corn seeds coated with an algal extract of the present invention or corn seeds coated with a conventional fungicide as described in example 5.

EXAMPLES

Example 1

Preparation of a Concentrated Algal Extract

[0062] An extract of Ascophyllum nodosum algae having a percentage dry matter of 5.1%, denoted GOACTIV by the applicant company, is concentrated by water evaporation by heating the extract at 50° C. in a rotary evaporator under (water-pump) vacuum until the percentage dry matter reaches 13%.

Example 2

Application of the Concentrated Algal Extract to Tomato Seedlings

[0063] An amount of extract per plant as indicated in the table below is sprayed once a week onto the leaves of tomato seedlings at the 3-leaf stage (3 weeks):

TABLE-US-00001 According to Comparative: the invention Algal extract GOACTIV (example 1) % dry matter 5.1% 13% Amount of extract 0.03 mg 0.01 mg sprayed per seedling

[0064] The tomato seedlings are thus treated with comparable amounts of each extract. After 5 weeks of treatment, the tomato seedlings treated with the concentrated algal extract of the present invention (example 1) are taller and bushier than the seedlings treated with the non-concentrated algal extract (GOACTIV).

[0065] For comparable amounts of extract applied, the concentrated algal extract of the present invention is therefore more effective at promoting the growth of tomato seedlings than a more diluted extract.

Example 3

Coating Corn Seeds with the Concentrated Algal Extract

[0066] 100 kg of corn seeds are wetted with 100 g of concentrated algal extract prepared in example 1, in a rotary mixer. The seeds are then left to dry at 20-25° C. for 24 hours.

Example 4

Effect of Coating the Seeds on the Emergence of Corn Seedlings

[0067] The coated corn seeds prepared in example 3 are sown on 20 m.sup.2 plots. A control is carried out with untreated corn seeds. A comparative test is carried out with corn seeds coated with a conventional fungicide comprising 25 g/l of fludioxonil and 9.7 g/l of metalaxyl-M.

[0068] 3 weeks after sowing, the number of corn seedlings is counted. The results are presented in FIG. 1. It is observed that emergence of the corn seedlings is favored when the seeds are coated with the concentrated algal extract prepared according to example 1, compared to the uncoated seeds or to the seeds coated with the fungicide.

[0069] Example 4 was reproduced and gave similar results.

Example 5

Bird-Repelling Effect of Coating the Seeds

[0070] During one of the experiments according to example 4, the field was subjected to a particularly aggressive attack by crows. The birds attack the seeds buried in the soil, which leads to a reduction in the number of healthy corn seedlings relative to the number of seeds planted.

[0071] The results are presented in FIG. 2, the values on the y axis being expressed as percentage of healthy corn seedlings relative to the theoretical number of seedlings.

[0072] A significant difference was observed in the degree of attack between the control plots or those treated with the fungicide and the plots in which the seeds were coated with the concentrated algal extract of example 1. Thus, the plots which had been sown with seeds treated with the concentrated algal extract of example 1 were relatively spared by the birds.

[0073] The concentrated algal extract of the present invention therefore has a bird-repelling effect.

[0074] Example 5 was reproduced and gave similar results.