The present invention relates to a concentrated extract of algae, containing between 6 and 100 pcnt 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 coated with said extract.