The present invention relates to the agri-food industry and obtaining seedless fruit. The invention consists of an active product whose composition comprises sulphur (S) as an octatomic molecule (S8) as its active ingredient, as well as optionally a surfactant and a plant hormone, preferably gibberellic acid or auxins and its use in a method for obtaining seedless fruit that comprises the application of the active product on crops, flowers, horticultural plants and/or fruit trees.