Fuente: WIPO "tomato" The present invention falls within the technical field of agricultural exploitation under abiotic stress conditions and describes a method intended to improve the yield and effectiveness of plant cultivation that combines the application of a biostimulant product on the aerial parts of the plant and the selection of a certain biostimulant product based on a cell-free filtrate of fungal origin obtained from the fungi culture of the genus Trichoderma. The aim of this method is to reverse or avoid the alteration of the expression of genes related to primary metabolism of carbohydrates, lipids and amino acids, and secondary metabolism, hormone production and signalling, RNA synthesis and processing, protein synthesis, modification and stabilisation, solute and nutrient transport and the structure of the cell wall in plants.