Fuente: WIPO "tomato" The present invention relates to a method of priming a plant against biotic and/or abiotic stress factors comprising the step of treating said plant or parts thereof with an aqueous composition comprising particles, wherein the particles have a particle size D98 of less than 30 pm, wherein the particles are obtainable by a method comprising the steps of : a) crushing a raw material comprising clinoptilolite, and b) subj ecting the crushed material of step a) to elutriation to obtain the particles.