The present invention relates to a plant strengthener in the form of a formulation comprising tocopherol or a derivative of a tocopherol, and to the use thereof for increasing the tolerance of crop plants to stress events, in particular to chemically induced stress, cold-induced stress, drought-induced stress or light-induced stress. The plant strengtheners are present in the form of formulations which comprise the following components A, B and C: a) at least one tocopherol or derivative of a tocopherol (component A) b) at least one nonionic emulsifier (component B) and c) at least one water-soluble boron compound (component C), and, if appropriate, d) one or more UV absorbers (component D) and e) one or more organic solvents.
