The present invention concerns the use of a compound of the following formula (I): Si(CH3)(OH)3-n(OX)n (I) in which X is a hydrogen atom or an alkali metal, in particular chosen from lithium, sodium or potassium, and n is an integer ranging from 1 to 3, for foliar application on crops, said crops being chosen, in particular, from the group comprising: -large-scale crops, in particular those chosen from cereals, oil crops, protein crops, leguminous fodder plants, forage grasses or sugar crops, -vegetable or market crops, in particular fresh vegetables, -fruit crops, in particular those chosen from fruits with cores, fruits with seeds, fruits with kernels, clustered fruits, small fruits or fruits from hot regions, -aromatic and medicinal plants, -floral and ornamental crops, and the mixtures of same, and for: -improving the growth and development of crops, -improving crop yield, -stimulating and reinforcing crops against biotic stresses, in particular by improving the resistance of same to phytopathogens and/or
