The invention relates to a composition for agricultural use comprising an active ingredient consisting of a mixture of galacturonic acid oligomers, wherein the number of galacturonic acid units ranges between 1 and 10. The invention also relates to a method for preparing said composition and a method for applying same. This composition induces and stimulates defense mechanisms in plants against damage caused by pathogens (biotic stress) and by drought, high and low temperatures, salinity, heavy metals, ultraviolet radiations, soil acidity, etc., (abiotic stress). This composition further activates mechanisms that cause vegetative development, promoting a general enhancement in the crop vegetation and health, with very little or no environmental impact.
