The present invention relates to a method for evaluating whether a substance is a biostimulant, wherein the method comprises the following steps: a) providing at least two seedlings or plants of the same species and of the same age, bi) incubating at least one of the seedlings or plants provided in step a) with a candidate biostimulant for at least 1 hour, b2) contacting the at least one seedling or plant after step bi) with 8-amino-5-chloro-7-phenylpyrido-[3,4-d]pyridazine-1,4(2H,3H)dione (L012) and with an elicitor inducing the production of a reactive oxygen species in the seedling or plant to thereby obtain at least one sample, wherein the at least one seedling or plant may be contacted with the L012 and with the elicitor simultaneously or staggered, c) treating at least another one of the at least two seedlings or plants provided in step a) as in steps b1) and b2) except that in step bi) no candidate biostimulant is added to thereby obtain at least one reference, d) monitoring the oxidative burst of each of the at least one sample and of the at least one reference induced by the elicitor over a time interval of at least one minute by measuring the chemiluminescence generated by the L012 to thereby obtain a curve of the oxidative burst over the time for the at least one sample and a curve of the oxidative burst over the time for the at least one reference and e) comparing the curve of the oxidative burst over the time of the at least one sample with the curve of the oxidative burst over the time of the at least one reference.La présente invention concerne un procédé pour évaluer si une substance est un biostimulant, le procédé comprenant les étapes suivantes : a) fourniture d'au moins deux semis ou plantes de la même espèce et du même âge, b1) incubation d'au moins l'un des semis ou d'au moins l'une des plantes fournis à l'étape a) avec un biostimulant candidat pendant au moins 1 heure, b2) mise en contact de l'au moins un semis ou de l'au moins une plante après
