The Role of Biostimulants in Plant Growth, Development, and Abiotic Stress Management: Recent Insights

Application of commercial seaweed extract-based biostimulants to enhance adventitious root formation in ornamental cutting propagation protocols: a review

“…In 2014, Calvo defined biostimulants as any substances or microorganisms that benefit the plant (Calvo et al, 2014), while Du Jardin et al stated, in 2015, that the definition is based on what they are not, rather than what they are; for instance, fertilizers and pesticides increase plant yields but do not fall into the biostimulants category. Most biostimulants are complex mixtures and on this basis (Povero et al, 2016), two definitions have been given and both share the requirement that the mode of action must be unknown but differ in the fundamental assumption that the function of the biostimulant is a consequence of the discrete components (Carletti et al, 2021;Pandey et al, 2022) or a consequence of the 'emergent' properties of the biostimulant. Therefore, Yakhin et al (2017) have developed a third concept that integrates the two previous concepts 'a formulated product of biological origin that improves plant productivity as a consequence of the novel, or emergent properties of the complex of constituents, and not as a sole consequence of the presence of known essential plant nutrients, plant growth regulators, or plant protective compound'.…”