Practical guide toward discovery of biomolecules with biostimulant activity.

The growing demand for sustainable solutions in agriculture, critical for crop productivity and food quality in the face of climate change and reduced agrochemical usage, has brought biostimulants into the spotlight as valuable tools for regenerative agriculture. Due to their diverse biological activities, biostimulants contribute to crop growth, nutrient use efficiency, abiotic resilience, and soil health restoration. Biomolecules, including but not limited to humic substances, protein lysates, phenolics and carbohydrates have undergone thorough investigation because of their demonstrated biostimulant activities. Here, we review the process of discovery and development of extract-based biostimulants and propose a practical step-by-step pipeline starting with biomolecule investigation, followed by extraction and isolation, bioactivity determination, identification of active compound(s), mechanistic elucidation, formulation, and effectiveness assessment. The different steps generate a roadmap that aims to expedite the transfer of interdisciplinary knowledge from laboratory-scale studies to pilot-scale production in practical scenarios aligned with the regulatory framework.