Sustainably advancing plant physiology through chitosan nanoformulations
Modern agriculture faces significant challenges due to excessive agrochemical use, resulting in environmental degradation and reduced sustainability. Bionanomaterials have emerged as eco-friendly alternatives, among which chitosan is widely recognised for its biodegradability, biocompatibility and multifunctional properties. This review demonstrates findings from recent studies (2015–25), highlighting that conventional nutrient use efficiency remains below 50 % for macronutrients and < 5 % for micronutrients, whereas chitosan-based nanomaterials (NMs) significantly enhance nutrient delivery and utilisation. These NMs function as nanofertilisers, nanocarriers, biostimulants and nanopesticides, improving nutrient uptake, enzymatic activity, stress tolerance and overall plant growth. From a physiological perspective, they enable controlled release, targeted delivery and modulation of metabolic processes, thereby enhancing crop productivity while reducing agrochemical dependence. However, key challenges persist, including limited field-scale validation, lack of long-term environmental safety data and absence of standardised formulations. Future research should focus on large-scale validation, mechanistic insights and integration with precision agriculture. Overall, chitosan-based nanotechnology offers a promising and sustainable strategy for advancing plant physiology, though its successful field application requires further validation and standardisation.