Methyl jasmonate and/or urea, conventionally and on nanoparticles, foliar applications: Influence on grape amino acids composition

Nanotechnology in agriculture provides a strategic and sustainable solution to climate challenges. In addition, foliar biostimulants serve to mitigate the effects of climate change in viticulture. This work aims to evaluate the impact of foliar applications of methyl jasmonate (MeJ), urea (Ur), and their combination (MeJ+Ur), applied either conventionally (free) or supported on amorphous calcium phosphate nanoparticles (ACP), on the amino acids composition of Tempranillo grapes. These nitrogen compounds were analyzed by high pressure liquid chromatography (HPLC). Among the conventional applications, MeJ+Ur proved to be the most effective in increasing the amino acids content in grape must. Moreover, the combined application of MeJ and Ur showed a synergistic effect, enhancing their effect on the grape amino acids content. The ACP-MeJ+Ur foliar treatment resulted in the highest increase in total amino acids content among all applications studied, using significantly less MeJ and Ur compared to the conventional treatment. Discriminant analysis highlighted the distinctiveness of MeJ+Ur and ACP-MeJ+Ur, emphasizing their influence on the amino acids composition of grapes. Nanotechnology in viticulture offers a promising approach for sustainable practices, reducing environmental impact while maintaining grape quality.