Changes on grape volatile composition after elicitors and nitrogen compounds foliar applications to 'Garnacha', 'Tempranillo' and 'Graciano' vines

Grape volatile compounds determine the wine quality and typicity. The aim of this work was to study the effects of several foliar applications in 'Garnacha', 'Tempranillo', and 'Graciano' grapevines in order to enhance their grape volatile composition. The field trial involved the application of two nitrogen compounds, urea (Ur) and phenylalanine (Phe), and two elicitors, methyl jasmonate (MeJ) and a yeast extract (YE). The analysis of grape volatile compounds was carried out by HS-SPME-GC-MS. For 'Garnacha', most terpenes, and C₁₃ norisoprenoids increased their grape content by applying Ur and Phe, and especially MeJ. For 'Tempranillo', treatments with Ur and MeJ improved the synthesis of most terpenoids. For 'Graciano', a trend to decrease the terpenoids content in grapes with the treatments was observed; however, Phe application increased C₁₃ norisoprenoids content. In conclusion, foliar application of, Phe or Ur, and an elicitor, MeJ, can be a useful tool to improve grape quality.