 IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Grapevine diversity and viticultural practices for sustainable grape growing 9 Is it possible to approximate the technological and phenolic maturity of grapes by foliar application of elicitors?

Is it possible to approximate the technological and phenolic maturity of grapes by foliar application of elicitors?

Abstract

AIM: The increase in the temperature and the more severe water stress conditions, trends observed in recent years as a consequence of climate change, are leading a mismatch between the technological and phenolic maturity of grapes [1]. As a strategy to face this situation, the use of apatite (Ap) nanoparticles as nano-transporters of the elicitor, methyl jasmonate (Ap-MeJ), is proposed. Elicitors are compounds that, when applied to plants, activate their defense mechanisms, increasing the synthesis of secondary metabolites, mainly phenolic compounds [2, 3]. To date, methyl jasmonate (MeJ) has been used conventionally, but its “nano” application could improve its penetration into the plant, releasing it slowly, which would allow a reduction in the dose to be applied. Therefore, the objective of this work was to study the influence of foliar application of conventional MeJ and MeJ formulated in “nano” form on the composition of Tempranillo grapes during ripening.

METHODS: The experimental design was a randomized block design with three treatments, each in triplicate, with 10 vines per replicate. Foliar applications were carried out at veraison and 7 days later. In each application, 200 mL of solution was applied per plant, being the treatments: control (water), MeJ (10 mM) and Ap-MeJ (1 mM). Grape samples were taken at five points in time: one day before the first application (Fol1), one day before the second application (Fol2), fifteen days after the second application (Pre: pre-harvest), the day of harvest (Vend) and 15 days after harvest (Post: post-harvest). In each sample, the general parameters were determined using official methods [4]: ºBrix, pH, total acidity, glucose+fructose, malic acid, and total phenols.

RESULTS: The results obtained with the foliar application of MeJ as a tool to approximate the phenolic and technological maturity are promising. It has been observed that both, conventional MeJ and Ap-MeJ treatments, slightly reduced ºBrix of grapes and increased their phenolic content. Throughout ripening, the increase in phenolic compounds was mainly evident from pre-harvest to post-harvest, with a higher content in grapes treated with Ap-MeJ.

CONCLUSIONS:

The application of MeJ could be an appropriate technique to mitigate the negative effects of decoupling in grape ripening related to the climate change. Moreover, the use of Ap-MeJ allows to optimize its dosage, contributing to a sustainable and economically viable viticulture.

DOI:

Publication date: September 1, 2021

Issue: Macrowine 2021

Type: Article

Authors

Teresa Garde-Cerdán , Carretera De Burgos, Pérez-Álvarez, Baroja, Ramírez-Rodríguez, Martínez-Vidaurre, Delgado-López P. Rubio-Bretón, Garde-Cerdán

Instituto De Ciencias De La Vid Y Del Vino (Csic, Universidad De La Rioja, Gobierno De La Rioja). Km. 6. 26007 Logroño, Spain,E.P.
Instituto De Ciencias De La Vid Y Del Vino E.
Instituto De Ciencias De La Vid Y Del Vino G.B. Universidad De Granada J.M.
Instituto De Ciencias De La Vid Y Del Vino J.M.
Instituto De Ciencias De La Vid Y Del Vino T.
Instituto De Ciencias De La Vid Y Del Vino

Contact the author

Keywords

Elicitors; nanotechnology; methyl jasmonate; foliar application; vineyard; grape composition; ripening; phenolic maturity; technological maturity; climate change

Citation

Evolution of the amino acids content through grape ripening: Effect of foliar application of methyl jasmonate with or without urea

The parameters that determine the grape quality, and therefore the optimal harvest time, suffer variations during berry ripening, related to climate change, with the widely known problem of the gap between technological and phenolic maturities. However, there are few studies about its incidence on grape nitrogen composition. For this reason, the use of an elicitor, methyl jasmonate (MeJ), alone or with urea, is proposed as a tool to reduce climatic decoupling, allowing to establish the harvest time in order to achieve the optimum grape quality. The aim was to study the effect of MeJ and MeJ+Urea foliar applications on the evolution of Tempranillo amino acids content throughout the grape maturation. Three treatments were foliarly applied, at veraison and 7 days later: control (water), MeJ (10 mM) and MeJ+Urea (10 mM+6 kg N/ha). Grape samples were taken at five stages of maturation: day before the first and second applications, 15 days after the second application (pre-harvest), harvest day, and 15 days after harvest (post-harvest). The amino acids analysis of the samples was carried out by HPLC. Results showed that the evolution of amino acids was similar regardless of the treatment; however, foliar applications influenced the nitrogen compounds content, i.e., there was no qualitative effect but quantitative one. Most of the amino acids reached their maximum concentration in pre-harvest, being higher in grapes from the treatments than in the control. In general, no differences in grape amino acids content were observed between MeJ and MeJ+Urea treatments. Foliar applications with MeJ and MeJ+Urea enhanced the grape amino acids content, without affecting their profile, helping to optimize their quality and allowing to establish a more complete grape ripening standard. Therefore, MeJ and MeJ+Urea foliar applications can be a simple agronomic practice, which has shown promising results in order to enhance the grape quality.

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