Methyljasmonate versus nanomethyljasmonate: effect on monastrell nitrogen composition

Abstract

AIM: The aim of this work was to evaluate the effect of preharvest application in Monastrell berries using two different types of applications: conventional treatments (methyl jasmonate) and nanocompounds (nanomethyl jasmonate) on Monastrell nitrogen composition in grapes and wines.

METHODS: The treatments was applied during two vintages (2019 and 2019) in a plot located in the southeast of Spain (Bullas, Murcia). Foliar applications were carried out at veraison and 7 days later. 200 mL per plant will be applied, using Tween 80 at 0.1% (v/v) in each solution. The applied treatments were the following: methyl jasmonate (MeJ) (10 mM) and the application of nanoparticles, nano-MeJ (0.67 mM). The corresponding analyses were made in grapes at harvest and in wines at the end of alcoholic fermentation. The ammonium ion (NH4 +) and the following free amino acids were analysed by HPLC: aspartic acid (Asp), glutamic acid (Glu), serine (Ser), asparagine (Asp), glutamine (gln), histidine (His), glycine (Gly) , threonine (Thr), β-Alanine (β-Ala), arginine (Arg), α-Alanine (α-Ala), γ-aminobutyric acid (GABA), proline (Pro), tyrosine (Tyr), valine (Val ), methionine (Met), cysteine (Cys), isoleucine (Iso), leucine (Leu), tryptophan (Trp), phenylalanine (Phe), ornithine (Orn) and lysine (Lys).

RESULTS: In general terms, the application of elicitors (MeJ and nano-MeJ) significantly increased the nitrogen composition of musts and wines of the Monastrell variety. Although the results obtained were influenced by the climatic differences experienced during the two years of study, so that during the first year more noticeable differences were obtained between the treatments and the control vineyards.

CONCLUSIONS

In conclusion, although the results are preliminary, the exogenous application of nano-MeJ could be an interesting alternative to be used instead of the conventional elicitor with two aims: to reduce the use of agrochemical in plants and improve nitrogen composition in grapes and wines.