Effect of methyl jasmonate and riboflavin applications on berry quality in Prima, Lival and Michele Palieri grape cultivars

This research was carried out in Middle Black Sea Transitional Zone Agricultural Research Institute (OKTAM) trial vineyard in Tokat Kazova condition in 2020. The aim was to study the influence of foliar and bunch applications of Methyl Jasmoanate (MeJA) and riboflavin (Rbf, vitamin B2) to vineyard on grape quality and amino acid composition. The study was carried out on Prima, Lival and Michele Palieri tablegrape varieties maturing in different periods. In the study, while MeJA was applied to vines at a dose of 1 mM (200 g / ha), Rbf treatment was applied at a dose of 0.5 mM (100 g / ha). In the control treatment, only pure water was applied to the vines. The foliar and bunch treatments of MeJA and Rbf were applied to the grapevines twice, at veraison and post-veraison. In the harvested grapes, cluster weight, berry weight, soluble solid conten, total acidity, pH, protein, free amino acid amounts were determined. In addition, CIELab, hue angle, chroma (ΔC) value and pigment content and color index (CIRG) values were determined as berry color value. Seventeen free amino acids were identified and measured quantitatively in grape cultivars. While glutamic acid, aspartic acid, arginine, and proline were determined as the dominant amino acids, lysine, alanine, leucine, glycine, valine, phenylalein, iso leucine, methionine and tryiptophan were the amino acids determined at medium concentration. The highest protein content in the berry was found in Michele Palieri variety and the lowest in Lival. Amino acid amount was most in control, followed by MeJA. Amino acid amount was determined as 188.5 mg in glutamic acid (Michele Palieri, Rbf) and 3 mg /100 g in lowest tryptophan (Michele Palieri/control; Prima/Rbf). The proline / arginine ratio was also found to be high in applications with high TSSC ratio. While MeJA application increased amino acid concentration in the earliest maturing Prima, Rbf was found to be more effective in later maturing Lival and Michele Palieri.