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MODIFICATION OF THE SOURCE RELATIONSHIP AND ITS INFLUENCE ON THE PRIMARY AND SECONDARY METABOLISM IN TANNAT GRAPES MODIFICACIÓN DE LA RELACIÓN FUENTE- FOSA Y SU INFLUENCIA SOBRE EL METABOLISMO PRIMARIO Y SECUNDARIO EN UVAS TANNAT
SALVARREY, Julia1*; FERRER, Milka1; GONZÁLEZ-NEVES, Gustavo2 1 Dpto. Producción Vegetal, Facultad de Agronomía, Universidad de la República, Av. Garzón 780, CP 12900 Montevideo, Uruguay. 2 Dpto. de Tecnología de los Alimentos, Facultad de Agronomía, Universidad de la República, Av. Garzón 780, CP 12900 Montevideo, Uruguay. *Corresponding author: jsalva@fagro.edu.uy
Abstract: In this study, the response of Tannat, an emblematic variety of the Uruguay, to the modification of the source relationship (S/S) was evaluated, through the leaf removal on fruit set and thinning of clusters at veraison, measuring the composition of the grape. The tests took place in a commercial vineyard (34º53'S, 56º19'W) and the results correspond to the years 2012 and 2013. Four treatments were defined: Control without intervention (T) Cluster thinning at veraison (R) and leaf removal on fruit set and cluster thinning at veraison (R+D). The experimental design consisted of complete random blocks, with 5 replicates and the experimental unit of 7 plants per treatment. Weekly sampling of 250 berries was carried out from veraison to harvest to determine: total soluble solids (TSS) and titratable acidity (AT), and at harvest the polyphenolic compounds. The concentration of SST was significantly higher in R and “R+D” for both years (p=0.0008 in 2012 and p=0.001 in 2013). The TA in 2012 did not show differences between treatments, and in 2013 R and “R+D” registered the lowest values (p≤0.001). For both years, potential and extractable anthocyanins (ApH1 and ApH3,2) were higher in “R+D”. The phenolic content presented differences in 2013, being higher in the “R+D” (p=0.003). The results indicate that the modification of the S/S balance increased the synthesis of primary and secondary compounds, when the two culture techniques were applied together.
Keywords: Tannat, leaf removal, cluster thinning.
Abstract: In this study, the response of Tannat, an emblematic variety of the Uruguay, to the modification of the source relationship (S/S) was evaluated, through the leaf removal on fruit set and thinning of clusters at veraison, measuring the composition of the grape. The tests took place in a commercial vineyard (34º53'S, 56º19'W) and the results correspond to the years 2012 and 2013. Four treatments were defined: Control without intervention (T) Cluster thinning at veraison (R) and leaf removal on fruit set and cluster thinning at veraison (R+D). The experimental design consisted of complete random blocks, with 5 replicates and the experimental unit of 7 plants per treatment. Weekly sampling of 250 berries was carried out from veraison to harvest to determine: total soluble solids (TSS) and titratable acidity (AT), and at harvest the polyphenolic compounds. The concentration of SST was significantly higher in R and “R+D” for both years (p=0.0008 in 2012 and p=0.001 in 2013). The TA in 2012 did not show differences between treatments, and in 2013 R and “R+D” registered the lowest values (p≤0.001). For both years, potential and extractable anthocyanins (ApH1 and ApH3,2) were higher in “R+D”. The phenolic content presented differences in 2013, being higher in the “R+D” (p=0.003). The results indicate that the modification of the S/S balance increased the synthesis of primary and secondary compounds, when the two culture techniques were applied together.
Keywords: Tannat, leaf removal, cluster thinning.