Giesco
EFFECT OF EARLY DEFOLIATION AND CALCIUM PROHEXADIONE APPLICATION ON THE INCIDENCE OF CLUSTER ROT AND GRAPE COMPOSITION EFECTO DEL DESHOJADO PRECOZ Y LA APLICACIÓN DE PRO-HEXADIONE CÁLCICO SOBRE LA INCIDENCIA DE PODREDUMBRES DE RACIMOS Y LA COMPOSICIÓN DE LA BAYA
ARRILLAGA, Leandro*; ECHEVERRÍA, Gerardo; FERRER, Milka; REY, Juan José; PALLANTE, Alejandra; IZQUIERDO, Bruno Facultad de Agronomía, Universidad de la República, Departamento de Producción Vegetal *Corresponding author: leaarrillaga@gmail.com
Abstract: Bunch rot is one of the main causes of grape quality losses, especially in rainy summers. In a Tannat vineyard, cultivation techniques were evaluated for two years in order to reduce cluster compactness and decrease rot incidence: early leaf removal (DPF) up to node 6 and calcium prohexadione (PHCa) at a single dose of 1500 ml*ha-1, at stages 17 and 23 of the Modified Eichhorn & Lorentz System (E-L System). Both treatments were compared to a commercial control (TC). All treatments received the same chemical management. The results of the study were conditioned by a marked yearly effect with; the 2017 season having highly favorable conditions for disease development. DPF treatment modified canopy microclimate, resulted in less compact clusters and reduced rot incidence, with a 30% yield reduction when compared to the control. PHCa treatment caused a reduction in berry size, without affecting yield, while disease incidence did not have a significant difference when compared to the control. Both treatments modified berry composition, in particular, increasing phenolic richness. DPF treatment resulted on a higher proportion of exposed clusters, whereas the PHCa modified berry components and flavonoid synthesis. Both techniques are promising to improve cluster sanitary status and must composition.
Keywords: Early leaf removal; calcicum pro-hexadione; bunch rot; grape composition
Abstract: Bunch rot is one of the main causes of grape quality losses, especially in rainy summers. In a Tannat vineyard, cultivation techniques were evaluated for two years in order to reduce cluster compactness and decrease rot incidence: early leaf removal (DPF) up to node 6 and calcium prohexadione (PHCa) at a single dose of 1500 ml*ha-1, at stages 17 and 23 of the Modified Eichhorn & Lorentz System (E-L System). Both treatments were compared to a commercial control (TC). All treatments received the same chemical management. The results of the study were conditioned by a marked yearly effect with; the 2017 season having highly favorable conditions for disease development. DPF treatment modified canopy microclimate, resulted in less compact clusters and reduced rot incidence, with a 30% yield reduction when compared to the control. PHCa treatment caused a reduction in berry size, without affecting yield, while disease incidence did not have a significant difference when compared to the control. Both treatments modified berry composition, in particular, increasing phenolic richness. DPF treatment resulted on a higher proportion of exposed clusters, whereas the PHCa modified berry components and flavonoid synthesis. Both techniques are promising to improve cluster sanitary status and must composition.
Keywords: Early leaf removal; calcicum pro-hexadione; bunch rot; grape composition