Unexpected relationships between vine vigor and grape composition in warm climate conditions

Abstract

Aim: The purpose of the research was to link vigor with vine growth response, yield and especially grape composition, in a climate change scenario. Methods and results: This work presents a 4-year study (from 2010 to 2013) in a rain-fed Tempranillo vineyard located in La Rioja (Spain). It is based on the acquisition of multispectral imagery at véraison; and a subsequent zoning in two different levels of vigor based on NDVI. Differences between the two vigor zones were found in terms of vegetative expression, yield and grape composition. Unexpectedly, in most of the years of study, anthocyanins were found to be higher in the highest vigor zone, which is particularly discussed in this work. Conclusion: Climatic conditions may affect considerably bunch microclimate and disturb the synthesis paths of major grape components, leading to maturation mismatches. In hotter years, high vigor vines may favour anthocyanin accumulation though a shading and protecting effect in the bunch area. Significance and impact of study: the most part of studies link negatively vigor and grape anthocyanins, but in this study the opposite trend has been observed in the hot years.