Effect of vegetal ground cover crops on wine anthocyanin content

Wine colour is a quality index that can provide information about conservation state, age or the presence of defects. Anthocyanin compounds are colour-related molecules and their concentration is affected by several factors such as grape variety, berry maturity degree or cultural practices. The aim of this work was to determine the anthocyanin composition of Mencía wines and how this is affected by the establishment of different cover crops (native vegetation, ryegrass and subterranean clover) respect to soil tillage treatment. This study was carried out during two consecutive seasons in the same vineyard. The use of cover crops significantly affected wine anthocyanin content; even though, their basic attributes were not altered by the treatments. In 2013, the wines from the ryegrass treatment had a significantly greater total anthocyanins concentration and, in 2014, the wines under the native cover had the highest concentration of these compounds. In both years, wines coming from the treatment under subterranean clover had a lower concentration of total anthocyanins when compared with those from the rest of the treatments. Cover crops increased wine anthocyanin concentrations when compared to the tilled treatment. However, the type of cover crop causing the highest increases differed from year to year.