Effect of the plot variability on the qualitative and quantitative characteristics of the berry's skins and seeds of grape cultivar Agiorgitiko (Vitis vinifera L.)

Abstract

Soil properties, climatic conditions and cultivation techniques constitute significant variables, which affect the quality of the final product. In particular, soil data (soil texture, soil electrical conductivity etc.) and weather data (average temperature, humidity etc.) affect both crop quality data (sugar content, anthocyanins content, phenolic compounds concentrations etc.) and crop quantity data (crop yield, berry weight and size etc.). The aim of this study was to investigate the variations of the microclimatic areas that exist within the same vineyard and their effect on the qualitative and quantitative characteristics of the berry skins and seeds of the grapes. These microclimatic areas could be identified and classified as those which could produce grapes for PDO wines and those which could be used for the production of other types of wines. The overall results of this study indicated important differences between the grapes of different sub-zones from the perspective of their chemical analyses, namely with notable differences identified between the grapes in the anthocyanin concentration and mainly in the concentration of malvidin, acetyl and coumaric esters of malvidin. A significant variability was observed in the characters of the must and in berry mechanical properties. More specifically, higher weight of berries was observed in the lower part of the vineyard, based on its slope. In the north-eastern part of the vineyard, a higher concentration of polyphenolic compounds was recorded. The concentration of total anthocyanins was found to be positively correlated with the soil slope, while significant variability in the concentration of total anthocyanins was revealed.