COMPARATIVE EVALUATION OF WINE AND TABLE GRAPEVINE VARIETIES BY THEIR YIELD AND ECOLOGICAL STABILITY IN VITICULTURAL REGIONS OF BULGARIA

Abstract

A comparative evaluation of wine and table vine varieties grown in the viticultural regions in Bulgaria in terms of grape yield and their ecological stability, was carried out during the period 2017–2021. It has been established with statistical reliability that the wine vineyards in the South-Eastern and North-Eastern regions have the highest yields, while the North-Central region is characterized by the relatively lowest yields, and the yields from table varieties are the highest in the South-Eastern region. The climatic and soil parameters in the viticultural regions of North Bulgaria – North-Western, North-Central and North-Eastern – determine ecologically stable, but low yields from the wine and table vine varieties grown there. The varieties in the South-Eastern and South-Central regions are characterized by high yields, but they are highly unstable in terms of the conditions of the external environment. According to the degree of proximity and re-moteness of grape yields, wine and table vine varieties are divided into three clusters. The first cluster includes the North-Central, South-Western, North-Western and North-Eastern regions, characterized by lower average yields from the table vine varieties; the second one consists only of the South-Central region, where the yields from the wine and table varieties are significantly higher; and the third cluster includes the South-Eastern region, which stands out with statistically proven 20% higher yields from wine varieties for the whole country, and approximately 55% higher yields from table varieties.