Characterization of vineyard sites for quality wine production. German experiences
The quality of grapevines measured by yield and must density in the northern part of Europe conditons can be characterized as a type of "cool climate" - vary strongly from year to year and from one production site to another. One hundred year observations in Johannisberg from 1890 to 1991 demonstrate for the yield formation a clear dependancy from the year combined with a steady increase in productivity; latter a proof of positive clonal selection efforts.