GDD base 50 accumulated since April 1 = 3155
http://agebb.missouri.edu/weather/reports/gddTable.asp

Phenology stages according to the Modified E-L system
http://door.uwex.edu/files/2010/10/ModifiedEichhornLorennzsystem.pdf

N Norton E-L Stage 37

MVEC Delaware E-L Stage 40

MVEC Valvin Muscat E-L Stage 40

MVEC Sunbelt E-L Stage 40

MVEC Chambourcin E-L Stage 38

W Catawba E-L Stage 37

R Cayuga White E-L Stage 40

Vidal Blanc E-L Stage 40

R Seyval Blanc E-L Stage 40

R Catawba E-L Stage 38

F Chardonel E-L Stage 40

F Traminette E-L Stage 40

D Concord E-L Stage 40