It is April 1, so we set our GDD base 50 count to 0. We track GDD at http://agebb.missouri.edu/weather/reports/gddTable.asp
and rate the phenology stages according to the Modified E-L System https://door.extension.wisc.edu/files/2010/10/ModifiedEichhornLorennzsystem.pdf
N Norton E-L Stage 1-2 Winter Bud to Bud scales opening.
MVEC Chambourcin E-L Stage 2 Bud scales opening.
W Chardonel E-L Stage 2 Bud scales opening.
R Norton E-L Stage 1 Winter bud.
F Vignoles E-L Stage 2 Bud scales opening.