Grape Phenology and GDD accumulation

May 22, 2023 by Jennifer Morganthaler

GDD base 50 = 477. 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

North Norton E-L Stage 16-17 8 leaves separated, shoot elongating rapidly;
single flowers in compact groups
to 10 leaves separated

Demo Mars E-L Stage 18 14 leaves separated; flower caps still in place,
but cap colour fading from green

Demo Concord E-L Stage 20 10% Caps off

Foundation Vivant E-L Stage 17 12 leaves separated; inflorescence well
developed, single flowers separated

Foundation NC-6 E-L Stage 16 10 leaves separated

Foundation Norton E-L Stage 15-16 8 leaves separated, shoot elongating rapidly; single flowers in compact groups to
10 leaves separated

Foundation Vignoles E-L Stage 16 10 leaves separated

Foundation Chambourcin E-L Stage13 6 leaves separated

Foundation Chardonel E-L Stage 16 10 leaves separated

Foundation Vidal Blanc E-L Stage 14-15 7 leaves separated to 8 leaves separated, shoot elongating rapidly; single flowers in compact groups

Foundation Traminette E-L Stage 13 6 leaves separated

Foundation Cayuga White E-L Stage 15 8 leaves separated, shoot elongating rapidly; single flowers in compact groups

Winery Norton E-L Stage 16 10 leaves separated

Winery Chambourcin E-L Stage 20 10% Caps off

Winery Chardonel E-L Stage 16 10 leaves separated

Winery Catawba E-L Stage 16 10 leaves separated

Winery Catawba E-L Stage 16 10 leaves separated

Genomics NC-6 E-L Stage 14 7 leaves separated

Genomics Norton E-L Stage 16-17 10 leaves separated to 12 leaves separated; inflorescence well
developed, single flowers separated

MVEC Sunbelt E-L Stage 23 17-20 leaves separated; 50% caps off

MVEC Chambourcin E-L Stage 15-16 8 leaves separated, shoot elongating rapidly; single flowers in compact groups to
10 leaves separated