Grape Phenology and GDD accumulation

May 30, 2023 by Jennifer Morganthaler

GDD base 50 =594. 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

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

Demo Concord E-L Stage 27 27 Setting; young berries enlarging (>2 mm
diam.), bunch at right angles to stem

Demo Mars E-L Stage 25 80% caps off

Foundation Vignoles E-L Stage 21 30% caps off

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

Foundation Traminette E-L Stage 13 6 leaves separated

Foundation NC-6 E-L Stage 17 12 leaves separated; inflorescence well
developed, single flowers separated

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

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

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

New Winery Norton E-L Stage 17 12 leaves separated; inflorescence well
developed, single flowers separated

New Winery Chambourcin E-L Stage 25-27 80% caps off to Cap-fall complete to Setting; young berries enlarging (>2 mm
diam.), bunch at right angles to stem

MVEC Sunbelt E-L Stage 27 Setting; young berries enlarging (>2 mm
diam.), bunch at right angles to stem

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

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

Genomics NC-6 E-L Stage 15 8 leaves separated; shoot elongating rapidly;
single flowers in compact groups

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

Foundation Norton E-L Stage 17-18 12 leaves separated; inflorescence well
developed, single flowers separated
to 14 leaves separated; flower caps still in place,
but cap colour fading from green

Winery Chardonel E-L Stage 19-20 About 16 leaves separated; beginning of
flowering (first flower caps loosening)
to 10% caps off

Winery Catawba E-L Stage 17 12 leaves separated; inflorescence well
developed, single flowers separated

Research Seyval Blanc E-L Stage 14 7 leaves separated

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

Research Catawba E-L Stage 12-14 5 leaves separated; shoots about 10 cm long;
inflorescence clear
to 6 leaves separated
to 7 leaves separated

North Norton E-L Stage 19 About 16 leaves separated; beginning of
flowering (first flower caps loosening)