Grape phenology and GDD accumulation

May 21, 2018 by Marilyn Odneal

GDD base 50 accumulation for May 21 = 487 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

Some cultivars have begun flowering.

N Norton E-L Stage 16 10 leaves separated.

G Norton E-L Stage 16 10 leaves separated.

G Cabernet Sauvignon E-L Stage 15 8 leaves separated, shoot elongating rapidly; single flowers in compact groups.

MVEC Delaware 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. — MVEC Delaware 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.

MVEC Sunbelt E-L Stage 21 30% caps off.

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

W Catawba E-L Stage 15 8 leaves separated, shoot elongating rapidly; single flowers in compact groups.

NWV Chardonel E-L Stage 15 8 leaves separated, shoot elongating rapidly; single flowers in compact groups.

R Seyval Blanc 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. — R Seyval Blanc 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.

R Vidal Blanc E-L Stage 16 10 leaves separated.

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

Vignoles E-L Stage 15 - 17 8 leaves separated, shoot elongating rapidly; single flowers in compact groups to 12 leaves separated; inflorescence well developed, single flowers separated. — Vignoles E-L Stage 15 – 17 8 leaves separated, shoot elongating rapidly; single flowers in compact groups to 12 leaves separated; inflorescence well developed, single flowers separated.

F Chardonel E-L Stage 15 8 leaves separated, shoot elongating rapidly; single flowers in compact groups.

F Traminette E-L Stage 17 12 leaves separated; inflorescence well developed, single flowers separated.

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

D Concord E-L Stage 18 - 19 14 leaves separated; flower caps still in place but cap colour fading from green to About 16 leaves separated; beginning of flowering (first flower caps loosening. — D Concord E-L Stage 18 – 19 14 leaves separated; flower caps still in place but cap colour fading from green to About 16 leaves separated; beginning of flowering (first flower caps loosening.

D Vivant E-L Stage 16 - 17 10 leaves separated to 12 leaves separated; inflorescence well developed, single flowers separated. — D Vivant E-L Stage 16 – 17 10 leaves separated to 12 leaves separated; inflorescence well developed, single flowers separated.

D Mars E-L Stage 15 8 leaves separated, shoot elongating rapidly; single flowers in compact groups.