Grape phenology and GDD accumulation

June 1, 2015 by Marilyn Odneal

GDD base 50 accumulated since April 1 = 647
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 23 17-20 leaves separated; 50% cap fall (=flowering).

MVEC Delaware E-L Stage 26 Cap fall complete.

MVEC Valvin Muscat E-L Stage 21-23 30% caps off to 17 to 20 leaves separated; 50% caps off (= flowering)

MVEC Sunbelt E-L Stage 29-31 Berries pepper-corn to pea size.

MVEC Chambourcin E-L Stage 19-23 About 16 leaves separated; beginning of flowering to 17-20 leaves separated; 50% caps off (=flowering).

W Catawba E-L Stage 26 Cap-fall complete.

R Vidal Blanc E-L Stage 21 30% caps off.

R Seyval Blanc E-L Stage 26 17-20 leaves separated, 50% flower caps off (= flowering).

R Catawba E-L Stage 29 Berries pepper-corn size; bunches tending downward.

F Vignoles E-L Stage 23 17-20 leaves separated; 50% cap fall (=flowering).

Chardonel E-L Stage 25-26 80% caps off to cap-fall complete.

F Traminette E-L Stage 23 17-20 leaves separated; 50% cap fall (=flowering).

F Cayuga White E-L Stage 27 Setting; young berries enlarging, bunch at right angles to stem.

D Concord E-L Stage 31 Berries pea-size.

D Vivant E-L Stage 26-27 Cap-fall complete to berries pepper-corn size.

D Mars E-L Stage 26 Cap-fall complete.