Grape Phenology and GDD accumulation

August 1, 2022 by Jennifer Morganthaler

GDD base 50 = 2292. 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

Norton N E-L Stage 33 Berries still hard and green

Mars Demo E-L Stage 36 Berries with intermediate sugar values

Concord Demo E-L Stage 33-34 Berries still hard and green to Berries begin to soften;
Sugar starts increasing

Vivant F E-L Stage 34-35 Berries begin to soften; Sugar starts increasing to Berries begin to colour and enlarge

Norton F E-L Stage 33-35 Berries still hard and green to Berries begin to soften; Sugar starts increasing to Berries begin to colour and enlarge

Vignoles F E-L Stage 35 Berries begin to colour and enlarge

Chambourcin F E-L Stage 35-36 Berries begin to colour and enlarge to Berries with intermediate sugar values

Chardonel F E-L Stage 34-35 Berries begin to soften; Sugar starts increasing to Berries begin to colour and enlarge

Vidal Blanc F E-L Stage 33-34 Berries still hard and green to Berries begin to soften; Sugar starts increasing

Traminette F E-L Stage 34-35 Berries begin to soften; Sugar starts increasing to Berries begin to colour and enlarge

Cayuga White F E-L Stage 35-36 Berries begin to colour and enlarge to Berries with intermediate sugar values

Norton R E-L Stage 33 Berries still hard and green

Catawba R E-L Stage 33 Berries still hard and green

Seyval Blanc R E-L Stage 36-37 Berries with intermediate sugar values to Berries not quite ripe

Chardonel W E-L Stage 34-35 Berries begin to soften; Sugar starts increasing to Berries begin to colour and enlarge

Catawba W E-L Stage 33 Berries still hard and green

NC-6 G E-L Stage 33 Berries still hard and green

Norton G E-L Stage 33 Berries still hard and green

MVEC Sunbelt E-L Stage 33-35 Berries still hard and green to Berries begin to soften;
Sugar starts increasing to Berries begin to colour and enlarge

MVEC Chambourcin E-L Stage 35-36 Berries begin to colour and enlarge to Berries with intermediate sugar values