Grape Phenology and GDD Accumulation

While we do not typically start phenology and or officially start tracking Growing Degree Days in our area until April 1st, we have had unually warm weather and our grapes have starting breaking dormancy. As a result, we started tracking phenology a little earlier this year.

GDD base 50 = N/A  . 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

E-L Stage 1 Dormant Bud

 

E-L Stage 2 Bud Swell

 

E-L Stage 3 Wooly Bud

E-L Stage 4 Bud Burst