GDD base 50 = 2357. 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.pd Most of our grapes are at E-L stage 35-36 which is 35 - Berries begin to colour and enlarge to 35 - Berries with intermediate sugar … [Read more...] about Grape Phenology and GDD accumulation