It is April 1, so we set our GDD base 50 count to 0. 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 Most grapes are at the E-L stage 1-2 winter bud to bud scales opening … [Read more...] about Grape Phenology and GDD accumulation