GDD base 50 accumulated since April 1 = 40 at Mountain Grove 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 R Catawba E-L Stage 1-2 … [Read more...] about Grapevine phenology and GDD accumulation