GDD base 50 = 198 at http://agebb.missouri.edu/weather/reports/gddTable.asp Phenology stages described according to the Modified E-L System http://door.uwex.edu/files/2010/10/ModifiedEichhornLorennzsystem.pdf We had hail on Monday afternoon, May 4, which was about dime size or less, slushy and came down during high winds in torrents horizontally mostly from the West. … [Read more...] about Grape phenology and GDD accumulation – hail damage