First frost and grapevine phenology and GDD accumulation

October 8, 2012 by Marilyn Odneal

The first frost occurred yesterday, October 7 when it dropped to 30.4 degrees F at 7:05am.

GDD base 50 accumulated since April 1 = +3919 (+472 departure from normal) at Mountain Grove http://agebb.missouri.edu/weather/reports/gddTable.asp

March 2012 GDD base 50: 306+3919 = 4225

Phenology stages according to the Modified E-L system http://door.uwex.edu/files/2010/10/ModifiedEichhornLorennzsystem.pdf

N Traminette E-L Stage 41

N Concord E-L Stage 41

N Sunbelt E-L Stage 41

N Norton E-L Stage 41

MVEC Chambourcin E-L Stage 40

W Catawba E-L Stage 40

R Vignoles E-L Stage 41

R Cayuga White E-L Stage 41

R Vidal Blanc E-L Stage 40

R Seyval Blanc E-L Stage 40

R Catawba E-L Stage 40

F Chardonel E-L Stage 40