Grapevine Phenology Mid-June
Grape cultivar developmental stages: June 21, 2019
By: Andi Nelson, Jacob Scharfetter, Annie Deutsch, and Amaya Atucha
At the West Madison Agricultural Research Station (WMARS) in Madison, WI, shoot development across most cultivars’ buds are at E-L* stage 19 (“About 16 leaves separated; beginning of flowering”) through E-L stage 23 (“17-20 leaves separated; 50% caps off”). Currently, vines are behind in development compared to 2017 and 2018 seasons due to the cooler spring. At the Peninsular Agricultural Research Station (PARS), all cultivars are at E-L stages 12 (“5 leaves separated; shoots about 10 cm long; inflorescence clear”) through 17 (“12 leaves separated; inflorescence well developed, single flowers separated”).
The following photos were taken on June 19, at West Madison Agricultural Research Station.
Brianna
“10% caps off”
E-L stage 20
Crimson Pearl
“50% caps off”
E-L stage 23
Frontenac
“50% caps off”
E-L stage 23
Itasca
“30% caps off”
E-L stage 21
La Crescent
“30% caps off”
E-L stage 21
Marquette
“10% caps off”
E-L stage 20
Petite Pearl
“30% caps off”
E-L stage 21
The following photos were taken on June 18, at Peninsular Agricultural Research Station.
Brianna
“inflorescence well developed”
E-L stage 17
Frontenac “inflorescence well developed”
E-L stage 17
La Crescent “inflorescence well developed”
E-L stage 17
La Crosse
“inflorescence well developed”
E-L stage 17
Marquette “inflorescence well developed”
E-L stage 17
St. Croix
“inflorescence well developed”
E-L stage 17
Growing degree-day accumulation April 1 to June 21
| 2019 | 2018 | 2017 | |
| Location: WMARS | 573 | 875 | 736 |
| Location: PARS | 256 | 480 | 411 |
Growing degree-day accumulation from April 1 to June 21 for the past three seasons. Currently, the 2019 season is running behind in GDD accumulation compared to 2017 and 2018 seasons. Degree-days were calculated using a base 50°F, starting on April 1 as a biofix. We calculated degree days using the NEWA website, and you can visit their “About degree days” page to learn more about the degree days and the formulas used for their respective calculations (http://newa.cornell.edu/index.php?page=about-degree-days).
*E-L stands for Eichhorn-Lorenz Phenological stages to describe grapevine development
This article was posted in Grapes and tagged grapes developmental stages.