Volume 10 Issue 2
February 12, 2021
For several years, the WA Blueberry Commission has funded WSU research to collect bud hardiness data and create a model. Our research team is still in the process of developing the model but we do collect, freeze, and cut buds to assess mortality of individ-ual flower initials. Below is the data for lethal temperatures. Important considerations when looking at the numbers are:
Date assessed and stage: If your buds have progressed in development since our date of assessment, the buds will be less cold hardy.
Location: Preceding and local temperatures are influential in the level of cold hardiness. Warmer sites will likely be less cold hardy with possibly more advanced buds.LT10oF: This is the Lethal Temperature in which 10% of the floral initials will die. This can vary by cultivar, site, temperatures, and stage.
|8-Feb-21||Prosser||Aurora||dormant and early bud swell||-2|
|8-Feb-21||Prosser||Draper||dormant and early bud swell||-0.4|
|8-Feb-21||Prosser||Duke||dormant and early bud swell||-4|
|8-Feb-21||Paterson||Aurora||dormant and early bud swell||-2|
|8-Feb-21||Paterson||Draper||dormant and early bud swell||-4|
|4-Feb-21||North Prosser||Aurora||dormant and early bud swell||-9|
|4-Feb-21||North Prosser||Draper||dormant and early bud swell||-2|
|Please note that in all prior years of studying cold hardiness, we have seen buds at bud swell reacclimate to cold weather within 24 hours. The 3 cultivars here are all highbush blueberries. Other cultivars with more southern highbush in the germplasm (e.g. Legacy) will have lower hardiness.|
For more information:
AgWeatherNet (http://weather.wsu.edu/) has grape and cherry cold hardiness models. Log on and go to crop models.
Eastern WA, Gwen Hoheisel (firstname.lastname@example.org) Western WA, Lisa DeVetter, Lisa Wasko (email@example.com)
Michigan Cold Hardiness Bud Chart (https://www.canr.msu.edu/blueberries/growing_blueberries/growth-stages)