Cold Weather Impact on Grapevines

Extreme cold temperatures were experienced across the state on December 23-24th 2022 (Figure 1). Temperatures ranged from -10- -5° F across most of the state with temperatures dipping below -10°F in some areas. Since then, there have been some additional cold events, such as 7° F on January 31-February 1 and 12° F on March 19^th. It is possible that these cold temperatures injured grapevine buds.

To assess the degree of cold injury, canes were collected from 11 varieties at the Meigs Purdue Agriculture Center located in Lafayette, IN. The percentage of primary bud injury was determined using the methodology outlined in the videos noted below. See the results in Table 1. Frontenac and La Crescent varieties, developed out of the University of Minnesota, had the least amount of primary bud injury (< 6%). Brianna and Prairie Star varieties, developed by Elmer Swenson, had < 10% primary bud injury. Frontenac gris, Frontenac blanc, Petite Pearl and Aromella had a moderate amount of primary bud injury (14-29%). Seyval, Steuben and Vidal had a significant amount of primary bud injury (< 45%). Buds with primary bud injury may still produce shoots from the secondary or tertiary bud, however these shoots are likely to be less fruitful.

Conducting bud assessments prior to pruning is recommended. See the below videos on how to conduct bud injury testing. See Table 2 below for the suggested pruning strategy to use based on the percentage of bud mortality in your vineyard. If you are experiencing > 20% bud damage, you will want to leave a higher number of buds during pruning.

Evaluating Bud Injury Prior to Pruning:

Part I: https://www.youtube.com/watch?v=_RHJ5mY3fAs

Part II: https://www.youtube.com/watch?v=eWtr0jzI2Dk&t=31s