Summerland Research and Development Centre
Grape Hardiness Special Update for January 2023 - BC
Attached, from Ben-Min Chang, are the results of the manual grape bud dissections on the extra canes collected during our standard grape variety bud hardiness sampling on Jan 4th and 5th. Results are presented as survival rate (%).
Also included is an infographic flyer indicating how damaged grape buds can lead to odd results from the DTA (differential thermal analysis) method used for standard bud hardiness estimation. It appears that damaged buds with some surviving remnant tissues still produce exotherm events but the exotherm peaks have a smaller amplitude and are shifted to a higher temperature compared to healthy buds.
“The current cold hardiness value might not represent the real cold hardiness of primary bud due to the low primary bud survival rate in certain locations. The lower bud survival rate might cause inaccurate estimation on the primary bud cold hardiness. The real critical temperature of a survived bud might be lower than what is currently showed in the report. Please use the bud dissection result for cold hardiness estimation only. The other attachment explains how damaged bud might interfere cold hardiness estimation.” – Ben-Min Chang