Cold Hardiness Warning
Cold hardiness tests performed this week on apple and cherry samples in Benton County suggest a risk of damage to cherry buds due to pending cold temperatures. While orchard management practices affect cold hardiness, there is currently a risk that temperatures will pass the threshold where damage to buds is likely to occur.
The following tables show critical injury temperatures for apple and cherry buds. LT 10 is the temperature at which 10% of the primary buds will be killed; LT 50 and LT 90 refer to 50% and 90% bud damage, respectively.
| Apple Samples | |||||
|---|---|---|---|---|---|
| Location | Date Sampled | Cultivar | LT 10 | LT 50 | LT 90 |
| Prosser (Roza) | March 18, 2013 | Fuji | 20.4 °F | 15.5 °F | 10.3 °F |
| Gala | 19.2 °F | 15.0 °F | 10.6 °F | ||
| Red | 18.3 °F | 14.5 °F | 10.3 °F | ||
| Cherry Samples | |||||
|---|---|---|---|---|---|
| Location | Date Sampled | Cultivar | LT 10 | LT 50 | LT 90 |
| Prosser (Roza) | March 18, 2013 | Bing | 23.8 °F | 16.7 °F | 8.7 °F |
| Chelan | 27.0 °F | 19.1 °F | 10.9 °F | ||
| Sweetheart | 26.6 °F | 18.8 °F | 10.2 °F | ||
- From dormancy to fruit set, the flower bud undergoes a number of developmental stages that are associated with a progressive increasing vulnerability to low temperatures.
- Freeze tolerance was analyzed using differential thermal analysis, this technique is only effective for cherries at early stages of bud development.