Managing Frost Damaged CanolaCanola seedlings can withstand a considerable frost (-5 to -8 degrees C) if plants have become acclimatized following a few days of cold temperatures. However, canola seedlings growing under warm conditions will be tneder, and can be killed by even a few degrees frost. Ice crystals will form on the leaf surface before they form within cells causing damage.
For further information on assessing frost damaged canola, refer to Canola Council Factsheet: Tips for Assessing Spring Frost Damage to Canola.
Figure 1 - Frost damage to winter canola
Figure 2 - Note new growth 3 days following several degrees frost
Frost can be more damaging to canola in flower. Pollination may not be affected, but freezing temperatures of -3 to -4 degrees C for several hours can damage developing seeds and begins as early as 8 days prior to pollination. These freezing temperatures can also reduce seed fill. Fortunately most areas experienced temperatures above this, but it will take several days to assess damage to newly formed pods. Check pods for damaged seeds that will have lost their green colour and turgidity. There is little experience with freezing temperatures at flowering to provide clear guidelines.
For more information:
Toll Free: 1-877-424-1300