Information can also be obtained from the Canola Council of Canada Bulletin:  

Media Bulletin

Hold off on reseeding frost-damaged canola

May 27, 2008: Canola growers in several areas of the prairies woke up to frost-damaged crops this morning. The Canola Council of Canada advises growers to wait a minimum of four days to assess the damage before taking drastic action.

Assessing frost damage in canola:

·       Wait a minimum of four days because plant recovery depends on frost severity and subsequent weather conditions.

·       Look at the growing point. If there is any green colour at the centre of the leaf rosettes, the majority of plants should recover and yields will be higher than if the field is worked and reseeded. Even with blackened cotyledons and/or leaves, regrowth can occur in four to 10 days.

·       Check the percentage of plants killed, the percentage recovered, and the weed population for the time of year. If most of the field (80%) has a minimum of 20-40 recovering, healthy plants per m² (2 to 4 per ft²) and a light and/or easily controlled weed population, do not reseed.

·       Remember that a re-seeded crop will be at greater risk for fall frost damage. Canola can compensate for lower plant populations because surviving plants can take advantage of reduced competition for light, moisture and nutrients. Plants will produce more branches, pods and seeds per pod, compensating for the lost plants.

For further information go to the Canola Council website and check out the following Canol@Facts on assessing spring frost damage and managing poor canola stands:

http://www.canola-council.org/canola_resources/product37.aspx

http://www.canola-council.org/canola_resources/product32.aspx