Going on 72 hours after severe frost damage (photo courtesy Anastasia Kubinec, MAFRI.)

Much of the later canola crop has been hit by frost this week.

"Damage to the canola crop really depends on what stage your canola is at, and what the seed moisture content is. If it's over 50 percent seed moisture content and very green, you probably will have some yield losses, and you definitely will have some quality losses," says Anastasia Kubinec. "If it's 20 to 30 percent moisture, you may have some smaller seed size and green seed content issues."

The first sign of frost damage is light speckling on the pods.

"The green tissue on the pod is going to dry down. It's been freeze-dried. So it's going to start getting drier and those speckle marks will become really obvious. Three or so days afterwards the pods will get pretty white and dry," she says. "That's when you should definitely swath because you want to make sure your pods aren't popping open."

She recommends waiting a few days before swathing frozen canola.

"I honestly wouldn't take the swather out until probably around three days after the frost," says Kubinec. "If you cut your canola too green and right after a frost, it is going to lock in the green chlorophyll content. To get that out, you're going to need a lot of rain or a lot of heavy dews. Based on the weather we're going to get in the next week, I don't see it, and I'd be worried that all that stuff would be sitting in swath with high green content until mid-October when the green content comes out."

"If you wait, you give the plant a little more time and wet-dry cycle, and those enzymes that take out the green chlorophyll content have been able to work," she says.

Kubinec says cutting canola right before frost likely had no benefit.

"If it was cut at least 48 hours before, it's probably okay, but I know there were some guys that went out and cut green canola the night before. You probably didn't save yourself anything by doing that. Cutting that canola too green locks in the green canola too."