Frost blanketed a large swath of Saskatchewan in the early morning of June 21, just as spring turned into summer on the calendar.
It took a few days for the province’s crop extension specialists to assess, but they have since determined that canola and lentil fields from Preeceville in the northeast to the southwest’s Val Marie suffered frost damage.
“It looks pretty widespread, especially across the east-central, west-central regions,” said Matt Struthers, a crop extension specialist in Moose Jaw.
Several producers said the large, cold finger between -2 to -4 C that reached across the province was not a killing frost, but it was still one for their record books. “Absolutely unprecedented. I’ve never dealt with frost this late in the year before, or on plants anywhere near this big,” said David Kucher, who farms north of Kindersley, Sask.
“They’re (canola) about four or five inches around now. The only other time I’ve ever had frost in the past, the plants are just coming out of the ground,” he said.
Kucher estimated the cold affected five to 10 percent of his canola, mostly in low-lying areas and side hills where the air was calm and settling.
“It turned the leaves a chlorotic yellow, kind of a bright yellow. It looks bad, but when you get down into the plants they look like it’s just individual leaves, and I don’t think it caused any damage to the growing points,” he said.
“Even some of the damaged plants, two-thirds, maybe three-quarters of the leaves look like they’re not going to survive, but there’s other leaves on the plant that are still green and in good shape.”
West-central crop extension specialist John Ippolito said lentils also suffered minor damage and was particularly worse in fields where there was heavy crop residue from previous crops, which acts as an insulation and does not allow heat in the ground to rise.
“It’s the reverse of what we think the blanket would do,” he said.
“We’re seeing patches in fields related to that crop residue and even to some degree differences from one field to another, depending on what type of seeding equipment was used and how much of that residue got pushed out of the way,” he said.
“It pushes residue out of the way, so then they have less injury as opposed to something like a disk drill that just cuts through the residue and doesn’t move anything around or expose any soil.”
Ippolito is not too concerned, but time will tell.
Frost damage morning of the longest day of the year,what else can be thrown at us this year?random pockets throughout.Can we hit restart on this season? pic.twitter.com/IjamIqdtBM
— Greg Oldhaver (@GregOldhaver) June 23, 2021
“It’s not like it was a killing frost on those plants. It just caused some setback and the plants are recovering, and we’ll carry on. None of us have a good handle on whether there will be any (yield) impact at all or what that impact might be.”
Struthers is also confident most canola will bounce back because of maturity and because the frost generally didn’t linger.
“Crops (canola) will probably be able to hold off frost for the most part with the stage of development they’re at right now. They are really young cotyledon, or two- to three-leaf canola and would take quite a hit if it got really cold for a few hours,” he said.
While it’s difficult to give an average for the entire province, he said canola is generally behind other crops because of a lack of moisture in the early spring.
“I’ve seen some three-leaf fields, and I’ve already seen fields that are bolting, so it all depends on where you are. When a crop is stressed, as some of them are, they’ll mature quite quickly and they’ll try to get to their reproductive stage as quick as they can,” he said.
“Hopefully with some moderate heat and some good rains in the forecast, they’ll bounce right back,” he said.
He advised farmers to keep a close eye on their frost-damaged crops, which were in a vegetative state and vigorously growing over the past few weeks and not prepared for the cold.
“When they go to assess that damage, look for the growing points. If the growing point is discoloured or mushy, then that crop’s probably done for, but if it’s still green and it looks like it’s relatively healthy, they should be all right. But take a few days, don’t immediately assess the damage. Let the symptoms set in and then take a look,” he said.
Added Ippolito: “Normally after a stress, we’d like to see them leave three, four days to recover from the frost stress before we apply herbicides.”