[UPDATED: May 31, 2021] Severe frost, particularly in the northwest and Interlake hammered emerging crops and forage stands between May 26 and 27, but experts are warning not to pull the plug too soon.
“Frost events by nature are extremely patchy,” said Dane Froese, oilseed specialist with the province.
“One part of the field may be badly affected the other area of the same field may not be, so each field needs to be scouted separately and come up with separate plant stand counts,” he added.
Altona was the lone escapee, provincial data shows, as temperatures plunged as low as –9 C across the province overnight on May 26. The freezing temperatures lasted anywhere from one to 11 hours.
Most of south central and southeastern Manitoba fared the best, seeing temperatures between –1 and –3 C.
Northwest and southwestern agro-Manitoba saw temperatures drop a bit lower, while the Interlake appears to have fared the worst. Narcisse and Poplarfield saw temperatures below –8 C for 11 hours.
“I do expect that there will be some serious damage to sensitive crops that emerged, particularly canola crops in the northern Interlake and the northwest region,” Froese said.
Froese spoke to the Co-operator in the morning on the 27th. It was too early to tell the full extent of the frost damage, he said.
However, because of see-sawing warm and cold temperatures in recent days, canola and other sensitive crops didn’t get much chance to harden off and may have been more vulnerable, Froese said.
St. Francois Xavier farmer Gunter Jochum posted a photo to Twitter of damaged and browning canola seedlings 24 hours after the frost.
“These plants hadn’t been stressed at all, germinated and good growth in warm weather,” he wrote. “They were not hardened at all.”
Jochum said he’d wait until Monday to make a decision but he would not be surprised if he’d be forced to reseed.
To the west, KAP president Bill Campbell said they’d seen –1 C near Minto. He’d seen damage only on the edges of his crops.
“My first field of canola is just coming out of the ground. Our cereals are all out now,” said Campbell. “I feel pretty confident they will handle this. They may be impacted a bit, but I think they can handle it.”
The frost will likely set back forage crops across the province said John McGregor, extension specialist with the Manitoba Forage and Grassland Association.
“We know there will be some damage in most areas,” McGregor said. He said he was most concerned about the northern reaches of agro-Manitoba.
McGregor said some areas may see mild leaf damage, whereas others may see top damage which will require plants to re-establish a growing point, or even damage down to the soil, requiring the plant to start over from the crown.
This could set back growth two to four weeks, he said.
However, McGregor cautioned that plants may look worse than they are, particularly since temperatures dropped below freezing again in some parts of Manitoba overnight on May 27.
Plant tops may appear wilted, but straighten as the day goes on, he said. Plant tops may turn black or brown, but in a week producers will likely see regrowth.
Soybeans may also regrow after frost damage said Dennis Lange, the provincial pulse specialist. Lange spoke during Manitoba Agriculture’s ‘Croptalk’ webinar on the morning of May 26.
He advised waiting four to five days and waiting for a regrowth. He also suggested doing a stand count.
With canola, Froese advised watching for regrowth after three to five days also, and then doing a plant count. He told ‘Croptalk’ viewers to dig plants out to see if the stems were pinched or if the seedlings were ‘floppy.’
*”Cereal crops and corn are less likely to be affected, Froese said, as their growing points are still below the ground. However, oats may be more vulnerable as their growing points are above the soil surface noted Shawna Mathieson, executive director of Prairie Oat Growers Association.
“Any type of reseed decision or spray decision should be held off for a couple days now to see exactly what the full extent of the damage may be and making crop decisions then with a clear head,” Froese said.
-With files from Allan Dawson
*Update: A statement regarding the growing points of oats was updated with a note from Shawna Matheson.