Corn producers worry about early frost but forecast calls for more heat

By Tom Collins
A late start to the planting season has pushed back the maturity for corn and soybeans, leaving farmers concerned about an early fall frost.

Agronomist Deb Campbell of Agronomy Advantage at Dundalk said farmers worry about frost every year, but this year’s growing season has amplified their worries. She said that as of Aug. 30, corn fields were 10 to 14 days behind normal. She explained that most crops would need to get to early October for the crops to reach full maturity.

Most years, there’s not a killing frost until the second week of October but there have been years when an early frost came in mid-September. The last mid-September frost that impacted crops occurred in September, 2014.
Campbell said if corn was at the early milk stage, a killing frost could be as severe as a 35 per cent yield loss.

“It’s not uncommon to have that (killing frost) once every five to eight years, depending on the geography,” she said. This year’s poor planting and growing seasons seemed to have taken place across most of Ontario, so the risk is more spread out, she said.

Even corn planted next to each other in the same field could be 10 days apart in their maturity, she said. “That’s not normal, that’s extreme for corn,” she said.

Campbell said there isn’t as much concern about soybeans as it can adapt to different weather seasons a lot easier than corn.

The Grain Farmers of Ontario said that most corn fields had pollinated by the week of Aug. 9, and on average it takes 60 days from pollination to physiological maturity, also known as black layer.

The good news from Accuweather is its forecast: Summer warmth and humidity will linger across most of Ontario throughout the fall and might delay the annual first frost by a week or two. The bad news is that weather forecasters can be wrong.