By Connor Lynch
GUELPH — Soggy, wet weather in Western Ontario wasn’t good news for corn or soybean planting, but wasn’t cause for panic either.
University of Guelph field crop agronomist David Hooker told Farmers Forum that as long as your corn was in by June 10, or by June 15 if you’re planting in Lambton, Kent, or Essex, planting time is not your biggest issue. After those dates, he advised switching to soybeans or face up to a 20 per cent hit to corn yield, Hooker said, or reduce planting populations by 10 per cent and nitrogen rates by 20 per cent.
If your corn was in by the end of May, yield won’t be affected, he said. If you planted the first week of June, you could lose up to 10 per cent on yield, he added.
Unfortunately, other factors weren’t terribly promising for the Western Ontario corn planting. Corn does better when conditions are dry early in the season; it develops deep roots in its search for water. Later in the season, when corn needs plenty of water, deep roots will absorb needed moisture and protect the plant from moisture damage if there’s too much. Short roots are more vulnerable.
Another important factor that comes out of late planting is moisture. Late-planted corn will be costlier to dry at harvest. Its higher moisture content also makes it more vulnerable to an early frost.
In particular, silking time, when the corn plant is being fertilized, is critical for rain. Corn has a two-week window around silking time, which usually ends up being the last week of July and the first week of August, where it really needs rain, Hooker said.
Soybeans are a hardier crop when it comes to planting time. If there’s a deadline to get them into the ground, Hooker said, it’d be the end of June. After that, save your yields by increasing seeding rates by 20 to 30 per cent. Soybeans are also less sensitive when they’re silking because their silking time is longer, so each day isn’t as critical. Dry conditions in Western Ontario tend not to last long enough to really hurt soybeans, Hooker said.
Ultimately, planting time isn’t the be-all and end-all of crop yields and it shouldn’t be top of mind, said Hooker. “The actual yield depends on so many other factors, really, we shouldn’t be worried that much about planting time.”
