By Connor Lynch
GUELPH — Torrential downpours throughout Eastern Ontario that wreaked havoc on planting schedules were no reason for panic.
University of Guelph field crop agronomist David Hooker told Farmers Forum that as long as your corn was in by June 10, planting time is not your biggest issue. After June 10, he advised switching to soybeans or face up to a 20 per cent hit to corn yield, Hooker said.
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 Eastern 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 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 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 July 5. 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 Eastern 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.”
