Record yields in 2022 after a late start are raising some questions about the assumption that earlier is always better for planting corn in Manitoba and other northern growing areas.
Historical averages in Manitoba show a downward trend in yield with each week that passes in May, but the 2022 crop set a new bar with provincial average yield over 140 bu/ac despite getting planted in late May and into early June.
“It makes us wonder if we can experiment with planting dates a little bit more and not rush to put the corn in on May 1st through May 5th,” says Morgan Cott, agronomy extension specialist with the Manitoba Crop Alliance, in this Corn School episode. “It’s certainly something that growers are wondering, whether they should be planting on May 5th, or if they can wait till May the 20th.”
While a late first-frost in fall was part of the equation that resulted in record yields in 2022, she also credits how quickly the crop emerged after the later planting, as seedlings were out of the ground within days rather than weeks.
Even when planted early, corn generally takes until after the May long weekend to emerge in southern Manitoba, notes Cott. “I feel like if you plant on May 5, or if you plant on May 12, it’s probably going to be coming out of the ground around May long, so we have that ability to wait,” she says.
Whether 2022 was an anomaly or a sign of a trend, Cott recommends spreading out yield risk — and potential — with different maturities and planting dates.
Check out the video below for more discussion with Morgan Cott on reassessing planting dates for corn on the Prairies: