Corn replant decisions loom as extreme weather bakes Ontario soils


It’s been a crazy May for corn growers in Ontario.

The weather has gone from cold rain and snow on May 10 to extreme heat two weeks later. That’s turned many super fit soils, which enticed growers to plant early, into rock hard seedbeds that have early-planted corn struggling to emerge.

“The extreme shifts have created some huge challenges for growers, especially those on heavy clay soils in the southwest part of the province” says Grain Farmers of Ontario senior agronomist Marty Vermey. Two to three inches of rain spread over a couple of days in mid-May has taken the air from the soil, making it extremely hard. “Clay soils and finer-textured soils have firmed right up,” Vermey told to an audience at Exeter-Mt. Forest agribusiness breakfast conference call on Tuesday.

Many growers have turned to rotary hoes, no-till planters and RTS machines to loosen the soil, but the issue goes beyond just soil crusting at the surface. PRIDE Seeds agronomist Matt Chapple, based at Chatham, says he’s looked at 2,000 acres of tough, uneven corn this week. Those farms need a rain to get corn plants pushing out of the soil or the seeds will suffocate and growers will need to consider replanting.

Parrish & Heimbecker CCA Ryan McLean is seeing the same challenges on the clays in Middlesex and Lambton counties.

Overall, the corn crop is highly variable across the province. On Wednesday, agronomists joining the Cobourg-Winchester agribusiness breakfast conference call also reported significant variation in corn performance.

James D’Aoust, Pioneer territory manager based at Cavan, Ont., noted that the condition of the corn crop across the mideastern portion of the province ranged from excellent to fields with up to a 10,000-plant-per-acre reduction. MacEwen Agricentre agronomist Clare Kinlin noted that growers will not see ideal stands on early-planted corn and some timely rain is needed to help plants navigate and survive the challenging soil conditions.

Corn replant decisions generated a range of insights during the breakfast meeting. Much of the discussion focused on whether a final stand of 21,000 plants per acre was sufficient or whether a replant would be required.

Agronomist Bill Norman said: “If you are in doubt about replanting, don’t do it. You’re already giving up heat units and there is no guarantee that the replant is going to come up better”.  Independent agronomist Pat Lynch echoed that sentiment. “If you have 20,000 good plants, leave it alone” he added.

Kinburn-based CCA Paul Sullivan recommended growers take a close look at the hybrid they planted to see if it has the ability to flex and add yield in lower populations. “A lot of these hybrids will put on a lot more yield with a great big cob,” he noted.

RealAgriculture agronomist Peter Johnson advises growers to consult the replant decision tool. He doesn’t disagree with Norman or Lynch, but when growers do the math, factoring in free replant seed and $120 per acre from crop insurance,  replanting at 21,000 does makes sense, he noted.



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