Early planted corn is starting to emerge in Ontario and usually when digging around, a nice straight plant can be seen coming out of the ground. This year, though, a few plants are a little wonky.
Down in Lambton County, Ont., agronomist Ryan Benjamins is seeing quite a bit of corkscrewing in corn this year, and to get to the root of the issue, he joins Bernard Tobin for this Corn School episode.
“We’re seeing it in the earlier May-planted and even in this field that was mid-May planted when temperatures were close to 30 degree air temperature at the time of planting,” says Benjamins. Temperature fluctuations — hot and cold swings right after planting — between germination and emergence seems to be the key factor in this problem.
As opposed to imbibitional chilling, where the damage is to the seed itself — causing almost a rotten seed — in corkscrewing situation, it’s the damage to the mesocotyl that’s the concern. The mesocotyl is the portion of the shoot, just above the seed that is the “coleoptile pusher” says Benjamins, and in corkscrewing, the mesocotyl starts curling and twisting underground.
In terms of yield, when corkscrewed plants represent less than 10 per cent of the field, there’s no real yield loss, says Benjamins. The risk of giving up yield potential by planting later is greater than the lost potential of some corkscrewed plants.
The odd plant with this condition might emerge, but it depends on the seed depth. “There’ll be the odd one that emerges, but if it does it’s going to be so delayed it’s not likely to produce anything at all, if anything it’ll just be competition for the healthy plants beside it,” adds Benjamins.
Check out the full conversation below: