Rarely are growers in the northern Corn Belt able to plant corn during optimal conditions. Proper soil temperature is more often a pipe dream than reality. Instead, planting dates are often determined by workload and field conditions. And that can result in cold stress and poor plant emergence.
According to experts at Pioneer Hi-Bred International, the optimal temperature for corn emergence is somewhere between 80 degrees F and 90 degrees F. Corn emerges more slowly in lower temperatures, and is effectively halted around 50 degrees F to 55 degrees F.
The degree of stress, and potential damage from it, is largely determined by soil and water temperature during imbibition and seedling emergence, explains Dan Wiersma, Pioneer Hi-Bred International field sales agronomist. “For successful emergence to occur, all parts of the shoot must work together to push the coleoptile above the soil surface and allow the first leaf to unfurl. Damage to any of the plant structures will likely result in loss of stand and likely yield.”
That means that you need to manage risk from cold stress and minimize seed exposure to adverse environments.
Therefore, when you decide to plant has the biggest impact on stand establishment. The risk of damage to emergence is greatest if the crop is planted into very cold soil or if planting is followed by severe cold weather.
So, for example, if a cold spell is predicted after you’ve decided to plant, plant fields with better drainage and the least amount of residue first. This helps promote soil warming and should help plant emergence, says Wiersma.
“Walking Your Fields”, Pioneer Hi-Bred International