The Risk Of Early Planting

Progressive Farmer:

Damage from exposure of above ground plant tissue to frost can range from minor leaf injury to complete death of all exposed leaf tissue. The growing point region of a corn seedling typically remains safe below the soil surface until V4 to V6 stages of development.

"There's a difference between simple frost events and lethal cold temperatures," Neilsen said. Frost can occur at temperatures up to 30 degrees F, but lethal cold temperatures for corn are generally thought to be 28 degrees F. or colder. Air temperatures are different than soil temperatures and how much the cold temperature penetrates the upper inch of soil near the growing point region of corn seedlings can also make a difference.

Neilsen wasn't surprised that farmers are reporting more damage in corn planted in corn stubble versus soybean stubble. He said crop residues (and cover crops) work as blankets upon the soil -- holding the heat and moisture in. That's beneficial under normal circumstances, but in the event of frost or cooler temperatures, bare soils radiate more heat and can actually help protect the tender young crop.

"Take your time to assess damage," he recommended. "These situations are going to vary from field to field and hybrid to hybrid."

Neilsen added that the corn plant doesn't have unlimited potential to regenerate. Repeated frost events can take a toll and cause stunting or death. "I guess the simple answer is the corn plant can take as much as it can take until it dies," he said.

Soliday suggested growers check plants about five to seven days after the freezing injury occurred. If conditions have been good, new leaf tissue should have emerged from the whorl in this time. The growing point is usually located 1/2 to 3/4 inch below the soil surface and can be seen by splitting the seedling lengthwise. The prognosis for recovery is good if the growing point appears white to light yellow and firm several days after frost.

Tom Burrus, Burrus Hybrids, Arenzville, Ill., told DTN that so far, his company had one customer with one field killed by frost. "The grower planted too shallow and the growing point was out of the ground too early," said Burrus in email correspondence. "We furnished him 12 units of replant and that is all we have shipped company-wide to date."

Our corn hasn't broken through yet.  Hopefully things start staying consistently warmer this week.  Yesterday's cold, wet conditions were well less than ideal for the recently planted seed.  Oh well, it is what it is.