Uniform emergence plays an important role in achieving top corn yields, according to Ron Heiniger, Extension cropping system specialist at North Carolina State University.
“I think it’s surprising how much impact emergence has on yield,” Heiniger said at the Northeast Ag Expo Field Day at Bear Garden Farms in Shiloh, N.C. July 30. ““I find it shocking. I find it shocking that we have situations where we only get 75 percent emergence on the first day. It’s clear that we need to have a plan, and that plan is based on when you think you are going into the field and what your conditions are going to be.”
Heiniger is conducting uniform emergence trials this year at Bear Garden Farms and other locations across North Carolina on the impact on yields of corn plants that emerge 24 to 48 hours later than the majority of the plants. In essence, farmers can’t achieve top yields if they have some plants that emerge one to two days late, Heiniger said.
Heiniger is looking at how time of planting, planting depth, seed treatment and hybrid selection impact uniform emergence in corn. Heiniger said farmers need a plan on how to control uniform emergence in their corn.
For farmers who want to plant early, selecting a variety that tolerates cooler temperatures is critical, according to Heiniger. Use of a seed treatment is also important in improving emergence ratings in early planted corn.
“Hybrid selection did make a difference on how this early season corn emerged,” Heiniger stressed. “If you’re going to plant in cool, wet conditions, hybrid selection is one of your best tools. Find a hybrid with good seedling vigor and emergence ratings.”
Heiniger said waiting a bit later to plant, when the weather is warmer, is another way to reduce late emergence in corn. “Environment does make a big difference on how many of these plants emerge late,” he said.
“You’re better off if you can to wait to an ideal planting situation. But you know as well as I know that that’s very difficult to do. How do you know that tomorrow is going to be a better opportunity than it was to plant today? You can’t always wait for another day hoping for the weather to get better,” he added.
In his research, Heiniger is looking at the impact of planting depths of 1.5 inches and 2.5 inches on yield. In general, planting depth did not play as big a role in uniform emergence, Heiniger said.
“It all comes down to how much attention you are going to put into it. It’s about paying attention to your corn every single day and paying attention to every single thing that goes into it,” he said.
Through it all, farmers need to plan for high yields. “You don’t just stumble upon high yields accidentally.” Heiniger emphasized.
For farmers who irrigate, a tall hybrid that can capture as much light as possible is a good way to go. For dryland corn producers, shorter hybrids that don’t require as much water are better, he added.
It all boils down to getting the corn crop off to a good start. Using a good starter fertilizer program and paying attention to the crop every day is critical during the first two weeks of growth, Heiniger said. A combination of nutrients is needed for top yields. For example, potassium is important, Heiniger said.
“You need to keep that that crop green from top to bottom all the way to physiological maturity or harvest. It doesn’t happen with one shot of nitrogen and then you go home. It happens when you pay attention to each day and try to move that corn along each day,” Heiniger said.