Fall notes help adjust 2020 management plans

Oct. 10, 2019

A walk through corn fields before harvest or a sharp eye on the crop at harvest could prove revealing this year. Farmers will see how hard corn plants worked to produce viable progeny, even in a year when Mother Nature stacked the deck against them. Farmers can also observe signals from the plants themselves which could help with adjusting population, planter settings, tillage practices, drainage and more for 2020 and beyond.

Producing “corn babies”

“Corn plants have one goal in life,” said Dave Nanda, director of genetics for Seed Genetics Direct, sponsor of Corn Watch ’19 . “These plants don’t care how much yield you harvest. Their mission is to produce as many viable ‘babies’ as possible. Hybrid corn plants don’t know you won’t be replanting what they produce as seed. Instead, a field of corn will do whatever it takes to produce as many viable progeny as possible- even in a challenging year like this one.”

Most of the time, when fields produce the maximum amount of progeny, farmers also realize maximum yield. However, plants occasionally take steps to preserve viable progeny that may result in fewer kernels.

“If you have dry weather during pollination or early grain fill, as happened in some areas this summer, plants will abort kernels and concentrate on preserving the kernels with the best chance to make it,” Nanda explained. “Kernels at the tips pollinate last, so they’re usually the first ones aborted if a dry spell signals to a plant that it may not be able to finish all the kernels which it started.”

Planter adjustments

Sometimes what is in the field reflects success with seeding rate selection and planter adjustment.

“If you see doubles, which are two plants very close together, it likely means the planter dropped two seeds at once,” Nanda observed. “Those two ears may not be as big as where plants were spaced evenly. However, if there’s a gap, plants on both sides of the gap may produce larger ears than where plants are spaced properly. Corn can’t compensate to the degree soybeans can, but it does what it can.”

When plants don’t see neighbors, they tend to produce larger ears in an attempt to maximize the number of kernels. The color of reflected light can signal a plant whether there are close neighbors or none nearby.

Too many doubles or skips within the field may indicate a need to pay closer attention to planter adjustment. If the population is so high that ears are smaller than expected or there are more barren plants than preferred, it could indicate a hybrid that has been pushed to the limit or beyond, at least under the environment present in 2019.

Two ears

Earlier in the summer, Nanda noticed many plants in fields were rebounding well after a late start. Several of these were sending out a second ear shoot during pollination at another node beside the main ear. Two ears per plant can be somewhat genetic, but it is also affected by weather conditions.

When he visited some of those fields again, after a dry stretch, many of those second shoots were still there. However, many didn’t even a cob, or if they produced a cob with very few kernels. Yet under vary favorable conditions, some plants produce second ears which contribute more potential progeny and yield.

Nanda also observed ears sending out silks and a tiny shoot from the same node as the main ear.

“It’s not a desirable trait because it just pulls energy away from the main ear,” Nanda explained. “However, it illustrates how hard plants try to produce as many progeny as possible. The natural tendency of a corn plant is to make every effort possible to produce babies. The take-away message is to keep potential reactions by plants mind when making management plans related to planting and fertilizing corn each season. “