Every spring corn growers set their sights on a bummer crop. Good seedling emergence sets the stage for a good corn crop. Several things influence seed germination and seedling emergence.
Uniform soil moisture is critical for uniform seed germination. Greg Luce, with University of Missouri Extension Plant Science Division, recommends planting corn at a depth of two inches. The soil surface can dry out quickly. By planting corn at least two inches deep, soil moisture will remain more consistent. This depth also encourages the formation of a strong nodal root system. Corn planted at a depth of less than one and one-half inches may not develop a strong root system resulting in lodging of young plants or even rootless corn syndrome. These roots not only help support the plant, but they also take up the majority of the water and nutrients needed for plant growth.
Corn should not be planted until soil temperatures are above 50 degrees. Cool soil temperatures delay germination and increase the risk of seedling diseases. In order for a seed to germinate, it must absorb water. When soil temperatures are below 50 degrees, the seed will absorb water but will not begin growing. This condition may lead to seed decay and poor emergence resulting in an uneven stand.
Little difference in yield potential is seen between planting dates in April. But, as May rolls around, yield potential begins to decrease. By early June, on average, corn yield potential decrease about 25 percent over April planting dates.
And finally, good seed to soil contact is also critical for good seed germination. Factors that may interfere with good seed to soil contact include rocks, clods or residue.
For more information, contact Valerie Tate, MU Extension Agronomist in Linn County by email at firstname.lastname@example.org or phone 660-895-5123. University of Missouri Extension programs are open to all.