Once corn seed is in the ground, experts recommend growers’ attention should turn to emergence and stand evaluation.
“Research has shown that we see a 5 to 9% reduction in yields in a stand that isn’t uniform,” said Matt Essick, Pioneer Agronomy Manager. “A plant that comes up even 72 hours late may only produce a three-quarter size ear.”
There are steps farmers can take to improve their probability of even emergence. Preparing seed beds, targeting a timeframe when soil temperatures are warming and ensuring uniform planter depth are three easy ways to help establish uniform emergence.
“There are three basic requirements for uniform emergence in corn,” Essick said. “A viable seed, as well as uniform soil temperature and moisture are necessary to establish a uniform stand. Last year I saw quite a few fields that were planted too shallow with seeds placed in dry soil. It is also really important to manage residue and keep it out of the seed furrow.”
Variations in soil temperature and moisture can be caused by excess field residue. Additionally, the lack of good seed to soil contact or the presence of surface crusts can be a barrier to uniform seed emergence. Insects, weather and seedbed conditions can also present challenges to stand establishment in corn fields, all of which can limit yield potential.
However, planting into ideal weather and soil conditions may not always be possible. Hybrids differ in their ability to tolerate stress at planting time. Selecting hybrids with higher stress emergence ratings can help reduce stand variability.