Spring is here and most of you are likely thinking about planting dates. Deciding when to plant is all about weighing the pros and cons of timing.

Though planting corn early often results in higher yields, choosing the wrong planting date can have adverse effects on crop establishment.

The earlier the seeds go into the ground, the more likely they will face stresses. Cold, wet conditions can make corn emergence difficult, causing yield loss.

In fields with non-uniform stands, the smaller, late-emerging plants are unable to capture enough sunlight and unlikely to reach optimal potential by harvest. Delayed emergence also lengthens the time that seeds and seedlings are most vulnerable to early-season insects and diseases.

The likelihood of reduced stand establishment is also greatest when planting into unfit seedbeds, when soils are excessively cold and wet, or when planting is quickly followed by a cold spell. Here are some tips to help you weigh your early planting options:

* Choose a planting date based on soil conditions and weather outlook. Plant when soil temperature is close to 50 degrees and the near-term forecast shows a warming trend;

* Delay planting for a few days, if a cold spell is expected, to allow emergence to begin at moderate temperatures;

* Be aware of the potential for large temperature swings to affect emergence in lighter soils planted early, especially if nighttime temperatures dip into the 40s;

* Consider strip-tillage and residue cleaners to improve seed to soil contact and warm the soils up faster in fields with high amounts of residue; and

* Select hybrids with higher stress-emergence scores to help reduce the risks associated with planting in cold-stress conditions.

Planting depth also affects yield in corn production. DuPont Pioneer has conducted planting depth trials for several years to determine just how much yield is impacted by different planting depths.

In the trials, emergence often was quicker with shallower planting depths, but root growth was more vigorous and tassel emergence was a day or two earlier when corn was planted at adequate depths versus shallow depths. Planting corn to a depth of 1.75 to 2 inches is optimum for nodal root development:

* 2 inches — best under normal conditions;

* 1.75 inches — may be favorable when planting early into cool soils; and

* Never plant shallower than 1.5 inches.

Corn planted too shallow results in:

* Decreased ability to absorb water and nutrients through the roots;

* Potential to develop a condition called “rootless corn syndrome” — this causes plants to fall over due to the lack of nodal root development in dry soil; and

* Possible exposure of corn seedlings to herbicide residue, increasing the potential for herbicide injury.