Tips on how to reduce early-season emergence stress
Spring is almost here and most growers have started thinking about planting dates. Though planting corn early often results in higher yields, choosing the wrong planting date can have adverse effects on crop establishment.
Planting corn early offers a number of potential benefits. For example, corn is more likely to flower sooner and escape yield-robbing effects of midsummer droughts.
“Many growers tend to begin planting early because they have a lot of ground to cover in a short time,” says Imad Saab, DuPont Pioneer research scientist in crop genetics, research and development. “They want to get ahead of spring rains that can delay planting past the optimal date for maximum yields.”
However, early planting also presents some challenges. The earlier seeds go into the ground, the more likely they will face stresses. Cold, wet conditions can make corn emergence difficult, causing yield loss. Delayed emergence also lengthens the time that seeds and seedlings are most vulnerable to early-season insects and diseases.
For growers, deciding when to plant is all about weighing the pros and cons of timing. Planting date is one of the biggest influences on stand establishment. The likelihood of reduced stand establishment is 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 from DuPont Pioneer experts to help growers weigh their early planting options:
- Choose a planting date based on soil conditions and weather outlook. Plant when soil temperature is close to 50º F and the near-term forecast shows a warming trend.
- If a cold spell is expected around planting time, stop planting for a few days to allow emergence to begin at moderate temperatures. With lighter soils planted early, be aware of the potential for large temperature swings that can affect emergence, especially if nighttime temperatures dip into the 40’s.
- If planting in a field with high amounts of residue, consider strip-tillage and residue cleaners to improve seed to soil contact and warm the soils up faster.
- When selecting hybrids, choosing those with higher stress-emergence scores can help reduce the risks associated with planting in cold-stress conditions.
“Growers believe they’ll gain growing days and yield by grabbing an early planting window,” Saab says. “This is usually true if the crop is planted into a well-prepared seedbed with adequate temperature and moisture. But if you expect a cold, wet spell, it’s best to wait or shut down the planter one or two days ahead of the cold event. This would likely result in more rapid and uniform emergence which typically translates into higher yields.”