Spring soil temperatures and field conditions vary from year to year. Keep this in mind and base your planting decisions on the current situation, rather than the date on the calendar. Planting date is a critical management factor to help minimize the risks associated with suboptimal conditions for germination. Successful corn emergence is a combination of three key factors – environment, genetics and seed quality.
- Environment – temperature, residue, compaction and water
- Genetics – stress tolerance and vigor
- Seed quality – harvest moisture, drying and conditioning
It is generally recommended to plant when soil temperatures are at or above 50 degrees and the near-term forecast shows a warming trend. Planting into cold, wet soils inflicts stress on corn seed emergence, as does planting just ahead of a cold spell.
Data suggests that planting just before a stress event such as a cold rain or snow can cause significant stand loss. To help mitigate the risk, consider the following tips:
- Stop planting one or two days in advance, if a cold spell is expected around planting time. Allow seed to begin hydration in warmer soils in order to minimize damage due to cold imbibition.
- Be aware that low nighttime temperatures can dip soil temperatures below advisable planting levels in sandy soils. Large temperature swings in lighter soils can also hurt emergence.
- Consider strip-tillage or use row cleaners to allow soils to warm up faster, if planting in fields with high amounts of residue.
- Select hybrids with higher stress emergence scores. The right seed treatment can also help reduce risks associated with planting in cold-stress conditions.