Lincoln, Nebraska, USA
May 2, 2013
Source: CropWatch
The extraordinary drought of 2012 is now being followed up by an unusual spring of 2013. Certainly, the drought continues — while recent rains have helped, many areas throughout Nebraska have severely depleted subsoil moisture levels. In addition, recent temperature swings have the potential to wreak havoc on recently planted crops.
While there is some debate over what temperatures cause imbibitional chilling – when seeds absorb water so cold it affects emergence -- and the time factor associated with the response, there is undoubtedly a response from corn plants that imbibe cold water in the first 24-48 hours after planting. With the recent cold weather and some growers planting fields to “beat” the rain, some corn fields may experience symptoms from imbibitional chilling.
It is generally recommended that soil temperatures be 50-55°F at planting to avoid this damge. Some reports have even suggested that corn will not be injured if the soil temperature is above 41° F, but there is certainly some risk that the early planted corn may be injured. The soil temperature measured here at North Platte at 8:30 am. May 1 was 42° F.
Like rubber and other elastic materials, the cells of the corn kernel will expand as the water is imbibed. When the water is cold, the cells will become brittle and are more likely to rupture. If the plant cells do rupture, the new seedling will fail to develop properly. When this happens, we are likely to see delayed emergence, inconsistent plant spacing, and/or “corkscrewing” cotyledons, including leafing out underground.
With modern hybrids, there is likely less risk of this happening because the seed and seedlings are more vigorous, but if you have early planted corn in the ground this year, it will be important to scout it early. Poor stands may need to be replanted.
More Information
For additional information see results from DuPont Pioneer's 2012 research on Stress Emergence in Corn.
Greg Kruger
UNL Extension Cropping Systems Specialist, West Central REC
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