By Roger Elmore and Lori Abendroth
30 May 2008 -
Storms last Sunday, 25 May, and then again on the 29th and 30th have unloaded extraordinary amounts of rain in many parts of Iowa. Soils are likely saturated; low lying areas of fields (tiled or not tiled) are covered with ponds; areas along streams and rivers are flooded.
Many wonder how long corn seedlings survive trapped in standing water. Corn that is just germinating can perhaps withstand 4 days of saturated and/or flooded soils. Seedlings with less than 6 leaves, can withstand 4 days under water if air temperatures are less than the high 70’s. If air temperatures are greater than that, seedlings may only survive for one day. Corn has fewer than 6 leaves at this time throughout Iowa. We have more information on this matter on our website here.
As fields drain and soils dry, many producers will need to assess their options for replanting. Feasible replant dates are closing fast. If a producer could replant in the next few days, corn may have perhaps 90% yield potential. In 10 days or so yield potential will be around 70% or less. Currently the best information we have on replanting is at: http://www.extension.iastate.edu/Publications/PM1885.pdf
Consider carefully your options with poor corn stands. If replanting is chosen as the best option, then a shorter-season, adapted corn hybrid is needed.