Field Notes: Corn replant decisions
Some crop fields have been flooded due to recent rainfall. As fields begin to dry and floodwaters recede, growers will need to evaluate their options. Corn and soybeans can survive two to four days of floodwater or soil saturation. Once the oxygen supply is depleted, the plants will die. Give plants three to five days to recover before evaluating them for regrowth.
Corn plants that survived may appear yellow which generally indicates a lack of nitrogen. But, if oxygen is lacking, the plants may not be able to take up nitrogen, even if it is present in the soil. Warm, wet soil conditions are prime for nitrogen loss. Monitor corn plant color for signs that nitrogen may be deficient. Side dress applications of nitrogen to corn up to three feet tall are just as effective as pre-plant nitrogen applications.
Several factors influence the decision about planting late or replanting crops. Delayed planting dates mean reduced yields as the number of days for grain fill diminishes. If herbicides were applied to corn this spring, the crops which can be grown after the application may be limited. Read and follow all label instructions.
Deciding whether to replant a sparse stand depends on several factors. Begin by estimating the revenue expected from the existing stand. Earlier planted crops have a greater yield potential than later-planted crops. Consider the cost of replanting, including seed, fuel, labor and pesticides. Then estimate the yield potential of the higher plant population at the later planting date. MU Extension Guide G4091 “Corn and Soybean Replant Decisions” provides information about yield potential over a range of plant populations and planting dates.
For more information contact Valerie Tate, field specialist in agronomy for MU Extension at
email@example.com or call 660-895-5123. University of Missouri Extension programs are open to all.
Valerie Tate is a field specialist in agronomy for MU Extension.