June 10, 2011

Often producers are confronted with whether to replant or plant another crop after hail, flood, or other events that damage the crop and/or reduce crop stand. Fields damaged from floods may require some tillage or other operations to fill in the washouts before replanting. Where soil erosion is minor, sweep tillage may be used while still maintaining much of the crop residue.

In many situations enough soil will need to be moved that all crop residue will be destroyed, leaving the soil more susceptible to wind and water erosion. In some areas crop residue may be so heavy that it will be impossible to plant through. The problem is greater where stalks were cut. These heavy residue areas will require the crop residue to be removed or in some situations to be incorporated into the soil before planting.

Producers must also consider such factors as weed management, diseases, insects, and how the crop will be affected. If the crop is herbicide tolerant, this helps in being able to manage weeds with reduced crop competition as a result of reduced plant populations, skips, delayed crop canopy, etc. Insect problems can increase, especially in non Bt hybrids by delayed plant growth. Also, disease problems usually increase in damaged plants.

If the damage to the corn crop was enough to consider replanting or planting to another crop, be aware of potential problems. If the damaged crop was Roundup Ready® corn, make sure that the previous crop is destroyed or volunteer corn could become a major problem. If the corn crop was conventional and Roundup Ready corn or Roundup Ready soybeans are planted, it will be easier to control the conventional corn. It is important to consider previously applied herbicides before switching crops as many corn herbicides have residues which will injure soybeans or other crops.

If Roundup Ready soybeans are planted after Roundup Ready corn and the corn prior to damage was taller than 18 inches, treatments with ACCase inhibitors such as Fusion or Select may not adequately control the regrowth.

Both soybeans and grain sorghum can be planted later than corn without compromising maximum yield potential as significantly. Most growers will be able to use Lumax for weed control in grain sorghum. (Check label).

Corn which is exposed to flooded (anaerobic) conditions for an extended time will appear yellow. Corn can outgrow these conditions if anaerobic conditions do not persist.What is the yield potential for late planted corn? In 1992, Paul Nordquist conducted research at North Platte (see Table 1) which may be helpful in addressing this.

Bob Klein
Western Nebraska Crops Specialist
Greg Kruger
Extension Cropping Systems Specialist
Both at the West Central REC, North Platte