Assessing Corn Plant Health
May 14, 2003 10(9):70
Joe Lauer, Corn Agronomist
Assessing plant health after a destructive event such as flooding, hail, frost or
insect feeding is important for replant decisions. This past week many acres were
temporarily flooded and in some parts of northern Wisconsin frost occurred Monday
morning. Often these events damage the exposed leaves, but will have little or no
effect on the belowground growing point or final seed yield.
To assess plant health after a destructive event and for making a replanting decision:
- Wait 3 to 4 days
- Observe growing point. If color is white to light yellow then plant is alive. If
you suspect the plant is not healthy or questionable, count as ½ of a plant for
population purposes.
- Consult replanting chart. (in Wisconsin Crop Manager 10(7):56-57)
Flooding at any time when the growing point is below the water level can kill the
corn plant in a few days, especially if temperatures are high. Growing point tissues
are depleted of oxygen. Frost should not be a problem with corn until the growing
point moves aboveground around V5 to V6.