What is the effect of the frost is the big question at the coffee shops this week. Actually this should be separated into three questions. Will my plants live? How will it affect yield? Should I replant? The first part is the easiest to answer. Plants will live if the growing point is not damaged. Dig plants up -- you may have to close your eyes at first because they look pretty bad. All of that limp brown, gray or bluish tissue is probably dead, but still may be okay. If the growing point, which on a V5 or less plant is below ground, is white and not soft, the plant is still alive and has a good chance of being normal. It will be susceptible to disease, though, primarily pythium and penicillum.

Will the yield be affected? Maybe. If the plant is between V3 and V5 yield will probably be affected. Between V3 and V5 most corn plants determines the number of rows around. Any stress can reduce the number of rows. Plants that are V1 or less should not be affected very much. As to the replant decision, you may want to visit with your agronomist about this. Most good agronomists have tables that are based on research that give planting expectations for various populations and planting dates. Use these tables to determine gain from replanting. Then consider the cost of replanting -- seed, insecticide, herbicide, fuel, labor, and cost of equipment. You make the call.

Source, Dave Harms, CPCC-I, CCA, CropTalk