Richard Taylor, Extension Agronomist; rtaylor@udel.edu
The warm late-March air temperatures and reports of soil temperatures in many locations well above the minimum 50º F required for corn to begin the germination process have encourage a number of growers, especially those with many acres to plant, to get an early jump on corn planting season. Recently the weather pattern has brought in cold air over our region and some areas are experiencing frost, albeit light frost. If even colder air arrives, early emerging corn may be frost injured. Until the corn’s growing point extends above the soil surface, corn often grows out of frost or freeze injury, although some minor yield reductions may occur. In the past we have seen such severe leaf injury on no-till corn which was at the third to fourth leaf stage that the growing point was unable to recover. This resulted in very thin, weak stands. It was thought that so much leaf tissue was killed that the decay process caused free-radical formation which overwhelmed the ability of the growing point to survive.
I point this possibility out so growers will be aware that there is a greater risk that more of the early planted corn fields will need to be replanted. I understand that the seed supply, especially for the better hybrids, will be very limited this year due to unfavorable weather conditions in Argentina where a lot of our seed corn is grown. Although growers who need to replant may be able to find replacement corn seed, it is likely that the best genetics will not be available. This fact should be kept in the back of the grower’s mind when planting early.