Will Replanted Corn Make it to Maturity?
Aug 10, 2010
Question: What is the likelihood of these corn fields I replanted making it to maturity prior to a killing frost?
Answer: It depends on a number of things, including the hybrid maturity, date of planting and average date of your first frost. Several years ago, Purdue University collaborated on field research that investigated the effects of delayed planting on the Growing Degree Day (GDD) needs of different hybrid maturities. That research indicates delayed planting actually decreases hybrid GDD requirements from planting to maturity. According to the Purdue study, after May 1, the number of GDDs from planting to kernel black layer (physiological maturity) decreased by about 6.8 GDDs per day. In other words, a hybrid that normally requires 2700 GDDs from planting to maturity would require slightly less than 2500 GDDs if planted on May 31 rather than May 1 (30 days of planting X 6.8 GDD-2700). Purdue University corn specialist Bob Nielsen reports that hybrids commonly grown throughout his state will mature safely when planted throughout most of the month of May. However, things get sketchy when planting is delayed further as the ever-shortening growing season finally exceeds the fuller season hybrids' abilities to adjust their developmental GDD needs. I hope this gives you a guideline on what to anticipate this fall. Let us know how you make out.
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