The 7-9” of rain that fell the last week of April and first week of May definitely has caused most farmers and seed professionals a few headaches and some heartburn as a good portion of the county’s corn acres went in the ground between April 19th and April 26th. Needless to say, where we were once tracking 7 inches below our 10 year average precipitation to date, we have now made up for that deficit. In scouting many corn field the last several days, I am surprised to find most of the corn seed is still viable after being in the ground for so long. The excessive rain that blanketed the area was fortunately followed by cooler weather resulting in single digit Growing Degree Units which prevented the seed from rotting in the ground. As I’m writing this, temperatures are 82 degrees and the ground is drying out rapidly resulting in heavy crusting. In most cases, a good shower, which is in the forecast for the next 24-36 hours, should allow a good portion of the seedlings to penetrate the crust and emerge. Of course is we miss the rain, many seedlings will leaf out underground and require replanting the field.
In visiting with growers the last several days, several have inquired about corn fields where the stands are less than ideal (18K-24K plants/acre) and whether or not they should consider replanting these fields or leaving them alone. These are the fields that can certainly be a head scratcher. When scouting fields, consistency is the key. If you have a consistent 22K-24K final plant population/acre, in most cases it pays to leave the field alone and walk away. There is a lot of information on the web in regards to determining whether or not to keep a stand or tear it up. One article I like is by Bob Nielsen, Purdue University, entitled “Delayed Planting & Hybrid Maturity Decisions”. Within the article Nielsen has a worksheet to help you assess your final corn stand based upon planting date and population and a quick check list to determine whether replanting the field makes financial sense. I have included a link below to access the article. Best of luck in assessing your stands this spring. I hope this worksheet helps take the guess work out of it.
Bob Nielsen & Peter Thomison, “Delayed Planting & Hybrid Maturity Decisions”.