Recent March weather has been really mild and corn planting has begun in some counties. We are late enough into March that I don’t think we are starting too early, even with the cool front and rain forecasted for early next week. But, if we knew what the weather was going to be like in April we would know how much March corn we should plant. Tennessee corn is typically planted between March 20 and May 10 with the bulk of acres planted in April. Southern counties tend to start and finish planting a few days earlier than more northern counties. Regardless of location, the perception is the earlier the better and as long as we obtain a good stand, early planted corn benefits from lower disease pressure, more limited pest pressure and sometimes higher yields due to better soil moisture during grain fill. But, very early planting does not always guarantee success. “Spreading risk” means to protect crop yields by managing specific things related to production — using Bt technology, planting a combination of different maturities of hybrids and varieties, etc. Spreading our planting dates is another way to spread risk associated with planting corn in Tennessee. April can be a very tricky month with tremendous potential to affect the stand quality of March and early April planted corn by being too wet, too cold or too dry. Look at a few past years as examples:
- 2007: Optimal planting window was second 2 weeks in April. We replanted roughly 200,000 acres of corn planted prior to March 22th after an April freeze took out many fields that were off to a great start. Late March planted fields survived but lower stands may have led to reduced yields.
- 2009: Optimal planting window was the third week in April and into May. Earlier planted fields struggled with cold, wet conditions and many had to be replanted due to poor stands.
- 2010: Optimal planting window was first 2 weeks in April. Last year even slightly later April planted corn yielded 10 to 20% less due to heat effects in the summer.
Bottom line: Every year can be different and since we can’t predict April weather, we can help offset potential stand loss problems by spreading out our planting dates. Planting early is a good goal and in some years we can plant a little more corn in March when conditions permit (this year it looks like they do). It is still a good practice to spread corn planting over a few weeks time to hit optimal windows for favorable soil and weather conditions which seem to vary from year to year.
