Corn Replant Considerations
The decision to replant a field is one of the most difficult decisions a producer may face early in the growing season. Experience has shown that each year some of your acres will not achieve desired plant populations due to adverse environmental conditions. Experience also shows that many corn acres are needlessly replanted every year. If you find yourself in a potential replant situation, there are several factors you need to take into consideration prior to replanting.
These factors include your desired versus actual plant population, your original planting date versus your replant date, the uniformity of plant distribution of the remaining plants, and the uniformity in size of the remaining stand. All of these factors need to be integrated to determine if the yield potential of the replanted corn will be sufficiently greater than the yield potential of the existing stand to pay for the cost of replanting. The factors of plant populations and planting date are taken into account in the following charts derived from Minnesota Extension Bulletin AG-FO- 5700-C. The information in these charts can be used to compare the yield potential of your existing stand (less plants, but earlier planted) to the yield potential of a replanted stand (more plants, but later planted). This will determine if the increase in yield would be sufficient to cover the cost of replanting.
The first step in making the replant decision is to estimate the amount of yield loss due to stand reduction on the field under consideration for replanting using chart A. For example, a remaining stand of 75% could be expected to have a yield reduction of 10%.
The above data is only valid if the stand is reduced uniformly. Large gaps in the row may not allow the remaining plants to fully take advantage of the additional light, water, and nutrients. This will result in a reduction in the yield potentials reported in the chart A. In addition, plants emerging more than three weeks late generally do not contribute to final yield and should not be counted when determining the plant population.
The second step is to estimate the amount of yield loss due to a later than optimum planting date using chart B. For example, when a replant date of May 25 is used, the grower could expect a yield reduction of 15%. The third step is to compare the results of steps 1 and 2. In our example, the grower could expect a yield loss of 10% due to stand reduction and 15% due to delayed replanting. In this case the grower would be better off to not replant.
Other factors to consider include: Cost of replanting, Herbicide implications (will the weed barrier be broken), Handling of wetter grain at harvest due to later planting date, and Greater potential for European corn borer damage. You must also consider you may not receive any better stand just because you replanted. Moisture stress or field conditions may result in lower stands.
Individual results may vary, and performance may vary from location to location and from year to year. This result may not be an indicator of results you may obtain as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible. Dyna-Gro® is a registered trademark of Loveland Products, Inc. Featured logos are service/trademarks of their respective owners.
