Replanting is something we hope we don’t have to do a lot of, but if we do, there are some good resources to use to help make those decisions.
Stand assessment and replant decisions are often (OK, almost always) agonizing. It is hard to leave a stand that is below a growers normal expectations; many of us just don’t like looking at it all year long and are prone to want to “start over.” The flip side of the coin is that if a stand is close to being a “keeper” but we are leaning towards starting over, we have to remember that there is no guarantee that the replanted stand will get in the ground and emerged and do any better. With that said, with some help from our own Dr. Mark Licht, replant decisions can be boiled down to a step by step process:
1) Stand Assessment: What is the big picture, how much of the field is impacted, how bad is it in general, is there a chance things will improve or degrade in the next few days?
2) Stand Counts: Do a solid determination of what sort of viable stand is out there and compare to replant charts.
3) Yield Potential: Determine the yield potential of the remaining stand based on its population and planting date, and use available charts to compare with the yield potential of a replant crop with expected plant populations.
4) Other Factors: Final decisions on whether to replant should also include the costs incurred from a replanted or existing stand. Some factors to consider include costs of replanting (seed, labor, fuel, other) and crop insurance. Also, take a look at any herbicide restrictions or pest management implications related to the current stand or a replant scenario.
5) The Decision: After gathering information about the compromised stand and potential replant implications, make your replant decision based on the best economic outcome of the two choices. Will the costs and yield potential of the existing stand have greater revenue than replanting?
I think this is one of the most important steps that you won’t find in the books; there are never exact or perfect answers, so I also like to have growers use their personal experiences and “gut feeling” to help make the final decisions. They are the ones with the investment on the line, so their experience and instincts are as valuable as any other step in the process.
More information on each step can be found here:
For soybeans- http://crops.extension.iastate.edu/cropnews/2014/05/early-season-soybean-replant-decisions