Ask the Agronomist—Replanting Corn

Thanks for tuning into Week Five of our “Ask the Agronomist” Audiocasts. To listen to Mark’s response to this week’s question about replanting corn, play the audio file below.

Q: How late can I replant when I’m replanting my corn?

A: Deciding whether or not to replant is never an easy decision. The cost of replanting is often the deciding factor. Many seed companies, like Latham Hi-Tech Seeds, have shorter maturity hybrids available.

There are several key factors that can determine a field’s overall yield potential. Iowa State University Extension has a publication called the Replant Checklist that will help you estimate the surviving plant stands, as well as estimate the yield based on planting dates and expected yield you could get.

Estimating Yield Potential for a Replant

If you have corn planted between May 25 and June 5, you can expect 65 to 70% of overall yield potential for that field. However, if the corn was planted more towards the middle of June, overall yield expectations go down to about 50% of normal yield.

If a farmer decides to replant, make sure the fields are dry enough. There are still advantages to planting corn in the middle of June in certain areas, but each individual will have to define his/her own yield expectations. If corn is planted at the end of May, yield can be up to 65 to 70% of normal yield. If your field average is around 200 bushels per acre, you can expect to get 130 to 140 bushels per acre.

Replanting Corn or Switching to Soybeans

There are definitely situations where replanting is a no-brainer, such as small areas of a field that were drowned out or damaged by insects. When an entire field of corn is lost, it might be best in this stage of the planting season to replace the corn with soybeans. However, take into consideration what herbicides have been applied to the field so that your soybeans don’t die.

There is certainly still time to receive good yields with soybeans. Most of the time in late May, we can achieve soybean yields of 85 to 90% of typical yields. June 20 to 25 is a target date for switching soybean maturities, depending on location. Soybeans can be planted into the beginning of July and still achieve decent yields.

If you have a question about what you’re seeing in the fields, feel free to ask! Send your questions via Twitter to @LathamSeeds, in a private message on Facebook or call our office at 1-877-GO-LATHAM (1.877.465.2842).

As always, you can access timely agronomic tips and information for your geographic location on New articles are posted each week day on our blog.  You can even search for “topics” by simply typing key words into the search bar on the upper right-hand corner.

Thanks for tuning in to this week’s Ask the Agronomist. We’ll be back again next week to field all of your questions during the 2016 growing season.