To Go or Not Go With Conventional Hybrids?

November 20, 2023 8:00 AM
Blog Post

Many are considering which corn hybrids to select for the 2024 crop. This also means I start getting questions about whether or not to plant transgenic or conventional hybrids. It is a really important decision to make because selecting the right hybrid, the right genetics is, in my mind, the single most important crop management decision to make.

There are several factors to consider, most notably the weather, which makes it difficult as this decision is typically made months in advance of the growing season. Other criteria are yield potential, grain drydown, lodging, insect and disease resistance, and maturity. Transgenics can help manage some of these criteria plus others. The decision should not be taken lightly and needs to factor in other management decisions. Will in-furrow insecticides be used? Do you plan to use foliar insecticides? Do you have herbicide weed resistance? Are earworms problematic? Have corn rootworms developed resistance?

So many things to think about your head starts to spin. That means transgenic hybrids must be the correct answer to make managing the crop in season easier, right? Maybe! Transgenic traits can protect the crop but will NOT increase yield potential. Make sure to consider hybrids for the transgenic traits you will use. While in the past insect and herbicide transgenic traits have been invaluable to management problematic weeds, European corn borer, corn rootworm and earworms, their usefulness is in question where resistance development has occurred. Transgenic traits can still be a powerful management tool if used judiciously across the crop rotation.

The big benefits of transgenic hybrids are they reduce reliance on harmful pesticides, increasing safety for the applicator but also reducing risk of off-target movement to neighboring properties and into the ground or surface waters. Additionally, over time they have reduced year-to-year variability.

Even with the benefits, the disadvantages cannot be ignored. The biggest challenge from the over reliance on transgenic hybrids has been the development of resistance. Corn rootworm management has become more problematic. Glyphosate is much less of an all-around herbicide than it once was.

And then there is the added expense transgenic traits bring. It is not uncommon for conventional hybrids to be $50 to $100 less expensive than transgenic hybrids. Pay attention to the cost of the transgenic hybrids and factor in the performance difference between transgenic and conventional hybrids. As I write this article, corn price is around $4.50 per bushel. If a conventional hybrid yields 5 bushels/acre less than a transgenic hybrid, it means the conventional hybrid needs to be at least $50 per bag cheaper assuming a bag plants 2.2 acres.

Consideration if going to conventional hybrids

If the final decision is to go with a conventional hybrid, start making other management decisions to ensure success. First and foremost, notify your herbicide applicator. Application of herbicides on non-tolerant crops can end poorly.

Second, put together a scouting plan. Controlling weeds is much easier when they are 1 inch tall compared to 1 foot tall. Know which insects to look for and when to expect them. Continue scouting throughout the year by evaluating lodging and late season weed escapes. A robust scouting plan not only helps in season but also into the future.

And finally, put pencil to paper. Okay, who am I kidding, get your phone calculator out to determine the results of the decision. Did the cost of conventional and associated management beat the cost of a transgenic hybrid?

In the end, net revenue is more important the maximum yield.


Mark Licht Associate Professor

Dr. Mark Licht is an associate professor and extension cropping systems specialist with Iowa State University Extension and Outreach. His extension, research and teaching program is focused on how to holistically manage Iowa cropping systems to achieve productivity, profitability and en...