Pre-Plant Considerations for Corn

Mar 15, 2021

Corn is the most vulnerable early in the season right after planting. Even before the seed goes in the ground, producers want to do everything possible to ensure it is off to the best start to make the highest yields. However, the first couple of weeks following planting can be stressful if insects get in the way.

Alabama does have some consistent corn pests, but for the most part, many are opportunistic and will take advantage of high risk fields. Those include soil pests that feed underground and aboveground pests that will feed on the plant right at the soil line. Wireworms, white grubs, cutworms, and armyworms can all threaten corn crops early in the season.

Assessing Risk

A field’s history can tell you a lot about how much risk there is for pests, especially early in the season. Problems can arise in fields that were previously in pasture or CRP. Similarly, fields that are next to pastures can also be at higher risk. Conservation tillage systems can help enable the survival of overwintering insects which can lead to early season damage. Fields with heavy residue can also have increased insect problems. The residue will help maintain soil moisture levels, as well as temperatures that lead to increased insect survival.

Reducing Risk

The first step to starting the season off right is with proper varietal selection. Growers should select a variety that is well-adapted to their area and contains a good yield and disease package. Aboveground and belowground insect traits are also available in Bt varieties if needed.

If planting Bt corn, it’s crucial to pay attention to refuge requirements. The best way to preserve the current genes we have—both in corn and cotton—is to plant a non-Bt refuge in corn. Here in the south, the majority of the corn earworm/cotton bollworm moths going into cotton are coming from corn. Ignoring refuge requirements can lead to increase resistant populations of moths and eventually complete resistance. Maintaining a refuge ensures that non-resistant populations are kept in the field to avoid selection of resistant genes.

Requirements vary based on the exact Bt gene used. In general, at least 20 percent of corn acres must be planted with non-Bt corn. When planting corn with a single Bt trait, 50 percent of the planted corn must be a non-Bt refuge. There are multiple options for refuge configurations. The minimum refuge requirement can be planted within, adjacent to, or as a separate block within a half-mile of each Bt corn field.

There are also other strategies producers can employ to reduce risk in our fields and help to preserve the effectiveness of Bt traits in both corn and cotton. Rotation is a crucial component of risk reduction and a strong integrated pest management plan. Rotating crops and Bt traits, as well as rotating insecticide seed treatments and applications will help to preserve our current and future technologies.

Timeliness

Timely planting is crucial so that the seed germinates at optimal temperatures in the beginning of the season. Planting in a timely manner also helps fields avoid ear-feeding pests later in the season. It is rare to see yield loss from late season ear-feeding pests like corn earworm with corn planted on time. In south Alabama, the planting window is from late February to early March. This is followed by mid-March to late April planting for central Alabama, and late March through mid-May planting in the northernmost parts of the state. These dates are important because producers want to make sure that soil temperatures at a depth of two inches are at least 55°F.

Seedbeds should be clean prior to planting. Extension professionals like to see burndown herbicides applied at least 30 days before planting crops. It’s important to control weeds both in the field and on field borders to eliminate alternate hosts for insect pests. If producers are unable to clear the winter weeds or cover crop prior to planting, the field may be at risk for cutworms. Broadcast applications of any pyrethroid can be applied at planting to control cutworms.

Seed Treatments

Seed treatments like Cruiser and Poncho are standard these days and can serve as insurance to get your corn out of the most vulnerable growth stages. They will ensure optimal seedling development and reduce risk from insects or diseases. At label rates, seed treatments have enough residual for corn to develop past the high-risk period for both below- and aboveground insects.

It’s most common to run into issues when insect pressures are high, or there are suboptimal conditions around planting. For example, in fields that are not rotated, insect pressure may be high enough to overcome seed treatments and higher rates may be necessary. Cooler temperatures during germination can delay plant development and lead to uneven stand emergence. This can increase the corn’s susceptibility to pests.

For information on seed treatments or other at-plant insecticides, read the ACES Corn IPM Guide for 2021. To stay up to date on current crop information, check out the Alabama Crops Report Newsletter or our new Alabama Crops Report Podcast.

Source : aces.edu

Video: Why Your Food Future Could be Trapped in a Seed Morgue

In a world of PowerPoint overload, Rex Bernardo stands out. No bullet points. No charts. No jargon. Just stories and photographs. At this year’s National Association for Plant Breeding conference on the Big Island of Hawaii, he stood before a room of peers — all experts in the science of seeds — and did something radical: he showed them images. He told them stories. And he asked them to remember not what they saw, but how they felt.

Bernardo, recipient of the 2025 Lifetime Achievement Award, has spent his career searching for the genetic treasures tucked inside what plant breeders call exotic germplasm — ancient, often wild genetic lines that hold secrets to resilience, taste, and traits we've forgotten to value.

But Bernardo didn’t always think this way.

“I worked in private industry for nearly a decade,” he recalls. “I remember one breeder saying, ‘We’re making new hybrids, but they’re basically the same genetics.’ That stuck with me. Where is the new diversity going to come from?”

For Bernardo, part of the answer lies in the world’s gene banks — vast vaults of seed samples collected from every corner of the globe. Yet, he says, many of these vaults have quietly become “seed morgues.” “Something goes in, but it never comes out,” he explains. “We need to start treating these collections like living investments, not museums of dead potential.”

That potential — and the barriers to unlocking it — are deeply personal for Bernardo. He’s wrestled with international policies that prevent access to valuable lines (like North Korean corn) and with the slow, painstaking science of transferring useful traits from wild relatives into elite lines that farmers can actually grow. Sometimes it works. Sometimes it doesn’t. But he’s convinced that success starts not in the lab, but in the way we communicate.

“The fact sheet model isn’t cutting it anymore,” he says. “We hand out a paper about a new variety and think that’s enough. But stories? Plants you can see and touch? That’s what stays with people.”

Bernardo practices what he preaches. At the University of Minnesota, he helped launch a student-led breeding program that’s working to adapt leafy African vegetables for the Twin Cities’ African diaspora. The goal? Culturally relevant crops that mature in Minnesota’s shorter growing season — and can be regrown year after year.

“That’s real impact,” he says. “Helping people grow food that’s meaningful to them, not just what's commercially viable.”

He’s also brewed plant breeding into something more relatable — literally. Coffee and beer have become unexpected tools in his mission to make science accessible. His undergraduate course on coffee, for instance, connects the dots between genetics, geography, and culture. “Everyone drinks coffee,” he says. “It’s a conversation starter. It’s a gateway into plant science.”