Agronomist: Crop protection key part of winter decisions

Western corn rootworm. (Illinois Farm Bureau file photo)

Farmers finalizing seed and input purchases for the upcoming season obviously focus on factors such as yield potential and price.

But formulating a solid plan to protect the crop from pests and diseases also plays a key role to maximize output and returns.

“Many farmers are finalizing seed purchases,” said Chris Kallal, DEKALB/Asgrow technical agronomist from Sherman (Sangamon County). “A lot of decisions are being made right now. I’d encourage people to think about how they can best protect the seed they’re putting out there this year as they consider trait options and different levels of protection, including decisions about herbicide, pesticide and fungicide.”

The roller coaster ride of weather conditions, from a dry fall and mild start to winter to the recent blast of ice and snow, will have little impact on potential pest populations come spring and summer, according to the agronomist.

But nearly 1,500 field samples conducted by Bayer across the Midwest found corn rootworm pressure increased in 2020, compared to 2019, and could represent a growing threat this season.

“A couple of years ago, it felt like we almost wiped (corn rootworm) populations out. But ever since, populations have been building over time,” Kallal said. “Based on what we saw (in field samples last year), populations are growing.”

Corn rootworms overwinter in Illinois, making the pest a potential threat every year. A pocket of the state that typically faces the most rootworm pressure encompasses a triangle that stretches from the Missouri border to the Indiana border up to the northeast portion of the state.

But regardless if pests overwinter in the state or migrate here during the growing season, such as corn earworms and black cutworms, winter conditions provide little direction as to potential pest pressure this season.

“The mild weather we’ve had so far and dry conditions (in the fall) doesn’t tell us much about what pest pressure could be like in 2021,” Kallal said. “It’s more about the environment we have in the springtime, summer storms and the weather pattern that could blow moths in (to Illinois).”

As for the potential corn rootworm population, soil conditions at hatch time, around early June, typically are key to determining the population.

“If it’s saturated at that time, many won’t survive,” Kallal said. “But if it’s drier, there could be a higher survival rate and more pressure.”

That’s why it’s important to have a good crop protection plan in place heading into the season rather than attempting to react to conditions as they change throughout the growing season.

“This is a great time to reflect on what are some minor tweaks you can do to drive efficiency or maybe squeeze an extra couple bushels,” Kallal said. “Of course, you have to pay attention to the return on investment. But at the end of the day, bushels are what pays the bills.”