Local ag experts look ahead to moisture, weeds, pests

May 24—With nearly all of Iowa's corn and soybeans planted, southeast Iowa's agriculture experts are turning their attention to the next challenges — moisture, weeds and pests.

The planting season is all but finished, with the United States Department of Agriculture's May 22 Crop Progress and Condition Report putting the statewide numbers at 95% corn planted and 84% soybeans planted. The document reports that 65% of the corn crop has emerged, along with 43% of the soybean crop. Southeast Iowa's numbers are even further along, with 78% of the corn crop emerged and 66% of the soybean crop emerged.

After kicking off planting season with favorable weather that allowed farmers to get a head start on the year, producers are now turning their minds to rain, which has been sparse in recent weeks, bringing up memories of the severe drought conditions that plagued the state throughout 2022.

"I know for some, especially in the Keokuk, Mahaska [and] Marion County areas where we were drier last year, I think they're just a little worried that we've built up some moisture, but it's making sure that we continue to get some timely rain. We'll kind of have to see what the rest of the growing season brings," says Rebecca Vittetoe, an Iowa State University field agronomist who covers an area that includes Mahaska and Marion counties. "We were dry last year, and that is very fresh in some of their minds."

Moisture levels aren't yet a serious cause for concern at this point, however.

"It's been a while since we've had a good, soaking rain, but not to the point that anyone's nervous about moisture content in the soil," says Alex Fynaardt, an agronomist at Key Co-op's New Sharon location. "Everything's still looking pretty good, and the main thing is we're getting a lot of heat, so stuff's really starting to come around, corn and beans both."

In fact, Fynaardt says the dry conditions can even have some benefits for the fledgling crops.

"Honestly, we kind of hope for a little dry like this," Fynaardt says. "For one, to get application work [of herbicides and pesticides] done in the field again, and then also it helps the crop to root down better early on so that hopefully that can help with them being able to grab nutrients out of soil, as well as just have better structural integrity for whatever summer storms might be coming."

While Fynaardt was initially watchful that the early start to the planting season might make crops more susceptible to disease, he says that so far, there are no major signs of trouble on the horizon.

"We're pleasantly surprised so far, not seeing a lot of seedling diseases or insect pressure or anything like that. Once the heat finally turned up a little bit and got into the 70s and 80s during the day, these crops have really come around," he says. "The earliest planted stuff came up pretty uneven ... but what plants never did come up, we should be able to make up for just in the fact that we got them planted early, so they've got more days to grow and mature through the summer here than what they normally have."

It's not just corn and soybeans that are ahead of schedule this year. Vittetoe says that farmers are beginning their first cutting of alfalfa early to avoid insect damage.

"A lot of first cutting hay or alfalfa is going on right now, has gone on, which might be a titch ahead. A lot of people couldn't wait until Memorial Day weekend," she says. "We've been having some issues with alfalfa weevils. It's the larvae part of the insect's life cycle that will feed on our alfalfa and can cause defoliation, which ultimately causes yield loss for the farmer."

An early first cutting can help to mitigate the crop damage.

"That's pushed some people to harvest their alfalfa maybe a titch sooner than they normally would have, so that's another big thing going on, there's been a lot of alfalfa being cut for the first time this year," Vittetoe says.

Of course, corn and soybeans are susceptible to insect damage as well. Vittetoe says the most important thing is for people to be diligent in scouting their fields for signs of damage.

"Specifically on the corn side is black cutworms and true armyworms," she says. "They don't winter in Iowa, the moths fly up from the south in the spring. They'll lay their eggs, and then those eggs hatch and they can potentially feed on our corn. Typically it's corn, but we can also sometimes see them in soybeans as well," she says.

The Iowa State Extension Office has a trapping network they do every spring with Iowa State University that allows experts to track the presence of harmful insects like these in Iowa.

"Based off of our moth traps and what we've seen there, now is the time to be scouting for those pests, and if we see an issue and we're at threshold, then we can spray. I encourage people just to be scouting for that or any other potential issues," Vittetoe says.

Looking ahead to the coming days, farmers will also be working to get their last application of herbicide in to combat unfriendly weeds that, once established, are harmful to crops.

"Right now, the biggest thing we're concerned about is weed control," Fynaardt says. "The biggest one — and it's probably been the biggest one for the last five years or so — is waterhemp. We track that one fairly closely, just because we know it's hard to control, so as soon as we start to see it emerge out of the ground, we want to get it sprayed because if it gets four, six, eight inches tall, it's going to be there all year. No matter what we go out there with, we might not get control of it.

"We try to be really timely with this last application of chemical, because we know it's the last time we're going to roll the sprayers through the field for the year, and we want to make sure we get it all cleaned up," Fynaardt says.

Channing Rucks can be reached at crucks@oskyherald.com.