If you wonder how well your corn hybrids can stand up to tar spot, you have plenty of company across the country.
Other corn growers are trying to learn the same thing as are seed corn companies.
That need for more information was a catalyst for work Bayer Crop Science researchers are implementing in company field test plots this season. They are artificially inoculating some of the company’s existing hybrids and more than 100 pre-commercial hybrids with tar spot to evaluate how well the products tolerate the disease.
“We want to understand tar spot better so we can deliver the best corn products to farmers and help them manage the disease more effectively in their fields,” says Jim Donnelly, a DEKALB technical agronomist based in northern Illinois.
The work will help researchers advance tar spot tolerance for DEKALB and Channel corn products, according to a Bayer press release.
Research Is Underway In Three States
Bayer is introducing the disease inoculum to its corn hybrids and upcoming hybrids in 1-acre plots in seven locations across parts of Illinois, Iowa and Wisconsin.
Donnelly told Farm Journal on Tuesday that the field locations selected for the testing sites are limited to areas where the disease inoculum was already present in commercial cornfields.
“We’re taking crop residue from the same areas where corn was infected with tar spot last year, and we’re introducing it into our plots,” he explains. “In addition to that, we’re adding moisture and a humidity component from a specially designed mister to increase the environmental factors that help contribute to the disease.”
Donnelly says the decision to artificially inoculate corn in the field with tar spot was made because Mother Nature wouldn’t cooperate with Bayer scientists’ previous efforts.
“We’d put plots out (in areas where the inoculum was naturally present), hoping to grow the hybrids under heavy disease, and we just couldn’t get the disease pressure we needed,” Donnelly says. “Mother Nature just didn’t deliver for us.”
In-Field Performance Results Are Needed
The in-field inoculation is important because Bayer’s researchers have previously replicated tar spot only in greenhouses. “That doesn’t always correlate to what is observed in how a plant will respond in field conditions,” says Christian Heredia, Bayer Crop Science market development manager, in the release.
Ultimately, Connelly says the company wants to help farmers select and manage hybrids.
“In the grand scheme of things, tar spot is just one component, and there are many other agronomic factors that farmers may be evaluating or wanting as they choose hybrids. But if they have to deal with tar spot, then this information will allow them to better manage their hybrids in the overall process,” he says.
Along with that, Donnelly says the information researchers learn this season will help guide conversations on how many fungicide applications corn growers might need to make – whether one application or two – in a given growing season.
“One thing we’re finding is even in hybrids that are, seemingly, fairly tolerant to disease pressure (tar spot), we’re still having to make at least one fungicide application to help protect against yield loss,” he says.
Long-term, Donnelly says the information researchers glean from the in-field testing will be used by the company to discover germplasm that has better tolerance to tar spot and the process can occur earlier in the development pipeline.
“This will help us beef up our breeding pipeline at an earlier stage,” he says. “We’ll be able to start the development process with better genetic parents and then make crosses from there to boost our hybrid tolerance in the long-term.”
More information on how to address tar spot is available here:
You Can’t Afford to Be Complacent About Tar Spot
New Research Finds Hope for Battling Tar Spot
Risk–Reward: Tar Spot Tolerant Versus Susceptible Hybrids
