A healthy, waving wheat field is a sight to behold in the spring, the key word being “healthy.” These days, the pile of wheat diseases that can take down your yield seem to be stacking up, but there are tools and tactics you can deploy to maintain crop yield.
“We’re looking at disease control for 2020,” says Dan Maxfield, agronomy service representative, Syngenta. “In 2019, we saw fairly low disease pressure. For 2020, so far, the first reports from Washington State University are showing presence of stripe rust.” This makes sense. If temperatures stay moderate and your fields get that insulating snow layer, you could be seeing spring infection of any of the three key wheat diseases — stripe rust, powdery mildew or septoria leaf blight.
Maxfield says scouting will be your best tool in 2020, noting that in winter wheat in more southern areas of Western wheat country, that field check is critical. “Wheat can jump out of the ground, and you need to know what to look for,” he says.
The fungicide application timing is key, too, yet Maxfield notes that doesn’t mean an added field pass. “Most people put a herbicide down at Feeks 4 to 6; put a fungicide in the tank, too, to protect against an early-season infection; or to clean up a fall infection that may have struck after planting.”
More than disease control
Maxfield notes that fungicide application can also boost plant health, giving those early spring plants a leg up going into the growth season. “In the spring, there are many different products to use, but the gold standard and the most common is propiconazole — and that’s pretty herbicide-compatible,” he says. From Syngenta, the propiconazole is Tilt.
With disease control, there’s rising concern about diseases becoming resistant to fungicides, which for many means adding more to the mix. A strobilurin fungicide offers a different mode of action, and often has overlap for the same diseases as the propiconazole, which helps combat resistance. For Syngenta that propi-strobe mix is Quilt XL.
Of course, companies are adding more fungicides to the mix with succinate dehydrogenase inhibitors (SDHI) or carboxamides. Syngenta has added to that with Trivapro, which is a three-way mix that includes a propiconazole, strobilurin and an SDHI called Solatenol by the company, “It’s a three-way mix, and it can be used on some acres at herbicide timing,” Maxfield says. “If you come out of fall with a high load of inoculum in the countryside, we’ll see more three-way fungicides in use, and you’ll want to go full rate.”
He says that full control is important, because diseases like stripe rust — if not fully controlled — can resporulate later in the season and infect the crop.
Imagery and scouting
Spotting disease early is key to control, especially around flag leaf stage. “You want to protect that flag leaf,” Maxfield notes, because the flag leaf has a key role in grain fill and can impact test weight and yield.
Some farmers are looking to different ways to scout, but Maxfield warns that waiting on a satellite image to track wheat diseases may not pay. “Scouting is the most effective way,” he says. “With [wheat] diseases like stripe rust, you can’t wait for satellite imagery. If you see hot spots, it’s too late. You have to get out of the truck.” That field time will also familiarize you with future hot spots to check for disease in subsequent years.
Key for 2020: Scout and have your fungicide plan ready. Considering a multiple-mode-of-action product — and the major fungicide makers have choices — is important to managing both existing disease and preventing future resistance.