Controlling FHB through a multifaceted approach

A couple of dry seasons may have provided a reprieve, but Fusarium head blight (FHB) is a not- too-distant bad memory for most Prairie cereal growers. Because the inoculum that causes FHB remains prevalent across the West, all it will take is moisture at the right time for the disease to flourish again. The good news is that today’s agronomics, technology, seed varieties and fungicides can combine to help manage the impact.
“Before the rise of FHB, the diseases of concern would hit the flag leaf and stem, so growers’ disease management was aimed at protecting the flag so that it could fill the kernels and heads and yields would be maintained,” says Rory Cranston, who is with Bayer’s Market Development team. “FHB directly attacks those heads, infecting kernels for a big impact on yield and grade. We now know that we need to push a fungicide application to that head timing for optimal disease management.”

Cranston says that waiting until as many heads have emerged as possible to apply a preventative fungicide at that FHB stage will provide protection for the head and flag leaf from mid- to late-season.
Group 3 fungicides such as Prosaro® XTR have both preventative and post-infection properties for effective leaf disease control as well as protection against FHB and the deoxynivalenol mycotoxin (DON) it creates.
“When it comes to disease control, it’s always better to be preventative than reactive,” says Cranston. “The window for fungicide control for FHB is small and can be difficult to hit. While it’s important to watch for signs of infection, if you can see symptoms of disease, it’s too late to manage it. We have conducted more than 240 field trials and in virtually every situation, growers get the best results with a head timing application.”

TWO ACTIVES

Prosaro XTR has two active ingredients that work together to provide protection throughout the high disease risk times of the growing season. “Tebuconazole gets in and gets to work fast, but tends to burn out a little quickly,” says Cranston. “Prothioconazole starts off slower but lasts longer throughout the high-risk time for late-season flag leaf disease and FHB infections. So between the two AIs (active ingredients); they really complement each other.”
Cranston says that the mode of action of Group 3 fungicides (used in Prosaro XTR) inhibits sterol biosynthesis. Of the three most common fungicide modes of action used in cereals today, Group 3, 7 and 11, Group 3 fungicides have the lowest potential for resistance development. Prosaro XTR also contains mefenpyr, which helps manage abiotic stresses like heat, drought, naturally occurring toxins and soil-borne pollutants to allow the crop to become more productive, which helps set it up to better battle disease.

MULTIFACETED MANAGEMENT
Cranston cautions growers not to become complacent in the growing season following a dry year because two sides of the disease triangle are always present — the inoculant is in the soil and cereal crops are being grown. “We are never immune to FHB infection,” he says. “While the amount of inoculum may decrease slightly after a dry year, fusarium survives well in the trash and on other susceptible hosts. We have the tools now to keep those levels low and make sure we manage disease levels in a timely manner before it can take down yield and grade.

FHB management involves an integrated, multifaceted approach in order to minimize the impacts of a disease that can’t be entirely controlled. In addition to fungicides, improvements in seed varieties are also helping to manage disease. While there are no varieties that are truly resistant to fusarium, some tolerate the disease better than others. Additionally, new varieties can help keep other disease levels low. “The disease package in many of the newer varieties has improved protection for those early leaf diseases, which allows growers to target the later disease through a fungicide application,” says Cranston. “These newer varieties are yielding higher, which means more kernels — but also means more sites of infection for fusarium.”

THE POWER OF DATA
Digital farming tools are also helping growers measure the value of their fungicide application. “There is so much data available using digital agriculture platforms, it’s really up to the user how much data they want to take into consideration,” says Kerran Clements, Regional Services Manager with The Climate Corporation. “These platforms can provide information such as historical and predictive weather, seeding dates, as applied data from farm equipment, soil test information and yield data.”

Bayer’s Climate FieldView™ digital platform takes data from a number of partner applications and presents it in one place so growers can see the value in their decisions based on as much information as possible.
The platform has been available to western Canadian growers for two growing seasons and is continually being updated with satellite data and other historical information. FieldView is compatible with multiple equipment manufacturers and is constantly increasing its equipment compatibility, making it easier to get all of your data in one place.
“The digital agriculture industry is all about taking a holistic approach to information gathering so farmers can make informed decisions,” says Clements. “When you map everything from planting through harvest, you have the most data points possible in order to use your resources and your inputs in the most sensible, timely manner.”
Climate FieldView is a subscription-based service and can be accessed from many local retail outlets or online at www.climatefieldview.ca