You might be looking for inputs to cut from your plans, but don’t be too quick to cut a fungicide application. Even in the absence of disease pressure, a fungicide can help improve the health of corn plants and lead to increased yield of almost 7 bu/A, on average, early season or almost 12 bu/A, on average, when applied at tassel.
How It Works
An early season fungicide application can improve the health of your corn plants by reducing lodging and improving stalk strength. This health means more than increasing the number of kernels on the ear, though. It helps your corn stay standing at the end of the season, putting more kernels in your combine hopper and leaving fewer on the ground.
A later fungicide application – typically right after tassel emergence – keeps diseases in check and protects yields.
But which factors go into choosing whether to use a fungicide? Clarke McGrath, Iowa State University (ISU) Extension field agronomist, says managing common diseases tops the list.
“Most everyone agrees that the number one factor impacting fungicide application profitability is management of common diseases like gray leaf spot, common rust, etc.,” says McGrath. “If crop diseases are present, yield responses to applications are typically higher on hybrids that have low disease resistance scores. If disease levels are high enough, hybrids with solid disease resistance may respond well, too.”
McGrath advises growers scout corn hybrids with moderate-to-low disease resistance more intensively. He also says late-planted corn is more susceptible to diseases. “And don’t cut the application rate of the fungicide product. Follow the label instructions,” McGrath says.
The ISU Corn Field Guide has seven fungicide input considerations for growers:
- Cropping history and percentage of surface crop residue affect disease risk as many pathogens survive in crop residue, which can be a source of inoculum.
- Disease presence before or at VT stage may result in greater yield loss than disease during grain fill.
- Hybrids vary in susceptibility to foliar diseases.
- Foliar diseases can develop easier in warm, wet weather.
- Adjuvant use in fungicide applications prior to VT may result in abnormal ear development.
- Fungicides do not affect bacterial diseases.
- Fungicide application profitability depends on the price of grain and the cost of application.
Last year, Anchor, Ill., grower Brent Lage performed yield checks with Stratego YLD at tassel on two varieties and saw a big yield difference between the treated and untreated checks for both varieties.
“[With the first variety], it was in the 220s in the untreated checks and when it was treated, [yield] went up to 250. In the other variety I did two checks, the untreated was 236 and 240, and the treated jumped up to 269 and 276,” says Lage.
It’s not just at-tassel applications that improve yield, though. Research of nearly 200 field trials shows an early season application of Stratego YLD can increase yield by nearly 7 bu/A.
“With corn near $4/bu, the ROI of an early season application when tankmixed with a planned postemergence application is $19.15/A, on average,” says Thorsten Schwindt, Bayer Product Manager. “Even if corn was $3/bu, the ROI would be $12.35/A, on average, due to the lower application rate for smaller corn plants.”
“I don’t know a grower who wouldn’t like a payoff like that,” says Schwindt.
The key to early season success, Schwindt says, apply Stratego YLD between the V4 and V7 stages to protect the corn plant during those critical growth stages from damaging diseases. An at-tassel application provides further disease protection and ROI.
“Stratego YLD promotes a healthier plant with stronger stalks. It reduces the risk of lodging and green snap for improved harvestability. Plants stay greener longer for an expanded period of grain fill,” explains Schwindt.
Stratego YLD is an important element in maximizing yield potential all year long. A pre-emergence herbicide like Corvus® gets your crop off to a clean start. Then tankmix Stratego YLD with Laudis® or Capreno® postemergence herbicide for season-long disease management and added weed control, all of which help maximize your corn’s yield potential.
Learn more about disease control and yield advantages: