corn field

From Day One - Earlier Trends in Corn Disease Management

April 26, 2022 5:00 p.m.


The value staked in disease control is higher than it’s ever been.

According to the Crop Protection Network, in 2020 five foliar diseases — Southern rust, gray leaf spot (GLS), Northern corn leaf blight (NCLB), bacterial leaf streak and tar spot — caused estimated corn yield losses of approximately 277.4 million bushels.

When looking at the effects of these diseases more closely:

  • Southern rust can have as much as a 20-bushel per acre impact depending on the year.
  • GLS when it has 10-15% severity throughout the canopy can result in a 10-15-bushel per acre loss.
  • NCLB under certain conditions, especially wet weather, can be aggressive and generate a 30-50% per acre yield loss.
  • Tar spot can create varying yield loss scenarios, ranging from a minimal effect to 50-bushel per acre losses in severe cases.

Simply put, foliar disease control is an economics game and the value placed in managing disease is at an all-time high. This raises the question: Is there a better way to deter the establishment, development and spread of disease in corn fields?

Early Bird Gets the Worm

To counter the mounting pressure foliar corn diseases are putting on farms — both from a dollars and cents perspective to a purely operational angle—the approach to managing them has to be different. A new strategy that’s emerging flips the script on the timing and application method: at-plant fungicides.

Typically, fungicides are going out during three key growth stage options: V5-V7, V8-V10 and VT-R1. At-plant is the new fourth option that’s enhancing disease control in the field throughout the season and improving the window of opportunity to better address late-season diseases like Southern rust and tar spot.

Before late summer rolls around and the heat and humidity build, it’s likely disease already has a foothold in a corn field, particularly in the lower plant canopy. The physical tell-tale signs might not be obvious but yield potential and crop physiology are already being chipped away at this time by fungal diseases. For example, Anthracnose starts emerging early in the season and attacks the lower leaves in the canopy. Plants impacted by the disease become susceptible to stalk rot later in the season.

Protection At-Plant with Xyway® Brand Fungicides

In 2021, FMC introduced a new approach to foliar disease protection: Xyway brand fungicides. These are the only fungicides that can be applied at-plant and provide unique inside-out protection from planting all the through harvest before disease pressure flares. Xyway brand fungicides utilize the most systemic triazole fungicide active ingredient, flutriafol, which allows the fungicide to be rapidly taken up by the root system and translocated within the plant to provide long-lasting disease protection. One convenient at-plant application of Xyway brand fungicides consistently delivers disease protection equivalent to an R1 foliar fungicide treatment without the difficulty of application timing, weather hassle, cost of foliar application when weather allows and disease timing. Research has demonstrated excellent performance against key foliar diseases such as GLS, NCLB and others. Additional protection from stalk diseases such as Anthracnose and Fusarium have also been seen, leading to greater standability through harvest. Xyway brand fungicides come in two formulations to meet growers needs: Xyway 3D fungicide and Xyway LFR® fungicide.

Full Plant Coverage, Better Season-Long Results

When treating 10-foot or taller corn, attempting to get complete coverage with a foliar fungicide is nearly impossible. With an at-plant fungicide like Xyway brand fungicides, this puts the fungicide at the beginning of growth, allowing the root system to pull it up and distribute it throughout the plant. With this level of coverage, the lower part of the canopy, which is typically not reached by a foliar fungicide and an area vulnerable to early season foliar diseases like Anthracnose and GLS, receives fungicide contact and protection.

The more the lower part of the corn plant canopy can be maintained and kept disease-free, the better the overall health of the plant will be later into the season. Having that plant healthier throughout the middle and later part of the reproduction phase can help it better combat late-season diseases like Southern rust and tar spot. This also provides flexibility in the situation a foliar fungicide is required to target those diseases. Instead of having to choose an earlier foliar fungicide application that might miss some diseases, the application timing can be reframed and targeted toward when those yield-robbing diseases are emerging later in the season.

To learn more about Xyway brand fungicides and how you can incorporate them into your disease management plans, talk to your FMC representative or visit

Always read and follow all label directions, precautions and restrictions for use. Some products may not be registered for sale or use in all states. Xyway 3D fungicide and Xyway LFR fungicide may not be registered for sale or use in all states. Contact your local FMC retailer or representative for details and availability in your state.  FMC, the FMC logo, LFR and Xyway are trademarks of FMC Corporation or an affiliate. ©2022 FMC Corporation. All rights reserved. 22-FMC-0165 04/22