For Fungicides, Timing Is Everything
MORGAN SCHMIDT
DELPHOS, KAN.
Many farmers are becoming more aggressive about investing in fungicide applications for soybean fields with the goal of increasing yield potential. Bayer research has shown that fungicide applications can help support plant health and reduce stresses triggered by disease.
The Bayer study, Soybean Yield Response to Variable Seeding Rates and Fungicide Application, demonstrated the greatest yield benefit with a fungicide application at the R3 soybean reproductive stage at all evaluated seeding rates, when plants are showing a 3/16-inch-long pod on one of the four uppermost stem nodes. To make sure you hit the spray window, evaluate fields regularly, keeping track of growing degree days for each field and schedule your fungicide applications just before or during the expected R3 period. Timing an application for the R3 growth stage can provide protection when the plant blooms, helping it retain flowers and often resulting in better retention of yield-making pods and larger soybean seeds for heavier grain. You can review the study at Channel.com/SoybeanYields.
With foliar fungicide applications, be sure to cover as much of the plant as possible. To get the best coverage, spray nozzles should be calibrated for a medium-sized droplet to spread an even distribution of active ingredients across the leaf surface. Because the first spray application of the year is often an herbicide that requires a large, coarse droplet, it’s important to take the time to recalibrate equipment for the following fungicide application.
In Kansas, fungicide applications can limit yield loss from brown spot, Cercospora leaf blight, and pod and stem blight. Brown spot and Cercospora have been more common in recent years due to the wet conditions. If you have never used a fungicide, 2020 may be the opportunity to conduct some trials on your farm.
Conducting regular field evaluations is a key step to deciding if a foliar fungicide is needed. Your local Channel Seedsman can help you monitor field conditions with a Channel Field Check Up Series visit and can advise you about applying fungicides to minimize crop losses to disease and maximize yield and economic returns in soybean production. In planning for the next season, your Seedsman can help implement disease management practices such as crop rotation, planting of disease-resistant cultivars and application of fungicides with multiple modes of action to effectively manage soybean disease. If you have questions about fungicides, contact your Seedsman or visit Channel.com/Ag. ∆
MORGAN SCHMIDT: Channel Technical Agronomist