Each new growing season presents soybean producers with tests that affect the bottom line. One of those challenges can be disease pressure. Fungal infections on soybean plants limit yield potential. This makes it even more important to efficiently identify and diagnose properly.
According to Iowa State University, disease is typically identified via visible symptoms on plants. Looking for changes in color, shape and/or function of the plant in response to a pathogen can help you identify issues. Leaf spots or blights, discoloration of plant tissue as well as stunting and wilting can also indicate an infection.
Finding the Problem
Before you can fix an issue, it’s important to know how to accurately recognize common issues and limit their damage. Here are common soybean diseases and symptoms:
"Applying a product like Stratego YLD fungicide at this stage can help limit white mold, brown spot or
frogeye leaf spot.”
- Randy Myers, Ph.D.
Product Development Manager,
How does one combat these diseases?
Randy Myers, Product Development Manager for Bayer, says that growers looking to limit damage from soybean diseases need to be aware of their fungicide application timing. “Timely fungicide applications will be your best defense. The most effective applications for most diseases will come around beginning of pod set, or about R3. White mold is an exception, however, as first applications need to be made at flowering, or R1, because blossom petals are the typical medium for infection. A second application around R3 is usually needed to get the full benefits of the treatments.”
“Applying a product like Stratego YLD fungicide around R3 can help limit a lot of damage from common diseases like brown spot or frogeye leaf spot,” said Myers. “With a single application at this timing, trials have shown yields improve on average about 3.25 bu/A.”
Along with timely applications, Farm Progress reports that scouting should happen before R3 growth stage,, especially if weather has been rainy and/or humid. These types of conditions prove to be particularly favorable to foliar disease.
Additionally, the Department of Plant Pathology and Microbiology at Iowa State University determined that “the yield response of soybeans was greater with an R3 application rather than an R1 application. So, an R3 application of a fungicide was more likely to break even than an R1 application. Although these data suggest that nearly 60-70 percent of R3 applications of a fungicide containing a strobilurin at least break even, spraying when disease is present will further increase your chances of getting your money back.”
Don’t let soybean seasonal factors limit your yield potential. Learn how to prevent damage from these other articles: