Your soybean growers can benefit in several important ways from soybean fungicide applications during the critical R3 growth period, also known as the beginning pod stage. As an ag retailer, it’s important to get ahead of this window with practical recommendations to protect yield, maximize plant development and strengthen plant health.
Here’s a look at key points you should be prepared to discuss with growers to help them make the best decision about soybean fungicides for their fields.
What makes the R3 window so critical for soybean fungicide decisions?
The R3 growth stage for soybeans is a big deal. That’s because it’s the time when pods begin to set and mature. If management isn’t optimal at this stage, soybean yield potential will be in jeopardy.
To evaluate whether your grower’s soybean fungicide timing is on schedule for optimal yields, evaluate on a field-by-field basis. At least half of all plants should be at the R3 stage before doing a fungicide pass.¹
To determine if plants are at R3, look for these characteristics:
- Pods between 3/16” and 3/4" long
- The pod should be located on one of the plant’s four top nodes extending from the main stem, and there should be an open, developed leaf immediately above it²
Once at least half of plants are at R3, work with your growers to evaluate fungicides for soybean plants and schedule the application based on the crop’s needs.
Physiological benefits of foliar fungicide for soybeans
Soybean fungicides are not just a one-trick pony in protecting from developing diseases. Help your growers understand the benefits beyond mitigating the risk of pathogens in wet operating conditions. Soybean fungicides are proven to aid plant health, which translates to a more resilient crop and benefits overall yield.
For example, research has found that foliar fungicide can help soybean plants get through dry conditions or drought. It helps plants retain chlorophyll, improving CO2 fixation that supports growth. It can also boost the activity of nitrate reductase, an enzyme found in soybean leaves that contributes to pod fill.³
How fungicide for soybean plants can help canopy and seeds
Fungicide application using products such as Revytek® fungicide from BASF’s fungicide portfolio can contribute to a green and functional canopy late into the growing season.
Specifically, fungicide can preserve bottom leaves, encourage middle leaf growth and conserve top leaves that get the greatest amount of sunlight.⁴ This prevents premature defoliation, ensuring plants can maximize energy production for optimal seed fill.
Managing crop resistance to fungicide for soybeans and product selection
For best long-term soybean productivity, recommend disease management plans that include herbicides with multiple modes of action to limit the rise of fungicide resistance. Making sure your growers start the season with certified disease-free seed, consider crop rotation and pick disease-resistant cultivars can also help.
Experts are available to help you support your growers in their use of soybean fungicides. Reach out to a nearby extension office agent or a company professional like your regional BASF representative.
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Endnotes
- Singh, Maninder, and Michael Staton. “Determining R3 Growth Stage in Soybean.” Michigan State University Extension, 15 July 2021,https://www.canr.msu.edu/news/determining-r3-growth-stage-in-soybean. Accessed 20 Mar. 2026.
- Lindsey, Laura. “What Is the R3 Growth Stage?” C.O.R.N. Newsletter, Ohio State University Extension Agronomic Crops Network, 2018,https://agcrops.osu.edu/newsletter/corn-newsletter/2018-23/what-r3-growth-stage. Accessed 20 Mar. 2026.
- Kanungo, Mansi, et al. “Foliar Application of Fungicide-Opera Alleviates Negative Impact of Water Stress in Soybean Plants.” Saudi Journal of Biological Sciences, vol. 28, no. 5, May 2021, pp. 2626–2633,https://www.sciencedirect.com/science/article/pii/S1319562X21001613. Accessed 20 Mar. 2026.
- “Healthy Soybeans from the Bottom Up.” BASF Agricultural Solutions,https://agriculture.basf.us/crop-protection/news-events/stories-from-the-field/healthy-soybeans-from-the-bottom-up.html. Accessed 20 Mar. 2026.
