Soybean Advice: Fungicide and Other Factors

June 1, 2020

If you’re a soybean farmer, you know a lot of factors go into planting — some you can control and others you cannot. So for all the variables out there, it’s important to focus on the best way to improve yield potential.

With information backed up by several studies, we’ll look into how fungicide and other key factors can change the performance of your soybeans:

Timing: Early planting vs. Late planting

Relative Maturity (RM): Early season vs. Full season

Fungicide Treatment: Seed applied vs. Foliar

Note: All of our studies kept these variables constant: Row spacing, seeding rate, tillage, weed management and time of harvest.

Why Timing Plays an Important Role

Planting early in the season is a high-risk, high-reward game. You’re prone to higher moisture and lower soil temperatures, which are perfect conditions for soil-borne and seed-borne pathogens. This is one instance when using fungicide applications can really come in handy. Even early on during germination or the seedling stage, diseases like Phytophthora and Pythium can wreak havoc. But if soil and weather conditions are on your side, early planting can maximize soybean yield potential.

Across different soybean products and fungicide treatments, early planting resulted in a higher average harvest population, meaning a higher average yield increase:


How to Pick the Right Relative Maturity

Soybeans are more prone to disease early in their life cycle, so you should choose a full-season (or higher relative maturity) product to mitigate this problem, right? Well, it’s not that simple. Some farmers choose to plant early (or lower relative maturity) products earlier in the season and then manage them at a higher level with seed treatments and foliar applications of fungicide and insecticide. This approach is called “relative maturity (RM) shift,” and it has benefits of its own: an earlier harvest and earlier cover crop seeding.

How to Pick Your Approach to Fungicide Treatments

There are two main approaches to fungicide treatment worth considering when planting your soybeans: proactive and defensive. Being proactive means going with a seed-applied fungicide like an Acceleron® product whereas being defensive means applying a foliar fungicide like a Delaro® product to the plant, usually between the R2 and R5 growth stage. Just remember that your specific conditions come into play when a Seedsman considers which specific fungicide treatment to recommend.

Across products and planting dates, foliar fungicide application resulted in higher average harvest population, indicating a higher average yield increase:

Finding the Right Fit for your Farm

Every farm is different, and a crop’s yield response to production factors will vary by region and environmental conditions.

But it’s worth noting that the added cost of applying fungicide ultimately seems to pay off. A two-year study found that using an Acceleron® seed applied fungicide resulted in an average 8.8 bu/acre advantage in early planted plots and an average 4.2 bu/acre advantage in late-planted plots. In another study, we found a benefit of fungicide outside of disease control. Even without identifiable disease pressure, a foliar fungicide application produced a substantial yield response for all soybean seeding rates.

The best way to find the right fit for your field is to consult your local Seedsman, Field Sales Representative or Technical Agronomist when making planting decisions.