How to save yields with early season management

Early-season disease can lurk below the soil surface, robbing soybean yields and profits with little warning. Smart management decisions are key to maximizing return on investments.

Four main diseases impact the seedling stage. Pythium seedling blight and Phytophthora root rot are water molds, while Rhizoctonia seedling blight and Fusarium root rot are fungal diseases. Generally speaking, these diseases can cost U.S. farmers 25 million to 50 million bushels a year.

“If you think about the market price of soybeans, that’s around half a billion dollars every year the United States is giving up to seedling diseases,” says Nick Tinsley, a seed treatment technical field representative for BASF. “That’s a lot of money that we’re leaving out of our wallets when we don’t think about managing these seedling diseases in a proactive way.”

Most commonly, cool, wet conditions exacerbate diseases. For most, the damage is irreversible before symptoms are seen above the soil surface. When symptoms appear, they are common in a field’s low-lying or compacted areas that tend to hold moisture.

Planting decisions

As more farmers look to plant soybeans before corn, diseases could become more of a concern, requiring farmers to implement proactive management plans. And, although these diseases’ end consequences are often similar, management for each can differ.

Farmers have little control over the environment or their fields’ disease presence, although some management practices can slightly increase risk.

It all comes back to the disease triangle, Tinsley says: “Anytime we use a management practice that may result in cooler soil temperatures, that has the potential to make diseases worse. For example, a lot of residue can make the soil cooler or hold more moisture. Those are things to consider, but generally, most farmers are in the same boat when it comes to threat level.”

Tillage can help break up the soil profile, allowing heat to be released. Farmers can also manage soybean susceptibility to some diseases, such as Phytophthora, through variety selection.

Seed treatments and plant populations

Managing seed and seedling disease is best achieved through planting practices that minimize stress, as well as applying fungicide seed treatments. Those can also benefit by protecting the seed’s development, although they’re not a one-size-fits-all option.

“Initial infections start early on in the root system,” says Steve Crafton, an LG Seeds agronomist. “A seed treatment can get around that root mass and protect the roots from infection.”

Understanding the diseases present in each field and the active ingredient in each seed treatment is essential to making good business decisions. Crafton says a good seed treatment includes several fungicides that cover a broad spectrum of problems.

Many seed treatments also protect against soybean cyst nematode and sudden-death syndrome, two yield robbers with little symptoms until late in the growing season.

Because early-season diseases impact stands, increasing seeding populations can help balance potential yield loss.

“If you’re pushing cooler soil temperatures early in the year, population is definitely something to be considered,” Crafton says.

Post-planting observations

Although few rescue treatments are available for early-season diseases, scouting fields and identifying issues are essential. Farmers should look for necrosis, or wilting of plants; and variations in plant height.

“If those issues are present, they should get in touch with their local seed advisers or agronomists to identify what’s going on,” Crafton says. “Then, in following years, they can plan on using a seed treatment that’s focused on the issue they’re having, or switch up the crop rotation.”

Disease issues can vary from year to year, depending on the environment. Routine stand checks can help confirm the effectiveness of input decisions. If seed treatments and varieties are not controlling disease pressure, a diagnosis from a local plant clinic may be necessary.

A farmer’s perspective

Steve Love, a corn and soybean farmer from Rio, Illinois, south of the Quad Cities, has seen greater yields through smart early-season management. He’s observed the push toward growing higher populations.

“On my farm, higher populations have played a big part in higher yields,” he says. That said, “Every plant experiences more stress. Seed treatment is our first line of defense.”

Love works with trusted advisers to make sound decisions on product and application timings. Focusing on a healthy base from root to stalk, he uses seed treatments, planter-box-applied biologicals to enhance root growth, and post-pass fungicides.

“Every year we’re planting higher populations, and we’ve seen the value in that,” Love says. “I think early-season disease mitigation is overlooked. We tend to react more than prevent. To me, those early-season products are a really good return on investment.”

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