What You Need to Know About Seed Treatments

Seed treatments can be a critically important element of an integrated pest management (IPM) program when addressing early-season pressure in acres planted to soybeans. A typical seed treatment includes a combination of insecticides and fungicides, but growers have also begun applying a nematicide to seed when a higher concentration of soybean cyst nematode (SCN) is present in their fields.

Most effective in the first three weeks following planting, seed treatments are formulated to help protect seedlings from diseases and pathogens, support healthy germination and establish early stand. They can help producers maximize their yield potential and, in some circumstances, guard against catastrophic loss due to certain forms of pest pressure. Particularly in years when soybean markets are strong, seed treatments can prove to be a great opportunity to maximize ROI.

An estimated 50 to 75 percent of all soybeans planted in the U.S. have a seed treatment applied, so chances are you’re already planting treated seed. But what should go into your decision-making process when evaluating seed treatments?

Knowing Your Field History Is Critical

The first thing to do when considering seed treatments should be to take a close look at your field history.

“What diseases or what pathogens have growers had in the past?” asks Connie Strunk, Plant Pathology Field Specialist with SDSU Extension. “They need to have a pretty good idea of which diseases they've had to help figure out which seed treatment is going to be best for them.”

In the case of SCN, analyzing a recent soil sample can help growers determine if a nematicide treatment is a smart decision. (Thanks to grant funding provided by South Dakota soybean farmers through their checkoff, in-state producers can receive a free SCN analysis by sending soil samples to the South Dakota State University Plant Diagnostic Clinic.)

Terry Schultz is CEO of Mustang Seeds based out of Madison, South Dakota, and serves as an industry representative on the South Dakota Soybean Association Board of Directors.

Schultz says field history is typically part of the seed treatment conversation between producers and their seed sales representatives.

“Most growers have an idea of what (seed treatment) they want. Sometimes they've had some issues with different diseases or bugs,” he says. “That’s when they'll ask more questions, and then we’ve got to do a little more investigation.”

According to Schultz, soybean growers cite white mold, soybean aphids, SCN and sudden death syndrome as primary concerns when exploring seed treatments with his sales team. While results vary based on weather and conditions, Schultz notes that producers typically see a yield difference of anywhere between two and 10 bushels per acre when applying a seed treatment.

Soil Conditions Are Important, Too

Another seed treatment consideration for growers relates to soil conditions, particularly heading into planting season.

If you’re working with early planting dates, soil conditions are likely to be cooler and wetter than normal due to winter and early spring conditions. This can be problematic in warding off soil-borne pathogens.

“Early planting can increase the chance for more seed rot and root rot, for those pythium and fusarium species to get in there and cause some problems later on,” says Strunk.

For that reason, Strunk generally advises pushing soybean planting back to allow the soil to warm up sufficiently. If and when that’s not possible, producers will want to explore available fungicide seed treatments.

Well-draining soil is also going to help your seed avoid fungal pressure more successfully than soil that tends to get waterlogged. So, if a particular field is susceptible to excessive moisture, you may want to consider seed treatment to help protect your investment.

Soybean Genetics and Quality Matter

Above all, Strunk advises growers to be mindful of genetics during the seed selection process. “Soybean varieties vary in their susceptibility to different plant diseases,” says Strunk.

By choosing genetics with demonstrated success against particular diseases, she observes, producers can start the growing season off on the right foot.

“That’s your first line of defense,” says Strunk. “The easiest thing you can do this time of year is look at the genetics out there and select varieties based off of your field history.”

Strunk also cautions against planting seed that is cracked, shriveled or poorly stored. She says treatments will only go so far in protecting your seed, so planting clean, disease-free and well-stored seed is critically important to achieving healthy germination.

Resources on Seed Treatments

For those interested in doing additional research, Strunk recommends SDSU Extension’s Best Management Practices for Soybean Production guide

for a complete list of seed treatments labeled for use in South Dakota. This free resource also includes valuable information on seed selection, soil management and other best practices for soybean producers.