For many soybean growers, there's no question of whether to plant treated seed. It's whether to buy seed treated commercially or to buy equipment and chemical to treat it on-farm.

Cotton producers have long recognized the benefits of treated seed. The protectants have helped shield seed from pythium, fusarium, rhizoctonia and other disease problems. Virtually all seed corn is treated. With more reduced tillage, soybean farmers are also seeing the advantages of protected seed.

The disease threat is greatest when crop residue is left on the surface. Residue provides shelter for diseases because soils are more cool and moist, breeding disease problems. With replanting costs at $50-60 per acre, not counting the time factor, preventing seedling disease and getting a good stand are vital.

But do growers buy treated seed, or treat it on-farm? Which method is most cost-effective? And what advantages does one offer over the other?

"Commercially treated seed is the best way to go," says Glen Karaffa, product manager at Gustafson in Plano, TX. "The characteristics of seed varieties are known by the commercial operator, and treatment is likely applied more precisely."

But Karaffa is quick to point out that it's often impractical for growers to buy treated seed. They may farm in an area not served by commercial treaters, or may face seasonal disease problems that can be served with an on-farm application. Then again, the varieties they plant may not be available treated.

Jerry Hartsock, a consulting agronomist from Geneseo, IL, agrees with Karaffa.

"If I took a poll, the majority of the farmers would rather buy commercially treated seed," he says. "But some commercial seed is not treated, so growers have to do it themselves."

George Stulz, who farms about 400 soybean acres near Illinois City, IL, prefers buying treated seed, which he says can yield up to 5 bu/acre more than untreated varieties.

"I buy new, treated seed each year," he says. "We put on a soybean inoculant in the planter box, and I think that takes too much time. Applying treatment on-farm would be even more time-consuming."

Stulz says treated seed "pays in this area, especially if you have a cool, wet year." He pays about $1.50/acre for commercially treated seed.

On-farm treatment is nearly as cost-effective. For example, growers can buy an easy-to-assemble, easy-to-use on-farm unit for about $300. One unit manufactured by Trace Chemicals, the Farmer Applied Seed Treater (FAST), can mount directly to a truck box or wagon to dispense fungicides and other chemicals into an auger-conveyor system.

It holds a 2 1/2-gallon jug, uses a Shurflo diaphragm pump, a metered ball for calibration and can be easily cleaned. It can be powered by 12 or 110 volts, is equipped with a 12-volt battery cable and has a remote on/off switch.

Another on-farm treatment system is the Gustafson Total Slurry Treater (TST), a 10-gallon stainless-steel premix tank unit that can also be mounted to a truck box or wagon to treat seed in an auger system. It uses a diaphragm pump and has attachments similar to the FAST unit's.

The cost of a seed treatment product will vary by region and dealer. It could include a combination of, say, Rival, a Gustafson product for protection against seedling blight or rhizoctonia, along with Allegiance for pythium and phytophthora root rot. For Southern production areas, Vitavax used for rhizoctonia control would be similar in price.

Apron XL, Protector L, a combination of Thiram and molybedum, or Vitavax T-L, are also popular for use in the FAST system at similar prices, says Dave Moe, a manager for Trace Chemicals in Dekin, IL.

"With FAST, farmers can treat when they're ready to plant," he says. "We've received good feedback on the system."

On-farm application minimizes problems associated with carryover commercially treated seed, which will likely be outdated for the next season.

"That's the only disadvantage I see in buying treated seed," says Stulz. "If you have too much seed, you can't get rid of it."

Karaffa says growers who want the best of both worlds for treated seed should consider a portion of each.

"For example, a grower will often plant about 70% of a crop in early beans that are more susceptible to wet and cooler weather," he says. "Those beans could be commercially treated. Then he could come back with on-farm treatments on later-planted beans. Those beans may be more susceptible to rhizoctonia, which can attack in wet and warm weather."

With the cost of high-quality seed, it's important to make sure it produces a good stand, adds Mike Glazer of Wilbur-Ellis Co., McPherson, KS. Glazer is also seeing more soybean producers buy treated seed.

In cotton areas, where seed may be treated at a delinter, Glazer says his company's NuFlow-M treatment continues to show strength in controlling diseases. Karaffa says some on-farm treatment interest is being seen in cotton regions.

Some growers using Flexi-Coil air planters have turned to a seed treatment unit sold by that company to treat while planting. It provides an even distribution of fungicide to the seed, Karaffa says.

Like virtually all ag chemicals, there are limitations placed on some seed treatments. Not all are labeled for on-farm use. Make sure to check with your seed dealer and/or chemical distributor to determine the limitations on treatments for your area.

"Also, get a seed efficacy chart from your dealer or distributor to determine which treatments are needed for disease problems in a particular area," Karaffa says.