The No. 1 threat to soybean yields is phytophthora root rot, contends Matt Hubsch, senior agronomist with Legend Seeds.

"Although the drought reduced the threat of this moisture loving fungus this growing season, we don't know what 2013 will hold," Hubsch said. "Just because this fungus needs moisture to infect your soybean fields — it actually needs to swim in order to infect its host — does not mean it needs moisture to survive. Its spores can live in soil, waiting for just the right conditions for years and years."

Hubsch explained that once phytophthora root rot infects a soybean plant, it begins to kill the plant and its potential yields, so the only way growers can protect their crop from phytophthora root rot is to take a preventative, three-step approach when purchasing seed for 2013.

As the first line of defense, he encourage growers to protect their yields with a seed treatment and his main recommendation is CruiserMaxx Vibrance.

The next step Hubsch suggests growers take is to select a soybean variety with a high "natural field tolerance" to fend off phytophthora. "Varieties with natural field tolerance are bred to fight off all races of phytophthora root rot," he said.

And last, Hubsch encourages growers to select a seed that carries the new gene, Rps 3a. "This gene has been developed to increase the plant's phytophthora resistance, by picking up race 25 phytophthora root rot, along with races 3 and 4," he said.

In the past, Hubsch said this was the job of the Rps 1k gene. However due to an increase of other races of phytophthora, this new gene was developed to increase resistance to encompass more races than Rps 1k.

He recommends buying seed that protects fields against phytophthora root rot with all three methods.