Phytophthora root rot could be the 2013 surprise in soybeans, say two private agronomists from seed companies serving the Dakotas.
It's a disease associated with wet weather. "With only 2-3 years of below normal moisture in the past 20 years, I would hedge on the fact that moisture will return and we could see Phytophthora issues again," says Adam Spelhaug, Peterson Farms Seed, Harwood, N.D.,
Phytophthora does not needs moisture to survive," says Matt Hubsch, Legend Seeds, DeSmet, S.D., "Its spores can live in soil, waiting for just the right conditions for years and years."
They recommend selecting a soybean variety with the Rps3a gene
"Rps1k and Rps1c have been the most used resistance genes in the past 10-15 years, but we have started to see issues now with these as we have selected against them," Spelhaug says. "The fields and plots I looked at in 2011 really showed the advantage of the Rps3a gene. In our replicated test plot in our heavy ground plot (Fargo clay with limited drainage) each replicate that had a variety with the 3a gene showed uniform stands and growth versus the other plots."
The Rps3a picks up race 25 -- a new race of Phytophthora that is out there -- plus races 3 and 4, Hubsch says.
He also recommends treating seed with CruiserMaxx Vibrance