Soybean white mold, aka Sclerotinia stem rot, is a common problem in North Central fields. Caused by the fungus Sclerotinia sclerotiorum, the occurrence and severity of white mold varies from year to year due to weather conditions. White mold can significantly reduce yield, especially when climatic conditions and management practices are just right.
While there are a few soybean white mold fungicides on the market, the Hefty Brothers encourage growers to look at their soil, especially their manganese level.
“If you feed the crop properly hopefully you don’t even have to spray any of this stuff,” said Brian Hefty, during the 2017 Ag Ph.D. Agronomy Workshop in Baltic, South Dakota Tuesday. “I would encourage you to go out and pull some soil cores and send in for analysis. I would be willing to bet your manganese levels are under 200 ppm in those spots.”
Ag PhD encourages growers to consider these soybean white mold strategies:
- Get your soil manganese levels over 200 ppm.
- Use Contans (fungus that eats sclerotia), preferably in the fall, but you can use it in the spring for no-till or conventional-till.
- Pick a more tolerant seed variety.
- Implement wide row spacing.
- Lower the planting population.
- Use Cobra right before flowering.