Minimize Soybean Yield Loss from White Mold
What is White Mold?
Sclerotinia stem rot, more commonly called “white mold,” is a very common and widespread soybean fungal disease (Sclerotinia sclerotiorum). Losses from this disease can be extreme depending on the year and the amount of inoculum in the soil, and it can spread to more fields if not managed properly.
Because white mold symptoms aren’t prevalent until late in the season, it’s important to know the factors that encourage growth and when you’re likely to see it so you can manage it as early as possible.
Disease Development
White mold infections occur at flowering in sustained wet soil or in high humidity, and thrive in temperatures lower than 85° Fahrenheit, according to the Soybean Research and Information Initiative.
Unless you’re scouting for white mold, foliar symptoms (yellow or brown leaves) will not appear until the fungus has progressed enough to kill the plant. University of Wisconsin Extension recommends that growers examine stems for white mold fungus, beginning as gray to white lesions at the nodes.
COMMON SYMPTOMS
A white growth on stems that appears fluffy or cottony
Dark black sclerotia along the stem or bean pods
Bleached or light-colored stems as soybeans become dry or die
Management and Prevention
To get ahead of white mold in your fields, one very good option is applying seeds treatments that offer protection against white mold, especially if there is a history of the disease in your fields. Furthermore, consider scouting early and continue evaluating your soybean fields for damage. If your fields have a history of this disease or you experience prime and consistent environmental conditions for white mold growth (cool, wet, and humid weather at flowering), you may need to consider a fungicide application. The timing of your application is critical for reducing the impact of white mold. Apply close to the R1 growth stage.
Cultural control for white mold may offer the best disease management if you experience persistent disease pressure year to year.
To reduce the prevalence of white mold:
Select management practices that work to reduce the fungal population in your fields
Carefully consider plant populations and row spacing in the future
Plant a variety with built-in resistance
Unified Ag Solutions offers N-COMPASS brand F/I SDS-White Mold Soybean Seed Treatment.
It’s an all-encompassing blend of fungicides, insecticides, polymer and stabilizers, as well as biological stimulants to bolster root development and plant health. It provides outstanding protection against Sudden Death Syndrome, White Mold and a variety of pests and diseases.