Managing White Mold in Soybeans and Dry Beans: What Farmers Need to Know This Season

The contents of this blog come from an interview conducted with Ken Deibert, BASF Technical Service Representative.

As planting season moves forward across farm country, growers are already thinking ahead to the diseases that can threaten yield potential later in the summer. One of the biggest concerns for soybean and dry bean producers is white mold — a disease that can cause significant yield losses if conditions are favorable and fields are left untreated.

I recently spoke with BASF Technical Service Representative Ken Deibert about what farmers should watch for this growing season, how white mold develops, and what management tools are available to help protect crops.

White mold primarily affects broadleaf row crops including soybeans, dry beans, canola, and sunflowers. According to Deibert, the disease becomes most active around row closure and early reproductive growth stages.

“In soybeans, we really target applications at the early R2 stage, which lines up very closely with row closure,” Deibert explained. “That’s when the earliest flowers begin to dry down, and that’s where white mold infections often begin.”

The disease survives in the soil through structures called sclerotia, which can remain dormant until moisture conditions are right. When fields receive adequate moisture, those structures germinate and produce small mushroom-like bodies that release spores into the crop canopy.

Once spores infect dying flower tissue, the disease can quickly spread throughout the plant.

Deibert noted that fields with a history of white mold often continue to see pressure in future growing seasons, making long-term management especially important.

“There are definitely some cultural practices growers can use to help manage white mold,” he said. “Crop rotation is one of the biggest tools.”

Rotating out of susceptible broadleaf crops and into non-host crops like corn or wheat can help break the disease cycle and reduce future infections.

Row spacing can also play a role. Narrow rows often create denser canopies with reduced airflow, which keeps leaves and soil surfaces wetter for longer periods of time — ideal conditions for white mold development.

“If we can dry that canopy out a little bit with wider rows, that certainly helps,” Deibert said. “But at the same time, growers also have to balance that with yield goals.”

In addition to cultural practices, fungicide timing remains critical for white mold management.

Deibert highlighted BASF’s new Zorina fungicide, which is designed to target white mold while also expanding disease protection in several crops.

In soybeans, Zorina also helps control frogeye leaf spot, while in dry beans it adds protection against dry bean rust.

“We’re excited about Zorina because it’s doing everything Endura was doing and more,” Deibert said. “It expands that disease footprint while maintaining strong white mold protection.”

Application timing and rates vary depending on the crop, but soybean applications are generally targeted around early R2 growth stages near row closure.

As growers head into the season, Deibert encouraged producers to work closely with local agronomists and crop advisors to evaluate disease risk, field history, and application timing.

With favorable environmental conditions, white mold can become aggressive quickly. But with careful planning, crop rotation, canopy management, and timely fungicide applications, farmers can take important steps to protect yield potential throughout the growing season.