Brown Stem Rot in Soybeans: Identification and Management

Brown Stem Rot (BSR) is a common yet often overlooked fungal disease in soybean production. Caused by Phialophora gregata, BSR thrives under cool, moist conditions and can reduce yields by up to 30%—most commonly around 15%. Early detection and proactive field management are key to minimizing its impact.

How to Identify BSR

BSR symptoms are not always visible at early stages. The most reliable diagnosis occurs during the reproductive phase by splitting the soybean stem lengthwise.

Key indicators include:

- Yellowing and browning between leaf veins (interveinal necrosis)

- Premature leaf drop and plant wilting

- Distinctive brown discoloration of the stem pith, especially near nodes

These symptoms can mimic other diseases such as sudden death syndrome, making accurate scouting essential.

Recommended Management Practices

Effective control of BSR requires an integrated agronomic approach. Here are the most reliable strategies:

1. Plant BSR-resistant soybean varieties – Select genetics with proven tolerance to the disease.

2. Rotate crops – Use a 2–3 year rotation with corn or small grains to break the disease cycle.

3. Manage crop residue – Tillage or shredding can reduce fungal survival in residue.

4. Maintain optimal soil pH (6.5–7.5) – Use King’s Landing SoilVitalizer to optimize soil pH and structure, creating a more suppressive environment against BSR development.

5. Control soybean cyst nematode (SCN) – Apply King’s Nema Off, a targeted nematode management solution, to reduce SCN pressure and its synergistic impact on BSR severity. King’s Landing TerraBoost enhances root vigor and resilience, supporting continuous growth even under nematode stress.

6. Avoid sole reliance on fungicides – Foliar fungicides and seed treatments are ineffective against BSR.

Protecting Your Yield Starts with Vigilance

BSR may remain hidden until significant damage is done. By incorporating disease-resistant genetics, maintaining healthy soil conditions with King’s Landing TerraBoost, and managing nematode populations using King’s Nema Off, soybean growers can mitigate risk and safeguard their harvest.

Need field-specific guidance or integrated disease control solutions?
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