Recognition of the disease is a major problem. Excessive leaf retention at maturity is another clue that BSR may be present. Farmers and agricultural consultants should know the symptoms and controls of this important soybean disease. The brown stem rot fungus appears to be widely distributed throughout Wisconsin, but it only increases to economic levels when soybeans are continuously or frequently grown in a field. The fungus survives in infested debris in the soil, but drops to low populations if nonhost are grown.
Soybean is the only host for the brown stem rot fungus.
Healthy stem on the right. The fungus produces spores that germinate, invade soybean roots, and progress into the vascular systems of soybean seedlings. The fungus remains restricted to the lower stem until the plant starts pod formation. Infection occurs over a wide range of soil conditions. Greater yield reduction often occurs when dry soil conditions prevail during at least part of the growing season.