Importance
Brown spot, caused by the fungus Septoria
glycines, is present in all soybean fields in
Kentucky. In most years the disease causes
little to no yield impact; however, up to 15%
yield losses can occur in select environments.
For example, brown sport tends to be worse
where soybeans follow no-till soybeans,
where early-maturing varieties are planted,
and/or when fields are planted in late April.
River bottom fields or fields subject to fog or
morning shade are frequently impacted.