Lee Butler and Lane Tredway
Department of Plant Pathology
North Carolina State University
The summer of 2008 has been vastly different from that of 2007 in that most of the state has seen rainfall on a semi-regular basis. This increase in moisture has led to an increase in Pythium root rot activity on creeping bentgrass putting greens across much of North Carolina in recent weeks.
The symptoms of Pythium root rot are typically very irregular in shape and tend to have no set pattern about the distribution, however a patch type symptom may be observed on occasion. These affected areas often start out looking orange and/or yellow and turn brown and/or tan rapidly. Although damage is usually worse in poorly drained or low lying portions of a green, it is not limited to those areas and can even be found on humps and ridges.
Fungicides are available for Pythium root rot control, and should be applied prior to forecasted wet periods or shortly there after. Just remember that when applying fungicides for Pythium root rot you will need to water the product in to the depth of your root system, which can vary greatly from course to course.
For more information about Pythium root rot and preventative fungicide programs, please visit the following link: