Wet Conditions Promote Fungus in Lawns

 

 by Tom Samples, UT Turfgrass Specialist

If you grow or manage a bermudagrass lawn in Tennessee, you may notice that this year several plants may have strange looking seedheads. Experts with University of Tennessee Extension say the odd seedheads may not contain seeds at all.

​These strange looking seedheads on bermudagrass are really bermudagrass inflorescence smut, which is caused by a fungus. Photo by A. Windham, UT Institute of Agriculture

“A dark, powdery substance may appear where viable seeds should be. This condition, referred to as bermudagrass inflorescence smut, is caused by a fungus,” said Tom Samples, a UT Extension turfgrass specialist. His colleague in the Department of Plant Sciences, Brandon Horvath, added that symptoms often go unnoticed until black, powdery spores, called teliospores, become noticeable to humans, for example when the teliospores discolor shoes and socks after you walk across the diseased turf.  Pets may also track spores indoors.

The fungus, Ustilago cynadontis, lives inside the bermudagrass plant. Both common and hybrid bermudagrasses are susceptible. Alan Windham, a plant disease specialist with UT Extension, says fungicides will not control this systemic fungal pathogen.  He also says you need not worry for the health of your lawn.  “Although unsightly, the fungus does not pose a threat to bermudagrass leaves, tillers and above- or below-ground stems. Applying a fertilizer containing nitrogen may help maintain vegetative growth, and frequent mowing will remove the infected seedheads,” Windham said.   

 

Bermudagrass inflorescence smut is just one of more than 1,400 species of fungi that are usually more prevalent during rainy periods in late spring and early summer. Fungal activity slows down somewhat as summer progresses, the UT experts said.

For more information about turfgrass production and maintenance go online to the UT Extension turfgrass website: http://tennesseeturf.utk.edu or visit the UT Extension publications website: http://utextension.tennessee.edu/publications You may also look online at the national extension website:  http://extension.org

UT Extension provides a gateway to the University of Tennessee as the outreach unit of the Institute of Agriculture. With an office in every Tennessee county, UT Extension delivers educational programs and research-based information to citizens throughout the state. In cooperation with Tennessee State University, UT Extension works with farmers, families, youth and communities to improve lives by addressing problems and issue at the local, state and national levels.