Cases of the turfgrass disease commonly identified as brown patch — more likely large patch in most warm-season turfgrasses — have spiked during a cool September that broke rainfall records across parts of the state, according to specialists with the Texas A&M AgriLife Extension Service.
Large patch and brown patch are caused by different groups of Rhizoctonia solani, a fungal pathogen, said Dr. Becky Grubbs, AgriLife Extension turfgrass specialist in College Station. The group associated with brown patch in cool-season grasses follows a different life cycle from the one responsible for large patch in Texas’ most common warm-season grasses, including St. Augustine and zoysiagrass.
Large patch appears in circular patches across the lawn with outer edges that are typically orange or yellow. Lesions also appear on infected grass sheaths and stems.
“Our weather over the last month provided the disease with perfect conditions to proliferate this fall,” Grubbs said.
And fall armyworms, whose populations also increased in September, cause damage by eating turfgrass leaves, while large and brown patch keep leaves intact as they rot.
- Shut off irrigation
- Avoid mowing wet turfgrass
- Remove objects causing excess shade
- Aerate to improve drainage and air circulation
- Order a soil test for deep insight on existing problems
- Apply a fungicide as recommended by a specialist
- Fertilize while turf is growing as directed by a soil test; reduce fertilizer in shaded areas
- Discontinue nitrogen application at least six weeks before your area’s historic first frost
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