Large Patch on Zoysia Grass

Rhizoctonia large patch occurs on zoysia grass in the fall and spring as circular, dis­ colored patches that expand over time . The disease is favored by cool temperatures and wet conditions and may be especially severe in poorly drained. Generally, patches begin to appear in early in April through late May and again in the early fall as temperatures cool and zoysiagrass slows growth before going into winter dormancy (University of Arkansas Extension, 2007).

Patches start as circular, discolored areas. At times, the borders of the patches will be orange, which indicates that the disease is active. The orange border consists of newly infected plants where the lower leaves are just starting to die as the fungus invades and kills the leaf sheath below the blades.

The fairways at Hyde Park are treated in the spring and fall each year for Large Patch. With over 13" of rain in April, signs and symptoms of Large Patch are active in small areas and will be retreated when possible.

This photo is taken on #5 fairway, notice the Large Patch thriving well in a puddle.

Thank-you,

Pat O'Brien

Grounds Superintendent