Brown Patch
Brown patch is active in the southeast and into the northern United States where hot humid weather along with nighttime temperatures exceeding 70s are present. Thunderstorms are hitting (and missing) through the region adding moisture to areas that have been dry. It is not surprising to see Rhizoctonia blight (or more commonly known as brown patch) active especially in shaded or low lying areas. The thing that is a little different is that some of the brown patch may not produce the "picture perfect" symptoms. The result is some self-doubt in what actually is causing the disease. For example, some brown patch this morning had mycelium present, or in other cases the patch may be the diameter of a spread hand with inner part of the circle appearing healthy.
Rust
Rust is appearing in many cool season lawns. Rust is often associated with slow-growing perennial ryegrass but may also occur on Kentucky bluegrass. Rust is especially severe on drought stress perennial ryegrass because it actually enhances water loss. In areas where conditions were dry prior to the cool wet weather, rust would likely be active. Rust is also present in shaded areas. Often times walking through these areas will turn your shoes and socks a reddish-orange color. Closer observation of the leaf blades reveals the brownish-orange colored pustules on the leaf. Rust will become more severe if the turf growth slows or becomes stressed. Cultural control practices include nitrogen fertilization, to stimulate growth and irrigation, if the areas infected undergo water stress.
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