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Brown Ring Patch or Yellow Patch?


Disease activity is relatively slow at this point, but there are some reasons to believe that this will change soon. So far, several cases of brown ring patch and yellow patch (i.e., cool temperature brown patch) have been identified from Pennsylvania to parts of New England. A quick way to distinguish between these two diseases is to incubate a cup-cutter plug in a tuperware container overnight. If mycelium is present in the morning, you are likely dealing with brown ring patch as yellow patch does not produce much visible mycelium.

Main areas of interest throughout the region have focused on annual bluegrass seedhead suppression and the application of early season fungicides for the control of dollar spot or fairy ring. In situations where chronic disease activity occurs, these early season fungicide applications have been shown to reduce the severity of each disease later in the year.

If you are in the Northeast and experiencing other disease problems, feel free to let us know in the comments section.

3 Responses to “Brown Ring Patch or Yellow Patch?”

Jim Connolly said...

How immportant is water volume per 1000 sq ft when trying to control brown ring spot with fungicide? is this a soil borne disease? Why doe it appear in different size ring sizes? Has it been growing outward for weeks, then just suddenly appear?

John Kaminski said...

Jim,

Good questions. I will do my best to answer and see if Frank has any additional information for you. The disease does not appear to be a soil borne disease, but rather resides in the thatch. If left unchecked, it can start to develop sunken patches due to thatch degradation. Higher water volumes would likely be more effective in getting the products into the thatch, but it does not need to be watered in to the soil. As with all diseases (esp. the patch diseases), the pathogen tends to grown in an outward fashion and therefore when conditions are right for symptoms to appear the patch will be approximately the size of the outer edge of where the active pathogen resides. This will vary depending on when infection took place and probably other factors like microclimatic conditions. A good comparison would be take-all patch...the pathogen is active in spring and fall, but symptoms don't appear until the disease is under stress. For more information, check out Frank's early link at http://www.turfpathology.ucr.edu/Downloads/Management_BRP.pdf

Hope this helps.

John

Frank Wong said...

Hi Jim -

John hit most of the important points on the disease already with his post - but just some added points.

Fungicide apps at 2 gal spray volume/1,000 sq ft are adequate since you have to only get the material into the thatch. One turn of the heads can help move it down a little - which can help. But don't water it in with several minutes of irrigation.

All of the cultural practices you do for anthracnose control (topdressing, N-fert, raising mow heights) should help reduce the impact of BRP.

Feel free to email or call me directly through ww.turfpathology.ucr.edu if you need more info.

Thanks,
Frank

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