Brown patch on Zoysia

Discussion in 'Pesticide & Herbicide Application' started by pben, Nov 3, 2004.

  1. pben

    pben LawnSite Member
    from Israel
    Posts: 8

    I've got brown patch (Rhizoctonia solani) starting on Zoysia El Toro. Most fungacides seem to slow down the spread of it and nothing seems to irradicate it.
    Suggestions please?
     
  2. Coffeecraver

    Coffeecraver LawnSite Senior Member
    from VA.
    Posts: 793

    Yellow Patch (also known as Cool Season Brown Patch)
    Causal Agent:
    Rhizoctonia cerealis

    Susceptible Turfgrass:
    Bentgrass, Kentucky bluegrass, annual bluegrass, perennial ryegrass,
    bermudagrass, zoysiagrass
    Symptoms:
    The symptoms of yellow patch (cool season brown patch) can vary depending
    on the grass cultivar, climactic and atmospheric conditions, soil and intensity
    of the turfgrass management. This disease occurs from the fall through the
    spring or as the warm season grasses approach or break dormancy. It causes
    rings and patches or circular patches that are yellow, light-brown or
    reddish-brown in color and that measure 5 inches to several feet in diameter.
    Leaf lesions rarely occur and gray "smoke rings"—thin borders around the
    diseased patches—never occur. Damage is generally superficial but thinning
    can occur during prolonged periods of wet weather in late winter and early
    spring. Yellow patch can also be a problem on overseeded greens
    (Poa trivialis) in the southern states.

    Conditions Favoring Disease:
    Yellow patch favors temperatures less than 60°F. It also occurs in areas that
    experience more than 10 hours a day of foliar wetness for several
    consecutive days. This disease is more severe in turfgrass with excessive
    thatch and high nitrogen levels.

    Management Tips:

    Use low to moderate amounts of nitrogen, moderate amounts of phosphorous
    and moderate to high amounts of potash.
    **Increase the air circulation.
    **Minimize the amount of shade.
    **Improve the drainage of the turf.
    **Reduce thatch.
    Chemical control ( Be sure to read the Label)
    Heritage
    Banner MAXX
    Medallion
     
  3. SWD

    SWD LawnSite Senior Member
    Posts: 989

    There is nothing to erradicate it. Most turf pathogens, particularly root borne, are constantly present in or on the turf. When in balance, turf shows no stress, yet when the pathogen overtakes the turf, the fungicide exists to supress the pathogen thereby restoring the balance.
    Actually there is a fungicide that had tremendous preventative and even better currative activity. Look for the heavy metal based mercury cadminium fungicides. Check the local agricultural suppliers, possibly those out of country near yours. I can tell you they aren't available in the US.
    As far as suggestions, a good reference for you is entitled Compendium of Turfgrass Diseases. ISBN 0-89054-124-8, printed by APS Press.
    As a quick tip, once the disease is id'd, do a web search on fungicides, pay attention to the actual fungicide listed, not the trade name - you stand a good bet they are available locally under a different trade name.
    Any other questions, PM me and I will try to assist.
     

Share This Page