Need help in identifying disease

Discussion in 'Pesticide & Herbicide Application' started by gegi, May 25, 2005.

  1. gegi

    gegi LawnSite Member
    Posts: 2

    Hello everybody,

    It looks as if this is a forum of expert people so please bear with a hobbyist rookie for a moment.

    Every year since I tried to start a lawn in my garden (three years ago), my lawn grows fine during the autumn and beginning of spring. As soon as I start mowing regularly in spring, the health of the turf rapidly declines and in about a month, most of my grass is suffering from some kind of disease. Basically, the grass turns brownish, then white like straw and dies. It always starts in the most sunny spots but it rapidly extends everywhere. It has no specific shape (no dollar spot, no fairy ring shape) and it is very rapidly widespread.

    The location is Roma, Italy. The lawn is quite small (about 250 square meters). I have done everything I could read in the preparation and maintenance of the lawn. I seeded in October, I used slow release fertilizer, I sharpened the blade of the mower, I cut the grass high, I irrigate deeply, not too frequently and in the morning.

    Basically, I have redone the lawn completely each autumn just to watch it getting destroyed in about a month each spring. Not a pleasant hobby.

    This year, thanks to a digital camera, I managed to take a macro shot of some filaments of grass in the "brownish" stage.

    Judging from some photos I saw on google it looks like rust. But according to the descriptions I have read, rust should not be so devastating as it is in my case.

    Could it be "leaf spot" ?

    Thank you,
  2. Ohio ProTurf

    Ohio ProTurf LawnSite Member
    Posts: 8

    Looks like Rust
  3. Premo Services

    Premo Services LawnSite Bronze Member
    Posts: 1,516

    Looks like a bad case of rust to me too..... :waving:
  4. marko

    marko LawnSite Senior Member
    Posts: 963

    As stated above, it looks like rust. What season are you in in Italy? It sounds like since it is a garden area, nitrogen has been depleted. Rust favors low nitrogen/water situations. It is also easily spread by shoes/equipment. Your best bet is to plant a variety of different cultivars that are resistant to this fungus, apply a good quality slow release nitrogen 4 times a year (if bluegrass/perennial rye grass) with 1 lb of nitrogen per 1000 SF, water 1/2 to 1" a week (in the morning to avoid grass being wet all the time), and when rust does come back, rake or collect the clippings and dispose of them so there are fewer spores.
  5. gegi

    gegi LawnSite Member
    Posts: 2

    Thank you all for replying.

    In Italy it's late spring, btw, north hemisphere. Is there anything I can do to stop the rust from spreading ? a fungicide ? I have got one that is based on Iprodione, I bought it last year when I thought it might be Fusarium. It's a contact fungicide. Is it any good for rust ?

    What about the grass that has apparently died (the one discolored, looking like white straw). Can it recover ? does rust affect the roots ?

    Finally, can there be a connection between the outbreak of the disease and the mowing of the grass ? would mowing less frequently help ?

    Thanks again.

  6. Garth

    Garth LawnSite Senior Member
    Posts: 382

    If it was tip blight or septoria leaf spot I'd recommend a fungicide containing chlorothalonil. It does have an effect on rust but you'd have to apply it at intervals of seven to ten days. A friend of mine was doing research into chemical rust control that affects Antirrhinum majus so badly here in Southern California. I'll see if I can get in touch with him concerning your lawn problem.
    Mowing, watering and walking across the lawn can spread rust. Even a slight breeze can do it. That's the reason it's so hard to control. It spreads rapidly with very little effort.
    If the blades have gone white there's little hope of recovery.
  7. marko

    marko LawnSite Senior Member
    Posts: 963

    Banner, Bayleton, Sentinel, Daconil, and Acti-dione RZ are some that are labeled for rust. I would concentrate more on improving the cultural practices rather than a fungicide. As long as the turf is not always wet, and proper fertilization, it should outgrow it.

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