Question
We live in central Nebraska and have serious fungus/rust problems in our new bluegrass lawn.  Our lawn service sprayed for the fungus, but it seem to be getting worse.  We have had a fairly cool summer, have underground sprinklers and have applied at least 1" of water every week.  Should we water more?  Today when I mowed, there was a cloud of orange dust around the mower, the rust is so bad.  Help!!!  

Answer
Hi Pat,

>"...seems to be getting worse..."?

Make sure your BLUEGRASS areas are getting lots of sun-light, good drainage and are not being over-watered.  These are the main causes of fungus diseases in turf-grasses.

The 'orange-dust' you mention is the millions of microscopic SPORES that can lay dormant in the soil and cause future infestations.  Lawn equipment and tools should be cleaned and sterilized with a 10% bleach solution.

KYB is susceptible to a number of fungal diseases including dollar spot, leaf spots, stripe smut, powdery mildew and summer patch.  Rusts are apparently less common, and your report is the first I have found.  Rust fungi can be voracious in attacking a suitable host plant and they can damage many types of commercially valuable plants. Rust fungi can become a chronic problem with certain conditions being in their favor.

KYB is considered a cool-climate grass-type and will not do well once temperatures rise above 85 degrees F. When under heat-stress, most cultivars will show diminished resistance to damage from insects, diseases and drought. With cooler weather, the problem may subside.  However, the spores from the fungi may remain on the scene to continually cause infestations.

Rust fungi can also attack many other species of plants and so the disease can rapidly spread through-out the entire neighborhood to include roses, apple and pear and other plants.  And as stated the infestations can become chronic and recurring.  If you see that this is the case, you are advise to destroy the entire lawn.  Under-till the top-soil and keep it fallow for a while.  You can then re-establish a lawn with a more disease resistant grass-type.

Cultivars of TALL FESCUE are recommended for their drought and disease resistance.

In summary, do not waste time and money dealing with a difficult fungus disease and a non-resistant grass type.  Up-grade to one of the new high-tech named-patented cultivars the grass breeders have been able to produce for the world's markets.
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If you decide to continue to battle the FUNGUS, here is some more information that may help:
(Forgive any repetition here)

FUNGICIDE CHEMICALS Include:

1. Apply a solution of 1/4 oz. IRON SULFATE per half
  gallon of water per square yard.

2. Use FUNGICIDES containing:
  > BENOMYL,
  > thiadendazole,
  > thio-phanate-methyl or
  > quintozone.


Also certain horticultural practices will help:

1. Rake up all dead vegetation and infected vegetation and
  dispose of it in plastic bags.  Do not incinerate infected vegetation,
  this can spread the spores.  Keep rakes and tools
  clean; dipping tools in a bleach solution will help to prevent
  spreading the fungus. Cleaning the under-housing of lawn mowers should also
  help to prevent spreading the spores.

2. Aerating the top-soil should help. Work to improve the drainage of the affected areas.
  Scarify the turf and thatch layer to improve aeration.  Adding some sand and gypsum to
  the root-zone can increase permeability of a compacted soil.   Tilling up the top soil
  strata will help to increase drying conditions. In severe cases, the lawn should be
  destroyed with ROUND-UP (Glyphosate), and the top-soil should be under-tilled and left
  fallow for a while.

3. Use lower or near zero NITRATE levels of fertilizer on the lawn,
  and do not fertilize late in the growing season.
  Too much moisture and nitrate= potential FUNGUS PROBLEMS.

4.  Avoid "Clock-timed" irrigation-watering.  Water only
   in accordance to the grass' needs.
   Almost all turf
   grasses will do fine with 1-3 inches of water per week.
   A healthy lawn should be able to go several days between
   a drenching soak and this practice promotes deeper root
   systems (a great deal depends upon your soil's chemistry
   and physics, however).

5. Where there is shade from trees,...increase the amount of sun-light
  that can reach the lawn areas.  You can sometimes thin-out and prune/shape the
  ambient trees so that the affected areas are more exposed to sun-light, and this can
  help to prevent fungus diseases by promoting dryer conditions.  This is only a
  temporary effect, and the trees may need a work-over every so many years.

6.  If your turf-grass type is more than 15 years old, consider 'up-grading' to one
   of the new super high-tech genetically engineered patented turf-grass hybrids now
   available.  These new lawn grasses have been produced to be more disease resistant.
   They are also more drought resistant, better textured and more care-free.

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Visit this web-site and link to the Lawn Diseases pages for more information and images of these types of diseases of lawn grasses:

http://plantpathology.tamu.edu/Texlab/index.htm
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I Hope this has answered your question(s)!

Visit my Lawn & Gardens webpage for more Lawn and Garden Tips, Facts and Links:
http://hometown.aol.com/eilatlog/lawnol.html

Your Questions and Comments are welcome at ALLEXPERTS.com

___ Jim Gibbs,
    Microbiologist/Botanist