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There are three types of disease that
we see most often are
BROWN PATCH
Brown Patch
is most common to St. Augustine Grass It is usually the most
active in the fall, but can occur in the late spring. Typical symptoms are
circular areas with brown centers with a yellow to light green band outlining
the brown area. The fungus is active within the yellow to green
area.
Conditions to watch for are: cloudy
days, excess moisture, night time temperatures from 65 - 70 degrees, and day
time temperatures in the mid 70's to mid 80's, and with excess nitrogen
available in the soil.
Treatment should begin at the first
sign of yellowing rings in the lawn. Effective fungicides are available such as
Sentinel, Eagle, and Daconil 2787. Depending on which fungicide is used,
treatments are made every 14 days to 30 days. Treatment must continue as long
as conditions are right for brown patch to occur.
Prevention of Brown Patch is
difficult, but here are a few suggestions: Do not use urea or nitrate based
nitrogen fertilizers in the late summer of fall; Do make sure that your lawn
drains, and that there are no areas where excess moisture stands.
TAKE ALL PATCH
Take
All Patch is a recently identified soil borne disease that looks similar to
Brown Patch except that it occurs when the temperature is too high for Brown
Patch to be active in the summer, and too cold for it to occur in the spring.
Unlike Brown Patch, this disease CAN kill the grass if not treated; multiple
treatments of fungicide are usually needed.
If Take All Patch is diagnosed in
your lawn, it can be treated with Sentinel, Eagle, or a combination of Daconil
2787 and Benelate
If you have had Take All Patch in
your lawn in the past, treatment with Rubigan in the fall is the only
preventative measure. If you have not had this disease in your lawn you may
apply the above mentioned fungicides during the springtime.
GRAY LEAF SPOT
Gray
Leaf Spot or Leaf Spot affects mainly bermuda grasses and in rare cases St.
Augustine grasses from springtime to fall. It appears as elongated circular
spots on the grass blades with a brown or straw colored center, and black to
purplish borders; and occurs during wet, humid weather. You will probably find
this disease first appearing in shady areas of the lawn.
You can use Anilazine,
chlorothalonil, or mancozeb to control this disease, treating it as soon as you
observe the symptoms, and repeating treatments every 20-30 days until it goes
away. |
