Brown Patch Fungus Disease
And
Take-All Fungus Disease
In Lawns
People who love their lawns in this area are REALLY upset about
Brown patch fungus damage to the appearance of lawns. Most of
the grief is about the damage that occurred last fall. As the
old saying goes, "It doesn't do any good to cry about spilled
milk!" or, as tough Texans like to say, "It doesn't
do any good to shut the corral gate after the livestock are
running loose!" The damage done by Brown patch was done
last fall AND TREATING THE DAMAGED AREA NOW WILL NOT HELP! The
areas affected by Brown patch last fall will be slower to green
up this spring but THEY WILL GREEN UP because BROWN PATCH FUNGUS
DOES NOT KILL! Just apply your spring application of fertilizer
AFTER you have mowed the lawn twice and ignore the weakened
Brown patch affected area. In several weeks you will not be
able to find it. If you want to insure a faster and complete
coverage of the damaged area, you can plant some plugs of grass
in the most barren areas.
I AM NOT saying that your troubles with Brown
patch are over. Given adequate moisture and high humidity, plus
temperatures in the 70's and 80's, means more plant disease-especially
Brown patch. But you DO NOT need to treat until you see the
first signs of Brown patch reappearing in exactly the same areas
that were affected last fall and that were so slow to green
up this spring. Once the damage begins to appear, you MUST treat
immediately with the best fungicide in the proper manner to
avoid severe damage to the lawn this spring and subsequent ugliness
all summer long.
Fungicides cannot repair the damage done by fungus;
they can only prevent the occurrence or spread of it. The most
important concept to remember in disease control is "an
ounce of prevention is worth a pound of cure." This is
the opposite of insecticides, most of which kill insects on
contact or when the insect eats the pest-control material covering
the plant. Therefore, fungicides should be applied when the
opportunity for disease raises its ugly head. Cool temperatures,
high humidity and available water are the perfect conditions
for most fungal diseases to attack. Increased growth of the
grass makes it more susceptible to Brown patch. This means that
all of those folks who "love" their grass so much
that they fertilize it twice a month and water it every three
days actually STIMULATE Brown patch proliferation. All of that
fertilizer may make the lawn nice and green for a while but
just wait until those cute brown spots begin to grow aggravated
by watering too much!
Brown patch is identified as a circular area
in the lawn, usually 3 to 10 feet in diameter. In the edge of
the area you will see browning or yellowing grass, yet the interior
of the circle may be a more healthy green. Pull blades of grass
at the edge of the circle. If the blades pull easily away from
the stems and look brown and rotted at the base of the blades,
then your lawn does have Brown patch and should be treated quickly.
Bermuda grass lawns have much less problems with Brown patch
but can still contract the disease.
Chemical controls recommended for Brown patch
are l) terrachlor - PCNB (ex. Turfcide, Fertilome - Lawn Disease
Control) and 2) bayleton (ex. Greenlight FungAway). The best
product seems to be the granular form of terrachlor but, because
it is so expensive, you must use it judiciously and precisely.
Watch for the small yellow patches (NO! It's not the neighbor's
dog violating your lawn space and depositing liquid waste!).
Treat the spot IMMEDIATELY with terrachlor granules and then
treat a 3-foot area around the spot. To avoid spreading the
fungus DO NOT WALK THROUGH infected areas when they are wet
or let pets run through the wet grass-a pet's feet are smaller
but they have more of them. DO NOT, hear me, DO NOT MOW GRASS
WHEN IT IS WET! Not only will it stain your clothing and clog
the mower but, as you trot merrily around the damp or wet lawn,
you become a disease spreader. Worse than Typhoid Mary, your
wet body parts and the lawnmower act as a vehicle of transport
for one of the worse fungus diseases of turf grass in Texas-Brown
patch.
Another way to discourage Brown patch after the
rains of spring is to eliminate watering in the evening. Water
droplets that stay on the grass all night will spread the Brown
patch spores. Therefore, water in the early morning hours so
that the grass will dry out during the day and before nightfall.
Thorough watering of lawns once a week is normally sufficient.
The people who love their lawns so much that they give grass
a "cool drink" every couple of days during the summer
can actually stimulate Brown patch disease in the middle of
the summer.
Now you know the "game plan" to protect
your precious lawn from one of this area's most serious lawn
problems in the fall and springi-Brown patch.
But, what if you have Brown patch-like symptoms
in the heat of the summer? Unlike Brown patch that is normally
a circular area with the edge of the circle having browning
or yellowing grass and the interior of the circle having a more
healthy green appearance, this patch disease symptom has brown,
dead grass throughout the circle. This summer-patch disease
is referred to as Take-All Patch. The products used to control
Brown patch DO NOT control Take-All Patch. For complete information
about control of Take-All Patch, see:
http://www.plantanswers.com/root_rot_fungus.htm
and the bottom section of:
http://www.plantanswers.com/garden_column/102001_slides/1020.htm