Released July 10, 2009
LITTLE ROCK, Ark. - Proper watering and mowing can help stop dollar spot, a fungal disease that attacks stressed lawns, said Steve Vann, extension urban plant pathologist for the University of Arkansas Division of Agriculture.
"Dollar Spot is a very common disease of turfgrasses that we see every year … especially this time of year when temperatures get quite a bit warmer than normal," he said.
The disease is common in Bermuda and zoysia lawns and attacks the above-ground parts of the plant. Typical symptoms include small dead, browned patches of about 2- to 3-inches in diameter that occur during hot, dry weather.
"However, most homeowners don’t take notice until these small spots merge into larger patches," Vann said.
Another key symptom can be spotted early in the morning.
"Homeowners can go out in their lawn first thing in the morning and examine these dead areas, and see a white fuzz that resembles cobwebs growing on those dead areas," he said.
Another symptom is light and dark bands or lines on the individual leaf blades.
Because the disease takes advantage of drought- and heat-stressed grass, dollar spot can be managed by good fertility and good soil moisture. Homeowners can also temporarily raise the cutting height by 0.5 to 1.0 inch.
"It’s also a good idea to maintain the appropriate cutting height of your individual grass," he said. "If we tend to cut our grasses too short, this may make them susceptible to a lot of infectious diseases."
There are several chemicals that can be used as a last resort to control this particular disease. Those that contain the active ingredient of propiconazole, myclobutanil or triadimefon are effective for this disease. One of the options for a homeowner may include the fungicide called Fertilome Liquid Systemic Fungicide that is labeled for this particular disease. Also another homeowner product is called Immunox.
Growing strong turf means proper fertilization, which Vann said should be done based on a recent soil test. Soil tests can be conducted free of charge through your county extension office.
"As far as irrigation practices go, it’s always a good idea to irrigate your yard early in the morning, primarily between the hours of 4 a.m. and 8 a.m.," he said. "This reduces the chances of other turf diseases getting started and allows that grass to dry out by at least mid to late morning."
Homeowners should irrigate deeply, but infrequently. Always avoid shallow, frequent irrigations that produce shallow roots prone to drought stress.
Helpful information may be found online at http://www.uaex.edu, including "Mowing Your Lawn," http://www.uaex.edu/Other_Areas/publications/PDF/FSA-6023.pdf, and "Fertilizing your Lawn," at http://www.uaex.edu/Other_Areas/publications/PDF/FSA-2114.pdf.
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http://www.uaex.edu/news/july2009/0710dollarspot.htm
Contact: Elizabeth Fortune, (501) 671-2120, efortune@uaex.edu
