Plant Diagnostic Clinic
573-882-3019
Figure 1
Symptoms of rhizoctonia brown patch
Rhizoctonia brown patch of tall
fescue
Barb Corwin
Extension assistant professor
Figure
2
Foliar symptoms of
brown patch
Symptoms
The onset of disease may be confused with moisture stress, because affected
areas first appear purplish gray. The areas rapidly fade to light brown as leaves
wither. The disease may occur in distinct patches or as a uniform blighting of
the turf. Distinct light brown lesions with a dark border occur on individual
leaf blades.
Figure
3
Mycelium of Rhizoctonia solani
Conditions
favoring disease
- Temperature
- Daytime mid 80's
- Nighttime 70 or above
- Moisture
- Extended periods of leaf wetness
- High relative humidity
- Excess thatch
- High nitrogen.
With moderating environmental conditions, blighted turfgrass often recovers,
but crown infection can occur during extended periods of high temperature and
high relative humidity. Brown patch symptoms may be unacceptable on high profile
lawns, requiring a preventive fungicide program.
Cultural
management
- Apply no more than 4 lbs nitrogen/1,000 sq ft per year
- Apply most of nitrogen in the fall
- Water between midnight and 6 am to avoid extending periods of leaf wetness
- Avoid frequent irrigation, especially during hot, humid weather.
- Some of the improved turf type tall fescue cultivars have a higher level
of resistance compared to Kentucky 31
Using fungicides
Refer to the table at right for a list of basic fungicides labelled for management
of brown patch.
Basic fungicides labelled for management of brown patch
Azoxystrobin
- Primary registrant
Syngenta
- Selected trade name
Heritage
Captan
- Primary registrant
Drexel
- Selected trade name
Captan
Chloroneb
- Primary registrants
The Andersons
PBI Gordon
- Selected trade names
Tee Time Chloroneb
Teremec SP
Chlorothalonil
- Primary registrants
Syngenta
Lesco
- Selected trade name
Daconil
Manicure
Cyproconazole
- Primary registrant
Syngenta
- Selected trade name
Sentinel
Fenarimol
- Primary registrant
Dow AgroSciences
- Selected trade name
Rubigan
Fludioxonil
- Primary registrant
Syngenta
- Selected trade name
Medallion
Flutolanil
- Primary registrant
Aventis
- Selected trade name
Prostar
Iprodione
- Primary registrant
Aventis
- Selected trade name
Chipco 26019
Mancozeb
- Primary registrants
Dow AgroSciences
Lesco
- Selected trade name
Dithane
Fore
Myclobutanil
- Primary registrant
Dow AgroSciences
- Selected trade name
Eagle
PCNB (quintozene)
- Primary registrants
The Andersons
Uniroyal
- Selected trade names
Pennstar 15G
Turfcide
Propiconazole
- Primary registrant
Syngenta
- Selected trade name
Banner Maxx
Thiophanate methyl
- Primary registrants
The Andersons
Cleary
- Selected trade names
Fungo Flo,
Cleary 3336
Thiram
- Primary registrant
Cleary
- Selected trade name
Spotrete
Triadimefon
- Primary registrant
Bayer
- Selected trade name
Bayleton
Trifloxystrobin
- Primary registrant
Bayer
- Selected trade name
Compass
Vinclozolin
- Primary registrants
The Scotts Company
BASF
- Selected trade name
Vorlan
Curalan
Note
Always read and follow label directions on all pesticides.
Updated
4/1/05
