Diseases ›

Yellow Patch

Symptoms

Yellow patch is a common disease of cool-season turfgrasses (bentgrasses, bluegrasses, fescues) during the fall, winter, and spring. Symptoms appear as irregular patches or rings up to 3 feet in diameter that are yellow or white in color. Multiple rings or patches may coalesce to form large, irregularly-shaped areas. Individual plants exhibit a yellow dieback of leaves or blighting of entire plants. No distinct lesions are evident on the affected plants. Recovery from yellow patch can be very slow because it occurs at a time of the year when the turf is growing slowly.

Development Factors

Yellow patch develops during extended periods of cool, cloudy, wet weather. The pathogen is most active when temperatures are between 50°F and 65°F, but may cause infections under a broader temperature range (45°F to 75°F). Excessive nitrogen applications, heavy thatch accumulations, and poor soil drainage also encourage development of this disease.

Cultural Control

Avoid high rates of nitrogen (>0.25 lb N/1000 ft2) during the late fall and early spring when yellow patch is most active, and use slow release fertilizers during this time so as to prevent flushes of foliar growth. Ensure adequate surface and subsurface drainage, and aerify and topdress to reduce thatch accumulations. Pruning or removal of trees will increase sunlight penetration and speed recovery from yellow patch if symptoms appear.

Chemical Control

Yellow patch is best controlled on a preventative basis where it is a persistent problem. Curative applications will prevent further spread, but recovery will be slow if weather conditions are not conducive to turfgrass growth. In North Carolina and other areas of the southern United States, yellow patch can be controlled curatively as fluctuating temperatures in fall, winter, and spring lead to intermittent periods of disease development and turfgrass growth.

Fungicide and Formulation1
Amount of Formulation2
Application Interval3
Efficacy Rating
Resistance Risk
Fungicide and Formulation1

azoxystrobin
(Heritage, Strobe)
(Heritage TL)
(Heritage G)
(Strobe L)

Amount of Formulation2


0.4
2
2 to 4 lbs
0.38 to 0.77

Application Interval3


28
28
14 to 28
28

Efficacy Rating

++++



Resistance Risk

Low



Fungicide and Formulation1

azoxystrobin + acibenzolar-S-methyl (Heritage Action)*

Amount of Formulation2

0.2 to 0.4

Application Interval3

14 to 28

Efficacy Rating

++++

Resistance Risk

Low

Fungicide and Formulation1

azoxystrobin + chlorothalonil (Renown)*

Amount of Formulation2

2.5 to 4.5

Application Interval3

14 to 28

Efficacy Rating

++++

Resistance Risk

Low

Fungicide and Formulation1

azoxystrobin + difenoconazole (Briskway)*

Amount of Formulation2

0.5 to 0.725

Application Interval3

14 to 28

Efficacy Rating

++++

Resistance Risk

Low

Fungicide and Formulation1

azoxystrobin + propiconazole (Headway)
ME
G

Amount of Formulation2


3
2 to 4 lbs

Application Interval3


28
14 to 28

Efficacy Rating

++++

Resistance Risk

Low

Fungicide and Formulation1

azoxystrobin + tebuconazole (Strobe T)*

Amount of Formulation2

1.5

Application Interval3

14 to 21

Efficacy Rating

++++

Resistance Risk

Low

Fungicide and Formulation1

chlorothalonil + fluoxastrobin (Fame C)*

Amount of Formulation2

3 to 5.9

Application Interval3

14 to 28

Efficacy Rating

++++

Resistance Risk

Low

Fungicide and Formulation1

chlorothalonil + propiconazole + fludioxonil (Instrata)*

Amount of Formulation2

8 to 11

Application Interval3

late fall

Efficacy Rating

+++

Resistance Risk

Low

Fungicide and Formulation1

chlorothalonil + thiophanate-methyl (Spectro) *

Amount of Formulation2

3 to 5.76

Application Interval3

14 to 21

Efficacy Rating

++

Resistance Risk

Low

Fungicide and Formulation1

fludioxonil (Medallion)

Amount of Formulation2

0.5

Application Interval3

1 application

Efficacy Rating

++

Resistance Risk

Low

Fungicide and Formulation1

fluoxastrobin (Fame)
SC
G

Amount of Formulation2


0.36
2.3 to 4.6 lbs

Application Interval3


28
14 to 28

Efficacy Rating

++++

Resistance Risk

Low

Fungicide and Formulation1

fluoxastrobin + tebuconazole (Fame T)*

Amount of Formulation2

0.45 to 0.9

Application Interval3

21 to 28

Efficacy Rating

++++

Resistance Risk

Low

Fungicide and Formulation1

flutolanil (Prostar)

Amount of Formulation2

1.5

Application Interval3

21 to 28

Efficacy Rating

+++

Resistance Risk

Low

Fungicide and Formulation1

metconazole (Tourney)

Amount of Formulation2

0.37 to 0.44

Application Interval3

late fall

Efficacy Rating

+++

Resistance Risk

Low

Fungicide and Formulation1

propiconazole (Banner MAXX, Propiconazole)

Amount of Formulation2

3 to 4

Application Interval3

late fall

Efficacy Rating

++

Resistance Risk

Low

Fungicide and Formulation1

tebuconazole (Mirage)*

Amount of Formulation2

1 to 2

Application Interval3

21 to 28

Efficacy Rating

++

Resistance Risk

Low

Fungicide and Formulation1

triticonazole
(Triton FLO)
(Trinity)

Amount of Formulation2


0.55 to 1.1
1 to 2

Application Interval3


21 to 28
21 to 28

Efficacy Rating

+++

Resistance Risk

Low

Fungicide and Formulation1

triticonazole + chlorothalonil (Reserve)*

Amount of Formulation2

3.2 to 5.4

Application Interval3

21 to 28

Efficacy Rating

+++

Resistance Risk

Low

1 Other trade names with the same active ingredients are labeled for use on turfgrasses and can be used according to label directions.
2 Apply fungicides in 2 to 5 gallons of water per 1,000 square feet according to label directions. Use lower rates for preventive and higher rates for curative applications.
3 Use shorter intervals when conditions are very favorable for disease.
* Products marked with an asterisk are not labeled for home lawn use.

Efficacy Rating
++++ = excellent control when conditions are highly favorable for disease development
+++ = good control when disease pressure is high, excellent control when disease pressure is moderate
++ = good control when disease pressure is moderate, excellent control when disease pressure is low
+ = good control when disease pressure is low
? = not rated due to insufficient data

Resistance Risk
Low = Rotate to different chemical class after 3-4 applications; tank mixing not necessary
Medium = Rotate to different chemical class after 1-2 applications; tank-mixing with low or medium risk product recommended
High = Rotate to different chemical class after EVERY application; tank-mix with low or medium risk product for EVERY application
? = not rated due to insufficient data

Presentations

Publications

Species Data

Host species

creeping bentgrass, annual bluegrass, Kentucky bluegrass, tall fescue

yellow patchabg10 ltc
yellow patchabg10 ltc
yellow patchabg10 ltc
yellow patchabg11 ltc
yellow patchabg11 ltc
yellow patchabg11 ltc
yellow patchabg12 ltc
yellow patchabg12 ltc
yellow patchabg12 ltc
yellow patchabg13 ltc
yellow patchabg13 ltc
yellow patchabg13 ltc
yellow patchabg3 ltc
yellow patchabg3 ltc
yellow patchabg3 ltc
yellow patchabg6 ltc
yellow patchabg6 ltc
yellow patchabg6 ltc
yellow patchabg9 ltc
yellow patchabg9 ltc
yellow patchabg9 ltc
yellow patchabg ltc
yellow patchabg ltc
yellow patchabg ltc
yellow patchbent20 ltc
yellow patchbent20 ltc
yellow patchbent20 ltc
yellow patchbent6 ltc
yellow patchbent6 ltc
yellow patchbent6 ltc
Months with symptoms

October to March

Stand symptoms

patches (4 to 12 inches), rings

yellow patchabg10 ltc
yellow patchabg10 ltc
yellow patchabg10 ltc
yellow patchabg11 ltc
yellow patchabg11 ltc
yellow patchabg11 ltc
yellow patchabg12 ltc
yellow patchabg12 ltc
yellow patchabg12 ltc
yellow patchabg13 ltc
yellow patchabg13 ltc
yellow patchabg13 ltc
yellow patchabg3 ltc
yellow patchabg3 ltc
yellow patchabg3 ltc
yellow patchabg6 ltc
yellow patchabg6 ltc
yellow patchabg6 ltc
yellow patchabg9 ltc
yellow patchabg9 ltc
yellow patchabg9 ltc
yellow patchabg ltc
yellow patchabg ltc
yellow patchabg ltc
yellow patchbent20 ltc
yellow patchbent20 ltc
yellow patchbent20 ltc
yellow patchbent5 ltc
yellow patchbent5 ltc
yellow patchbent5 ltc
yellow patchbent6 ltc
yellow patchbent6 ltc
yellow patchbent6 ltc
Foliar symptoms location/shape

dieback from leaf tip, blighting of entire leaves, leaf lesions

Foliar symptoms color

yellow

Root/Crown symptoms

none

Fungal Signs

none