Best Management Practices for Anthracnose

Bruce Clarke and James Murphy

John Inguagiato, Joseph Roberts, Charles Schmid, James Hempfling,

and Ruying Wang

turf.rutgers.edu

NE-1046 Multi-State Research Project

Useful references on BMPs:

• Best management practices for anthracnose on annual bluegrass turf. Murphy et al. Aug 2008 GCM.http://www2.gcsaa.org/GCM/2008/aug/pdfs/bestmanagement.pdf

• Best management practices for anthracnose on annual bluegrass. Murphy et al. May 2012 GCM.http://archive.lib.msu.edu/tic/gcman/article/2012may104.pdf

Anthracnose Symptomology

Acervuli on Infected

Poa annua Tillers

Chlorotic

Leaves

Photo: Landschoot,

APS Press

Cultural Management Strategies for the Control of Anthracnose

0.141-inch 0.110-inch

31 August 2005

Mowing Height

Mowing Frequency Effecton Anthracnose Severity

0

20

40

60

80

100

30-Jul 13-Aug 27-Aug 10-Sep 24-Sep 8-Oct

% D

ise

as

e

14 / wk 7 / wk

Lightweight Rolling Practices Effecting Anthracnose

Rolled every other day

No rolling

TRUE-SURFACETM vibratory rollers

The Take-Home message is …

… you can significantly reduce anthracnose and

maintain green speed (ball roll distance) by:

(1) increasing heights of cut AND either

(2) increasing mowing frequency, and/or

(3) initiating frequent lightweight rolling

Nitrogen (N) Fertility

• Crucial to the health and vigor of the turf, which, in turn, affects playability

• 0.1 lb per 1000-ft2 per week (late springthrough summer) reduces anthracnosecompared toevery month

• 0.2 lb per 1000-ft2

per week is better

Nitrogen (N) Fertility

• N at 0.3 to 0.5 lbper 1000-ft2 per weekvery effectiveat reducing anthracnose

• However, as these ratescontinued into thesummer, we see a dramatic increase in disease

Effect of Soluble N Rate on Anthracnose Severity of an Annual Bluegrass Green: 2010

Date

01-Jun-10 01-Jul-10 01-Aug-10 01-Sep-10

Dis

ease

Se

ve

rity

(%

)

0

10

20

30

40

50

60

70

80

90

0.1 lbs 1000 ft-2

0.2 lbs 1000 ft-2

0.3 lbs 1000 ft-2

0.4 lbs 1000 ft-2

0.5 lbs 1000 ft-2

Anthracnose severity response to total N applied

on annual bluegrass in 2009, 2010 and 2011

Total N (lb 1000 ft-2

)

0 2 4 6

AU

DP

C

0

10

20

30

40

50

2010

2011

2009

Superintendent Questions:

What about granular fertilization?

EFFECT OF SEASON OF

GRANULAR N FERTILIZATION

– Spring granular-N reduced disease severity more than autumn granular-N

• Late-season N is not an efficient timing to manage anthracnose disease

– Summer timing is the most effective time to apply N

– Spring compliments the summer program

01-Jun 01-Jul 01-Aug 01-Sep

Dis

ea

se

Se

ve

rity

(%

)

0

10

20

30

40

50

60

70

Autumn

Spring

01-Jun 01-Jul 01-Aug 01-Sep

Dis

ea

se

Se

ve

rity

(%

)

0

10

20

30

40

50

60

70

2009

2010

Season of Granular NGranular N at 4.5 lb per 1,000-ft2

(2/3 total in each season - IBDU)

20 July 2009

No Summer N (0 lbs per 1000ft2)

Autumn Spring

2/3 total Spring Granular (IBDU) 0 lbs 1000 ft-2 Summer 20 July 2009

0 lbs 1.5 lbs

3.0 lbs 4.5 lbs

Granular Rate

Nitrogen Source & Anthracnose

• Recent studies indicate that N Source affects anthracnose severity

EFFECT OF NITROGEN FORM ON DISEASE SEVERITY

0

20

40

60

80

1-Jun 15-Jun 29-Jun 13-Jul 27-Jul 10-Aug 24-Aug

Dis

eas

e S

eve

rity

(%

)

Date

Potassium Nitrate

Ammonium Sulfate

Ammonium Nitrate

Calcium Nitrate

Urea

Untreated Control*

* Untreated control not included in statistical analysis

2012

Potassium can improve winter hardiness and reduce winter injury

Ammonium Sulfate

Potassium Nitrate

Snow Melt / Ice Damage (2011 Rutgers Univ.)

Why Does Nitrogen Source Affect?

- N form- Ammoniacal vs. Nitrate - not solely responsible

- Potassium- May help uptake of N- Stress tolerance

- Soil pH- Ammonium acidifies soil

POTASSSIUM SOURCE STUDY 2012

0

10

20

30

40

50

60

1-Jun 15-Jun 29-Jun 13-Jul 27-Jul 10-Aug 24-Aug 7-Sep

Dis

eas

e S

eve

rity

(%

)

Date

N, no K (1:0)

KCl, no N (0:1)

KCl (1:1)

KCl (2:1)

KCl (4:1)

K2SO4 (1:1)

K2SO4 (2:1)

K2SO4 (4:1)

K2CO3 (1:1)

KNO3 (1:1)

First year data

CONVERSION CHART POTASSIUM RATIOS

Elemental ratio Ratio by Wt. Ratio by Wt. Pounds of K2O Pounds of K2O

N : K N : K N : K2O per application* per year *(16 apps)

1 : 1 1 : 2.8 1 : 3.3 0.34 5.38

2 : 1 1 : 1.4 1 : 1.7 0.17 2.69

4 : 1 1 : 0.7 1 : 0.8 0.08 1.34

* Per 1000-ft2

Typical potassium recommendation 1 : 1 (N : K2O by weight)

ANTHRACNOSE POTASSIUM STUDY10 SEPT. 2012

K2SO4 (1:1)

No Potassium

Anthracnose pH STUDY

SULFUR(0.5 AND 1.0 LB 1000FT-2)

LIME(2.4, 11.7, 24.3, 35.6 AND 46.1 LB 1000FT-2)

pH Effect on Anthracnose (AUDPC): 2011

Target pH

4 5 6 7 8

AU

DP

C

0

5

10

15

20

25

30

R2 =

0.837

Sand Topdressing

Modify thatch/soil

Smooth the surface

Crown protection

Winter protection

Southern Hills CC, Oklahoma

Impact of Summer Topdressing Rate and Frequency on Anthracnose

Interval (days)

7

14

28

Rate (ft3 1000-ft-2)

No sand

1 (0.3 L m-2)

2 (0.6 L m-2)

1 ft3 1000 ft-22 ft3 1000 ft-2

All plots brushed uniformly

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

12-Jun 22-Jun 2-Jul 12-Jul 22-Jul 1-Aug 11-Aug 21-Aug 31-Aug 10-Sep

% D

ise

as

e

0 1 2

a

ab

b

a

b

b

a

b

b

a

b

b

a

b

C

a

b

c

Effect of Topdressing Rate on Anthracnose

of Annual Bluegrass

sand ft3/1,000ft2

What About Sand Typeand Incorporation Method?

Incorporation

– None

– Vibratory roller

– Soft-bristled broom

– Stiff-bristled broom

Sand Type

– Round

– Sub-angular

No

Sand

Sand

1 ft3/1000-ft2

2.0 ft3/1000-ft21.0 ft3/1000-ft2No Sand

Topdressing improves surface characteristics

Firmer surface raises effective height of cut

Deeper crowns reducing stress

Topdressing Practices

• Research indicates that both fall and spring applications reduce anthracnose severity

• Spring topdressing is the most beneficial timing

0

2

4

6

8

10

12

14

0 1 2 3 4 5 6 7

AU

DP

C

Sand L m-2

Anthracnose severity response (AUDPC) to total amount of sand applied (L m-2) during 2009

•1

,00

0 lb

per

1,0

00

ft2

•2

,00

0 lb

per

1,0

00

ft2

Irrigation Management

• Turf growing in saturated soil due to poor surface and slow internal drainage is more susceptible to anthracnose (Sprague and Evaul, 1930; Vargas and Turgeon, 2004).

Irrigation Management

• Field research has confirmed that drought stress also increases anthracnose severity on annual bluegrass

• Specifically, deficit irrigation that subjects turf to frequent wilt stress during warm dry weather (e.g., 40 and 60% ETo) will increase anthracnose disease

Irrigation Practices Influence on Anthracnose of an Poa annua Green

0

10

20

30

40

50

60

70

80

7-Jun 21-Jun 5-Jul 19-Jul 2-Aug 16-Aug

100% ET 80% ET 60% ET 40% ET

Dis

ease

(%

)

Verticutting

• Used to improve surface playability and reduce other problems associated with thatch

• Reputed to enhance anthracnose due to wounding of tissue

Verti-cutting

• Recent detailed studies of mechanical injury indicates that neither wounding of leaves, crowns, nor stolons dramatically affects anthracnose severity

Plant Growth Regulators

The widespread use of PGRs on putting green turf

over the past decade has coincided with increased

incidence of anthracnose

Trinexapac-ethyl (Primo MAXX) is used to reduce

vegetative growth (increased density & vigor)

Mefluidide (Embark) and Proxy (Ethephon)

suppresses seedheads

Objective: Examine the effects of mowing height, N fertility, and topdressing on anthracnose severity and playability of ABG turf.

Factors:

Mowing height0.090 vs. 0.125 inch

N Fertility2.05 vs. 4.1 lb N per 1000 ft2 per yr

Topdressing950 vs. 2400 lbs sand 1000 ft-2

Combining BMPs - 2012

0

10

20

30

40

50

60

7-Jun 28-Jun 19-Jul 9-Aug 30-Aug 20-Sep 11-Oct

% D

ise

ase

0.090 in

0.125 in

7-Jun 28-Jun 19-Jul 9-Aug 30-Aug 20-Sep 11-Oct

Low N

High N

Fig. 2. Anthracnose severity affected by nitrogen fertility

0

10

20

30

40

50

60

7-Jun 28-Jun 19-Jul 9-Aug 30-Aug 20-Sep 11-Oct

% D

ise

ase

Low Sand

High Sand

Fig. 3. Anthracnose severity affected by sand topdressing

Fig. 1. Anthracnose severity affected by mowing height

2012

Controlling Anthracnose Basal Rot with

a Sound Fungicide Program

Chemical Control of AnthracnoseI. Demethylation

Inhibitors(Sterol Inhibitors)

Banner, Bayleton,Eagle, Torque, Tourney, Trinity, Triton

II. Strobilurins Heritage, Compass

Insignia, Disarm

III. Antibiotic Endorse, Affirm

IV. Benzimidazoles

Fungo, 3336

V. Nitriles

Daconil, ChloroStar, Echo, Concorde

Combinations (III/IV, I/II, & I/ IV)

ConSyst, Spectro,

Headway, Tartan , Reserve, Renown,

Pillar, Interface, Concert, Disarm C

Efficacy of DMIs on Anthracnose of ABG

Green – Rutgers 2009

% Turf Area Infested

Applied @ 14 day (15 May – 21 Aug)

c

Good Control of ABR until Late August

٠Phosphonate – fosetyl-Al

• Chipco Signature 80WG (4.0 oz)

٠DMI – myclobutanil

• Eagle 40W (1.0 oz)

٠Dicarboximide – iprodione

• Chipco 26GT 2SC (4 fl oz)

٠Phenylpyrrole - fludioxonil

• Medallion 50W (0.25 oz)

◊ Civitas, Daconil Action, Velista?14 – d interval

Evaluating Tank Mixtures for

the Control of Anthracnose

Wong et al (2002) Plant Dis Mgm’t Rpt 1:T064

Applied every 14 days from 15 Jun – 1 Sept

Rated on 24 July

Curative Control of Anthracnose Basal Rot on an

Annual Bluegrass Green – Univ. Riverside, CA

Chemical Control of Anthracnose

New Fungicide Mixtures:

Concert (chlorothalonil + propiconazole)

Disarm C (fluoxastrobin + chlorothalonil)

Disarm M (fluoxastrobin + myclobutanil)

Honor (boscalid + pyraclostrobin)

Instrata (chlorothalonil + propiconazole

+ fludioxonil)

Interface (iprodione + trifloxystrobin)

Pillar (pyraclostrobin + triticonazole)

Renown (chlorothalonil + azoxystrobin)

Reserve (chlorothalonil + triticonazole)

Tartan (trifloxystrobin + triadimefon)

Objective: To determine the effect of best management practices (BMPs) on fungicide efficacy.

Factors:Mowing Height

0.090 vs. 0.125 inch

N Fertility

2.05 vs. 4.1 lb N per 1000 ft2 per yr

Fungicide Program

- Calendar-based 14-day interval at 100%, 75%, 50% and 25% rates of fungicides (3.2 oz/M Dac Ult + 4 oz/M Signature)

- Threshold-based schedule at 100% rate of fungicides

- None

Putting It All Together

BMPs Effect on Fungicide Efficacy -2012

0

5

10

15

20

25

30

35

40

7-Jun 5-Jul 2-Aug 30-Aug 27-Sep 25-Oct

% D

ise

ase

0.090 in

0.125 in

7-Jun 5-Jul 2-Aug 30-Aug 27-Sep 25-Oct

Low N

High N

Fig. 2. Anthracnose severity affected by nitrogen fertilityFig. 1. Anthracnose severity affected by mowing height

N fertility had a greater effect on disease severity

than mowing height.

N fertility interacted with fungicide program, which

means the effectiveness of a fungicide program

depended on the level of N fertility!

FUNGICIDE EFFICACY TRIAL: RESULTS

NITROGEN X FUNGICIDE RATE INTERACTION*

0

10

20

30

40

50

60

70

80

High N Low N

% D

ise

ase

None 25% 50% 75% 100%

Low N

cb

a

d

High N

dc

b

a

bc bc

* Interaction data shown from Sept. 14, 2012 is representative of all rating dates in 2012.

5%

50% less fungicide than calendar-based schedule

Low Mow(0.090 in )

High Mow(0.125 in)

Low N(2.05 lbs N 1000 ft-2 yr-1)

9 9

High N(4.1 lbs N 1000 ft-2 yr-1)

5 2

TOTAL # OF FUNGICIDE APPLICATIONS (MAY- SEPT 2012):

COMPARISON OF THRESHOLD APPLICATIONS TO COMBINATIONS OF NITROGEN PROGRAMS AND

MOWING HEIGHTS

80% less fungicide than calendar-based schedule10% less fungicide than calendar-based schedule

For Additional information - Turf.rutgers.edu