Page | 1

October 21, 2011 Scouting Report – Cold, Windy and Wet: Dollar Spot’s Last Dance, Rust Rages, Yellow Tuft, Earthworm Activity, and Tim’s Nice Summary of Dollar Spot in 2011 Chicago/Northern Illinois Update: Derek Settle - e DSettle@cdga.org Blog www.cdgaturf.org It was Thursday and my daily notes said, "Clouds are above and light rain is falling. It all began Wednesday with 0.75 inch recorded on Sunshine Course." As it turned out, Chicago had been enjoying an Indian Summer the first two weeks of October, but by the 20th our high would not cross 50 degrees. Weathermen would tell us it was our coldest day since 26 May. It got windy too and little Sunshine Course recorded winds at 9-19 mph every hour that same day. Now that's unusual. Closer to Lake Michigan, Soldier Field would clock gusts of 53 mph and north shore places like Highland Park would feel winds of 45 mph. In the landscape the cold, wet, windy weather meant the peak fall color of many trees promptly ended. Within the week, cottonwood leaves would be completely down, though I had to wait to see the change – I was out of town.

Fall Continues. Cottonwood leaves are now completely down, Sunshine Course. Settle 10-20-11 This week saw our first real hard frost as low temps dropped below 30 degrees in places like North Barrington and Aurora. Nevertheless, effects of a warm October are still with us and my weekly scouting would find terrific rust, amazing dollar spot, and that yellow tuft stuff. Superintendents noted earthworms had returned and course projects were in their concluding phases. Next up, irrigation pumps will be off and folks will say two short words – SNOW mold.

Page

WeatherIt got cotemperatusoil tempThat mea

30

40

50

60

70

80

1O

ct

Tem

pera

ture

(F)

2

3

3

4

4

Low te

mpe

rature (˚F)

| 2

r Review – Wld, windy anure graph shperature on Sans we will n

1-Oct

2-Oct

3-Oct

Suns

Ahhh

5

0

5

0

5

1st Ha

We experiennd wet. Thhows the rapSunshine Conow see rapi

4-Oct

5-Oct

6-Oct

shine Golf C

Chicago:

44

38

ard Frost Arr

nce our firsthat little sentpid decline oourse is nowid leaf senes

7-Oct

8-Oct

9-Oct

Course (Lem

October

3736

rives for Som

t hard frosttence sums uof temperatu

w below 50 dcence and on

10-Oct

11-Oct

12-Oct

mont - a so

Has Gotte

3534

me In Chicag

t on Friday,up the weature in a weedegrees for nset of turf d

13-Oct

14-Oct

15-Oct

uthwest Ch

en Cold, W

Coldest autu

3432

go ‐ Friday, O

NorO' HMidJolieWaGleLemKanN. BAur

, October 21ther over theek. For examthe first timdormancy fr

15O

t

16-Oct

17-Oct

18-Oct

hicago subu

Windy, anHighLowSoil (avg

umn temp yet

3028

October 21, 

rtherly Island, AHaredwayetukegannview, North Smont, SunshinenkakeeBarrrington, Birora

1 e past weekmple, the av

me since 28 Arom here on

45

18O

ct

19-Oct

20-Oct

21O

ct

urb)

nd Wet

g. 2 inches)

t

8

2011 

Adler Planetar

Shore CCe GC

ltmore CC

. The erage April. out.

54

34

49

21-Oct

rium

Page | 3

Windy, Chilly in Chi versus Warm in San Diego? Thursday, October 13, 2011 Weather Blog San Antonio National Crop Science Meeting (Oct 16 to 19, 2011). Some ‘basic research’ Dollar spot. The big take-home message for me, plant path stuff, was that dollar spot doesn't have the right name and the nearest relatives aren't so near. Rutgers researchers with molecular tools were able to show that Bennett in 1937 named something that now needs a Latin name change - Sclerotinia homoeocarpa is no longer adequate given current fungal genetic knowledge. Interestingly, collected isolates of dollar spot group differently based on whether their photosynthetic pathway is C3 (cool-season turf) or C4 (warm-season turf).

I saw a familiar face while in San Antonio. That was Tom Lively (blue shirt) and his ultradwarf ‘Champion’ bermudagrass greens have few issues, but one can be dollar spot. Settle 10-16-11 Many other studies were 'applied research' Cultural practices versus disease. I think the best was the work from Michigan State that showed am versus pm rolling on golf greens reduced dollar spot. It meant that morning dew/guttation removal could not explain the reduction entirely. Rolling twice in the pm worked well to suppress S. homoeocarpa (remember, this name will change). They found rolling increased soil moisture. They found rolling increased microbes and some of those may be providing antagonism towards the dollar spot fungal pathogen (soil microbial activity peaks at 65% water-filled pore space). Specifically both gram positive and gram negative bacteria show increased numbers in response to rolling. It also may be that rolling stimulates natural plant defenses in some way. I would say dollar spot was the star in the realm of turf diseases because we still know so little. What is its real name? What is its biology? What is its epidemiology? How do environmental and cultural practices influence its development?

Page | 4

Tim Sibicky, MS – TSibicky@cdga.org Manager of Turfgrass Research 2011 Dollar Spot Disease Development – Curative Fungicide Approach Superintendents are always looking for ways to reduce fungicide inputs needed to control turfgrass diseases for a variety of reasons that include reducing potential for environmental impacts as well as gaining financial savings by using fewer products. Dollar spot, caused by the pathogen Sclerotinia homoeocarpa, continues to demand the greatest cost from fungicide budgets in northern Illinois – more so than any other disease. This is attributed to the long duration of disease activity which, in our cool-humid region, spans almost the entire growing season from May through October. By comparison, other diseases like brown patch, caused by the pathogen Rhizoctonia solani, only appear during the heat of the summer from late June through mid-September. Research continues to push the envelope in seeking ways to best utilize the tools that superintendents have available (i.e., standard and newer fungicide products).

Figure 1. Comparison of 3 trts: 1) Untreated, 2) Chlorothalonil, 3) Pyraclostrobin + Boscalid. On Sunshine Course, a fungicide study was established on our number 2 golf green beginning in May. The idea was to compare different fungicides and their efficacy on a curative basis. To establish a baseline, treatments were all applied May 31st and included Daconil Ultrex at 3.2 oz, Daconil Ultrex 3.2 oz + Emerald 0.13 oz, Emerald 0.18 oz, Honor 1.1 oz and Insignia SC 0.7 fl oz. Subsequent applications were as needed whenever disease damage levels became objectionable (threshold of 5% dollar spot damage). Between May 31 and September 1 the treatments requiring the most curative applications were Daconil Ultrex and Insignia SC with 6 needed. The Daconil + Emerald and Emerald treatments required a total of 5 applications, but the clear winner was Honor with only 3 applications (May 31, July 19 and August 29). Honor is a combination product with the active ingredients pyraclostrobin (Insignia SC) and boscalid (Emerald) and did not require a second application until brown patch broke through on July 19.

0

10

20

30

40

50

60

31‐M

ay

7‐Jun

14‐Ju

n

21‐Ju

n

28‐Ju

n

5‐Jul

12‐Ju

l

19‐Ju

l

26‐Ju

l

2‐Au

g

9‐Au

g

16‐Aug

23‐Aug

30‐Aug

6‐Sep

13‐Sep

20‐Sep

27‐Sep

4‐Oct

Infection cneters (% per plot)

2011 Dollar Spot Development on a Bentgrass GreenCurative Fungicide Approach

Untreated Check

Daconil Ultrex 3.2oz/M(Curative Treatment Applied)

Honor 1.1 oz/M(Curative Treatment Applied)

Page

Figure 2.for dollarcontact fu

Dollar spcurative treatment

0

1

2

3

4

5

6

7

8

9

Visual Quality (1‐9, 6

 = accep

table)

| 5

. Honor fungr spot and br

fungicide Da

pot disease Daconil Ultts. This mak

31‐M

ay

7‐Jun

14‐Ju

n

201

Untre

Daco(CuraHono(Cura

gicide showsrown patch

aconil Ultrex

can cause trex plots (r

kes sense as i

21‐Ju

n

28‐Ju

n

5‐Jul

11 Visual Q

eated Check

onil Ultrex 3.2oz/Mative Treatment Aor 1.1 oz/Mative Treatment A

s better visugiven the sy

x (chlorothalo

significant right) begin it is a contac

12‐Ju

l

19‐Ju

l

26Jul

Quality ofCurative 

Mpplied)

pplied)

ual quality raystemic actioonil) has a sh

levels of dato show inc

ct fungicide l

26‐Ju

l

2‐Au

g

9‐Au

g

f a PennG2Fungicide A

atings due toon of its comhorter residu

amage whencreasing damlabeled for 1

16‐Aug

23‐Aug

30‐Aug

2/L93 BenApproach

o a longer dumponents. Inual.

n left untremage 22 day14 days. Sib

6‐Sep

13‐Sep

20‐Sep

ntgrass Gre

uration of con compariso

ated (left). ys after the

bicky 9-22-11

27‐Sep

4‐Oct

een

ontrol on the

The final

1

Page | 6

Final Images. I toured San Antonio TPC, Canyons Course, with Jack and Nathalie Fry

The rough is a little different than the Kentucky bluegrass we use in Illinois. This is Tifway 419 (Tif = Tifton, GA). Its growth habit means it won’t get near as tall as bluegrass. Settle 10-16-11

It was my 1st time to set foot on an ultra-dwarf ‘Champion’ bermudagrass green. Settle 10-16-11

Page | 7

18 Green. Of two courses, Pete Dye’s Canyons Course was hosting the AT&T PGA Senior Championship. Tom Lively was kind to give us a tour on the event’s last day. Settle 10-16-11

I found a discarded ticket and photographed it to tell the story of the event. We saw Nick Price play Fred Couples on hole 18. Jack would say, “Nick has the dark pants Derek.” Settle 10-16-11 Website weekly blogs: Weather, Research, Diagnostics – www.cdgaturf.org Derek and Tim plus Chris and Niki, The CDGA Turfgrass Program