LESCO, Inc., 20005 Lake Road, Rocky River. Ohio 44116 (216) 333-9250

Manufacturers, Formulators and Distributorsfor the Green Industr~

Measurable Increases in FairwayBentgrass Populations Associated with

Lightweight MowingRandy Kane, U of I/CDGA Turfgrass Advisor •

Dave Ward, Supt., Olympia Fields CCRandy Wahler, Supt., Knollwood Club

Since the late 1970's and early 80's, increased attention hasbeen focused on maintenance practices to improve manageabili-ty, playability, and aesthetics of fairways. These newer manage-ment strategies, the cornerstone of which is "1ightweight" mow-ing, not only increases the quality of the playing surface, butalso appears to favor bentgrass competitiveness over Poa an-nua. Dramatic increases in percentages of bentgrass in fairwayshave been reported after only one or two seasons of lightweightmowing.

Much discussion and experimentation among area super-intendents has insued, especially in regard to: which typesof mowers should be used; whether to collect clippings; timingand amounts of irrigation, fertilization, and aerification; use andabuse of growth retardants; and other issues that may impactPoa annua survival, seed production, and competitiveness withthe desired bentgrass.

The consensus at this time is that you can indeed see increasesin bentgrass with changes in management. But how much ofan increase in bentgrass can you get? And, how soon can youget it? In order to try to answer these two questions, we begana study in early 1986 to measure increases in bentgrass popula-tions in fairways that were previously mowed in gang mowers, .but were subsequently mowed with lighter weight units (triplex •or pentaplex),Methods

Two Chicago-area country clubs were chosen where mixturesof bentgrass and Poa annua were indigenous in fairways, andwhere superintendents had recently (1983-86) introducedlightweight mowing and other management strategies to reducePoa competition. Also, the clubs were selected to represent twodifferent environmental and geographical areas.

To the north lies the Knollwood Club in Lake Forest, whichis near the lake shore and exposed to cooler temperatures atvarious times of the year, At Knollwood, superintendent Ran-dy Wahler has converted a number of fairways using Roundup,and has been on lightweight mowing of all fairways since 1983or '84 (Jake HF-5's). Certain fairways at Knollwood havereceived treatments of Cutless and TGR as well.

On the south side, superintendent Dave Ward then at RavisloeCC began lightweight mowing of fairways (GM 3's) on par 3sand decks in 1982. He added a few full fairways in 1984 andall fairways were used on the fairways during the study, as wellas little or no N.

Two separate methods were used to assess the increase in ben-tgrass in fairways over the next two seasons. First, a visualassessment of percentage bent vs. Poa was made on large scaleareas of fairways. Several candidate fairways were selected ateach club, than % bent was estimated on rectangular segments(plots) of fairway delineated by sprinkler head locations. Most •plots were 6-8000 sq. ft. Ratings were made in spring of '86and again in spring of ' 88.

The second method used was to map and measure individualpatches of bentgrass within certain defined, relatively small plot

(cont'd. page 6)

• Equipment• Replacement Parts• Golf Course Accessories• Safety Products

(800) 825-3726

LESCO Has It!Everything you need for

professional turf management.

• Fertilizers• Plant Protection• Seed• Irrigation

-4-

•

N IlliNOISYOUR NORT:E~F TRIPLOIDDISTRI~~?TE AMURAvailable for .• White Amur Now of Nuisance AquatiCBiologicalControl

ae &Weeds.Aig . I& Safer than• More EconomlcaChemicals . I 0 Available. of Fish as• Other Species k About Ourfor Stocking - As gement ServicesComplete Fish Mana

LARK ROAD8609 C D IL60071RICHMaN ,815-675-6545

k ~..!.:ij},.'

,.. :d::::;ib••' /;,>:;:.-1f '. ':::". "':':'::":::.; ... :: "';~'.;:::.:.. ":':'::':,,;-.•

BROADVIEW, IL 601539TH AVE. •2612 S. (708) 450-1400

· · n Engineering Co.Irrl ga tl0 QUA LlTY MA TERIA LSSOUND ENGINEERING and •

... Your Exclusive

h ~!malic,Weal er l' IRRIGATIONLAWN AND TURF

Distributor

where r = rad~U:easuredn = # of rad 11

Percent Bent,grass -

change1988+13

198679

+ 6

# notes66

74+ 7

IVCHMOND

Fairwaycut less

6869

-+-13

KWD 8pgr

-

no62

78+15

11cutl./tgr

ISDERIE

6573

+ 9

16cutless

5869

+ 7

18year1st

6075

+22

RAV 21st year

6879

+17

8year3rd

5771

~

101st year16

year 54

-~+11.5

1st

Z.L74.6

173rd year

63.1~

•• , •• ", ••• TG' ,. '.,- are the lnltlal n 'B6 and scotts

for

two years",,"•• '0. "8;.0.'".' '"" ••• ';'h,"."h' .O"~'v•• , 0'note: Knollwood #lband #18 had been

were

in their Isisloe #10 fail'wayS

~:~or to . Bt: o~~~:r 1 applications1ightweight m - teffectsof Cut ess d #16re the apparen #11 KnollwooAl so of note ;~ and # 18 vs. untreated ed'in ryegrass.Fair-on Knollwood nnua but mcreas . ht mow-. rcentPoa a, of 1ightweigdecreased In pe h twere in their3rd year . crease in ben-R is10et a h d less mways at av . ing of thisstudy s owe f lightweightmow-

ing at the begmn f:I'rwaysin their1styear.o f fairways #10pared to a pulatlOns 0 .tgrasscom .. tialbentgrass po h' observation.ing. However, the ml which could accountfor t IS are slowerd #18 were hIgher, . further mcreasesan over tIme,(As % bent increa~es ation withinand more diffi~UI~lriablenature of the turf P:ft~:n individual

Because of tee broke down the ratmgs d 3 contain thea single faIrway, :'bedin Figure 1. Tables 2

han

tsome areas in-. s as descn . Note tabfaIrway opulation estimates. reas decreased yresultsof these p h 20-25% whIle other a . ate 10% in-d by as muc as n approxim

crease . on average, we saw a owever, siteto site7-1

0%. Agam, after2 years of study. H . creases in ben-crease in bentgr~ss h' h and in certain areas m ntT . qUIte Ig , fi r ten perce .variabl Ity IS more dramatic than Ive 0 (cont'd. page 8)tgrass can be

'ng cont'd.) t markers(Lightweight Mowl re located near permanen ped onsmall plots we and were map

areas. Thes~ 1 heads or valve boxes, d that they couldh Pnnk er marke so Isuc as S The sheets were fter season. nclear plastic Sh~~~S~xactsame location sea:~:n~ patches couldbe replaced m . the size and shape 0 f new patchesthis way, changes m d the appearance 0 . f '86

. d over tIme, an k d .n the sprmg 0 ,be mOnItore t d Patches were mar e. lble and easy to markcould be detec e . much more VISI P a and

d ' 88' patches were between bent, 0,'86, an , f color differences. because 0

in sprmg d patches were. lar shape drye. f the mostly Irregu . ommonly use

Surface areas t~e average radius teChnIq~:r csurfaces on theestimated usmg and other Irregu. g greensto measure puttIn

golf course:

"n" (~~~-~~:~:=~),.. SA .

here r = radiusw f radii measured .

n = # 0 . to estImate.ntendents ISResults surement for supen ki g at the big pic-mon mea (i e 100 n d

A com of entire fairways .. four Knollwoopercent bentgra~ows over all results from t~e Note the 11.5%ture). Table I~ fairways that were studle . period, also theand five RaVISoe. rass for the 2 year

increase In bentg 6 22 % increases).average . bTty observed ( - 1966-66.

ount of vana 1 1 _ Entire P'airways.am Visual AssessmentsTABLE 1. Large Area

-6-

TABLE 2. Breakdown of Fairway Ratings - selected fairways at Ravisloe CC.

Percent Bent.iu~ss - Visual Patings _

(Lightweight Mowing cont'd.)

___ ~_F ..;drwav ___ ____ "16 F3i~ _ -- ____ li'2-LiLj_L.~ - --

- -- ,'36 ~ ~' 56 ~ L..:.L=. ...2..!? ~ ~.1 r:- 42 62 ...20 37 S5 016 55 67 I -- 3 72 07 I 5 57 95 +28 67 80 1 Cl- 55 60 S 52 75 >l 3 67 82 I 5

6': :>0 18 62 .::':: .. 20 E.=:', 0 ".J 3.. il2 •. ~ S 0

" ; c ....£2_ -- I.? ., -"_'-2--.00 '" ? ? 57 79 -- ~3 -;-:;

•than other fairways areas. Some areas more than doubled inbentgrass coverage, up to as much as 90% bentgrass.

Note that as percent bent increased over time and patches ex-panded, the number of patches measured decreased, since manypatches grew together ("coalesced"). Of note also is the plotthat did not have a large increase in bentgrass (Knoll wood 16a),but did increase in perennial rye as Poa annua populationsdecreased. The increase in ryegrass observed here may berelated to use of Cutless and TGR growth retardants, which haveno inhibitory effect on perennial rye.TABLE 4. Small Plot - Individual Bentgrass Patch Measurements:

cerltgr3ss popul-3ti~ns

-turn = "_~e e;-:::1 cf f.3.~r',Ja'; "t'Jl-nal'o'J:-,-j" I

~~e~~_ :: :: 3~~~~:~:~~~~;~:::.~r ::1ecrease i n ~bzerved

TABL~ 3. Breakdown of Fairway RatIngs - selected faIrways Knollwood Club ..Percent 8entgrass

Q (II of patches)b

#11 Fairwav #16 Fairwav --- #18 Fairwav

si te '86 .:.M. ~c: •86 .:.M. %...-.:..L::. ~ .:.M. %...-.:..L::.turr.- 53 75 +.22 55 67 +12 53 70 + 172-3 67 75 + 8 50 70 +20 73 80 + 7.... - .5 70 70 + 0 57 50 .. 7 65 75 +106-7 70 60 -10 65 80 +15 63 75 +l~3-9 67 70 + 3 67 80 +13 62 80 + 1810-11 57 70 +13 60 60 + 0 57 70 +13r.:1ecj..b ~ .2L !.....2 .....:z.:L .....22- ~ ~ ....22.... :!:..!2

68 74 +06 62 69 65 78 ..13

b numbers in parentheses are the number of pa tches in each surveyed area.

a Percent surface area covered by bent patChes within a defined plot area.

c: this plot contaminated by increasing amount of ryegrass - percent of poaannua in plot decreased more dramatically than data indicates ...

~l-ea21.2ft2

16.3 ft'"47.6 ft'"28.0 ft~29.3 ft~47.2 ft~

El.Q.L1 Spr 86 ~ Spr 88RAV 2 42 (8) 61 (10) 91 (2)RAV 8 31 (7 ) 61 (5) 90 (3)RAV 10 55 (8) 74 (51 88 (2)RAV 16 41 (10 ) 70 (31 86 (2)Y.WD 16Ac 19 20 28KWD 168 44 (11 ) 52 (9) 75 (4 )

Bent2rass - Visual Ratin.e:.s______________ Percent

•

•FAIRWAY

RANSOMES

WHERE GREAT IDEAS START

Table 5 shows data on selected individual patches of ben-tgrass. These numbers were included only as a summary of ourobservations on patches; many patches could not be followedover two years because of coalescence. Note that patchdiameters increased two to three inches per year on average.These relatively small increases in patch diameter often led toas much as a doubling in surface area covered by the patch.

(cont'd. page 10)

CHRISTENSENPOWEREaUIPMENT INe.

UoeI w. AlONEI!...ANHAnAH RD.fRANKFORT. Ill0422

PHONE 1815\ 469-5898

Folds for easy transport.Hydraulic control reducesoverall width to a narrow 71 ".

High quality cuteven at top speedof 6mph. Transportspeed of 9mph.Interchangeablecutting units are quick andeasy to change. No toolsrequired. Accepts four types ofcutting units.

SchwarzentraubImplement Inc.1040 W. JefferlonMorlan, IIl1noll61550Phone (309) 263.7322

;>222 nnn:t1 IlAY 110.EVI\IIAIOIl. IL 00201

708-864-5045

For a FREE d~mnnstration_ contact=

106" cutting widthcombines with fastcuttingspeed for high productivity.Light weight mowing offerssmooth, easy handling andreduces turfcompaction.Three-Wheel Drive PWS(patent pending) makesFairway 5000 a great hillclimber:

NEW FAIRWAY 5000SPECIAUZED FORTOp.QUAUTYFAIRWAY MOWING

These dramatic increases in percent bentgrass in isolated areasare also evident when looking at the individual small plot/ben-tgrass patch measurements. Table 4 shows data from six suchplot areas. These results include percent bentgrass (totalarea)for each plot and the number of patches measured. These plotareas had clearly defined bentgrass patches, but generally hadlower percent bentgrass coverage at the beginning of the study

aturn = tee end of fairway ("turnaround")"'deck = approach to greenC% +/_ = percent increase or decrease in observed bentgrass populat.ions

-8-

TABLE 5. Increase in Oia.eter of Selected Individual Patches

(Lightweight Mowing cont'd.)

patct"1 diamet.er (iriJ •WITH 7% WIN

NEW COMBINATIONIN SLOW RELEASE NITROGEN

Spr 88350265219163

patch area (ln~ _

Spr 86 Spr87160 242123 179105 19260 114

Spr B821.0IB.O16.714.4

Spr 8717.615.0

15.612.0

Spr 8614.212.511.58.7

~1

note: a 2 - 4 inch increase per year in patch diameter was often seenbefore patches coalesced.

SummaryIt appears that the claims of increased bentgrass populations

following lightweight mowing have not been exaggerated! Insome fairway areas the rapid increase in bentgrass was quitesurprising. The reader should note that there were no controlareas or check plots that were mowed with heavy gang mowers.Therefore, the observed increases in bentgrass may have beeninfluenced by hot, dry weather patterns of 1986-88 or other en-vironmental factors that we could not detect. In other years,we may not have seen these increases in bentgrass; for exam-ple, the weather in '89 may have been more conducive to Poaannua, but we have no data for this.

Also, other management factors probably playa role in in-creasing bentgrass populations. For example, at Ravisloe, verylittle fertilizer has been added to the fairways (virtually no N)for the past few years, and irrigation and aerification practiceshave been changed. Also, as mentioned at Knollwood, the useofpgr's may have had an effect. In any case, we have seen fromthis study what the potential for increasing bentgrass popula-tions can be, given appropriate management inputs and favorableenvironmental conditions .

15-1-10 FERTILIZER• Combines Benefits of Nutralene & Milorganite• Organic Base• Non Burning• Low Salt Index• For Turf & Ornamentals• Uniform Release of Nitrogen• 50/lb Bag Covers 7500 SQ. FT.• Can Be Used Any Time - Spring - Summer - Fall

ALSO AVAILABLE: A 6-1-16 FertilizerWith High Quality Sulphate of Potash

Call Us Today For Pricing!

LAKE-COOK SPECIALTY PRODUCTS(A Division of Lake-Cook Farm Supply Co.)

Wauconda r::S1 Tinley Park27310 W. Case Rd. ~ 6730 South St.(708) 526-0007 ~ (708) 532-4723 •

Northern Illinois Golf DayMonday, August 20, 1990

MAX-FLOW 1" HOSE NOZZLES

Hosted by 51. Charles Country Cluband Geneva Golf Club

$95 per golfer includes:lunch on course

half a cartgreens fees

dinner

Dam Grotti Award forsuperintendent and assistant combined score

Tee sponsorships available for $195

Call Illinois Turfgrass Foundation312 • 644 • 0828

to register

Proceeds benefit turf research projectsat University of Illinois

FOR SYRINGING/W ATERING GREENSAND FAIRWAY DRY-SPOT WATERING.AT ]]0 PSI. DISCHARGE RATES ARE APPROX.MAX-FLOW #], 30 GPM (GREENS)MAX-FLOW #2, 60 GPM (FAIRWAYS)

SMALL DROPLETS WILL NOT MAT BENT GRASS.GRADUAL SHUT-OFF, NO WATER HAMMER.

THESE ARE NOT FOG NOZZLES

AVAILABLE IN ILLINOIS FROM -

ARTHUR CLESEN, INC. (708) 537-2177543 DIENS DR., WHEELING, IL 60090

ORFRANK D. SMITH & ASSOCIATES, INC.

P.O. BOX 517, PALATINE, ILLINOIS 60078 (708) 359-4571•

-10-