Turfgrass - University of Missouri · Oklahoma City). Th e bed, located at the U n i versity of...

FR O M T H E

UN I V E R S I T Y O F MI S S O U R I- CO L U M B I A

TU R F G R A S S RE S E A R C H CE N T E R

Experiment Station ■ University Extension Missouri Valley Turfgrass Association

2001 Research & Information Report

TurfgrassTurfgrassTurfgrass

MU TURFGRASS CENTER 3

Missouri Gravel Bed update .............................................................................................................................................. 5

MU builds new baseball ‘field of dreams’ hoping students will come for turfgrass careers ........................................................................................................................................ 7

Evaluation of fungicides for management of brown patchon bentgrass greens, 2000 ................................................................................................................................................ 8

2000 Crabgrass demonstration trial .................................................................................................................................. 10

Evaluation of fungicides for management of dollar spot on bentgrass greens, 2000 .............................................................................................................................................. 11

2000 Broadleaf weed control trial .................................................................................................................................... 12

ZPP1560 (Glyphosate Formulation) for edging weed control ............................................................................................ 13

Root-zone blends for safe and effective sand-based athletic fields, 2000 .......................................................................... 14

Rhizoctonia zeae .............................................................................................................................................................. 16

Amendments and construction systems for improving the performance of sand-based greens .......................................................................................................... 19

The Turf Disease Diagnostics program at MU .................................................................................................................... 23

Sweetgum ball control ...................................................................................................................................................... 25

Evaluating annual herbaceous ornamentals for performance in Missouri .......................................................................... 26

Cold tolerance of zoysiagrass as influenced by cutting height and Primo .......................................................................... 27

Bermudagrass cold tolerance ............................................................................................................................................ 28

Compatibility of tall fescue and Kentucky bluegrass in mixtures ........................................................................................ 30

Companies and organizations that contributed to the 1999-2000 Turfgrass Research Program .................................................................................................. inside back cover

Turf and Ornamental faculty and staff .................................................................................................................. back cover

Table of Contents


Chris Starbuck

R e s e a rch continues on theMissouri Gravel Bed (MGB)method for extending the

planting season for bare root treesand shrubs. When using MGB, dor-mant, bare root trees and shrubs areplaced with their roots in a bed offrequently-irrigated river rock. Studiesto date have shown that plants in awide range of species can ber e m oved from the rock and plantedbare root, in mid-summer, with a sur-v ival rate equal to or greater thanballed and burlapped (B&B) or con-tainer grown plants. MGB show spromise as a technique to allow nurs-eries, landscapers, grounds crewsand urban foresters to take adva n t a g eof the savings in labor, equipmentand fuel costs associated with han-dling plants bare root.

The main focus of current researchis to compare the performance ofsummer planted, bare root, 2-inch -caliper trees from MGB with that ofc o m p a rable B&B trees. In a prelimi-nary study in 2000, 2-inch ash trees(donated by Bailey Nurseries) werer e m oved from the gravel and plantedin July and September at field day s .Despite being watered only once,t wo days after planting, the Ju l y -planted tree showed no sign of wilt-ing or scorch and had normal-sizedl e aves in 2001.

On March 16, 2001, 12 2-inch -caliper B&B ‘Summit’ ash trees wereobtained from Rosehill Nursery (6donated). Six trees had the soilr e m oved and were placed with theirbare roots in a bed of pea grave lunderlain with 20 mil pvc pond liner(donated by Regal Plastics,

Oklahoma City). Th ebed, located at theU n iversity ofMissouri SouthFarms in Columbia,was on a slope,a l l owing irrigationwater to be collect-ed in a sump andr e - c i rculated viadrip irrigation tubinga t t a ched to a sumppump, activated bya time clock. Th ebed was irrigatedwith drip lines,spaced 12 inch e sapart and with 0.9GPH, in-line emit-ters spaced 12 inch-es apart in the line.During the springand summer, thepump operated forthree minutes eve r yhour between 8a.m. and 6 p.m.Trees were fertilizedonce per week withPeters 20-20-20 soluble fertilizerapplied at a concentration of 200ppm N to the gravel surface. The sixB&B trees were heeled into pea grav-el and irrigated, manually, asrequired to keep the soil balls moist.All 12 trees will be field planted inJuly 2001 and evaluated for the fol-l owing two growing seasons forcaliper and shoot growth.

In June 2001, trees in the MGBhad smaller leaves than the B&Btrees. How e ve r, there was extensiveroot growth in the gravel and sometrees put on a second flush of grow t h .There was also considerable root

g r owth from the soil balls of the B&Btrees into the gravel. Early resultswere similar to those of a coopera t ives t u dy at Ohio State University com-paring B&B and MGB 4-inch - c a l i p e rred oaks.

In addition to the tree project, ag ravel bed was constructed in Marchof 2001 on the MU campus to eva l u-ate the potential for using MGB tohold bare root plants that will beplanted in campus landscape projectsduring the summer. The bed is 8 x 30feet and 18 inches deep, filled with0 . 5 - i n ch river rock containing about10% concrete sand. It is equipped

On March 24,2001,2-inch-caliper bare root ‘Summit’green ashtrees were placed using the Missouri Gravel Bed method.

Missouri Gravel Bed update

6 2001 TURFGRASS RESEARCH & INFORMATION

with a re-circulating irrigation systemas described for the tree bed above .On March 15, 180 12-inch, bare root‘ Wintergreen’ boxwoods were placedin the bed. One hundred plants werer e m oved after four weeks to replace ap r ivet hedge on campus. The remain-ing plants will be planted at sometime during the summer. In mid A p r i l ,bare root roses were placed in thebed. These grew well, bloomed pro-fusely in the bed and will be plantedon the campus during the summer. ■

This research is being funded by WesternNursery and Landscape Association.

‘Carefree Sunshine’ roses after six weeks in a gravel bed and ‘Wintergreen’boxwood plantsafter 10 weeks.


Robert E. Thomas, Brad S. Fresenburg

and Chad Follis

“If you build it, they will come”goes the memorable line fromthe baseball movie, Field of

Dreams. University of Missouri –Columbia turfgrass researchers willtest that theory. A state-of-the-artinfield diamond is now under con-struction at its research facility at theMU South Farm. The goal is to drawstudents learning the profession ofsports field management.

The diamond, on par with the play-ing surfaces used by professionalteams such as the St. Louis Cardinals,will provide the only working labora-tory in the country for students seek-ing careers in this area, said BradFresenburg, turf researcher in the MUhorticulture department. “No one inthe country, to my knowledge, has afull-size infield like this for teaching,”he said. “This will be an outdoorclassroom for us. We can show stu-dents just about everything.”

The laser- g raded diamond is beinginstalled free by MJM Services ofBelleville, Ill., a company that installssports fields and golf courses. Th efirm installed two bermuda gra s sp ractice fields for the Mizzou Ti g e r sfootball team.

In research, as much attention willbe paid to the study of skinned infieldsoils as to the lush green grass dia-mond. “Seventy-five percent of thebaseball game is played on infielddirt,” said Chad Follis, a graduate stu-dent from Fredericktown, Mo. “Youhave the pitcher’s mound, batter’s boxand base paths. To date, there has notbeen much research generated on

infield (soil) mixes.”The field will be nearly pool-table

level. It will have one-half of one per-cent grade on four planes around thepitcher’s mound. A laser beam is shotacross the field and picked up by anelectronic eye on a tractor. That con-trols the valves for a blade on the trac-tor. “We don’t touch the controls,”said Mike Munie, MJM Servicesowner. “When we did the two MUfootball practice fields, we laid aNumber Two pencil on the far endand you could lay down and see thepencil from 300 feet away. We werewithin a hundredth of a foot.”

A playing surface must be firm andplayable yet workable so the cleatscan dig in for traction. “Safety andplayability are the main things welook for on skinned infield areas,”Fresenburg said. While the infield dia-mond will be “Baby” bermuda grass,

the aprons will be planted in a turf-type tall fescue, he said. Bermudagrass holds up better and can bemowed to five-eighths of an inch for abetter playing surface.

MU is considering replacement of theb l u e g rass on its diamond at the infield ofSimmons Field, home of the baseballTigers, with “Baby” bermuda gra s s .

In addition to installing the infielddiamond, MU researchers plan to addresearch plots nearby to test differentsoil blends. Mixtures will includecombinations of round and sharpsand, silt and clay from native soilsand calcined clays.

“It’s possible that the MU baseballteam may come over and use thefield,” Fresenburg said. “That’s beendiscussed. It would relieve their gamefield from excessive wear and allowus to look at wear patterns to teachfield maintenance.” ■

University of Missouri research associate Brad Fresenburg,right, works with Mike Munie,center, and Dave Niebruegge of MJM Services to grade the new infield.Using a laser level-ing device, they were able create a 0.5 percent slope on four quadrants surrounding thepitcher’s mound as the center point.

MU builds new baseball ‘field of dreams’ hoping students will come for turfgrass careers


Evaluation of fungicides for management of Brown Patch on Bentgrass greens, 2000Brad S. Fresenburg and Barb Corwin

T his study was conducted on a‘ Penncross’ bentgrass green atthe MU turfgrass Research

C e n t e r. The green profile is a 10-inchbase of 90/10 sand and peat blendover drains in sub-grade. Th e‘ Penncross’ was established in the fall of 1992.

The green was mowed on Monday,We d n e s d ay and Fr i d ay of each weekat 5/32 of an inch. Fertility leve l swere maintained at a high level with0.38 lbs of nitrogen per 1,000 squarefeet being applied every three weeks.Moisture levels were maintained atoptimum levels with thorough, butinfrequent, watering plus dailysyringes as needed. During hot

weather moisture levels wereincreased to promote high humidityl e vels insuring better infection condi-tions for brown patch. Fungicidetreatments were initiated on 31 Mayand sequentially applied on 15 Ju n e ,29 June and 12 July based on the rec-ommended application intervals fore a ch treatment. Plots were 5 feet by 5feet replicated four times in a ra n-domized, complete block .

Treatments were applied with aCO2 backpack sprayer, walking speedof 2.5 mph, using TeeJet XR 8008 tipsdelivering 87 GPA at 32 psi.

Brown patch infection was naturaland rated as moderate to heavy.Cooler temperatures during the dayand night during late July reduced theinfection period. Early evaluations

observed a moderate infection of dol-lar spot in these plots and infectioncounts were taken on 24 June.Evaluations for brown patch infectionand turf quality were taken on 11 July,17 July and 27 July. Percent infectionwas taken on a scale of 0 to 100 with100 being equal to total infection ofthe plot with brown patch. Qualitywas taken on a scale of 1 to 9 with 9being equal to the best turf quality.

All treated plots were equal in con-trol of brown patch. Infection levelsfor control plots were 33, 38 and 24percent for 11 July, 17 July and 26July, respectively. All treatments hadless than 5 percent infection of brownpatch over all dates with one excep-tion: Fore on the first evaluation daterated a 9 percent infection. ■


Brown Patch on Bentgrass greens trial, 2000

24 Ju n e 1 Ju ly 1 Ju ly 11 Ju ly 11 Ju ly 18 Ju n e 24 Ju n eR a t e Dollar Spot Dollar Spot B e n t g r a s s Dollar Spot Dollar Spot B e n t g r a s s D o l l a r

S p o tTr e a t m e n t o z / 1 0 0 0 I n t e rva l I n fection counts % I n fe c t i o n Q u a l i t y % I n fe c t i o n Q u a l i t y % I n fe c t i o nQ u a l i t y

Control — — 15 33 3 38 4 24 4Chipco Triton 0.5 14 0 0 5 3 6 0 7Chipco Triton 1.0 14 1 0 6 0 7 1 7TADS 12529 0.15 14 0 0 6 1 6 0 7TADS 12529 0.30 14 1 0 6 1 7 0 8

Prostar 1.5 14 11 1 5 3 6 0 6Prostar+ 1.5 14 9 3 5 1 6 0 6Banol 2.0Heritage 0.2 14 1 0 7 0 7 0 7Heritage 0.4 28 1 1 6 0 7 0 7

Compas 0.15 14 5 1 5 2 6 1 7Compas+ 0.15 14 0 4 6 3 6 0 7Banner MAXX 1.0Compas Alternate 0.15 14 1 0 6 0 7 0 7w/Dacnil Ultrex 3.2

Eagle 1.2 28 0 0 5 0 7 1 6ForeRainshield 6.0 14 2 0 7 0 8 0 8ForeRainshield 8.0 14 3 3 6 3 7 3 6FORE 8.0 14 10 9 5 1 6 0 7Dacnil Ultrex 3.2 14 0 1 5 1 6 0 7

Chipco 26 GT 4.0 14 0 1 6 1 6 0 7Bayleton 0.25 14 0 1 5 1 6 1 6Banner MAXX 1.0 14 1 0 5 4 6 3 6

LSD (0.05) = 10 12 2 10 1 5 2


Brad S. Fresenburg

T his study was conducted on astand of Ke n t u cky bluegrass atthe MU turfgrass Research

C e n t e r. Soil classification is a “Mexico”silt loam with pH of 6.7 and 2.1 per-cent organic matter. The bluegrass wa sseeded in the fall of 1999, fertilizedwith 3 to 4 lbs of nitrogen per 1,000square feet per year and mowed twicea week at 1.25 inches. Moisture leve l swere maintained to prevent wilt. Th eentire block was seeded with large

c ra b g rass (Digitaria sanguinalis) at arate of one quart of seed per 1,000square feet using an Olathe model 84slit-seeder on 7 A p r i l .

Treatments were initiated on 7 A p r i lwith Pre 1 applications being watered inwith approximately 0.5 inches of irriga-tion. Some Pre 1 applications hadsequential applications made on 25 May.Post-emergence applications were madeon 17 July at a 1 to 3 leaf stage of cra b-g rass. A sequential application of MSMAwas made on 27 Ju l y, 10 days later.

Treatments were applied with a

CO2 backpack sprayer, walking 3mph, using TeeJet XR8008 tips deliver-ing 56 GPA at 20 psi.

An evaluation for phyto was takenon 14 April followed by evaluationsfor turf quality and percent crabgrasscontrol on 27 April, 6 June, 6 July and5 September. Evaluations for phytowere taken on a scale of 1 to 9 with 9showing no phyto. Quality was takenon a scale of 1 to 9 with 9 being equalto the best turf quality. Percent controlwas taken on a scale of 0 to 100 with100 giving complete control. ■

2000 Crabgrass demonstration trial

Crabgrass demonstration trial, 2000

Rate Phyto Quality Control Quality Control ControlTreatments lbs ai/A Timing 14 April 27 April 6 June 6 July 6 July 5 Sept.

Control — — 9 8 5 8 4 15Ronstar G 4.0 Pre 1 9 8 0 8 0 1Ronstar G 2.0 Pre 1 9 8 0 8 0 0Ronstar G 2.0 Pre 2Baricade 0.65 Pre 1 9 8 0 8 0 0

Pre-M 1.5 Pre 1 9 8 0 8 0 6Pre-M 1.5 Pre 2Balan 1.5 Pre 1 9 8 0 8 0 6Balan 1.5 Pre 2Team 1.5 Pre 1 9 8 0 8 0 2

Team 1.5 Pre 2Blank fertilizer __ Pre 1 9 10 0 8 0 0Dimension 0.25 Pre 1Blank fertilizer __ Pre 1 9 10 0 9 0 0Dimension 40W 0.25 Pre 1

Blank fertilizer __ Pre 1 9 10 0 9 0 0Dimension 40W 0.38 Pre 1Dimension 0.25 Pre 1 9 9 0 8 0 3FertilizerDimension 40W 0.18 Pre 1 9 8 1 8 1 3

Daconate 1.0 1-3 leaf 9 8 1 8 3 10Daconate 1.0 10 daysDimension 0.50 1-3 leaf 9 8 0 8 2 0X-77 0.50%v/v 9 8 0 8 2 0Acclaim Extra 0.058 1-3 leaf 9 8 1 8 3 0

Drive 0.75 1-3 leaf 9 8 1 8 2 0Crop oil conc. 1 pint

LSD (0.05)= — — 0 0 1 0 1 4


Brad S. Fresenburg and Barb Corwin

T his study was conducted on a“ Penncross” bentgrass green atthe MU turfgrass Research

C e n t e r. The green profile is a 10-inchbase of 90/10 sand and peat blend ove rd rains in sub-grade. The “Pe n n c r o s s ”was established in the fall of 1992.

The green was mowed on Monday,Wednesday and Friday of each weekat 5/32 of an inch. Fertility levels weremaintained at a moderate level with0.38 lbs of nitrogen per 1,000 squarefeet being applied every four weeks.Lower fertility levels favor dollar spot,therefore, we were trying to insure ahigh level of natural infection.Moisture levels were maintained atoptimum levels with thorough, butinfrequent, watering plus dailysyringes as needed. Fungicide treat-ments were initiated 12 May andsequentially applied on 25 May, 15June, 29 June and 12 July based on

recommended application intervals foreach treatment. Plots were 5 feet by 5feet replicated four times in a random-ized, complete block.

Treatments were applied with aCO2 backpack sprayer, walking speedof 2.5 mph using TeeJet XR 8008 tipsdelivering 87 GPA at 32 psi.

Dollar spot symptoms were becom-ing visible on 8 May by natural infec-tion. The firstapplications weremade at this time, 12M ay. After a week,infection rates werem o d e rate and datataken included anactual infection count(spots per plot) andquality on 24 June, 1July and 11 Ju l y.

Infection countswere actual number ofspots per plot. Qualitywas taken on a scale

of 1 to 9, with 9 being equal to thebest quality.

All treated plots were significantlybetter than the control plots over allevaluation dates. Control plots hadaround 10 infection spots per plot ini-tially and decreased as temperaturesstarted to increase. All treated plotswere equal to one another during thetreatment period. ■

Evaluation of fungicides for management of Dollar Spot on Bentgrass greens, 2000

Dollar spot on Bentgrass greens trial, 2000

24 Ju n e 1 Ju ly 1 Ju ly 11 Ju ly 11 Ju lyR a t e Dollar Spot Dollar Spot B e n t g r a s s Dollar Spot Dollar Spot

Tr e a t m e n t o z / 1 0 0 0 I n t e rva l % I n fe c t i o n % Contro l Q u a l i t y % I n fe c t i o n % Contro l

Control — — 10 11 5 2 3Daconil Ultrex 0.6 14 0 1 6 0 5Heritage+ 1.2 28 0 0 7 0 6

Daconil Ultrex 6.0 14 0 0 7 0 6Chipco 26 GT 8.0 14 0 0 7 0 6Chipco Signature 8.0 14 2 1 6 0 6

Chipco 26GT+ 3.2 14 0 0 6 0 5Chipco Signature 0.27 14 0 0 7 0 6Chipco Triton 1.8

Daconil Ultrex 4.0 14 0 0 7 0 5Model 1.0 14 0 1 7 0 5Daconil Ultrex 0.25 14 0 1 6 0 5

LSD (0.05) = 3 2 1 1 1


Brad S. Fresenburg

T his study was initiated in astand of Kentucky bluegrass(POAPR) grown on a “Mexico”

silt loam soil with a pH of 6.7 andorganic matter of 2.1 percent.Applications of fertilizer totaled 3 to 4pounds of nitrogen per 1,000 squarefeet per year. Pre-emergence herbicide(Barricade) was applied on 16 Aprilfor annual grass control. Plots weremowed twice per week at 1.25 inch-es. Moisture levels were maintained toprevent wilt. Plots were 5 feet by 5feet replicated 3 times in a random-ized, complete block.

Treatments were applied with aCO2 backpack sprayer, walking 3mph delivering 56 GPA through TeeJetXR8008 tips at 20 psi.

Treatments were initiated on 6 Juneas a post-emergence on broadleafweeds in the 4 to 6 leaf stage ofgrowth. Phyto was evaluated 6 and 18days after application on 12 June and

24 June, respectively. Phyto was takenon a scale of 1 to 9 with 9 beingequal to no observed phyto. An evalu-ation for efficacy was taken 18 and 30days after application for dandelion(TAROF), plantain (PLALA), whiteclover (TRFRE), and dog fennel(EUPCP). Efficacy was taken on a

scale of 0 to 100 for percent control.No phyto was observed with any

treatment 6 and 18 days after treat-ment. NB20332, NB30401 and TrimecClassic were equal to all other treat-ments for control of plantain, whiteclover, dog fennel and dandelion overboth evaluation dates. ■

Broadleaf weed control trial, 2000

12 June 24 June 24 June 24 June 24 June 24 June 6 July 6 July 6 July 6 JulyRate POAPR POAPR TAROF PLALA TRFRE EUPCP TAROF PLALA TRFRE EUPCP

Treatments lbs ai/A Timing Phyto Phyto Control Control Control Control Control Control Control Control

Control — — 0 0 0 0 0 0 0 0 0 0NB20332 0.625 Post 0 0 86 72 68 78 93 92 93 95NB30401 0.468 Post 0 0 97 86 77 80 99 98 93 98Trimec C 1.61 Post 0 0 80 73 77 73 92 89 94 97Cool Power 1.58 Post 0 0 96 83 57 94 99 95 85 99

Horsepower 1.71 Post 0 0 95 75 80 96 99 92 97 99Millenium 1.41 Post 0 0 88 73 70 91 98 94 93 99Tri-Power 2.05 Post 0 0 87 63 77 84 98 87 94 93Triplet 1.98 Post 0 0 81 68 68 97 93 90 93 99Turflon Ester 1.00 Post 0 0 95 70 80 89 98 93 96 97

Confront 0.75 Post 0 0 91 30 87 91 99 38 98 69Three-Way 1.98 Post 0 0 93 75 77 95 99 93 94 99

LSD (0.05)= — — 0 0 15 29 17 20 8 13 8 27

2000 Broadleaf weed control trial


14 Au g 14 Au g 14 Au g 14 Au g 14 Au g 18 Au g 18 Au g 18 Au gE P H S U D I G I S TA RO F F E S A R C Y N DA E P H S U D I G I S TA RO F

Tr e a t m e n t C o n t ro l C o n t ro l C o n t ro l C o n t ro l C o n t ro l C o n t ro l C o n t ro l C o n t ro l

Control 0 0 0 0 0 0 0 0ZPP1560 13 23 6 4 4 38 49 25Roundup Pro 11 22 5 4 5 36 53 25

LSD (0.05) = 3 2 3 1 2 2 11 4

18 Au g 18 Au g 28 Au g 18 Au g 18 Au g 18 Au g 18 Au gF E S A R C Y N DA E P H S U D I G I S TA RO F F E S A R C Y N DA

Tr e a t m e n t C o n t ro l C o n t ro l C o n t ro l C o n t ro l C o n t ro l C o n t ro l C o n t ro l

Control 0 0 0 0 0 0 0ZPP1560 30 22 100 100 93 97 85Roundup Pro 30 21 100 100 92 97 83

LSD (0.05) = 3 4 0 0 4 2 3

Brad S. Fresenburg

T his study was initiated at variouslocations at the MU turfgrassResearch Center. Several weed

species were selected to test the effi-cacy of ZPP1560, a glyphosate formu-lation, in comparison with RoundupPro. Each product was appliedthrough a Solo-backpack sprayer at aone percent solution. Weeds weresprayed wetting leaf tissue thoroughly,but preventing runoff. Weeds evaluat-ed were prostrate spurge (EPHSU),crabgrass (DIGIS), dandelion (TAROF),tall fescue (FESAR) and commonbermuda (CYNDA).

Treatments were initiated on 11August and evaluated for burn downon 14 August (3 days after treatment),18 August (7 days after treatment) and28 August (17 days after treatment).

Both treatments were equal in initialburn down and final efficacy on totalweed control. ZPP1560 and RoundupPro were equal in performance as edg-ing weed control products. ■

ZPP1560 (Glyphosate formulation) for edging weed control


Chad C. Follis and Brad S. Fresenburg

A s the athletic field industrymoves forward, the best possi-ble move may actually be back-

ward. Sand-based athletic fields haverevolutionized the industry, but at thepossible cost of safety. Traction, foot-ing or stability all explain the player’sability to move, turn, and cut on theplaying surface. Stability has becomea point of contention throughout theindustry. This is the reason the ongoingstudy “Root-zone blends for safe andeffective sand-based athletic fields”was initiated in August 2000.

The objectives of this research are tofind a root-zone that 1) provides opti-mal root growth, 2) provides propersurface stability without compromisingthe known benefits of a sand-basedathletic field, 3) provides an inexpen-s ive alternative for native soil athleticfields at both the high school, andparks and recreation levels.

The research process began withthe construction of 21 root-zones,each block measuring 8 ft X 8 ft X 6 ft.Borders between blocks were back-filled with 100% sand. The root-zoneswere mixed off-site and trucked to theconstruction location. Treatments werereplicated in a randomized completeblock design. Kentucky bluegrass (Poapratensis L., ‘abbey’, ‘viva’, ‘ascot’,‘Buckingham’) sod was installed onJuly 24 2000, with data collectionbeginning on August 25, 2000. Datawas collected at 2-week intervalsthrough October 2, 2000.Maintenance consisted of mowingtwice per week at a height of 1.5 in,applications of Lange-Stegmanns 23-3-23 (N-P-K) fertilizer 1 lb/1000 sq ftnitrogen, .06 lb/1000 sq ft phospho-

rus, and .83 lb/1000 sq ft potassiumbeginning on August 1, 2000 andoccurring every 3 weeks until October19, 2000. On April 2,and 23, and May14, 2001 fertilization applicationswere reapplied at the same rates usedin 2000. Approximately 1.5 cm to1.75 cm of irrigation were appliedweekly to maintain acceptable turfquality and cover. Solid tine aerifica-tion was conducted in the spring of2001 to alleviate compaction from theprevious growing season.

On the first data collection period(4 weeks past sod installation), treat-ments 80-7.5-7.5 (sand-calcine clay-Zeopro), and 85-5-10(sand-Zeopro-soil) resulted in greaterroot weights when compared to thecontrol (90-10 sand/peat). Native soilalong with 90-10 (sand-peat-fibers)

had the lowest root weights of alltreatments during this time. The sec-ond collection period (6 week pastsodding) saw the treatment 85-10-5(sand-peat-calcine clay) having thehighest root weights. On data collec-tion periods 3 and 4 (weeks 8 and 10past sodding) root weights for sand-peat (90-10) were significantly greaterthan all other treatments. Shear vane,which measures resistance to rotation-al force, showed no differences at anydata collection period, visual qualityimproved from the initial timing to thelast, and clegg readings as a measureof hardness stayed in an acceptablerange of 50-70 Gmax for all treat-ments. The 85-15 (sand/compost), 75-20-5 (sand-soil-compost), and80-10-10 (sand-zeopro-soil) werehigher than the other treatments with

Root-zone blends for safe and playable sand-based athletic fields


regard to phosphorus, with the 85-15(sand-compost) being significantlyhigher that the 75-20-5 (sand-soil-compost), and 80-10-10 (sand-zeopro-

soil). This difference also held true forthe 85-15 (sand-compost) and 70-20-5(sand-soil-compost) for potassium.Phosphorus differences at week 10

were consistent with those at week 4,while potassium levels were highest atweek 10 in treatment 70-15-15 (sand-calcine clay-soil). ■

Blends Ratio Components

1. 90-10 Sand-Peat2. 90-10/1lb/12ft2 Sand-Peat-Fibers3. 90-10 Sand-Soil4. 85-15 Sand-Soil5. 80-20 Sand-Soil

6. 70-30 Sand-Soil7. 100 Soil8. 85-10-5 Sand-Peat-Calcine Clay9. 85-10-5 Sand- Peat-Zeopro

10. 85-10-5 Sand-Calcine Clay-Soil

11. 85-5-10 Sand-Calcine Clay-Soil12. 85-10-5 Sand-Zeopro-Soil13. 85-5-10 Sand-Zeopro-Soil14. 80-10-10 Sand-Calcine Clay-Soil15 . 80-10-10 Sand-Zeopro-Soil

16. 85-7.5-7.5 Sand-Calcine Clay-Zeopro17. 70-15-15 Sand-Calcine Clay-Soil18. 70-15-15 Sand-Zeopro-Soil19. 70-20-5 Sand-Soil-Compost*20. 85-15 Sand-Compost21. 100 Sand

*System One Compost.Fine grade sterilized steer manure.

Table 1. Treatment List.

19 9 7 1 16 12 21

11 5 18 8 14 17 13

15 4 3 6 2 10 20

10 5 17 8 14 18 21

11 6 9 4 2 12 16

3 20 7 19 15 13 1

15 16 17 18 19 20 21

8 9 10 11 12 13 14

1 2 3 4 5 6 7

Planting schematic of root-zone blends North


Chad C. Follis, Barb Corwin

and Brad S. Fresenburg

I n mid summer 1999 and again in2000, a disease problem occurredon the bluegrass/ryegrass mixture

on Faurot field (Figure 1). Close exam-ination revealed a sheath blight symp-tom on the bluegrass but not theryegrass. Numerous sclerotia werefound in association with the blightedbluegrass. A Rhizoctonia sp., tentative-ly identified as Rhizoctonia zeae wasisolated from the diseased bluegrasson Faurot field and also from a sampleof bluegrass from the St. Louis Ram’spractice field in Earth City, MO. Theidentification of the fungus was con-firmed by Dr. Ned Tisserat, KansasState University. The disease causedextensive damage on Faurot field in2000 and did not appear to respondvery well to a preventive applicationof Heritage. In 1999, R. zeae was alsoidentified on bentgrass from a bent-grass/ryegrass fairway in the KansasCity area.

In the fall of 2000, a pilot study wasconducted by Chad Follis, under thedirection of Barb Corwin and BradFresenburg. The objectives of thegreenhouse study were to evaluate theefficacy of two experimental strobil-urin compounds and Heritage appliedpreventatively or curatively against R.zeae and to evaluate the pathogenictyof R. zeae on bluegrass and ryegrass.

MATERIALS AND METHODS

The R. zeae isolate used in this studywas isolated from infected bluegrass inthe bluegrass/ryegrass mixture ofFaurot Field. The inoculum was grown

in 500-ml flasks containing a 1:1 ratioof Kentucky 31 fescue seed and water.After autoclaving three times at 121 Cfor 20 minutes, the flasks were inocu-lated with disks of 1/4 strength PDAcontaining 5 day old cultures of R. zeae. The flasks were incubated for2 weeks, with periodic shaking toallow homogeneous growth through-out the fescue medium.

Pea gravel (1.3 cm) was placed inthe bottom of each 10.2 cm geraniumpot (n = 48). Bluegrass plugs (10.2cm) were taken from a mature, estab-lished plot and placed directly intothe pots. Ryegrass was seeded at arate of 0.09kg/m2, on top of 1.3 cmof pea gravel with the remainder ofthe pot filled with Zeopro‘. Each potwas allowed to establish in the green-house for one month prior to trial ini-tiation (Figure 1). Water was appliedthrough sub-irrigation to provide aminimum of 1.3 cm of water at alltimes. Pots were trimmed weekly to6.4 cm. The greenhouse had an aver-age temperature of 15.57C, withhumidity about 55%.

A 0.5 g sample of inoculum wa sdistributed over the surface of theg rass canopy in each pot. A clearplastic bag was placed over each potto maintain high relative humidityand temperature. The bags werer e m oved 5 days after inoculation.

P r e ve n t a t ive treatments (strobilurin1 at .2 oz/M, strobilurin 2 at .2 oz/M,Heritage at .4 oz/M, and a water con-trol) were applied two days beforeinoculation. Cura t ive treatments (stro-bilurin 1 at .2 oz/M , strobilurin 1 at.9 oz/M, strobilurin 2 at .2 oz/M, andHeritage at .4 oz/M and a water con-

trol) were applied six days after inoc-ulation. Pots were taken outside anda r ranged in a unit area to allow theuse of a CO2 back p a ck sprayer with152 cm boom delivering 814.4 l/hathrough XR8008 tips at 32 psi toapply all fungicides evenly acrosstreatments. After fungicide applica-

Italicized entries represent data collection points.

Figure 2.Timeline for trial of Rhizoctonia zeae.

Oct. 12Potted bluegrass and

planted ryegrass. Potsplaced in greenhouse.

Nov. 16Inoculated and

applied plastic bags.

Nov. 20Second mycelium

observed. Disease isolated.

Nov. 22Curative treatment

applied.

Dec. 1Infection rating

(% of pot) Dec. 7Infection rating (% of pot)End of 14 day inter val.

Nov. 27Infection rating (% of pot)

Nov. 21Mycelium count (% of pot)

Nov. 17First myceliumobserved.

Nov. 14Preventative treat -ment applied.

Evaluation of the efficacy of strobilurin fungicides against Rhizoctonia zeae

Figure 1. Symptoms of Rhizoctonia zeaeon Faurot Field, 2000.


tion, pots were returned to the green-house and arranged in a completelyrandomized design.

Mycelial growth was observed theday after inoculation in all inoculatedpots. Microscopic examination veri-fied that the mycelium was character-istic of Rhizoctonia sp. Because thereappeared to be obvious differences inamount of mycelial growth amongpreventative fungicide treatmentswhen compared to the untreated pots,the amount of mycelial growth wasestimated as a percentage of pot sur-face covered.

The amount of disease was mea-sured as a % pot area infected.P r e ve n t ive treatments were rated at11, 15 and 21 days after fungicideapplication. Cura t ive treatments were rated 5, 9 and 15 days afterfungicide application.

RESULTS

Five days after inoculation, all preven-tative fungicide treatments resulted inincreased mycelial growth comparedto the untreated control, but differ-ences were only statistically significantfor the ryegrass preventative treatments(Tables 1 and 3).

In the ryegrass and bluegrass pre-ventative trial, following an initialincrease in visible mycelial growth, nodifferences in % infection amongfungicide treatments compared to thecontrol were noted 11, 15 or 21 dayspost treatment Tables 1 and 3).

With the ryegrass curative treat-ments at 5, 9 and 15 days after appli-cation, strobilurin 2 at .2 oz/M hadsignificantly higher % infection thanthe untreated control (Table 2). At 15

days after application, all fungicidetreatments had a significantly higher% infection than the untreated control.

With the bluegrass curative treat-ments, strobilurin 2 at .2 oz/M had asignificantly higher % infection thanthe untreated control 5 days afterapplication (Table 4). By 9 days afterapplication, this treatment had thesame % infection as the untreatedcontrol and strobilurin 1 at .2 oz/Mhad significantly lower % infectionthan the untreated control. At 15 daysafter application all fungicide treat-ments had % infection statistically

equal to the untreated control.

DISCUSSION

On the untreated control there wa sa peak in % infection 15 days afterinoculation, followed by a ra p i ddecline 21 days after inoculation.This same natural decline in diseaseprogress has been noted by other turfpathologists working withRhizoctonia diseases.

In this pilot study, R. z e a einfection was better controlled pre-ve n t a t ively than cura t ively with strob-ulurin materials.

% infection

Treatment Rate (oz/m) Mycelium* Day 11 Day 15 Day 21**

Control __ 26.7b 10.0a 6.7a 1.7aStrobilurin 1 0.2 73.3a 10.0a 0.0b 0.0aStrobilurin 2 0.2 50.0a 10.0a 0.0b 0.0aHeritage 0.4 46.7a 10.0a 0.0b 0.0a

LSD (.05) __ 22.100 0.00 5.80 2.90Std.Dev. __ 11.055 0.00 2.887 1.443

Means followed by the same letter do not significantly differ.

*% pot area covered 5 days after inoculation.

**days past treatment

Table 1.Preventative Ryegrass

% infection

Treatment Rate (oz/m) Day 5 Day 9 Day 15

Control __ 10.0b 6.7b 1.7bStrobilurin 1 0.2 13.3ab 10.0b 8.3aStrobilurin 1 0.9 16.7ab 13.3ab 7.7aStrobilurin 2 0.2 23.3a 20.0a 6.7aHeritage 0.4 20.0ab 13.3ab 6.7a

LSD (.05) __ 11.70 6.90 4.50Std.Dev. __ 6.191 3.651 2.401



Table 2.Curative Ryegrass


Preliminary evidence form this pilotstudy suggests that the R. zeae isolatedfrom Faurot Field is more pathogenicon bluegrass than ryegrass. This sup-ports field observations in whichhealthy ryegrass was located withindiseased bluegrass areas.

Results from this study also suggestthat there may be at least some initialfungal growth enhancement followingapplication of the stobilurins.

Further studies will be conductedon a larger scale both in the green-house and in the field. ■

% infection

Treatment Rate (oz/m) Mycelium* Day 11 Day 15 Day 21**

Control __ 26.7a 30.0a 33.3a 5.0aStrobilurin 1 0.2 73.3a 13.3b 10.0b 0.0aStrobilurin 2 0.2 60.0a 13.3b 10.0b 0.0aHeritage 0.4 43.3a 10.0b 10.0b 0.0a

LSD (.05) __ 52.100 8.800 5.80 5.00Std.Dev. __ 26.088 4.410 2.887 2.50


*% pot area covered 5 days after inoculation.


Table 3.Preventative Bluegrass

% infection

Treatment Rate (oz/m) Day 5 Day 9 Day 15

Control __ 30.0b 33.3a 5.0aStrobilurin 1 0.2 43.3ab 20.0b 5.0aStrobilurin 1 0.9 36.7ab 23.3ab 6.7aStrobilurin 2 0.2 46.7a 33.3a 10.0aHeritage 0.4 33.3ab 26.7ab 5.0a

LSD (.05) __ 13.80 10.60 6.40Std.Dev. __ 7.303 5.627 3.416



Table 4.Curative Bluegrass


Amendments and construction systems for improvingthe performance of sand-based greens

C-H. Ok, S.H. Anderson, Erik Ervin,

Brad Fresenburg, J.H. Dunn, Chad C. Follis

I n recent years, a major considera-tion of putting green constructionhas been the properties of the

materials used in root zone mixes.There are many important physicalcharacteristics of desirable turfgrassroot zone mixtures. These include ahigh infiltration rate, adequate aera-tion, high cation exchange capacityfor retaining plant nutrients, highwater retention, and a low tendencyfor compaction. Due to the heavy traf-fic on putting greens, they are primari-ly constructed of sand to provide aroot zone that is resistant to com-paction. However, sand has a lowercation exchange capacity and water-holding capacity, and allows forexcessive drainage rates.

Typically, the addition of certainorganic materials as amendments tosand improves root zone properties.Peat is the most commonly usedorganic material and is recommendedby the USGA. The advantages ofamending sand with organic materialsinclude increased water and nutrientretention. Even though sand-basedroot zones with organic materials havesome benefits, there are some disad-vantages. Disadvantages include toomuch organic matter accumulation,formation of a black layer over time,slightly higher tendency for com-paction, and lower oxygen diffusionrate. When USGA greens are con-structed, they contain about 1.5 to 2.5% (by weight) organic matter (i.e., 10to 15 % by volume). However, organicmatter will accumulate over time as

grass roots grow and die. After two orthree years, the surface 2-inch zonemay contain 7 to 12 % (by weight)organic matter which can decreasewater infiltration and oxygen diffusion.

The use of inorganic amendmentss u ch as porous ceramics and zeolites inputting green root zone mixtures offer anumber of benefits for improving sand-based root zones. They are less proneto compaction than organic materialsand have higher cation exch a n g ecapacity and water holding capacity.They are essentially permanent addi-tions to the root zone, demonstra t i n gvery little break down over time. Th eaddition of zeolite may improve thenutrient status of sand-based rootzones, especially, selective retention ofNH4+ and K+ ions. These inorganicmaterials may be a suitable replace-ment for organic matter as an amend-ment to a sand-based putting green.

An increasing number of golf cours-es are building greens in a California-style — cutting costs by establishing a10 to 12 inch sand layer over nativesoil. During humid Midwest summers,the extra moisture potentially availablein a USGA green due to perchedwater tables may not be a positive fea-

ture. Systems that result in perchedwaters produce lower air-filled porosi-ty which decreases oxygen diffusion.Lower aeration causes greater rootstress, and possibly more summerbentgrass decline.

PROCEDURES AND OBJECTIVES

A study is underway at the MU turf-g rass Research Center to compare threeamendments and three systems ofgreen construction. Four treatments arebeing compared: a California profile, aUSGA profile, and two modifiedCalifornia profiles. The California pro-file referred to as the California treat-ment consists of 12” of 100% sandover a 5” layer of silt loam with a dra i nat the top of the silt loam laye r. Th eUSGA profile referred to as the USGAtreatment consists of 90% sand and10% Dakota reed sedge peat by vo l-ume, with a 12” root zone mix over a5” pea gravel layer (0.10”-0.25” diame-ter) over a drain. The sand/peat mix wa sblended at the supplier, Capitol Sand,Jefferson City, MO. There are also twomodified California profile green treat-ments, each consisting of a 10” rootzone mix over a 7” layer of silt loamwith a drain at the top of the silt loam

Diameter USGA 90/10 Fine mason Particle size (mm) recommendation (%) peat (%) sand (%)

gravel > 2 < 3 0.9 0.1

v. coarse sand 1 - 2 < 7 3.4 2.3

coarse sand 0.5 - 1 60* 19.9 13.0

medium sand 0.25 - 0.5 minimum 49.1 49.9

fine sand 0.1 - 0.25 < 20 23.7 31.6

v. fine sand 0.05 - 0.1 < 5 2.4 1.9

silt and clay 0.05 or less < 8 0.6 1.2

*Coarse sand plus medium sand are recommended to be 60% as a minimum.

Table 1: Particle size analysis of the two sands used in this experiment


l aye r. The first modified profile referredto as the California-P treatment consistsof 82% sand, 15% porous cera m i c(ProfileTM), and 3% humate; the sec-ond modified profile referred to as theCalifornia-Z treatment consists of 85%sand and 15% zeolite (ZeoProTM).These two mixes were blended at theTurf Research Center with a smallcement mixer. Two sands were used forthe different rootzone mixes in thiss t u dy: a coarse mason sand was blend-ed with Dakota reed sedge peat for theUSGA treatment and a fine mason sandwas used in the three California-styletreatments. Their particle size analysesare presented in Table 1.

Treatments were established in 4’ x4’ wooden boxes equipped so thatd rainage leachate could be monitored.The four treatments are arranged in arandomized complete block with fourreplicates. The amended and unamend-ed root zones were installed in Au g u s tand ‘Pencross’ creeping bentgrass wa sseeded on September 27, 1998 at 1lb/M (M=1000 ft2). From seedingthrough May 1999, each plot was sup-plied with 6 lbs N/M, 2 lbs P/M, and15 lbs K/M, either from granular fertiliz-er or, in the case of the ZeoPro amend-ed plots, as nutrients estimated to beavailable from the nutrient-ch a r g e dZeoPro (0.1-0.05-0.6). From May 2000through May 2001, all plots receive d4.7 lbs N/M, 1 lb P/M, and 4.3 lbs K/M.The green was initially mowed at 0.5”wh i ch was reduced to 0.373” and then0.25”. It is now being mowed at0.156”. Mowing occurs four timesw e e k l y. Irrigation is applied every oneor two days based on atmometer esti-mated eva p o t ra n s p i ra t i o n .

The research plan is to comparethese amendments and systems of

green construction in termsof short- and long-termperformance and resourceefficiency by measuringresponses such as: qualityand color, root mass, soilphysical and chemicalproperties, oxygen diffu-sion rates, and nitrogenand potassium leaching.

RESULTS (MAY 2000 TO

MAY 2001)From May 2000 to May 2001,

ZeoPro-amended (California-Z) plotshad higher color and quality ratings(Tables 2, 3). The Profile (California-P)and ZeoPro amended (California-Z)plots had darker color and higherquality (recovery) after severe droughtthan the other two treatments in

August of 2000. The California andUSGA treatments performed with sim-ilar quality throughout the study.

Root mass measurements have beenvariable, making it difficult to reacha ny meaningful conclusions relative todifferences among the treatments. A f t e rthe summer 2000 growing season, thel owest levels of root mass were found

Color ratings:1 - 9

Treatments 2000 2001

5/29 6/26 7/25* 8/30 9/29 10/28 5/31

C a l i fo r n i a 4.6 bc 5.3 bc 4.0 a 4.9 bc 5.9 a 5.6 ab 4.9 a

USGA 3.9 c 4.9 c 3.1 b 4.0 c 5.0 b 5.0 b 5.1 a

California-P 4.9 b 5.6 b 4.3 a 6.3 a 6.0 a 5.9 a 5.6 a

California-Z 6.3 a 6.1 a 3.3 b 5.9 ab 6.4 a 6.3 a 5.5 a

LSD (0.05) 0.9 0.4 0.7 1.0 0.6 0.7 0.9

*End of dry down (measured after no irrigation from June 19 to July 24)

Table 2:Color ratings of bentgrass sand/amendment root zone study (2000-2001)

Quality ratings


5/29 6/26 7/25* 8/30 9/29 10/28 5/31

C a l i fo r n i a 4.1 c 4.8 b 4.4 a 5.1 b 5.5 b 5.3 b 4.8 b

USGA 3.8 c 4.8 b 2.3 b 3.9 c 5.0 c 4.8 c 4.8 b

California-P 5.0 b 5.3 b 3.8 ab 6.0 a 5.6 b 5.9 a 5.8 a

California-Z 6.3 a 6.0 a 3.4 ab 6.1 a 6.1 a 6.1 a 5.3 ab

LSD (0.05) 0.5 0.7 1.2 0.6 0.5 0.3 0.7

*End of dry down (measured after no irrigation from June 19 to July 24)

Table 3: Quality ratings of bentgrass sand/amendment root zone study (2000-2001)

Root mass :2.5”x 4”depth (grams)


4/27 7/28 10/18 5/31

C a l i fo r n i a 1.19 ab 1.23 a 0.69 ab 0.87 a

USGA 0.99 b 0.97 a 0.63 b 0.91 a

California-P 1.39 a 1.21 a 0.68 ab 0.84 a

California-Z 1.38 a 1.15 a 0.83 a 1.02 a

LSD (0.05) 0.29 0.34 0.18 0.39

Table 4:Root mass of bentgrass sand/amendmentroot zone study (2000-2001)

in October (Table 4). Although therewere no significant differences in A p r i l2001, root mass increased slightlywhen compared with the precedingyear (Table 4).

All amendments increased the capil-lary porosity of the mixtures in relationto the 100% sand treatment, resulting ingreater water retention at field capacity( Table 5). The peat mixture had the low-est saturated hy d raulic conductivity andthe highest capillary porosity in lab testsof the mixture without the gravel laye r( Table 5). The USGA treatment had al ower Ksat during 2000 (Table 6). Th eCalifornia treatment had the lowest Ksatin May 2001 because this treatment hasa higher fine sand content resulting inless porosity over time. The high Ksat ofthe California-Z (Table 6) can be attrib-uted to its high non-capillary porosity( Table 5).

USGA, California-P, and California-Z treatments had increased values ofCEC compared to the California treat-ment with the highest CEC value inCalifornia-P treatment (Table 7). TheCalifornia-Z treatment contained moreavailable P and K then the others,while the California-P treatment alsocontained high amounts of available P,Ca, and Mg relative to the Californiaand USGA treatments. Greater nutri-ent retention due to the additional ofZeoPro and Profile seemed to corre-late with higher average quality andcolor ratings over the last three years.These results indicate that substitutingProfile or ZeoPro for peat may allowfor the maintenance of high qualitybentgrass with less fertilizer inputs.

The USGA treatment had the highestn i t rate leachate concentration for theN ovember 1998 sampling (data in pre-vious report 2000). How e ve r, two ye a r s

after planting, the results show thatthere were no significant nitrate leach-ing differences among the treatments( Table 8). The California-Z treatment,with its high affinity for K, consistentlyhad the lowest K leachate concentra-tion, whereas USGA had the highestmeasured losses in September 1999.Higher losses through the USGA treat-ment may be associated with largeflushing events through the gravel laye r

rather than with the peat itself.Potassium leachate declined for mosttreatments by July 1999 (Table 8).

Oxygen diffusion rates and soilmoisture contents were not differentamong the treatments (Table 9).Further measurements will be takenduring 2001 following the dry-downcycle to determine if differences innon-capillary porosity will influenceroot zone oxygen diffusion rates. ■


Treatment Ksat (in/hr):Saturated field infiltration rate

5/22/00 8/2/00 10/10/00 5/22/01

California 16.4 b 28.4 a 15.6 c 12.4 c

USGA 15.1 b 21.6 b 20.2 b 14.1 bc

California-P 20.0 a 25.9 a 19.3 bc 16.5 ab

California-Z 22.2 a 25.9 a 25.4 a 17.4 a

LSD (0.05) 2.2 4.2 4.3 2.6

Table 6:Saturated field infiltration rate as green matures

Treatments CEC Organic P Ca Mg KpH (meq/100g) Matter % (lb/A) (lb/A) (lb/A) (lb/A)

C a l i fo r n i a 6.9 a 2.76 c 0.18 b 43.8 c 864 c 100.8 c 139.5 b

USGA 6.8 a 3.72 b 0.33 a 47.5 bc 1189 b 143.5 b 114.8 b

California-P 6.8 a 5.25 a 0.35 a 67.0 ab 1624 a 192.5 a 297.0 b

California-Z 6.9 a 4.39 b 0.13 b 72.8 a 1213 b 132.5 bc 629.8 a

LSD (0.05) 0.1 0.8 0.11 22.0 226.4 34.5 216.6

Ta ble 7: Soil chemical pro p e rties of bentgrass sand/amendment root zone study :5 / 2 9 / 0 1

Table 5:Root zone physical analysis at establishment:September 1998

Amendment Non-capillary Capillary Water retentionKsat (lab)* (air-filled) (water-filled) at field capacity

in/hr vol/vol, % percentage vol/vol, %

100% sand 22.8 26.3 13.1 8.1

Peat mixes 11.2 16.3 21.7 13.3

Profile mixes 23.2 26.2 18.9 13.2

ZeoPro mixes 24.3 28.5 14.8 9.9

*Analysis performed by Tifton Physical Soil Testing Laboratory: Ksat = Saturated hydraulic conductivity of the sand-based root zone mix, without subsurface pea gravel or silt loam layer, in the lab.


Table 8:Nitrate and potassium leachate concentration from bentgrass sand/amendment root zone study (1999-2000)

Treatments NO3- (mg L–1) K+ (mg L–1)

9/2/99 7/6/00 9/2/99 7/6/00

C a l i fo r n i a 0 . 2 0 a 0 . 1 5 b c 3 8 . 8 5 b 1 3 . 8 5 a

U S G A 0 . 1 8 a 0 . 0 9 c 4 9 . 3 0 a 1 7 . 1 7 a

California-P 0.45a 0.74ab 35.75b 18.09a

California-Z 0.34a 0.98a 4.58c 6.05b

LSD (0.05) 0.28 0.65 10.31 5.54

O x y g e n Soil moisturediffusion rates content

Treatments (mg/cm2/min) (vol/vol, %)

6/13/2000

C a l i fo rn i a 0 . 1 4 a b 2 4 . 2 4 aUSGA 0.09b 22.85bCalifornia-P 0.15a 25.70abCalifornia-Z 0.14ab 25.95ab

LSD (0.05) 0.05 3.31

Ta ble 9: O x y gen diffusion rates with soil moisture content of sand/amendment study


Barb Corwin

S uperintendents and other turfmanagers rarely need assistanceto identify the “classic” infec-

tious diseases of turfgrass such asbrown patch, dollar spot, rust or leafspot. So why ask for help? The field ofturfgrass science and management is adynamic one, resulting in adoption ofnewly released turfgrass cultivars; newproducts for disease, weed and insectcontrol; new equipment and methodsof delivery — the list goes on.Because of the constantly changingpicture, old diseases that were easilycontrolled , e.g. dollar spot, may bedifficult to manage, causing the super-intendent to doubt his own judgmentand seek help in making sure that itreally is dollar spot. And in the last 8years or so, I have seen the emergenceof entirely new diseases and resur-gence of old ones such as anthracnosebasal rot, spring dead spot of bent-grass, downy mildew of zoysiagrassand Rhizoctonia zeae on bluegrass. Ihave also encountered a variety ofemerging insect problems such asJapanese beetle, billbug and chinchbug.

Further complicating diagnosis isthat many turfgrass health problemsare not caused directly by infectiousdisease, but result from poor construc-tion, misapplication of products orproduct failure and environmentalextremes. Many of the symptomscaused by non infectious diseasemimic those caused by turfgrasspathogens and disease organismsoften compound the situation byinfecting stressed turfgrass.

The Extension Plant DiagnosticClinic at the University of Missouri has

provided plant diagnosticassistance since the mid-1960s, but it has only beenworking closely with theturf industry in Missourisince 1994. turfgrass diseasediagnostics and problemsolving are available tosuperintendents and otherturf managers upon request.

The Turf DiseaseDiagnostics program at MUis a fee-based program, designed toassist in identifying the cause of poorturfgrass health before unnecessarypesticides and other managementpractices are applied. A superinten-dent or turf manager can participate inthe program in several different ways.

The traditional method has been toovernight mail or hand deliver sam-ples to the Plant Diagnostic Clinic.Depending on the type of turfgrass,samples should be taken with a cupcutter or a knife to the depth of the

root zone. The ideal sample willinclude at least one plug that has thetransition zone between healthy andaffected turfgrass. Insert samples in aZiploc bag with open top. If the rootzone is holding together well, tape theplastic tightly around the core to pre-vent soil coming in contact with thegrass leaves during transit. Alwaysleave the grass itself uncovered. Thisavoids physical damage to grassblades and buildup of mold duringshipping. The bottom third of a liter

The Turf Disease Diagnostics program at MU


soda bottle works particularly well forgreens sample. Package in such a wayto avoid plugs falling apart and soilcovering the grass. It is always best tocall ahead of time to alert me to thearrival of a sample. I like to get somebackground information and adescription of the problem ahead oftime. It is also very helpful to receivepictures illustrating the distribution ofsymptoms. Digital images can beemailed directly to [email protected] or submitted through ourwebsite athttp://agebb.missouri/edu/pdc

R e c e iving pictures along with a sam-ple is really only the next best thing toactually making a site visit. I havecome to the conclusion that a site visit,when possible, is the best way to go toa ch i e ve an accurate diagnosis. Notonly can I observe the pattern of symp-toms on-site, but I also learn a little

about the superintendent, his or hermanagement style, the course historyand layout, and what managementoptions will or wo n ’t work for a partic-ular budget. On-site visits can beaccomplished either by requesting avisit as needed or by subscribing to theMU Mobile turfgrass Progra m .

Participants in the MU MobileTurfgrass program receive regularmonthly visits, whether there are prob-lems or not. The advantage to thisapproach is that developing a one-on-one relationship with a superintendentand getting to know the course beforeproblems arise, help me respond morequickly when something goes wrong.We charge $50 per sample for greenssamples submitted to the clinic. Thecharge for on-site visits is variable,depending on the distance traveledand time spent on-site. The fee for asubscription to the MU Mobile Turf is

$1200 for the season.A special thank-you to MVGCSAA

for support of my diagnostic efforts.The association is purchasing a dis-secting microscope with travel case.Although ownership will reside withMVGCSAA, I will use the scope dur-ing my on-site visits.

To take advantage of the turfgrassdisease diagnostic program at MU,contact Dr. Barb Corwin at 573-882-3019 or mobile 573-219-1156. Forhelp with athletic field constructionand maintenance, contact BradFresenburg at 573-442-4893.

The services of the clinic are alsoavailable to help horticulturalists andlandscape managers identify problemswith trees and shrubs. For more infor-mation on submitting samples to theclinic, visit our web site athttp://www.agebb.missouri.edu/pdc ■

Chris Starbuck

I n the spring, when trees bloom,Extension centers begin to get thedreaded, “isn’t there something I

can spray to keep those stupid ballsfrom forming on my sweetgum tree”,calls. The caller usually goes on todescribe several episodes in whichgum balls have caused extremeannoyance, pain or severe bodilyinjury. Finally, the client usually statesthat, unless the Extension office canprovide a guaranteed gum ball pre-vention technique, the chain saw willgo into action within minutes. Until afew years ago, the answer was simple;“No, there is nothing one can do toprevent sweetgum balls from forming.”Chain saws could sometimes be heardstarting in the background. However,now there is a product that is labeledfor this purpose, commercially avail-able and actually works if usedaccording to label directions.

The material is Florel FruitEliminator®, made by MontereyChemical Company. It is availablethrough normal wholesale distributionchannels and is becoming more com-

mon in retail garden stores. Theproduct is also sold retail viathe Monterey Chemical website at http://www.monterey-lawngarden.com/info/florel.htmlwhere it is listed at $20.15 perpint, $27.75 per quart or$67.50 per gallon. It is alsoavailable in a 2.5 gallon size.

Florel Fruit Eliminator is usedat a rate of 1 quart per 10 gal-lons of spray and must bes p rayed to runoff on the flowers wh e nthe flower clusters begin to separa t eand the leaves are about half expand-ed. There is a narrow time window (2weeks at most) when it will be effectiveand it should only be applied when thet e m p e rature is between 65 and 95degrees F. The label also cautionsagainst spraying trees that are understress from disease, drought or othercauses. It may be challenging to sprayto the top of a large tree. A retail nurs-ery operator tells me that he carries ahose-end sprayer that can be adjustedto siphon 1 quart per 10 gallons (set tod e l iver 6 tablespoons [3 ounces] ofc o n c e n t rate per gallon of spray) andwill spray up to 30 feet with good hose

pressure. If one gets good cove rage atthe proper time, my sources tell methat the product is usually effective inp r e venting fruit development. For largetrees or when multiple trees must betreated, it is best to retain the servicesof a firm with the proper equipment todo the job.

For those interested in a non-chemical approach there is a cultiva rof sweetgum, Liquidambar styra c i f l u a‘Rotundiloba’, that is fruitless. It wa sd i s c overed in 1930 near PinehurstN.C. While seve ral of these havebeen planted at Missouri BotanicalGarden it should be noted that thisplanted is generally considered hardyonly to Zone 6. ■


Sweetgum ball control


David Trinklein and Amy Riesselman

C olorful beds of annual floweringplants have become an impor-tant component of the created

landscape. This is true for public areasas well as private residences. Sales ofannual flowering plants increase inscope each year by double-digit fig-ures, with no end in sight. Many annu-al herbaceous plants carry the stigmaof being somewhat difficult to grow,especially under severe heat and waterstress conditions typical of Missouri’ssummers. This fact has, in certaincases, prevented them from beingmore widely used in large-scale planti-ng such as those typical of color bedson golf courses, surrounding commer-cial buildings, etc. Plant improvementvia introduction and breeding providesus with many new cultivars of orna-mentals each year. Unfortunately, theability of these new cultivars to toler-ate the heat and humidity typical of aMissouri summer is, for the most part,unknown. The purpose of this trial wasto evaluate a number of new herba-ceous ornamental cultivars for theirsummer performance in Missouri.

Twenty-nine cultivars of annualherbaceous ornamental plants (Table 1)were grown under garden conditions atd e m o n s t ration plots located at theU n iversity of Missouri Turf ResearchCenter located on the Unive r s i t y ’sSouth Farm wh i ch is near Columbia,Mo. The plants were started from seedor received as established plants inFebruary and cultured to tra n s p l a n t a b l esize in the greenhouse. On May 10,

2001 they were planted in the outdoorplots wh i ch had been amended the pre-vious fall with four inches of horse bed-ding along with one pound ofammonium nitrate per 100 square feet.Plants were hand-watered until estab-lished and then supplied with one andone-half inches of water per week.

Weed control was accomplished byhand-weeding, when needed.

Data will be collected for early per-formance, mid-summer performance,and late season performance; eva l u a-tion will be preformed by a panel ofjudges using a numerical rating scale. ■

Evaluating annual herbaceous ornamentals for performance in Missouri

Argyranthemum ‘Comet Pink’Brachycome ‘Mauve Delight’Cleome ‘Sparkler Bush’Gazania ‘Daybreak Red Stripe’Geranium ‘Rocky Mountain Deep Coral’Geranium ‘Rocky Mountain Lavender Pink’Geranium ‘Rocky Mountain Light Salmon’Geranium ‘Rocky Mountain Magenta’Geranium ‘Rocky Mountain Pink’Marigold ‘Aspen Mix’Neimesia ‘ Peach Sachet’Nicotiana ‘Avalon Bright Pink’Ornamental Pepper ‘Medusa’Osteospermum ‘Light Purple’Pentus ‘Cherry Rose’

Pentus ‘Lavender Light’Nicotiana ‘Avalon Bright Pink’Pentas ‘Butterfly Red’Pentas ‘Lavender Light’Petunia ‘Happy Dream Pink’Petunia ‘Tidal Wave Cherry’Petunia ‘Tidal Wave Lavender’Petunia ‘Tidal Wave Silver’Petunia Calibrachoa ‘Color Burst Rose’Petunia Cascadias ‘Yellow Eye’Portulaca ‘Margarita Rosita’Rudbeckia ‘Cherokee Sunset’Scaevola ‘Purple Fan’Vinca ‘Jaio Scarlet Eye’

Table 1. 2001 ornamental plant evaluation.


John H. Dunn, Michele R. Warmund


C old tolerance of warm seasongrasses is dependent, in part, onproduction of carbohydrates

and other products of photosynthesisduring autumn. Raising the cuttingheight is believed to enhance the fallhardening process by increasing theamount of photosynthetic tissue avail-able to the turf. The additional growthmay also help insulate crowns andother plant parts in winter.

Use of growth regulators to slowtop growth may also contribute toimproved cold tolerance. In this situa-tion, energy and carbohydrates nor-mally used for top growth may beconserved for cold hardening as topgrowth slows in response to growthregulator applications.

The purpose of our study was toinvestigate the influence of cuttingheight and the growth regulatingchemical Primo (trinexapac-ethyl) oncold tolerance of ‘Zenith’ and Z-9(experimental) zoysiagrasses.

PROCEDURE

Zenith and Z-9 were seeded in Ju n e1995, in 20 x 35 ft plots with three repli-cations. Fo l l owing establishment, turfwas mowed at 5/8 inches and irrigatedas needed to prevent drought stress, Tu r fr e c e ived a total of 2 lb N per 1000 sq ftin the form of 24-4-12 (N-P-K) or 31-0-0( with part slow release N) during sum-m e r. Cra b g rass and broadleaf weedswere chemically controlled.

In August 1998, plots of each entrywere equally divided and triplex-

mowed east-westonce per week at5/8 and 1 inches.Applications of 0,1/8 and 1/4 oz a.i.Primo per 1000 sq ftwere made north-south to 5 x 12 ftplots within eachcutting height.Applications weremade at 4-weekintervals untilOctober 7. A similarprocedure wasrepeated in 2000.

In September andOctober of 1998and 2000, measure-ments were made with a disc-metalruler device to estimate the influence ofPrimo on vertical growth. Color ra t i n g s(9 = best) were taken at approximately3 week intervals. In Fe b r u a r y, 1999 and2001, rhizomes were removed frome a ch treatment plot and exposed tot e m p e ratures of 18° F, 14° F, 10° F, and6° F in a freezing chamber to deter-mine the influence of cutting heightand Primo on cold tolerance of thez oy s i a g rasses.

RESULTS

Primo applications reduced verticalgrowth in 1999 by an average 19% atthe 1/8 oz level and 30% at 1/4 ozcompared with untreated plots. Colorratings during fall of Primo-treatedplots were inconsistent. Color of turfgiven 1/8 and 1/4 oz Primo was some-times slightly less (1.0 unit or less)than that of untreated plots. At other

times, color of treated turf slightlyexceeded that of the untreated turf.Growth and quality measurements for2000 are being summarized.

C o n t rary to our theory, neither Primonor cutting height had an influence oncold tolerance of either zoy s i a g rass inFe b r u a r y, 1999. For example, the 1999freezing test showed that survival ofz oy s i a g rass rhizomes sampled from turfm owed at the lower cutting height of5/8 inches and given no Primo, wa sequal to or better than any combina-tion of turf given 1/8 or 1/4 oz Primoper 1000 sq ft and mowed at 1 inch. Inthe field, there were no differences inspring greenup according to treatments,and plots were indistinguishable in latespring, 1999 and 2001. How e ve r, inFebruary 2001 there was a small effectof Primo on rhizome survival ave ra g e dover freezing test temperatures (see fig-ure). ■

Cold tolerance of zoysiagrass as influenced by cutting height and Primo

Figure. Average number of Zenith and Z-9 rhizomes of a possible fivesurviving four freezing test temperatures in February, 2001.Level1=control, level 2= 1/8 oz a.i., and level 3=1/4 oz a.i.Level 1 is signifi-cantly different from levels 2 and 3, P=0.03.

Freezing Survival

Primo

Level 1 Level 2 Level 30

0.2

0.4

0.6

0.8

1

1.2

1.4


John H. Dunn, Michele R. Warmund


B ermudagrass is a possiblechoice for golf and athleticfield turf in the Midwest

Transition Area. However, new culti-vars must be evaluated for cold toler-ance before they can be usedextensively. Field evaluation for coldtolerance is a slow process that mayrequire several years before a “test”winter is encountered. It may be possi-ble to accelerate the process byscreening less hardy experimentals incontrolled-environment freezing tests

We selected bermudagrass entriesfor our freezing tests from the Nationalturfgrass Evaluation ProgramBermudagrass Field Test, established atthe MU Research Center in 1997. Turfwas mowed at 5/8 inch and irrigatedas needed to prevent severe droughtstress. Turf received a total of 2 lb N(24-4-12, 20 % slow release N)/ 1000sq ft from late May to mid-August.Rhizomes were removed from thefield for freezing tests in November1998 and 1999, and February 1999and 2000.

Minimum freezing test temperaturesthat entries survived in February ofboth years were:

Based upon two years of freezingtests and field observations, Midlaw n ,Q u i ckstand, and OKS 95-1 were bestadapted to our mid-Missouri env i r o n-ment. Freezing tolerance of NuMexS a h a ra, Baby, Sundevil II, Ti f way 419,and Tifgreen, was significantly poorerthan that of the topthree cultivars (seeFreezing To l e ra n c eg raph) and all fivewere slow to recov-er following at leastone test winter inthe field (see Fi e l dR e c overy gra p h ) .These five cultiva r swould be expectedto show frequentwinter injury, some-

times annual, depending upon culti-var and environmental conditionsyear to ye a r.

Our two year results suggested thatcontrolled environment freezing testsm ay be useful for early identificationof least cold tolerant bermudagra s s e s ,

Bermudagrass cold tolerance

<217F ‘NuMex Sahara’217F ‘Baby’217F ‘Sundevil II’217F ‘Tifway 419’217F ‘Tifgreen’187F OKS 95-1147F ‘Midlawn’147F ‘Quickstand’

< cultivar did not survive 217F

Freezing Tolerance

Cultivar

0.5

1

1.5

2

2.5

3

3.5

4

0

21F

18F

14F

thus conserving time and researchland required for field eva l u a t i o n s .H ow e ve r, observations of cold toler-ance based upon spring greenupwere confounded in year 3 with thea p p e a rance of spring deadspot dis-ease (see photo). Cultivars in theNTEP test that showed good cold tol-e rance based upon field recovery ra t-ings and laboratory freezing tests in1999 and 2000, such as OKS 95-1sustained up to 40% spring deadspotinjury in 2001. ■


Field Recovery

Cultivar

2

3

45

6

7

8

9

1

1999

2000

2001

0


John H. Dunn, Brad S. Fresenburg

and Chad C. Follis

A reason for mixing species isadditional env i r o n m e n t a lstress resistance compared

with that of a single turfgrass species.In past years, turfgrass managersattempted to mix tall fescue andKe n t u cky bluegrass, how e ve r,Ke n t u cky bluegrass would consistent-ly dominate in mixture with older tallfescue cultivars, such as ‘Ke n t u cky3 1 .’ The objective of this study is todetermine the influence of seedingrate and Ke n t u cky bluegrass blendcomposition on the competitive n e s sof newer, turf-type tall fescue in mix-ture with Ke n t u cky bluegra s s .

Three Kentucky bluegrass blends, A(‘SR 2000’ + ‘SR 2010’), B(‘Blacksburg’ + ‘Midnight’ + ‘Glade’ +‘Baron’), and C (‘Limousine’ +‘Princeton’ + ‘America’) and a tall fes-cue blend ( ‘Houndog V’ + ‘Jaguar III’+ ‘Falcon II’ + ‘SR 8210’ + ‘Rebel III’+ ‘Mustang II’) were seeded inSeptember, 1996. Mixtures of each ofthe three Kentucky bluegrass blendswith the tall fescue blend were alsoseeded, with tall fescue comprising90% (H), 50% (M), and 20% (L) ofeach mixture by seed weight for atotal of nine mixture combinations.

The test was planted in two adja-cent locations. One location is irrigat-ed and the other is not irrigated. Turf ismowed at 2 inches as needed andreceives 3 to 4 lb N per 1000 sq ft peryear with most of the fertilizer appliedin the fall.

Botanical composition is measuredwith an optical point quadrat (see

photo) thatwe con-structedbased upona design byBritishresearchersLaycockandCanaway.This devicehas tenfixed opti-cal pointsspaced twoinchesapart on a wood frame. Populationcounts are made by visually aligningpoints of paired sewing needles andsighting on the plant part. A Plexiglasstrip is added as a safety feature toprevent contact with the needleswhile allowing light to pass through.Ten random settings of the ten fixedpoints are taken for a total of one hun-dred per treatment plot.

NON-IRRIGATED LOCATION

Tall fescue was the dominantspecies of mixture H at 71% one ye a rafter seeding and 63% after threeyears (see Non-Irrigated gra p h - 1 ) .Mixture M consisted of 42% tall fes-cue at one year and 57% after threeyears. Ke n t u cky bluegrass was thedominant species of the L mixtureafter one ye a r, but declined by 30%

Compatibility of tall fescue and Kentucky bluegrass in mixtures

20

30

4050

60

70

80

90

100

Non-irrigated mixtures-1

KB

TF

Year-seedling rate


from year one to year three so thatKe n t u cky bluegrass and tall fescuewere evenly balanced at three ye a r safter seeding. Mixture A consisted ofan ave rage 58% tall fescue and 41%Ke n t u cky bluegrass (see Non-Irrigatedg raph-2). Mixtures B and C weree venly balanced between the twos p e c i e s .

IRRIGATED LOCATION

Trends for mixture compositionaccording to seeding rate were similarto that of the non-irrigated locationexcept that Kentucky bluegrassappeared to be more competitive inthe irrigated location at three yearsafter seeding, especially, at the L (90%Kentucky bluegrass ) seeding rate.While tall fescue was the dominantcomponent of mixture A in the non-irrigated location, the species weremore evenly balanced in the irrigatedlocation at one and three years after

seeding. Mixtures B and C alsoshowed good balance after three yearswith a difference between species of10% or less.

In summary, both seeding rate andKe n t u cky bluegrass blend affectedmixture composition, the extent

being influenced by irrigation man-agement. Tall fescue was competitivein mixture with Ke n t u cky bluegra s sthree years after seeding at all seed-ing rates and in all combinations withKe n t u cky bluegrass blends. ■

Non-irrigated mixtures-2

Kentucky bluegrass blend

20

30

40

50

60

70

10

KB

TF

0A B C

2001 TURFGRASS RESEARCH & INFORMATION

MU TURFGRASS CENTER

*Aventis Environmental ScienceMontvale, NJ

*Bayer CorporationKansas City, MO

Beacon BallfieldsMiddleton, WI

Capitol SandJefferson City, MO

CassCo TurfSteelville, MO

Columbia Country ClubColumbia, MO

E & E EnterprisesSt. Charles, MO

Eco-Green TechnologiesSt. Louis, MO

Emerald View Turf FarmsO’Fallon, MO

Endress Horticultural ServicesKirkwood, MO

Florissant SodHigh Hill, MO

Gateway Chapter of STMA

*Heart of America Golf Course Superintendents’ Association

Hunter IndustriesSan Marcos, CA

*Keeven Brothers Sod FarmO’Fallon, MO

Laser Turf LevelingSt. Charles, MO

*Mississippi Valley Golf CourseSuperintendents’ Association

*Missouri Valley TurfgrassAssociation

MJM ServicesBelleville, IL

Monsanto CompanySt. Louis, MO

MOKAN Chapter of STMA

MU Athletic DepartmentColumbia, MO (internships)

*National Turf Eval ProgramBeltsville, MD

PBI Gordon CorporationKansas City, MO

Research Support ServicesSouth Farms Columbia, MO

*Rohm & HaasPhiladelphia, PA

Simplot FertilizersSt. Louis, MO

Stabilizer Solutions, Inc.Phoenix, AZ

SyngentaLincoln University, PA

*Turf-Seed, Inc.Hubbard, OR

Turf Professionals Equipment Co.Springfield, MO

Williams Lawn SeedMaryville, MO

* Grants-in-aid

Industry support is essential to our research program. If your organization provided financialor material support for the program and was not listed, please contact Brad Fresenburg so your

name can be added to future reports.

Companies and Organizations that contributed to the 2000-2001 Turfgrass Research Program


Mr. Brad Fresenburg Turfgrass Research and

Extension A s s o c i a t e

Dr. Barbara Corwin Extension Assistant Professor

Plant Pathology

Dr. John Dunn Professor of Horticulture Turfgrass

Teaching, Research and Extension

Dr. Lewis Jett Assistant Professor of Horticulture

and Vegetable Specialist

Dr. Bruce Barrett Associate Professor of Entomology

Dr. Patricia Donald Research Assistant Professor

Plant Pathology

Dr. Chris Starbuck Associate Professor of Horticulture

Dr. David Trinklein Associate Professor of Horticulture

Dr. Michele Warmund Associate Professor of Horticulture

Dr. Stephen AndersonProfessor of Soil & Atmospheric Science

Mr. Changho OkPh.D. Candidate, Turf

Mr. Chad FollisM.S. Candidate, Turf

Ms. Katherine FresenburgField Technician

Ms. Kim FresenburgField Technician

Mr. Michael Fresenburg Field Technician

Amy Riesselman Horticulture Student

Mrs. Rita Gerke, SecretaryHorticulture and Entomology

MVTA Lawn & Turf Conference &

Trade Show

December 4-5, 2001Holiday Inn Select

Columbia, Missouri

Mark your calendarAnd watch your mail for announcements

Turf andOrnamental Faculty

and Staff

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