Kentucky Bluegrass Characterization and Blending Strategies

Leah A. Brilman, Ph.D.

Research DirectorSeed Research of

Oregon

Why Blends and MixturesNo perfect grass cultivar

Increased genetic diversity

Strengths and weaknesses matched

Natural selection for microenvironments

Insurance policy

Match color, growth form carefully

Price competiveness

Why Blends and MixturesKentucky bluegrass apomictic

Single genotype - other turfgrass species are mixture of genotypes

Vegetative cultivars comparison

Vegetative bentgrasses

Vegetative bermudas, zoysias, St. Augustine

Merion Kentucky bluegrass - stripe smut

Not just for disease resistance

Why Blends and MixturesSports Turf Needs

Rapid establishmentStrong lateral spreadHigh shoot density

High sod tensile-strength

Rapid repair of wear

Late fall, winter and early spring growth

Shade tolerance

Abiotic and biotic stress resistance

Types of KentuckyBluegrassesCompact Types CELA Type

Compact BVMG Type

Midnight Shamrock type

America Cheri Type

Aggressive Type Julia Type

Bellevue Type Common Type

Mid-Atlantic Type Other Type

Midnight Type CultivarsDo not have blend of only this type

Very dark green colorLow, compact growthHigh quality turf1/2 inch cutting heightExcellent resistance to leaf spotLong winter dormancyMost do poor in the shadeHigh heat tolerance

Midnight Type CultivarsMidnight ArcadiaLiberator OdysseyNuGlade PerfectionTsunami Chicago IIAwesome ExcursionFreedom II BarristerBeyond Rugby IIImpact Quantum LeapAbsolute AwardTotal Eclipse Midnight II

America Type CultivarsBright dark green colorLow, compact growth1/2 inch cutting heightExcellent resistance to leaf spot, powdery mildewFiner leaf, higher densityModerate winter dormancyModerate summer recoveryHigh summer patch resistanceGood in shade

America Type Cultivars

America ShowcaseApollo SR 2284Unique SR 2394Brilliant LangaraAvalanche Blue RidgeGlenmont RoyaleLakeshore GoldstarArrow Mallard

SR2394/Arcadia Kentucky

Shamrock TypeModerate winter colorGood resistance to leaf spotGood turf quality and sod strengthBillbug susceptibleHigh seed yieldsLess stemmy than BVMG typesSummer performance variableThis type is an excellent substitute for BVMG type - Higher quality with

reduced costs

Shamrock Type VarietiesShamrock SR 2100Champagne Atlantis Parkland

BVMG Type CultivarsHigh seed yields

Medium-good turf

Drought tolerance

Medium low growth

Medium wide leaves

Very stemmy in spring

Good resistance to necrotic ring spot

Often used to reduce costs, can reduce quality

BVMG Type CultivarsBaron CannonVicta MeritGnome Clearwater Goldrush DragonAbbey BlueStarCrest NassuaRaven MarquisBlueChip FortunaEnvicta Baronette

Aggressive Type

Aggressive lateral growthHigh shoot densityVery wear tolerantQuickly knit sod and repairMay predominate in blendVariable in other characteristics

Julia TypeHigh turf quality

High density

Good summer performance

Moderate winter performance

Good leaf spot, stripe smut resistance

Susceptible to brown patch and dollar spotHigh winter wear toleranceJulia Type VarietiesJulia SR 27832Caliber Ikone

Bellevue TypeMedium growth and shoot density

Medium wide leaves

Excellent winter color, early spring green-up

Stemmy in spring

Moderate recovery from summer

Good leaf spot, stripe smut resistance

Susceptible to billbugsBellevue Type Varieties Bellevue SuffolkGeorgetown ParadeClassic Dawn

Mid-Atlantic TypeDeep extensive roots and rhizomes

Vigorous turf and medium-high density

High summer stress tolerance

Early spring green-up

Good winter performance

Rapid recovery from disease

Mid-Atlantic Type VarietiesMonopoly SR 2000Preakness EagletonLivingston PlushWabash

Common TypeErect growth and narrow leaf blades

Good summer stress tolerance

May go dormant in summer

High leaf spot susceptibility

Poor winter color and performance

Early seed production, drylandCommon type VarietiesSouth Dakota KenblueGeary ParkS-21 NewportAlene GingerGarfieldPiedmontHuntsville

Science and nonscience of blendsBlending of resistant / susceptible varieties

Creeping bentgrass - dollar spot (Abernathy, et al. 2001. Crop Sci. 41:806-809.)

Crenshaw - susceptible, L-93 resistant, others

Blends of resistant and moderately resistant cultivars with Crenshaw reduced dollar spot from 46 to 67 % less infection centers and 71 to 91% less blighted area

Benefit of including Crenshaw for heat tolerance

Science and nonscience of blendsKentucky bluegrass

(Vargas and Turgeon, 1980. Proc. Third ITRC 45-52.) Melting-out resistance of blend of twocultivars intermediate between same cultivars in monostandsInoculum from susceptible cultivar reduced resistance of resistant cultivar

Blends of two cultivars generally show resistance intermediate between each alone

Science and nonscience of blendsProblems with disease resistance data

Disease organism not verifiedLarge CV in disease data - uneven in trial

Disease racesDifferent in different locationsChange over time

Stripe smut - Merion, Adelphi and BVMGDollar spot in bentgrassesSummer patch

Summer patch 96-00 NJ NTEP 91-95 MD NTEP

Summer Summer

Cultivar Patch Patch

SR 2000 6.8 8.5

Unique 8.2 7.8

Nustar 5.4 7.7

Eclipse 8.2 7.5

Midnight 7.3 7.5

SR 2100 7.8 7.5

Blacksburg 4.5 7.3

LSD@5% 1.8 1.5

Science and nonscience of blendsEarly blend analysis - Dr. Funk, Rutgers

Sprigged out plants to ID

Aggressive types dominated

Aggressive types based on invasion in plots

New DNA techniques allow blend analysis (Lickfeldt et al, 2002. Crop Sci. 42:842-847.) 3-way blend - Unique, Midnight, BlacksburgDifferent management, % of each at seedingFinal composition, 40%, 46%, 14%

Science and nonscience of blendsStiers et al. 2003.

Most cool-season turf areas and athletic fields are mixtures of Poa pratensis and Lolium perenne

A 50:50 sward is desirable for traction,

recovery, and disease resistance

L. perenne germinates quickly and can outcompete P. pratensis seedlings

Science and nonscience of blendsMain plot: % P. pratensis:L. perenne

95:5 90:10 85:15 75:25

65:35 50:50 25:75

Sub-plot: P. pratensis type

Aggressive: Touchdown, Limousine, Fairfax

BVMG: Victa, Merit, Cannon

Compact: Midnight, Indigo, Alpine

Common: Alene, Kenblue, Ronde

Composition of P. pratensis (PP) and L. perenne (LP) Turf Stands with wear

Mixture Aggressive BVMG Compact Common

95:5 PP/LP 7711..77 6677..33 6655..00 44.3

85:15 PP/LP 45.3 43.0 45.3 12.3

75:25 PP/LP 39.3 28.7 30.3 11.0

65:35 PP/LP 30.3 35.0 22.7 10.0

50:50 PP/LP 17.3 20.0 10.3 4.7

25:75 PP/LP 8.7 10.3 7.3 1.3

LSD (0.05) 8.5

Science and nonscience of blendsTurf quality occasionally better with primarily

Poa pratensis.

All types of P. pratensis provided similar

results except for common types

At least 85% P. pratensis needed in seed mixture to provide approximately 50:50 Poa:Lolium turf sward

Fairfax predominated in Aggressive blend although classified as Other.

Science and nonscience of blendsHow to determine which cultivar will

predominate in a blend?

How to predict aggressiveness?

Dependent on components

Dependent on environment

Competitive environment

Components of IL Blend1996 - 2000 NTEP

Cultivar Mean length/width UB Sod Strength

7/97 11/98 MD NE Mean

Princeton 105 28.5 65.3 28.7 42.8 35.8

Unique 29.1 59.9 22.3 38.7 30.5

Midnight 26.0 56.4 21.0 37.7 29.3

Blacksburg 23.6 47.8 19.7 10.8 15.3

Limousine 22.9 36.6 15.7 21.0 18.3

LSD@5% 4.7 8.0 5.4 20.9 14.6

Components of IL Blend 96-00 NTEP 91-95 NTEP

Leaf Seedling Leaf Seedling

Cultivar Spot Vigor Spot Vigor

Blacksburg 7.1 5.1 7.8 3.0

Midnight 6.8 5.1 6.8 5.1

Unique 5.2 5.3 6.8 5.2

LSD@5% 0.2 0.3 0.6 0.8

Components of IL BlendLickfeldt et al, 2002. Golf Course Management.

Third site reported, Univ. of IL

Managed as lawn, year after

establishment no irrigation or herbicides

Blacksburg 24%, Unique 35%,

Midnight 41%.

Higher percentage Blacksburg.Blacksburg good stress survival, dark color

Science and nonscience of blendsHow to determine which cultivar will

predominate in a blend?

How to predict aggressiveness?

Further studies to compare competitiveness

within and between types

Compare in varying environments

Climatic zones, wear, shade, management

Coordinate with NTEP / Financing?

Science and nonscience of blendsHow to determine which cultivar will

predominate in a blend?

Examination of blends with sports field management - Irrigated, nonirrigated

Look at blends after wear during different seasons

Management after wear

Sports managers work with universities to examine

Science and nonscience of blendsWhy combine types in blends?Each type has weakness as well as strengthsSingle type has weaknesses

Midnight types - powdery mildew, winter colorAmerica types - not as dark greenAggressive - dominate in blendsShamrock types - billbug susceptibleBVMG - Very stemmy turf, poor winter performance, stripe smut susceptible

Science and nonscience of blendsHow to select best in type?

Ask breeders what varieties are in typeVisit local test sitesReview data from similar locationsExamine data for important characteristicsData can be sorted by NTEP for special reports

Darkest in type Establishment rateInfluenced by age of seedImportant diseases

Science and nonscience of blendsCultivar availability

Seed availability and priceNo production of low yielding varietiesHard to determine yields outside fields

Seed quality - true sod qualityPrevious agreements with other buyers

Blends by seed companies - each company only has access to certain varieties

Long Term PerformanceOlder cultivars may no longer be availableLooking at sod older than 6 years may find information not usefulMany varieties in 1990 to 1995 NTEP no

longer producedSome types are seeing less varietal

development such as Bellevue or CELA typesDecisions on development often made first few years of trials

ConclusionsBlends do provide benefitBest method and number of types uncertainKentucky bluegrasses difficult to breed

Multiple Julia hybrids - little improvementUnique type hybrids - good potentialMid-Atlantic types - difficult to obtain seed

Cooperative work breeders and NTEP to define types and publish

Contributions to looking at competitiveness in different environments and management Tall fescue/ bluegrass blends need to be examined

Texas x Kentucky bluegrassFemale P. arachnifera x P. pratensisTexas bluegrass drought and heat tolerantKentucky bluegrass higher qualityCombine attributesCan be used with tall fescueSelection for improved establishmentApomixis needs to be restoredImproved types

Reveille - Dr. James Reed, Texas A&MScott’s Company - Thermal BlueSRX 2TK95 in initial increase

Texas x Kentucky bluegrass

Texas x Kentucky bluegrass