Kentucky Bluegrass Characterization and Blending Strategies

Leah A. Brilman, Ph.D. Research Director Seed Research of Oregon

Why Blends and Mixtures No 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 Mixtures Kentucky 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 Mixtures Sports Turf Needs Rapid establishment Strong lateral spread High 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 Kentucky Bluegrasses Compact TypesCELA Type CompactBVMG Type MidnightShamrock type AmericaCheri Type Aggressive TypeJulia Type Bellevue TypeCommon Type Mid-Atlantic TypeOther Type

Midnight Type Cultivars Do not have blend of only this type Very dark green color Low, compact growth High quality turf 1/2 inch cutting height Excellent resistance to leaf spot Long winter dormancy Most do poor in the shade High heat tolerance

Midnight Type Cultivars MidnightArcadia LiberatorOdyssey NuGladePerfection TsunamiChicago II AwesomeExcursion Freedom IIBarrister BeyondRugby II ImpactQuantum Leap AbsoluteAward Total EclipseMidnight II

America Type Cultivars Bright dark green color Low, compact growth 1/2 inch cutting height Excellent resistance to leaf spot, powdery mildew Finer leaf, higher density Moderate winter dormancy Moderate summer recovery High summer patch resistance Good in shade

America Type Cultivars AmericaShowcase ApolloSR 2284 UniqueSR 2394 BrilliantLangara AvalancheBlue Ridge GlenmontRoyale LakeshoreGoldstar ArrowMallard

SR2394/Arcadia Kentucky

Shamrock Type Moderate winter color Good resistance to leaf spot Good turf quality and sod strength Billbug susceptible High seed yields Less stemmy than BVMG types Summer performance variable This type is an excellent substitute for BVMG type - Higher quality with reduced costs Shamrock Type Varieties ShamrockSR 2100 ChampagneAtlantis Parkland

BVMG Type Cultivars High 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 Cultivars BaronCannon VictaMerit GnomeClearwater GoldrushDragon AbbeyBlueStar CrestNassua RavenMarquis BlueChipFortuna EnvictaBaronette

Aggressive Type Aggressive lateral growth High shoot density Very wear tolerant Quickly knit sod and repair May predominate in blend Variable in other characteristics

Julia Type High turf quality High density Good summer performance Moderate winter performance Good leaf spot, stripe smut resistance Susceptible to brown patch and dollar spot High winter wear tolerance Julia Type Varieties JuliaSR CaliberIkone

Bellevue Type Medium 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 billbugs Bellevue Type Varieties BellevueSuffolk GeorgetownParade ClassicDawn

Mid-Atlantic Type Deep 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 Varieties MonopolySR 2000 PreaknessEagleton LivingstonPlush Wabash

Common Type Erect 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, dryland Common type Varieties South DakotaKenblue GearyPark S-21Newport AleneGinger GarfieldPiedmont Huntsville

Science and nonscience of blends Blending of resistant / susceptible varieties Creeping bentgrass - dollar spot (Abernathy, et al Crop Sci. 41: ) 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 blends Kentucky bluegrass (Vargas and Turgeon, Proc. Third ITRC ) Melting-out resistance of blend of two cultivars intermediate between same cultivars in monostands Inoculum from susceptible cultivar reduced resistance of resistant cultivar Blends of two cultivars generally show resistance intermediate between each alone

Science and nonscience of blends Problems with disease resistance data Disease organism not verified Large CV in disease data - uneven in trial Disease races Different in different locations Change over time Stripe smut - Merion, Adelphi and BVMG Dollar spot in bentgrasses Summer patch

96-00 NJ NTEP MD NTEP Summer Summer Cultivar Patch Patch SR Unique Nustar Eclipse Midnight SR Blacksburg

Science and nonscience of blends Early 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, Crop Sci. 42: ) 3-way blend - Unique, Midnight, Blacksburg Different management, % of each at seeding Final composition, 40%, 46%, 14%

Science and nonscience of blends Stiers et al 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 blends Main plot: % P. pratensis:L. perenne 95:590:1085:1575:25 65:3550:5025:75 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

Science and nonscience of blends Turf 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 blends How to determine which cultivar will predominate in a blend? How to predict aggressiveness? Dependent on components Dependent on environment Competitive environment

Components of IL Blend NTEP Cultivar Mean length/width UB Sod Strength 7/9711/98MDNEMean Princeton Unique Midnight Blacksburg Limousine

Components of IL Blend NTEP NTEP Leaf SeedlingLeaf Seedling Cultivar SpotVigorSpot Vigor Blacksburg Midnight Unique

Components of IL Blend Lickfeldt et al, 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 blends How 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 blends How 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 blends Why combine types in blends? Each type has weakness as well as strengths Single type has weaknesses Midnight types - powdery mildew, winter color America types - not as dark green Aggressive - dominate in blends Shamrock types - billbug susceptible BVMG - Very stemmy turf, poor winter performance, stripe smut susceptible

Science and nonscience of blends How to select best in type? Ask breeders what varieties are in type Visit local test sites Review data from similar locations Examine data for important characteristics Data can be sorted by NTEP for special reports Darkest in type Establishment rate Influenced by age of seed Important diseases

Science and nonscience of blends Cultivar availability Seed availability and price No production of low yielding varieties Hard to determine yields outside fields Seed quality - true sod quality Previous agreements with other buyers Blends by seed companies - each company only has access to certain varieties

Long Term Performance Older cultivars may no longer be available Looking at sod older than 6 years may find information not useful Many varieties in 1990 to 1995 NTEP no longer produced Some types are seeing less varietal development such as Bellevue or CELA types Decisions on development often made first few years of trials

Conclusions Blends do provide benefit Best method and number of types uncertain Kentucky bluegrasses difficult to breed Multiple Julia hybrids - little improvement Unique type hybrids - good potential Mid-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 bluegrass Female P. arachnifera x P. pratensis Texas bluegrass drought and heat tolerant Kentucky bluegrass higher quality Combine attributes Can be used with tall fescue Selection for improved establishment Apomixis needs to be restored Improved types Reveille - Dr. James Reed, Texas A&M Scott’s Company - Thermal Blue SRX 2TK95 in initial increase

Texas x Kentucky bluegrass