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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
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Leah A. Brilman, Ph.D.Research DirectorSeed 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-strengthRapid repair of wear • Late fall, winter and early spring growth • Shade tolerance • Abiotic and biotic stress resistance
Types of KentuckyBluegrasses • Compact 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 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 • Midnight Arcadia • Liberator Odyssey • NuGlade Perfection • Tsunami Chicago II • Awesome Excursion • Freedom II Barrister • Beyond Rugby II • Impact Quantum Leap • Absolute Award • Total Eclipse Midnight 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 • America Showcase • Apollo SR 2284 • Unique SR 2394 • BrilliantLangara • Avalanche Blue Ridge • Glenmont Royale • Lakeshore Goldstar • Arrow Mallard
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 • Shamrock SR 2100 • Champagne Atlantis • 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 • Baron Cannon • Victa Merit • Gnome Clearwater • Goldrush Dragon • Abbey BlueStar • Crest Nassua • Raven Marquis • BlueChip Fortuna • Envicta Baronette
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 • Julia SR 27832 • Caliber Ikone
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 • Bellevue Suffolk • Georgetown Parade • Classic Dawn
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 • Monopoly SR 2000 • Preakness Eagleton • Livingston Plush • 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 Dakota Kenblue • Geary Park • S-21 Newport • Alene Ginger • Garfield Piedmont • Huntsville
Science and nonscience of blends • Blending 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 blends • Kentucky bluegrass • (Vargas and Turgeon, 1980. Proc. Third ITRC 45-52.) • 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
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 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, 2002. Crop Sci. 42:842-847.) • 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. 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 blends • Main 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
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 • 1996 - 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 Blend • Lickfeldt 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%, • Midnight41%. • 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