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 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
Liberator
NuGlade
Tsunami
Awesome
Freedom II
Beyond
Impact
Absolute
Total Eclipse
Arcadia
Odyssey
Perfection
Chicago II
Excursion
Barrister
Rugby II
Quantum Leap
Award
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
Apollo
Unique
Brilliant
Avalanche
Glenmont
Lakeshore
Arrow
Showcase
SR 2284
SR 2394
Langara
Blue Ridge
Royale
Goldstar
Mallard
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
Shamrock
Champagne
Parkland
SR 2100
Atlantis
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
Victa
Gnome
Goldrush
Abbey
Crest
Raven
BlueChip
Envicta
Cannon
Merit
Clearwater
Dragon
BlueStar
Nassua
Marquis
Fortuna
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
Caliber
SR 27832
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
Cultivar
SR 2000
Unique
Nustar
Eclipse
Midnight
SR 2100
Blacksburg
LSD@5%
96-00 NJ NTEP
Summer
Patch
6.8
8.2
5.4
8.2
7.3
7.8
4.5
1.8
91-95 MD NTEP
Summer
Patch
8.5
7.8
7.7
7.5
7.5
7.5
7.3
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
65:35
50:50
25:75
75:25
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
67.3
43.0
65.0
45.3
44.3
85:15 PP/LP
71.7
45.3
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
95:5 PP/LP
LSD (0.05)
8.5
12.3
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
7/97
11/98
Princeton 105 28.5
65.3
Unique
29.1
59.9
Midnight
26.0
56.4
Blacksburg
23.6
47.8
Limousine
22.9
36.6
LSD@5%
4.7
8.0
Sod Strength
MD NE
Mean
28.7 42.8 35.8
22.3 38.7 30.5
21.0 37.7 29.3
19.7 10.8 15.3
15.7 21.0 18.3
5.4
20.9
14.6
Components of IL Blend
Cultivar
Blacksburg
Midnight
Unique
96-00 NTEP
Leaf
Seedling
Spot
Vigor
7.1
5.1
6.8
5.1
5.2
5.3
LSD@5%
0.2
0.3
91-95 NTEP
Leaf
Seedling
Spot
Vigor
7.8
3.0
6.8
5.1
6.8
5.2
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%,
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
Texas x Kentucky bluegrass