Transcript Gray Leaf Spot - Seed Research of Oregon

Perennial Ryegrass Improvement
Seed Research of Oregon
Dr. Leah A. Brilman
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Improving Perennial
Ryegrass
Gray Leaf Spot
Germination with salt stress
Winter-active growth
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Perennial ryegrass
Advantages in mixtures
Quick establishment
Very dark green color
Resistant to different diseases than KBG/TF
Endophyte-enhanced
Disadvantages in mixtures
Overdominate other components
Bunch-type growth
Reduced stress tolerance
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GLS - What me worry?
• Gray leaf spot in perennial ryegrass
– First reported in 1991 Pennsylvania
– Epidemics in 1995, 1997 and 2000 in Mid-Atlantic,
Northeast and transition zones
• Verified also in MidWest, New England, now West
• Large areas of fairways, roughs and athletic fields
can be rapidly lost
• In California both permanent and overseeded turf
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Gray leaf spot
Water-soaked
lesions
Dark colored spots
Gray to brown
lesions with
darker border
Twisting, hooked
leaves
Leaf and plant death
Grayish color
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Gray Leaf Spot Fairway CA
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GLS in CA 2003-2004
Almost 30 courses with
positive diagnoses –
mainly perennial ryegrass
1st epidemic:
– August – September
2nd epidemic
– October – November
Ryegrass
Kikuyugrass
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What we know
• Gray leaf spot spores primarily airborne and spread
by mowers, equipment (How did it get to CA?)
• Gray leaf spot overwinters as dormant mycelium in
dead tissue - cold winters can reduce initial
innoculum
• Long periods of leaf wetness under hot conditions
favor the disease
• Initial innoculum builds up under lower temperatures
then it explodes
• Often first occurs in shady, wet areas
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Temperature and Leaf Wetness
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What we know
• Initial symptoms are an off-color, wilted appearance
• Often mistaken for drought stress so irrigation is
applied increasing period of leaf wetness = more
disease
• Seedlings tend to be more susceptible than mature
plants - could partially be due to maintenance of wet
conditions in seedbed
• High nitrogen makes it worse
• Primo in spring can make it worse, but not in fall
• Putting a tarp on a field not a good idea during heat
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What we know
• Fungicide control
QoIs - Heritage at high rate good with high disease
pressure, Compass at label rate sometimes has reduced
control
Benzimidazole - Clearys 3336 good at 3 oz except highest
pressure
• Always add in a contact fungicide for spores
• Resistance already reported to QoIs - switch to fungicide
with moderate activity for part of year
• Best long term solution lies in breeding for resistance
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What we know
• California has four strains of disease - more than
Eastern US
• Appears to indicate longer term presence or multiple
introductions
• Origin of strains uncertain
• Resistant cultivars show variability in resistance from
Eastern US
• High resistant cultivars still show resistance but
highest level may vary
• One verified incidence in Oregon
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Gray Leaf Spot Resistance
Rutgers University - 2002 Trial 1-9, 9 = Best
2002
2002
Cultivar
GLS Res.
Quality
MS1 Comp.
8.0
7.0
Integra C1
7.0
5.2
SR 4550 (1557)
7.0
4.3
Integra
5.7
3.3
Amazing
5.0
3.5
Pizzazz
4.3
3.2
LSD@5%
1.4
1.0
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Gray Leaf Spot Resistance
Rutgers University - 2003 Trial 1-9, 9 = Best
2003
2003
Cultivar
GLS Res.
Quality
SR 4600
7.7
7.2
Panther GLS
7.8
6.9
SR 4550 (1557)
6.0
5.3
Integra C1
6.0
6.7
Integra
4.0
4.2
Pizzazz
3.8
3.8
LSD@5%
1.2
1.2
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SR 4600 Perennial ryegrass
• Superior Gray Leaf Spot resistance
• Excellent wear tolerance due to spreading growth
habit
• Superior Summer stress tolerance
• Enhanced Winter active growth
• Fine leaf texture and vivid, dark green color
• Widely adaptable to differing climates
• Highest rated wear tolerance Puyallup, WA
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Harrier Perennial ryegrass
• Excellent Gray Leaf Spot resistance
• High close mowing quality due to upright-growth habit
• Superior Spring green-up
• Excellent traffic stress tolerance
• Fine leaf texture and viivid, dark green color
• Upright-growth habit reduces stemminess for dense finetextured turf under close mowing
• High Red Thread and Brown Patch resistance
• High seedling vigor for fast emergence and establishment
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Gray Leaf Spot Resistance
2004 NTEP National Perennial Ryegrass Trial Gray Leaf Spot Ratings - Mean of 2
Locations - 2005 Data Disease Rating: 1-9; 9=No Disease
Variety
Mean
Variety
Mean
Fiesta 4
9.0
Keystone 2
6.8
SR 4600
8.8
Overdrive
6.5
Harrier
8.5
Pizzazz
5.5
Derby Xtreme
8.3
Palmer III
5.3
Manhattan 5 GLR
8.3
Affinity
5.2
Charismatic II GLSR
8.2
Pianist
5.2
Palmer IV
8.0
Brightstar SLT
4.7
Regal 5
7.8
Pinnacle
3.3
Revenge GLX
7.7
Fusion
7.3
Buena Vista
7.2
LSD Value
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1.1
Gray Leaf Spot Resistance
2004 Perennial ryegrass
NTEP Gray leaf spot Rutgers University
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Ryegrass and GLS
Further studies and needs
Pyricularia grisea (Magnaporthe grisea) can rapidly
change races
Currently unknown number of races in US
Do resistance genes work against all current races?
Some variability in results from seedling trials in NJ
and mature plants in MD - high resistant types
remain resistant
New germplasm sources - many resistant genes from
European collections
Genetic studies currently being done
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Ryegrass and GLS
Current and future buying decisions
Varieties take two years to get some production
started, three years for maximum production
Current varieties with good resistance in last NTEP
SR 4500, SR 4220. SR 4350, Racer 2, Calypso II
Varieties with improved resistance in production
SR 4550, SR 4600, Peregrine, Harrier
Varieties available next year
SRX 4692, SRX 4682, LCK
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Perennial ryegrass
Gray leaf spot is not only characteristic - other goals
Salt tolerance for effluent use, rapid blight resistance
Wear tolerance
Rapid establishment - Best species for establishment
during play
Winter-active growth for many uses
Daylength-dependent dwarf types less suitable
Heat, drought and cold tolerance
Decumbent, spreading growth - superior in Europe for
repair
Reduce nitrogen requirements
Quick transitioning
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Headstart II Perennial ryegrass
• Excellent winter color and winter active growth
• Superior Spring green-up
• Excellent traffic stress tolerance
• Fine leaf texture and vivid, dark green color
• High Red Thread , Pythium Blight and Brown Patch
resistance
• High seedling vigor for fast emergence and establishment
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Firebolt Perennial ryegrass
• High performance under “Schedule C” homeowner
• High turf quality in Transition zone
• Excellent performance in PNW - low light intensity
• Excellent performance Mountain West
• Very Dark Green Color, fine leaf texture
• Superior red thread resistance
• Good brown patch resistance
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Salt tolerance in ryegrass
Tolerance during seed germination
May be different than tolerance as adult plants
Important to aid establishment - especially in
overseeding
Temperatures shown to have an effect
Different salts - we use artificial sea salt
Studies with barley looking for genes suggest
relationship to ABA synthesis
High varieties in our trials also show high adult salt
tolerance and rapid blight resistance
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Germination with salt
Fig 1. Salt screening of SRO Perennial ryegrass at 10,000 ppm salt concentration
date of planting 4/8/04
date of planting 11/4/04
f
d
100
ef
de
cd
90
c
Germination percentage
c
d
80
70
ab
a
ab
b
b
a
60
50
40
30
20
10
0
Omni
Charger II
Brightstar SLt
Peregrine
SR 4420
Hawkeye
SR 4220
Perennial ry egrass v arieties
Note: Values followed by the same letter on the same color bar do not difer significantly according to the Duncan's Multiple Range Test (P<0.05)
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SRX Pengs
Germination with salt
Fig. 3. Seedling vigor of Perennial ryegrass planted in tw o different dates at 10,000 ppm salt
concentration.
8
Date of planting 4/8/04
Date of planting 11/4/04
e
Germination percentage
7
c
d
6
cd
bc
bc
b
5
b
4
b
a
ab
ab
ab
3
a
2
1
0
SRX Pengs
SR 4220
Hawkeye
SR 4420
Peregrine
Brightstar SLT
Perennial ryegrass varieties
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Charger II
Omni
Germination with salt
Fig 2. Salt Screening of SRO Pe rennial ryegras s at 12,000 ppm salt concentration
d
30
cd
Germination percentage
25
bc
bc
20
abc
ab
15
ab
a
10
5
0
Brightstar SLT
Omni
SR 4550
Charger II
Peregrine
SR 4420
Perennial ryegrass varieti es
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Hawkeye
SR 4220
Salt tolerant and other ryes
• STR 4PSLT - plants from salt screening planted
and rouged for uniformity, color and yield. Has
germplasm from Penguin plus SR 4420, 4220 and
Hawkeye. Planted fall, 2005.
• STR 4TPC - Progeny of survivors in very heavy salt
at TPC Scottsdale.
• STR 45AB - Winter-active material.
• STR 4QTR - Quick transitioning ryegrass
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Gray leaf spot resistant ryes
• Peregrine - 1st cycle - certified seed
• SR 4550 - 2nd cycle - certified seed
•
SR 4600 (SRX 4SP) - Certified this fall - brown patch
resistance, lateral spread, highest turf quality
• Harrier (SRX 4UP3) - Certified this fall - stress tolerant, high
turf quality
• SRX 4682 - Certified next fall - Hawkeye II, high gray leaf
spot resistance
• SRX 4692 - Certified next fall - SR 4220 der.
• LCK - Certified next fall - High brown patch and GLS
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Why overseed with different species?
• Use mixtures for genetic diversity
• Resistance to diseases and stresses
• Color contrast
• Improved transition
• Improved quality
• Smaller seeds
• Potential cost savings
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Velvet Bentgrass - Overseeding
• Very small seed size (best for ultradwarfs)
• Best putting surface
• Highest wear tolerance, high density
• Medium establishment
• Germinates well at low soil temperatures
• Medium dark green – Mixes well
• Best low light or shade tolerance
• Excellent Spring transition
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Velvet Bentgrass - Overseeding
Creeping bentgrass
SR 7200 Velvet bentgrass
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Why overseed with different species?
Labyrinthula on Poa trivialis in SC
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Fine fescues - Overseeding
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Very fine with stiff texture
Good wear tolerance
Winter-active growth
Improved transition with high quality
Rapid germination - Chewings and red
Resistance to Labyrinthula fungus
Medium seed size
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Fine fescues - Overseeding
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High salt tolerance
Color and texture contrast
Increase genetic diversity of mixtures
Mixtures with perennial ryegrass,
bentgrasses, Poa trivialis
Seeding rates (alone) - Do not mow too soon
Greens 25 - 30 lbs./1000 sq. ft.
Tees 20-25 lbs./1000 sq. ft.
Fairways 10-15 lbs./1000 sq.ft. - Excellent
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Chewings Fescue
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Strengths
– Rapid germination - close to perennial ryegrass
– Winter-active growth
– Heat tolerance - improved cultivars
– Tolerant of low height of cut - most improved cultivars
– Shade tolerance
– Recent studies on low maintenance fairways in WI, MN
and IL showed highest performance by Chewings
– WI NTEP Fairway Trials with wear applied Chewings
fescue was highest ranked
– Good summer patch, leaf spot resistance
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Chewings Fescue
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Where to use
– Fairways - Northern United States, PNW, Coastal CA
– Fairways - Overseeding blends with perennial ryegrass
– Roughs - Northern through transition zone.
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How to use
– With all bentgrasses for divot repair or greens repair
– Low maintenance fairways
– Roughs - shaded, ornamental seedheads
– Overseeding blends - better transition, fine textured
– In blends with Kentucky bluegrass for fairways/roughs
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Slender Creeping Red Fescue
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Strengths
– High salt tolerance
– Resistance to rapid blight
– Short rhizomes for repair
– Tolerant of short cutting heights for fairways
– Improved ones with high heat tolerance
– Excellent fall, winter and spring color
– Extensively used in Europe for fairways . European
types have less heat tolerance, higher density, low
seed yields.
– Short growing height
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Slender Creeping Red Fescue
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Weaknesses
– Brighter green color - not as dark green
– Limited number of cultivars with endophytes
– New cultivars tolerate heat in Central Valley of
California - others not enough heat tolerance for
some areas
– Most cultivars with good resistance to leaf spot
and red thread, but poor resistance to dollar spot
and summer patch. Newest cultivars improved
resistance to all diseases.
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Slender Creeping Red Fescue
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Where to use
– Fairways - areas with salt problems overseeding
blends and permanent turf in cool season areas
– Greens and tees for overseeding in salt areas used for permanent greens in UK
– Roughs - mown and unmown.
– Important component in links style blends
– Besides parking lots, roadways where salt is used
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How to use
– Blends with other fine fescues, colonial bentgrass,
bluegrass and perennial ryegrass
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Dawson slender creeping red fescue
Perennial ryegrass
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Transitional Ryegrass
Percent Cover Annual, Transitional, Perennial + mixtures.
Seeded Feb. 20, 2004. Puyallup, WA.
Treatment
March
12
March
25
April
2
April
9
April
16
April
22
Axcella AR
Transeze TR
PR Blend
TR + PR
AR + PR
26.7
23.3
8.3
21.7
25.0
50.0
48.3
23.3
38.3
43.3
68.3
70.0
53.3
70.0
71.7
91.7
90.0
53.3
85.0
90.0
98.3
95.0
76.7
100
98.3
100
100
95
100
100
LSD@5%
10.2
12.7
11.7
24.9
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Dr. Gwen Stahnke - Washington State University Puyallup, WA
0
Dr. Leah A. Brilman - Seed Research of Oregon
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Transitional Ryegrass
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Strengths
– Very quick establishment
– Less expensive seed
– Lasts only one to two seasons
– Germination and growth at cooler temp.
– Moderate green color
– Less mowing requirement than annual
– Does not overdominate mixtures
– Can be used with Kentucky bluegrass as nurse
grass
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Transitional ryegrass
PR
TR
AR
PR/TR
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Transitional Ryegrass
•
Weaknesses
– Poor mowing quality in spring
– Lighter green than current perennial ryegrass
varieties
– Low salt tolerance as mature plants
– Germination excellent with salts
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Dr. Gwen Stahnke - Washington State University Puyallup, WA
Dr. Leah A. Brilman - Seed Research of Oregon
Transitional Ryegrass
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Where to use
– Overseeding south
– Nurse crop north
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How to use
– Overseeding - to improve transition
– Nurse grass
– Repair during colder times of the year
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Dr. Gwen Stahnke - Washington State University Puyallup, WA
Dr. Leah A. Brilman - Seed Research of Oregon