Larry Stowell, Ph.D. @paceturf on …...California Climate (San Diego) 0 20 40 60 80 100 123456789...
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Kikuyugrass “The poa of warm-season grasses” Larry Stowell, Ph.D. www.paceturf.org @paceturf on Twitter
Transcript of Larry Stowell, Ph.D. @paceturf on …...California Climate (San Diego) 0 20 40 60 80 100 123456789...
Kikuyugrass“The poa of warm-season grasses”
Larry Stowell, Ph.D.www.paceturf.org
@paceturf on Twitter
Kikuyugrass
The wild ones
Kikuyugrass
• Climate where kikuyugrass is grown• Most destructive diseases• Scalping• Troublesome insects
Growth Potential (GP)
0102030405060708090
100
10 30 50 70 90 110Temperature (F)
Gro
wth
Pot
entia
l
Tropical (Manila,
Philippines)
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oten
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Inland Desert California (Cathedral
City)
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oten
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Cool season (Worchester
, MA)
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oten
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Inland SouthernCalifornia(Riverside)
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oten
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Coastal CaliforniaClimate
(San Diego)
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Guadalajara, Mexico 5,085 ft elevation
Grafton, New South Wales, Australia
Nairobi, Kenya
Origin of kikuyugrass
Solar Radiation
& Shade
Optimum solar
radiation
• Cool‐season (C3) grasses116 – 233 w/m2/da10 – 20 moles/m^2/da
• Warm‐season (C4) grasses390 – 485 w/m2/da30 – 40 moles/m^2/da
Solar Radiationw/m2
Average Monthly Solar Radiation
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Sola
r Rad
iatio
n (w
/m^2
)Phoenix AZ
San Diego
Long Beach
Warm season requirement
Cool season requirement
Shade224 w/m2
17 w/m2 poa invades during winter and poadies during summer leaving bare spots
Kikuyugrass
• Climate where kikuyugrass is grown in California
• Most destructive diseases• Scalping• Troublesome insects
KikuyugrassDiseases
• Gray leaf spot• Leaf spot• Brown/large patch• Decline
Gray leaf spot
Gray leaf spot
Pyriculariaspp.
Gray leaf spot
Pyriculariaspp.
Gray leaf spot
Pyriculariaspp.
Gray leaf spot
Pyriculariaspp.
Gray Leaf Spot
Pyriculariaspp.
Gray Leaf Spot
Pyriculariaspp.
Gray Leaf Spot
Pyriculariaspp.
Gray Leaf Spot
Management
• Mostly warm summer weather conditions. Drought seems to increase severity (Max T (F) + Min RH% > 140)
• Rotate between DMI and thiophanate‐methyl plus chlorothalonil (watch chlorothalonil label limits)
• Low rates on 14 day interval seem to be better than full rates on 28 day interval
• Widespread resistance to QoI fungicides in California
KikuyugrassDiseases
• Gray leaf spot• Leaf spot• Brown/large patch• Decline
Leaf SpotBipolarisspp.
Leaf Spot
Leaf spot and crown rot
management
• Low light and moderate temperature disease• Normally can grow out of the problem when weather improves
• In coastal areas, treatment may be needed to prevent continued decline of the kikuyugrass late summer – before cool fall weather
• Chipco 26GT, Curalan, Disarm, Fore, Medallion, Velista, Heritage, Insignia, Interface Stressgard, Lexicon
KikuyugrassDiseases
• Gray leaf spot• Leaf spot• Brown/large patch• Decline
Large patchbrown patchRhizoctonia
spp.
Large patchbrown patch
Rhizoctoniaspp.
Large patchbrown patch
Rhizoctoniaspp.
Large patch/brown
patch management
• Prevention is the key where the disease is prevalent
• Cool fall weather, rainfall, low light results in slow growth of kikuyugrass and limited recovery
• Heritage, Insignia, Prostar, Medallion, Fame, Xzemplar, Affirm, Briskway, Headway, Honor Intrinsic, Encave, Fame C, Fame+T, Lexicon
KikuyugrassDiseases
• Gray leaf spot• Leaf spot• Brown/large patch• Decline
Decline Gaeumanno‐myces spp.
Decline Gaeumanno‐myces spp.
Decline Gaeumanno‐myces spp.
Declinemanagement
• Prevention is the key where the disease is prevalent
• Damage begins when soil temperature exceed 65 F (18 C)
• Maintain adequate Manganese (30 ppm M3 extraction)
• DMI, benzimadizole, and QoI fungicides are effective. Gray leaf spot programs also suppress decline.
Kikuyugrass
• Climate where kikuyugrass is grown in California
• Most destructive diseases• Scalping• Troublesome insects
Scalping
Scalping
Scalping
Scalping
Roots near crown no scalping
Roots near crown no scalping
No roots near crown results in scalping
No roots near crown results in scalping
Scalping
Kikuyugrass
• Climate where kikuyugrass is grown in California
• Most destructive diseases• Scalping• Troublesome insects
