Practical Turfgrass Microbiology - Sommet du Golf · 2015-12-21 · Field Studies ÜTifEagle hybrid...
Transcript of Practical Turfgrass Microbiology - Sommet du Golf · 2015-12-21 · Field Studies ÜTifEagle hybrid...
PracticalTurfgrassMicrobiology
JimKerns,[email protected]
Soil Organisms Macrofauna > 2 mm
Vertebrates, Arthropods, Annelids, Mollusks
Macroflora Vascular Plants, Bryophytes
Mesofauna 0.1 – 2 mm
Arthropods, Annelids
Microfauna < 0.1 mm
Nematodes, Rotifera, Protozoa
Microflora < 0.1 mm
Roots of vascular plants, Algae, Fungi, Actinomycetes, Bacteria
SOIL FOOD WEB
Relative # of organisms in soils (surface 15 cm).
Organisms Number per m2 Biomass (g/m2)
Microflora
Bacteria Trillions 40-500
Actinomycetes Trillions 40-500
Fungi Billions 100-2000
Algae Billions 1-50
Fauna
Protozoa Billions 2-20
Nematodes Millions 1-15
Mites Thousands to Millions 0.5-1.5
Collembola Hundreds to Millions 0.5-1.5
Earthworms Few to Hundreds 10-170
Others Hundreds to Thousands 1-10
Bacteria• Nutrientcycling• Humusformation• Soilstabilization
Gram positive bacteria: stress tolerating, rigid cell wall, often dominant in extreme soil conditions
Gram negative bacteria: important for nitrogen cycling, weak cell wall, usually dominant bacteria
Thereareonehundredtrillionbacterialcellsinyourbody,outnumberingyourowncells10to1
“The prokaryotic diversity in a handful of soil is said to be equal to the diversity of all the insects, birds and mammals in the Amazon basin!” p. 346, Brady and Weil
Estimate from Gans et al. (2005) Science 309:1387-1390: 8,300,000 different species of bacteria in 10 g soil Number of species on earth Mammals 4,500 Birds 10,000 to 20,000 Plants 230,000 Insects 1,000,000
Bacterial diversity in soil is greater than in any other habitat
Soil: A structured habitat
Computer model of soil porosity
T.Eickhorst,R.Tippkotter/SoilBiology&Biochemistry40(2008)1284–1293
Partial hydration of bacterial habitats
Field capacity: average film thickness = 10 nm = 10-8 mcell diameter = 5 x 10-7 m
Restricted diffusion
water pocket supplying nutrients
water pocket supplying nutrients
strong
Competing bacteria
weak
soilExample: lake water
start
day 30
Reduced competition may facilitate expansion of bacterial diversity
Do microbes communicate?
Chemical Communication
Fungi• Decomposers• Interactdirectlywithplants
– disease– symbiosis
Saprophytic fungi: important for organic matter decomposition
Arbuscular mycorrhizal fungi: form symbiotic relationships that facilitate nutrient and water uptake
Mycorrhizae myco (fungus) rhiza (root)
fungal hyphae
Pine rootTomato root
mutualistic symbiotic association with roots (95% of all plants): plant supplies fungus with carbon fungus supplies plant with mineral nutrients (mainly P and N)
Arbuscular mycorrhizae
hypha outside of cell
arbuscle in plant cell
Mycorrhizal symbioses and nutrient flow CO2
SOM
CO2
minerals
Improved growth
carbon
Improvement of plant growth by mycorrhizal associations
Citrus
+ mycorrhizae- mycorrhizae - mycorrhizae
Mellon
Protozoa
Whatdoprotozoado?
• Eatbacteria
• Excretenutrients
Bon
kow
ski e
t al.,
200
4
PartII:Howdowemeasurethem?
Waystomeasuremicrobes• Fumigation
– Givesusatotalbiomassestimate– Tellsusnothingaboutthefunction
• AgarCulture– Onlyabout2%oforganismscanbecultured
• GeneticAnalysis– Expensive– Difficulttointerpret
• PLFA(phospholipidfattyacid)Analysis
Differentmicrobeshavedifferenttypesofmembranes(phospholipidsandfattyacids)
Forexample:
• Actinomycete
• Gramnegativebacteria
• Fungus
Figure 2. Relative abundance of four major microbial functional groups: gram positive bacteria, gram negative bacteria, saprophytic fungi, and arbuscular mycorrhizal fungi. Average functional group biomass is reported as a percentage of the average total biomass. Differences in microbial community structure are compared among the averages of 42 lawns and 9 prairies in WI.
Vermontsaying,mid1900s fromMagdoffandVanEs,2000
“Usedtobeanybodycouldbefarm.Allyouneededwasastrongback...butnowadaysyouneedagoodeducationtounderstandalltheadviceyougetsoyoucanpickoutwhat’lldoyoutheleastharm.”
Fromtheinternet:
• “Chemicalfertilizerswilleventuallydestroyeventhebestsoilsbykillingthebeneficialorganismsthatplantsrelyontogathernutrientsandmoisture.Growersarethenforcedtopouronlargerandlargeramountsofexpensivepetroleum-basedfertilizertomaintainyields,buttheoverdosescreateunbalanced“deadsoil”.
SurveyofmicrobialdiversitybyDr.ZubereratTexasA&MUniversity
• Allsand-basedrootzones
KyleField
32millioncfubacteria/gramsoil
50000fungi/gram
Sand-BasedSoccerField
35-63millionbacteria/gramsoil36000fungi/gram
Sand-BasedBaseballField
• 63millionbacteria/gramsoil• 80000fungi/gramsoil
Bigelowetal,2000:sand-basedgolfgreen
• Beforeseeding:1000000bacteriapergramofsoil
• Sixmonthsafterseeding:1000000000bacteriapergramofsoils
Whatwedon’tknow• Doesthesheersizeofthemicrobialpopulationmatter?Or,isfunctionmoreimportant?Orboth?
• Whichofthesemicrobesarethe“right”ones?
• Canweencouragethe“right”onestospread?
• Isthereaneedtoaddmicrobes?
MicrobesRequire:
1. Organiccarbon–turfgrowsfoodforthemicroorganisms
MicrobesRequire:
1. Organiccarbon–turfgrowsfoodforthemicroorganisms
2. Goodenvironmentalconditions:– Air/WaterBalance– pH>5.5– Temperature>10C– Nutrients
Therhizosphereisthenarrowregionofsoilthatisdirectlyinfluencedbyrootsecretionsandassociatedsoilmicroorganisms.
rocklandcountryclub.blogspot.com
Getairintotherootzonetomaximizemicrobialfunction
oxygencarbon dioxide
“Ventilation”Soil Aeration
Microbescoulddepleteoxygensupplyinminutes
SoilpHandmicrobialprocesses
• Nitrosomonassp.optimumatpH7.5–8,notactiveatpH<5.5
• Mineralizationcarriedoutbyhugevarietyoforganisms,solesssensitivetopH
Source: Peer-reviewed research article (Höberg et al., 2007)
CyanobacteriapreferhighsoilpHandhaveahighlightrequirement
From turfdiseases.org May 1, 2012 – John Kaminski, Micah Woods
WhatistheEffectofPesticidesandChemicalFertilizerson
Microorganisms?
Fertilizersimpactonsoilorganisms
• “Mineralfertilizershavelimiteddirecteffects,buttheirapplicationcanenhancesoilbiologicalactivityviaincreasesinsystemproductivity,cropresiduereturn,andsoilorganicmatter”
• “Themainlessonlearntisthatanypracticethatincreaselevelsofsoilorganicmatterwillalsoincreasesoilbiologicalactivity.”
Impactofagriculturalinputsonsoilorganisms–areviewBunemannetal.2006
Fertilizer impact on soil organisms
Material Bacillus Total fungi Total bacteria
Bio 6.21 a 4.64 a 6.80 a
Milorg. 6.10 a 4.67 a 6.82 a
Ringer 6.20 a 4.61 a 6.75 a
IBDU 6.26 a 4.60 a 6.84 a
(Elliott and Des Jardin, 1999)
Fungicidesimpactonsoilorganisms
Fungicides
Fungicides
57
Effects of fungicides on phyllosphere microbiology
0E+00$
1E+08$
2E+08$
3E+08$
4E+08$
Ac,nomycetes$ Fluorescent$Pseudomonads$ General$Bacteria$ Pseudomonads$
CFUs%p
er%gram%of%.
ssue
%
Fluazinam$ Fluxapyroxad$Chlorothalonil$ FosetylCAl$Pyraclostrobin$ Control$
B$
A$A$A$
A$ A$ A$
A$
A$
A$
A$
B$
B$
A$AB$AB$
A$
A$
A$
A$
A$A$
A$A$
58
0E+00$
2E+06$
4E+06$
6E+06$
8E+06$
1E+07$
Filamentous$Ac8nomycetes$ Filamentous$Fungi$
CFUs%p
er%gram%of%.
ssue
%Fluazinam$Fluxapyroxad$Chlorothalonil$FosetylBAl$Pyraclostrobin$Control$
A$
A$
A$
A$
A$A$
ABC$ BC$ C$ C$BC$ A$
cellwall
cellmembranecytoplasm
mitochondria
microtubules
nucleusvacuole
ApicalGrowth--activityoccursatthehyphaltips
Notethatinactivecells,thecellwallisincompleteatthetip---andthatthewallisthickerawayfromthetip!
(dormant)(active)
mitochondriaseptumnucleus
cytoplasm
cellmembrane
cellwall
microtubulesvacuole
Fungalcellsfittogetherlikecarsonacommutertrain
fungicide
Fungicide
Asfungicideisabsorbedbythepathogen,thetoxin’seffectslowsgrowth
Fungicide
Asfungicideisabsorbedbythepathogen,thetoxin’seffectslowsgrowth
Fungicide
Asfungicideisabsorbedbythepathogen,thetoxin’seffectslowsgrowth
Fungicide
Asfungicideisabsorbedbythepathogen,thetoxin’seffectslowsgrowth
Thefungicidewillkillmany(most)cells...butnotall.Growthwillresumeoncetheactiveingredientdissipatesfromtheimmediatesurroundings.
Fungicide
Asfungicideisabsorbedbythepathogen,thetoxin’seffectslowsgrowth
??
?
Thefungicidewillkillmany(most)cells...butnotall.Growthwillresumeoncetheactiveingredientdissipatesfromtheimmediatesurroundings.
Herbicidesimpactonsoilorganisms
• Summaryof28pagereviewarticle:– “Fewnon-targeteffectsofherbicidesonsoilorganismshavebeendocumented”
Impactofagriculturalinputsonsoilorganisms–areviewBunemannetal.2006
PercentofUSgreenkeepersusingturfgrasssupplements
0
13
25
38
50
Bioslmulants Aminoacids Compost Composttea None
Throsselletal.,2009
Molasses• ResearchbyProvinetal.
• Nodifferencesinbacteriaorfungicountsat1xor16xrates
• Stimulationindollarspotwasobservedfortreatmentscontainingmolasses,however,atreatmentresponsewasinconsistent.(TudorandBigelow,2011)
Molasses• Reportedthat"CPRandThatch-Xsignificantlyreducedthatchlayerdepthcomparedtotheuntreatedcontrol"inCrenshawcreepingbentgrassand"alltreatmentssignificantlyreducedthedepthofthethatchlayerinA-1creepingbentgrass,butmolasseshadthegreatesteffect."
• Notareplacementforaerationandtopdressing!
Willisetal.,2005
PennStateEvaluationofI-MOL
Schlossberg,2008
PennStateEvaluationofI-MOL
Schlossberg,2008
ExtracellularEnzymes• Morerigorousapproach
HumicSubstances
HumicSubstances• Humic substances are split into three fractions,
based on their solubility in water:
1. Humic acid 2. Fulvic acid 3. Humin (not soluble)
• classified on solubility, not structure
• wide variation due to source – leonardite is a common source
Claims of Humic Substances:
• Increases soil carbon • Improves plant health • Improves germination and viability of seeds • Chelates macro and micro nutrients to increase
availability to the plant for a longer period of time • Increases cation exchange capacity (CEC) • Improves soil structure for better aeration and water
movement • Stimulates beneficial microorganisms, which can
improve long-term soil pH • Especially effective on sandy soils
Effect of humic substances on root and shoot growth, creeping bentgrass, sand-culture
Menefee humate (granular) 36.9 a soil humic acid (spray) 33.0 ab peat humic acid (spray) 33.8 ab leonardite HA (spray) 36.1 ab Sustane HA (spray) 34.1 ab control 32.2 b
grams dry roots
Cooper, 1999
max length (cm)
HumicSubstancesResearch
• Appliedthreehumicacidproductsmonthlytothreesandbasedputtinggreens
HumicSubstancesResearch
• Appliedthreehumicacidproductsmonthlytothreesandbasedputtinggreens
HumicSubstancesResearch
• Appliedthreehumicacidproductsmonthlytothreesandbasedputtinggreens
Humic substances - summary
• Most tests with positive results performed in sand or solution culture
• Differences usually quite small
• Greatest use might be with low fertility soils or sand-based greens
Products with hormonal activity:
• Sea kelp extracts or seaweed extracts (Ascophyllum nodosum)
• Yucca extracts (Yucca schidigera)
• Humic substances
Plant Hormones
An organic compound synthesized in one part of a plant and translocated to another part where, in very low concentrations, it causes a physiological response –include auxin, cytokinin, gibberellin.
Research with Plant Hormones
ÜIn general – examined in stress situations ÜHigh UV-B light stress (inc. during
summer)
ÜDrought ÜHeat or cold stress
ÜShade
ÜEstablishment
Greenhouse Studies
Ü Adding foliar seaweed extract and/or humic acid improved photochemical efficiency (PE) of tall fescue sod.
Ü Decline of Kentucky bluegrass (photochemical efficiency and visual quality) alleviated.
Ü ‘Increasing robustness of the antioxidative protective system… through the application of phytohormone supplements….mitigated pigment destruction, delay senescence, improve recovery’
Zhang et al., 2003; Ervin, et al., 2004)
More Greenhouse Studies
Ü Penn G-2, L-93, Penncross.
Ü Seaweed extract (0.01 lb/M) and/or humic acid (0.03 lb/M).
Ü No drought or allowed to dry.
Ü After 28 d of drought HA + SWE trt had least decline in quality.
Ü Greater root mass in HA + SWE trts, too.
Zhang and Ervin, 2004
Field StudiesÜTifEagle hybrid bermudagrass
ÜTwo biostimulants, both sea plant extracts (containing cytokinin)
ÜOne product increased root mass (>11%) after two years of use, but only at lowest N rate (1/4 lb N/M/week). That N rate produced turf with unacceptable quality.
(Tucker et al., 2006)
Field Studies
• PanaSea (2 and 4 wk), Kelpak (6 wk), control • no stress, full fertility, applied via manufacturer
directions • No difference in turf quality in 44 ratings - no color
differences • 22 different clipping harvests, 1 significant
difference due to treatment (Kelpak had lower yield)
• no differences in root weight (8 samplings)
Elliott, 1996
More research with seaweed extracts (SWE)
• SWE did not increase the duration or quality of late-season growth of bermudagrass (Munshaw et al., 2006).
• In the greenhouse, application of SWE and HA improved physiological functions and root growth (Zhang et al., 2002).
• In the greenhouse, combinations of SWE + HA increased bentgrass root mass from 21-68% (Zhang and Ervin, 2004).
• SWE or SE+HA had no effect on quality, root strength or antioxidant activity in an 88% shaded bentgrass green (Ervin et al., 2004).
Conclusions• hormone-containing products
stimulated shoot and root growth, although inconsistently
• Seaweed extracts and humic substances may enhance antioxidant activity
• higher antioxidant activity contributes to drought tolerance
Mycorrhizae myco (fungus) rhiza (root)
fungal hyphae
Pine rootTomato root
mutualistic symbiotic association with roots (95% of all plants): plant supplies fungus with carbon fungus supplies plant with mineral nutrients (mainly P and N)
Spore Fungal hyphae
Vesicles Arbuscles
Turfgrass Mycorrhizae Research
• very specific P range in which VAM enhance growth
• fungicides may eliminate VAM benefits
• naturally infected by growth from edge of green
(Koske et al., 1997)
Low Phosphorus Medium Phosphorus High Phosphorus
UniversityofWisconsinTesting
UniversityofWisconsinTesting
NomeasurableeffectonvelvetorcreepingbentgrassestablishmentacrossdifferentratesofPfertilization.
Naturalinfectioninnon-treatedareasshortlyafterplanting.
GuelphUniversityResearch
Effectofmycorrhizalinoculatedturfunderextremewaterstress(Lyonsetal.2007)
VisualRatings
ChlorophyllIndex
RecoveryAfterDrought
CompostTea• Liquidextractmadebysteepingcompostinwaterfor3–7days.
• DiscoveredinGermanytosuppressfoliarfungaldiseasesbynatureofthebacterialcompetition,suppression,antibiosisontheleafsurface(phyllosphere).
• Ithasalsobeenusedasafertilizeralthoughlabtestsshowitisveryweakinnutrients.
Therhizosphereisthenarrowregionofsoilthatisdirectlyinfluencedbyrootsecretionsandassociatedsoilmicroorganisms.
Phyllosphere:
CompostTeaandDollarSpot• InCanada,Compostteassuppresseddollarspot(HsiangandTian,2005):– Cattlecompost:63%– Sheepcompost:70%– Turkeycompost:72%– Mushroomcompost:86%
• InNewYork(Rossi,2007):– “Teaapplicationssuppresseddollarspot40to60percentwhencomparedtountreatedplotsinoneofthreeyears.Itisunlikelythatduetothevariabilityofbrewingresults,littlemicrobialbenefit,andthelaborrequiredforbrewingteathatthistechnologywillseewidespreadadoptioninitscurrentform."
OrganicManagementPracticesonAthleticFields:TheEffectsonColor,Quality,Cover,
andWeedPopulations
NathanielA.MillerandJasonJ.Henderson,2012
• “Compostteaapplicationsshowednoenhancementofturfgrasscolor,quality,orcoverovertheentiredurationofthestudy.”
BacterialAdditives• Nonsymbiotic - do not form symbiotic
associations with plants • Diazotrophs - can use atmospheric
nitrogen for growth
• Examples: Azotobacter, Azospirillum, Xanthobacter, Acetobacter Pseudomonas, Bacillus, Enterobacter etc.
TAZO® Inoculants for Grasses
WhyTAZO®?•Improverootsystems•Increasenitrogenfixation•Increasestresstolerance
WhatisTAZO®?ThebacteriaAzospirillumstabilizedinaliquidform.
ModeofAction?TAZO®stimulatesrootgrowthandnitrogenfixationresultinginimprovednutrientuptakeandincreasedrooting.
HowApplied?TAZO®issprayedonthetargetarea.
TAZO® attaches to the grass root system and produces compounds that stimulate root growth.
TAZO® fixes atmospheric nitrogen, adding nitrogen to the plant.
Formulations ▪ TAZO-ST Dry - Powder Seed treatment ▪ TAZO-B – Broadcast spray ▪ TAZO-ST Liquid – Liquid Seed treatment
HowisTAZO®Different?Using proprietary formulation technology TAZO® has
been stabilized in easy to use formulations. This is key to TAZO® performance. TAZO® stabilization
technology keeps more bacteria viable so consumers
receive more benefit.
RH=RootHair,RS=RootSurface,B=AttachedAzospirillumBacteria
B
B
B
Manufactured By: TerraMax, Inc. 7769 95th St. So. Cottage Grove, MN 55016 651-458-4401
2015BiologicalProductTestingatUniversityofWisconsin
Treatment Startdate Rate ApplicationFrequency
GenNextA+B 19May 8oz/M(each) EverytwoweeksGenNextC+D 19May 8oz/M(each) EverytwoweeksAccelerateRoots 19May 5oz/M Every28days
Holganix 19May14oz/M(first)7oz/M(after)
1timeEverytwoweeks
HSCProgram1 19May3gal/A(first)(8.8oz)
1.5gal/A(after)(4.4oz)Weekly4timesEverytwoweeks
HSCProgram2 19May7gal/Afirst(22oz)
3.5gal/A(after)(11oz)Weekly4timesEverytwoweeks
TazoB 19May 0.8oz/M EverytwoweeksN-Plus-B 19May 0.73oz/M Everytwoweeks
Non-treated N/A N/A N/A
‘Focus’creepingbentgrassputtinggreenonasand-basedrootzone
Maintenance• Moweddailyat0.125inches(3mm)• IrrigateddailytoreplaceET• IrrigationstoppedinAugusttotestdrought/localizeddryspotresistance• Fertilizedsothatallplotreceivedequalnitrogenfortheseason(~3lbs/M)
Evaluated• Visualqualityandcolor• Diseaseoccurrence• Localizeddryspotoccurrence• Rootingcharacteristics
DollarSpotSuppression
Dollarspo
tsperplot
0
7.5
15
22.5
30
GenNextA+B AccelerateRoots HSCProgram1 TazoB Non-treated
Notreatmentsweresignificantlydifferentfromnon-treatedcontrol
IncidenceofLocalizedDrySpot%Localize
dDrySpots
0
3
6
9
12
GenNextA+B AccelerateRoots HSCProgram1 TazoB Non-treated
Indicatestreatmentwassignificantlydifferentfromnon-treatedcontrol
** * *
*
Non-TreatedControl
HSCOrganics
VisualTurfgrassQualityVisualTurfgrassQuality
5.4
5.6
5.8
5.9
6.1
GenNextA+B AccelerateRoots HSCProgram1 TazoB Non-treated
Notreatmentwassignificantlydifferentthannon-treatedcontrol*
VisualTurfgrassQualityVisualTurfgrassQuality
0
1.5
3.1
4.6
6.1
GenNextA+B AccelerateRoots HSCProgram1 TazoB Non-treated
Notreatmentwassignificantlydifferentthannon-treatedcontrol*
Rootlengthwassimilarforalltreatments(stillanalyzingrootweight)
SummaryofWisconsinResearch
• Fewdifferenceswereobservedinplotscomparedtothenon-treatedcontrol
• HSCandTerraMaxprogramssignificantlyreducedtheoccurrenceoflocalizeddryspot
• Differencesmaytakemoretimetodevelop
HSC Trials 2014
Treatment Quality Brown Patch Yellow Spot
Sig/Dac 5.6 a 0.7 b 1.1 b
HSC 4.4 b 3.5 b 2.8 b
HSC/Sig 3.9 bc 16.0 a 5.5 a
Control 3.8 c 13.2 a 7.0 a
Inoculating Soil - Keys to Success
1. inoculum must be viable 2. must be sufficient inoculum to
bring about a change 3. ability of the microorganisms
to survive and multiply must be ensured
TheDilutionProblem
• Canyouapplyenoughmicrobestomakeadifference?
NutriLifeExample• Label:Applyat6oz/1000sqft=~1millioncfu/1000sqft
• Thereare~onequadrillion(1015)bacteriain1000sq.ftofsoil.
• ThismeanstherewillbeonebacterialcellofNutrilifeforevery1billionnativebacterialcells
• Applyat0.8oz/1000sq.ft.– (200,000cfu/mL=6millionperoz)– About5millioncfu/1000sq.ft.
• ~onequadrillion(1015)bacteriain1000sq.ftofsoil.
• 1appliedbacteriumforevery200millionnativecells
Compostteaexample• Tenmillion(10000000)CFUbacteria/mL
– 300millionperoz
• Applyat1galper1000sq.ft(nodilution)
• Result:38billionCFU/1000sq.ft
• 1compostteabacteriacellforevery25,000nativecells
MarketingCanBeMisleading
• Microbescannot:–Loosencompactedsoils–Tightenloosesoils–Removesalts–Makesoils“comealive”–Eliminate“drugaddiction”
Summary• Manyproductsavailable–toomanytoscientificallyevaluate
• Viewtestimonialsandmarketingmaterialswithskepticism
Summary• Sciencewillcontinuetobeignoredandtakenoutofcontexttosellproducts
• Vieworiginaldatafromunbiasedsources
• Location,climate,weather,soiltypemayallaffectresults
OverallProductSummary
• Humicacids–minor,inconsistentbenefitsseeninyoungsandrootzones.
• Hormones–somewhatmorereliableeffects• Mycorrhizae–ubiquitous,maybebeneficialattimeofseedinginsandrootzones.Resultsinconsistent
• Composttea–inconsistentdollarspotsuppression,applicationratesmaybetoolowtomodifysoilbacterialdiversity.
• Bacterialadditives–typicallynotshowntobebeneficial