practical turfgrass microbiology - sommet du golf · 2015-12-21 · field studies Ütifeagle hybrid...

PracticalTurfgrassMicrobiology

JimKerns,Ph.D.NorthCarolinaStateUniv.jpkerns@ncsu.edu

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