inguagiato roberts - stma biocontrol 2020 final · biocontrol application: 1 x 109 bacterial cells...
TRANSCRIPT
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Improving biological control of turfgrasspests in the wake of public opinion
John Inguagiato, Ph.D.Joseph Roberts, Ph.D.
Connecticut Pesticide BanJuly 2010
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Connecticut Pesticide BanJuly 2010
• Areas affected?– K-8 grade school grounds– Day care centers
• Systematic implementation
• What’s banned?– all EPA registered pesticides– Exemptions (2015):
• microbial biopesticides• biochemical biopesticides• horticultural soaps• 25(b) Minimum risk pesticides
Unrestricted Management
Jan 2006
Monitored IPM
Jul 2010
Pesticides Banned
Impacts of Connecticut Pesticide BanField quality change from
IPM to pesticide-free management after 2 yrs
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Percentage of Responses
Decreased No change Increased
a
b
cBartholomew
et al., 2015
CT municipalities surveyed:31% response rate (47/151)
Impacts of Connecticut Pesticide BanPractices used by turf managers under
various state regulation
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100Conventional IPM Pesticide‐free
Pesticide apps
Hand weeding
Over seeding
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Wallace et al., 2016
Biological control
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ing
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CT municipalities surveyed:31% response rate (47/151)
Benefits of Biological Control:
• Reduce pest populations
• Environmentally friendly alternative to synthetic pesticides– Lower risk to non-target species
– Decompose rapidly
• Less toxic to humans
• Reduce number of chemical pesticide applications
• Reduce pesticide resistance
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Biological Control (Biocontrol)a simple definition:
• Using beneficial organisms to reduce populations of pest organisms, or to maintain them at sufficiently low levels– General Suppression vs. Specific Suppression
General Suppression• Promoting a ”healthy” habitat
– Physical, Chemical, and Microbial Environment – Solid or foliar applied amendments
• May contain microbes• Stimulate existing beneficial microbes
• Activation of plant defenses• Induced systemic resistance (ISR)• Systemic acquired resistance (SAR)
Compost
Compost
Composts• Enhance native soil microbe populations
• Monthly topdressing with 10 lbs/1000 ft2shown suppressing several diseases– Dollar spot– Brown patch– Pythium root rot
• Control varies based on target disease, type of compost, and degree to which material is composted
• Pythium blight• Necrotic ring spot• Red thread
Amendment Benefits
• Improve soil physical properties
• Soil fertility
• Alter microbiome
• Plant health
Specific Suppression• Utilizing a specific microbe for combating
plant pests
• Form of suppression varies by organism
• Formulated and sold by companies
Clarireedia sp.1
Pseu
dom
onas
sp
.
1Salgado-Salazar et al., 2018
Biocontrol DefinitionsDo you talk the talk?
• Pesticide: – any substance or mixture of substances used to kill pests or to
prevent or reduce the damage pests cause
• Biopesticide:– pesticides derived from such natural materials as animals, plants,
bacteria, and certain minerals• Microbial biopesticide
• Biochemical biopesticide
• Plant-Incorporated Protectants (genetic engineered)
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Biocontrol DefinitionsDo you talk the talk?
• Microbial biopesticide: • active ingredient is a living
microorganism or a product made by a microorganism
• GrubGONE
• Rhapsody
• Companion
• Nemasys
• Biochemical biopesticide: • natural compounds including plant
extracts and naturally-occurring chemicals
• Insect sex pheromones
• Neem oil
• Corn gluten meal
• Potassium bicarbonate
Biocontrol DefinitionsDo you talk the talk?
• Predators: • Prey on insect pests as young
and/or mature bugs, beetles, flies, lacewings and spiders
• Specialists
• Generalists
Biocontrol DefinitionsDo you talk the talk?
• Predators: • Prey on insect pests as young
and/or mature bugs, beetles, flies, lacewings and spiders
• Specialists
• Generalists
• Parasitoids: • seek other insects as hosts for
egg laying and development eventually kill host
Biocontrol DefinitionsDo you talk the talk?
• Biostimulant: – substance(s) and/or microorganisms that stimulate natural
processes to enhance/benefit nutrient uptake, nutrient efficiency, tolerance to abiotic stress, and plant quality
• Seaweed extracts
• Humic acids
• Microbial inoculants
No pest control = Not pesticide
• Formulated as traditional pesticides
• Increase population of suppressive microbes (dramatic/temporary)
• Requires frequent applications
Microbial Biopesticides
Microbial BiopesticidesMode of Action:
• Current products work to control pests using one or more mechanism– Parasitism
– Antibiosis
– Competition
– Induced resistance
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How Microbial Biopesticides Work:Parasitism
• Consuming or parasitizing the pest, directly
Sores de Melo & Faull. 2000. Scientia Agricola
• Trichoderma spp.
• soil inhabiting fungi consume hyphae of pathogens – Obtego
– RootShield Plus
How Microbial Biopesticides Work:Parasitism
• Consuming or parasitizing the pest, directly• Nematodes carrying bacteria lay eggs inside grubs
– Nemasys G– Nemashield HB
Dunn & Wickings. Biocontrol Bytes Blog. Cornell Univ.
How Microbial Biopesticides Work:Antibiosis
• Poisoning the pest: production of antibiotics toxic to pests
• Bacillus spp.– Rhapsody
– Companion
– CEASE
– Serenade
• Pseudomonas spp.– Zio
Dollar Spot Control in Bentgrass with Pseudomonas aureofaciens (TX-1)
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Untreated CheckTX - 1
(TX - 1 = 109 cfu Mon, Wed, Fri; 19 May - 14 Aug ‘98)
# S
po
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B. Clarke
Figure 1
Trends in Plant Science 2012 17, 478-486DOI: (10.1016/j.tplants.2012.04.001) Copyright © 2012 Elsevier Ltd Terms and Conditions
Take-all Patch Decline - Wheat
Disease reduction – Pseudomonas spp.
How Microbial Biopesticides Work:Antibiosis
• Poisoning the pest: production of antibiotics toxic to pests
• Bacillus thuringensis– GrubGONE
• Toxins active in high gut pH degrade stomach
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The effect of endophyte on red thread in creeping red fescue
E- E+
Bonos et al. 2005
How Microbial Biopesticides Work:Competition
• Crowd the pest: antagonists reduce pest growth by competing for food and space
• Bacillus spp.
• Pseudomonas spp.– siderophore
production
Dunn & Pethybridge. Biocontrol Bytes Blog. Cornell Univ.
Microbial siderophores
Saha et al. 2012 J. of Basic Microbiology 53(4)
Raudales
• Iron required by most living things
• Siderophores are small molecules that sequester iron from the rhizosphere
• The sequestered iron can only be used by the microbe that produced it and by certain plants
Microbial biopesticides
In 1979, the first microbe was registered at EPA for the use of biocontrol.
Agrobacterium radiobacter strain K84 was registered as an active ingredient for the control of crown gall caused by A. tumefaciens.
RaudalesRaudales
How Microbial Biopesticides Work:Induced Resistance
• Stimulating plant’s own natural defenses
Microbial BiopesticidesMode of Action:
• Current products work to control pests using one or more mechanism
Dunn & Pethybridge. Biocontrol Bytes Blog. Cornell Univ.
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Current Microbial Biopesticides for TurfBiofungicides:
Trade name Active ingredient Activity
EcoGuard Bacillus licheniformis SB3086 dollar spot, anthracnose
Rhapsody Bacillus subtilils QST713 brown patch, dollar spot, gray leaf spot…
Companion Bacillus subtilils GB03 brown patch, dollar spot, gray leaf spot…
Zio Pseudomonas chlororaphisAFS009
brown patch, Pythium, anthracnose
Obtego Trichoderma asperellum &T. gamsii
brown patch, Pythium
Current Microbial Biopesticides for TurfBioinsecticdes:
Trade name Active ingredient Activity
GrubGone G Bacillus thuringiensis var galleriae
white grubs
Grandevo PTO Chromobacterium subtsugaestrain PRAA4‐1
white grubs, caterpillars,chinch bugs
Nemasys G Heterorhabditis bacteriophora white grubs
NemAttack Steinernema carpocapsae billbugs, caterpillars
BotaniGard ES Beauveria bassiana GHA chinch bugs, billbugs, (toxic to bees)
Current Microbial Bioinsecticides for TurfgrubGONE G (Bt galleriae SDS-502)
• grubGONE!® - 9% ai granular formulation
• Applied at 100-150 lbs/ac (9 – 13.5 lbs ai/ac)
Cost ~$280-420/ac
• > 2 years shelf life
• OMRI approved
• Apply vs. young grubs (L1, L2)
• Most effective vs. Japanese beetle
• More variable with masked chafers and oriental beetle
Slide courtesy of: A. Koppenhoffer, Rutgers
Microbial BiopesticidesState of current products in turf
• Efficacy of microbial biopesticides variable
– Bt applications for white grub control seem promising
– Potential for additional insect pest controls
• other bacteria, nematodes, fungi
– Bioherbicides: none registered in U.S. for use in turf
– Biofungicides: less effective turf disease control:• 24 Trials evaluating: Bacillus subtilis, B. licheniformis, Trichoderma
harzianum, T. virens
• Only 33% of trials reduced disease compared untreated
(J. DOHERTY)
Clarireedia jacksonii Pseudomonas bacteria
Biocontrols Exist Naturally?
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2 d 3 d 4 d
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ial G
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W9 Inhibition of Clarireedia jacksonii
2d Bac Co-plate Control
Isolating New Biocontrol Sources
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Isolating New Biocontrol Sources
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W9 Inhibition of Cool Season Rhizoctonia solani
2d Bac Co-plate Control
Remember the Disease Triangle?
Microbe
Success of Biological Organism
Inoculating Beneficial Microbes
• Microbes must be viable– Biological products have a shelf-life
• Need to have enough microbes to bring about a change
• Microbes must be successful in surviving and multiplying
Quorum Sensing in Bacteria
• Bacteria produce signal compounds that are perceived by other bacteria
Signal PeptideSignal Receptor
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• When the signal has been received by a certain number of cells, this is called a quorum
# of bacteria cells
Sig
nal s
tren
gth
Quorum Sensing: What’s the Big Deal?• Density related processes
– Pathogenicity– Motility– Biofilm formation– Sporulation– Antibiotic production
• Cross-talk exists between fungi and bacteria– Microbial Competition can limit disease
Can we apply or recruit beneficial microbes to
outnumber existing microbes?
Biologicals and Fungicides to Control Brown Patch in 2018
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% B
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atch
Tekken 3.0 fl oz 21 d Lexicon Intrinsic 0.34 fl oz 21 d Velista 0.7 oz 21 d
Exteris Stressgard 4.0 fl oz 21 d Insignia 0.7 oz 21 d Heritage TL 2.0 fl oz 21 d
Rhapsody 10.0 fl oz 7 d Non-treated Check
Fungicides applied beginning 1 June until 31 July 2018
Environmental Hurdles
• Temperature
• Moisture
• UV light
• Other microbes
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Man-Induced Hurdles• Mowing
• Irrigation
• Fertilizing
• Pesticides
A Game of Numbers
Biocontrol Application:
1 x 109 bacterial cells per gallon
Soil bacteria:
~1 x 1015 per 1000 ft2
~0.0004% alteration to population
(C. Bigelow)
Traditional Biocontrol Application
Biological Product
Reducing Competition
Surface Disinfestant
Reducing CompetitionH2O2 + P. chlororaphis AFS009
P. chlororaphis AFS009
H2O2 + B. subtilis QST-713
B.subtilis QST-713
H2O2 + B. subtilis EXP-W9
B. subtilis EXP-W9
H2O2 + None
None
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Succeeding with Biocontrols
• Applications must be frequent
• Apply under favorable environmental conditions
• High rates may help
• Consider rotations with conventional fungicides
• Temper expectations
Current Best Practices for Optimizing Biocontrol Efficacy
• Accurate identification of pest problems
• Use preventively
• Utilize in IPM program
• Store carefully
• Be mindful of product compatibility
• Combine biocontrol modes of action
• Wear personal protective equipment
Developing Field Research
New project initiated with Montgomery County MD in 2019
Locations – College Park, MDRockville, MD
Grass Type – Tahoma Bermudagrass
Scope of StudyYear-round organic vs conventional programs evaluating disease, insect, and weed control
John Inguagiato, Ph.D.
@UCONNturfpath
Joseph Roberts, Ph.D.
@ClemsonTurfPath
Thank You
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