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1 Biological Control of Diseases in the Nursery Julie Graesch Biological Program Manager – Insect Management December 17 th 1:55-2:45pm
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Biological Control of Diseases in the
Nursery Julie Graesch
Biological Program Manager – Insect Management
December 17th 1:55-2:45pm
Overview • IPM • General biopesticide info• Programs
– Foliar disease– Soil disease– Available solutions
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3Journal of Integrated Pest Management, (2019) 10(1): 12; 1–
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• Sanitation ‒Remove weeds‒Manage surrounding grounds‒Remove diseased plants and crop residues‒Do not re-use potting media ‒Wash hands regularly ‒Sanitize tools and equipment ‒Sanitize surfaces, pots/trays/containers‒ Filter and treat recycled irrigation water
Disease IPM
• Cultural – Obtain clean seed and plant material– Keep fungus gnats under control– Crop rotation– Irrigation – Soil solarization – Fertilization
• Other measures– Obtain proper diagnosis of disease
• Damping-off, wilt, crown and root rots – Host plant resistance – Pest biology – Preventive biofungicides– Rotation of registered fungicides for high disease pressure
Disease IPM
Scouting & Recordkeeping
• Log and track pest presence/populations• Current & past info on ID and location of pests• Evaluate treatment effectiveness• Invite consultants
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Photo credit: Griffin Sales
• Need to change your mindset• Biopesticides typically not chemicals• Do not expect to use the same way• Don’t always expect the same results
– Non-systemic– Pests don’t drop dead immediately– May not preform under high pressure
• Shelf life• Plant safety
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The Chemical Paradigm
Plant Safety• Biopesticides have not been tested
on all varieties or in all tank mixes‒Check compatibility
• Mineral oil and sulfur • Use caution when making
applications during bloom• Test on a small number of plants to
check for phytotoxicity
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Why Biopesticides1. Low REIs and PHIs2. Safer for workers, consumers, &
environment- Many exempt from tolerances and MRLs
3. Reduced resistance to synthetic pesticides
4. Improve efficacy of chemicals5. Improve plant, soil and environmental
health over time with continued use6. Consumer demand
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Biopesticides Can…
• Be used to help prevent disease – Sometimes curative
• Manage disease at low to moderate pressure
• Trigger induced plant resistance• Manage chemical residues • Help prevent loss
– Season long and after dormancy• Produce healthier more productive crops • Help provide quicker turns• Manage diseases via multiple MOA
Multiple Modes of Action: Trichoderma 1. Antagonistic metabolites
• Bioactive compounds: antibiotics, anti-fungal peptides/proteins, enzymes, biosurfactants, specific toxins, etc.
2. Competition • Nutrients and niche in soil and plant
surfaces3. Rhizosphere competence
• Form of niche competition• Physically and biochemically blocking
access to root systems4. Predation / Hyperparasitism
• Pathogen as a food source• Physically attacking, infecting and/or
consuming by force, bioactive compounds, and/or digestive enzymes
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Biopesticides Can't…• Offer 100% protection• Cure diseases and insect pests• Work in environmental extremes• Work at high disease pressures• Last indefinitely
– Defined shelf lives and storage conditions– Frequent applications, especially on foliage
Factors Affecting Biopesticide Efficacy • IPM program
– Tank-mixing or rotation with synthetic fungicides• Active ingredient • Pathogen species • Pathogen incidence and severity• Rate • Application interval• Potting medium • Fertility regime
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• Preventative‒Diseases: At first
detection or when conditions are optimal for pathogen development‒Insects: As early as
possible upon detection or before economic threshold is reached
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Factors Affecting Biopesticide Efficacy Application Timing
Factors Affecting Biopesticide Efficacy
Coverage
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• Incorrect timing and poor coverage are primary causes of biopesticide failure
• Directed spray nozzles –Hydraulic sprayers–Backpack sprayers–Cold-foggers
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Factors Affecting Biopesticide
Efficacy Shelf Life
Many biopesticides are living organisms
• Physical compatibility– Jar test– Avoid multiple
inputs• Spore viability
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Factors Affecting Biopesticide Efficacy
Chemical Compatibility
BCA Compatibility
• Varies with biopesticide/chemical
• Compatibility guides • Companies/consultants
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Disease AI Insect AIBacillus sppStreptomyces sppPseudomonas sppExtract of SwingleaUlocladium oudemansiiCopperHyrdogen Dioxide Potassium bicarbonate
Beauveria bassianaMetarhizium anisopliaeIsaria fumosoroseaMineral Oil AzadirachtinPyrethrinsBurkholderia sppChromobacterium subtsugae
TrichodermaMycorrhizae Bacillus sppStreptomyces sppPseudomonas sppPlant proteins/amino acids Extract of SwingleaHyrdogen Dioxide
Beneficial Nematodes AzadirachtinBeauveria bassiana Plant extracts
Foliar
Root
Developing a Program
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Programs:Decision-Making Considerations
• Product cost‒ Cost per application:
• product, labor, and equipment‒ Number of applications per crop‒ Number of diseases controlled by
product
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Programs:Decision-Making Considerations
• Direct and indirect benefits‒ Cost savings
• Same or improved efficacy‒ Increased productivity:
• low REI, low/no PHI‒ Greater plant safety ‒ Greater worker safety‒ Lower resistance to conventional
fungicides and insecticides‒ Compatibility with other inputs
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Developing or Modifying a Program• Preventive: exclusion, sanitation, environment• Properly ID, don’t assume• Advice from manufacturers, growers, extension & consultants
– No one program fits all• Identify gaps in your program
– Efficacy– Resistance– Compatibility– Safety– Convenience– Market– Labor
How do you measure these?
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• Test new products on a small scale – Set-up a good comparison– Integrate vs. replace
• Document your tests– Keep track of what, how, when– Record what you see and experience– Photos: the good, the bad, the surprises
Developing a Program – Cont.
Adding Products to your Current Program • Current rotation program products• Is this a new MOA• Does the new product offer
– Efficacy– Lower REI– Plant or worker safety – Environmental safety – Broad or narrow spectrum – Application considerations – Resistance management
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Define what Success looks like
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Foliar Programs (Preventive)
Initial Spray(single or tank mix)
Biopesticide Spray
Rotation Partner
Biopesticide Spray
Rotation Partner
Basic Biological Program
General Rotation Program
Dip (first true leaves and/or transplant)
Dip (first true leaves and/or
transplant)
Products with multiple MOALow pressure Short turns
Incorporate BCAs
Biopesticide spray before harvest
Repeat ApplicationsApplication interval
depends on product & pressure
Biopesticide spray before harvest
Biopesticide Spray
Products with multiple MOAApplication interval depends on product and pressure
Single or tank-mixedLonger turns
Incorporate BCAs
How you start the program will depend on disease pressure
at season start
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Untreated Check
% L
eaf S
urfa
ce A
ffect
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• Treatments applied I=7 DAP, II=14 DAP, III=21 DAP, IV=28 DAP, V=35 DAP • Treatments applied in 40 gal water per acre. Disease evaluation 42 DAP
• Powdery mildew: Sphaerotheca fuliginea and Erysiphe cichoracearum
Squash
University of FloridaHomestead, FL, 2009
97% Reductionin Leaf Surface
Affected
Procure®8oz/a
biweekly
Regalia®
1% v/vweekly
Actinovate®12 oz/aweekly
Regalia® 1% v/vAlt.
Procure 8oz/aweekly
Actinovate 12 oz/aAlt.
Procure 8oz/aweekly
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Biofungicides Used Early and in a Program with Complementary Fungicides Provides Powdery
Mildew Control in Squash – Pam Marrone
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Soilborne Disease Programs Preventive & Knockdown
Pythium, Fusarium, Rhizoctonia diseasesInitial Drench
WP, WDG, L, etc.Single or tank-mix
Pre-plant Incorporation (G) Container/tray bath WP, WDG, L, etc.
Repeat Drench Applications
2-12-week IntervalsDepends on product
DipSeeding, sticking
or transplantBiopesticide Drench
before Shipping
Chemical Knockdown Drench Alone or tank-mixed with
biofungicide
Chemical KnockdownTransplant
Pre-Treatment
5. Define what success looks like
Tips for Developing Your Own Program
5. Define what success looks like
Tips for Developing Your Own Program
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