1
Pest Management in
Organic Crop Production
Geoff Zehnder, Coordinator
IPM & Sustainable Agriculture Programs
Clemson University
Outline
• Principles of IPM and Organic Pest Management
• National Organic Program • Standards for Pest Management
• Organic (preventative) pest control strategies
• Use of approved organic pesticides
National Organic Program
http://www.ams.usda.gov/nop
2
Integrated Pest Management The Foundation of Organic Pest
Management
IPM is a sustainable approach to managing
pests by combining biological, cultural,
physical and chemical tools in a way that
minimizes economic, health, and
environmental risks.
(National IPM Network)
History of IPM
• IPM concept presented in
historic 1959 paper
• Recognized pest
management benefits
from the natural
ecosystem, and
disruptive effects of
pesticides
• Economic threshold
concept
Vern Stern, Ray Smith,
Robert Van den Bosch, Ken Hagen
3
The Economic Threshold
Concept (insect pests)
• Goal: control pest
populations below
levels that result in
economic damage
(EIL).
• The economic
threshold (ET): occurs
before the EIL is
reached
– Estimated benefits
cover cost of treatment
Time # o
f In
sects
EIL
ET
IPM: Emphasis is on Prevention
Challenges :
• IPM is knowledge intensive – Planning takes time
• Pesticides are
relatively cheap – Costs increasing
PAMS: Prevention, Avoidance, Monitoring, Suppression
4
Organic Pest Management (Certified Organic Production)
Foundation is in IPM, but:
•Preventative (cultural) practices must be
used (long-term planning)
•Use of pesticides is limited to those that
are produced from natural sources, not
synthetic chemicals
•Approved pesticides are to be used
only as a last resort
Principles of IPM in
Organic Systems • View cropping system
as part of larger
ecosystem
• Try to achieve natural
ecosystem balance for
pest regulation
• Integrate control
strategies in a
compatible manner
• Allowable pesticides as
a last resort
Flowering strips in celery
production: Tanimura & Antle
Growers, California
5
Organic Pest Management Takes
Advantage of Nature’s Services
“Ecosystem Services”
Products: clean drinking water, food, pharmaceuticals, biofuels, etc.
Processes: waste decomposition, carbon sequestration and climate regulation, nutrient cycling, biological pest control, etc.
The value of global Ecosystem Services estimated at
$33 trillion (Costanza et al., 1997. Nature vol. 387).
The value of ground dwelling predators
Dollar value of biological control of aphids in selected organic fields
H.S. Sandhu, Lincoln University, New Zealand
6
To implement an organic pest
management plan, growers must have…
• Guidelines to
manipulate the farm
ecosystem to address
the following questions:
– Why is the pest there?
– How did it arrive?
– Why doesn’t the
natural enemy
complex control the
pest?
ATTRA.org: Biointensive IPM
National Organic Program Pest Management Guidelines
• No synthetic pesticides
• No GMOs
• Preventative pest
management plan
• If necessary, use of
approved biological or
mineral based products
• Buffer between organic
and conventional fields
7
• Organic Certification Process
– Complete and submit farm plan questionnaire and
application fee ($500)
• Includes field history, farm map, product profiles
– Program review and comments
– On-site inspection
• Inspection report
• Checklist of items to be addressed by grower
– Program review
– Certification decision and certificate
– Annual inspections for re-certification ($400)
Organic Certification Program
Contact: Ryan Merck; [email protected], 864.646.2129
Transitioning to Organic IPM
Low Level IPM
Scouting, use of thresholds, timed pesticide applications
Medium Level IPM (multi-tactic approaches)
Begin to manipulate habitat, augment biodiversity,
crop rotations, resistant varieties
Biointensive IPM (reliance on preventative measures)
Multiple steps to enhance soil quality and plant health,
habitat enhancement, conservation of natural enemies,
strategic use of cover crops
8
Organic Pest Management Planning Focus on Preventative Practices
Zehnder et al. 2007. Arthropod pest management in organic crops.
Ann. Rev. Entomol. 52: 57-80
Preventative Strategies (Foundation of Organic Pest Management)
• Cultural practices
implemented in the
initial stages of farm
planning
• Prevent and avoid
problems beforehand
• Have roots in
traditional agriculture
9
Pest Prevention Strategies with Examples
Strategy Examples
Make crop unavailable to
pests in space/time
Site selection, crop isolation,
crop rotation, timing of
planting/harvest
Make crop less
acceptable/apparent to pests
Intercropping, trap cropping,
mulching
Reduce pest survival by
enhancing natural enemies
Increase crop ecosystem
diversity; farmscaping, cover
cropping
Alter crop susceptibility to
pests
Resistant/tolerant varieties,
soil quality, fertility
Isolation of Susceptible Crops In Space or Time
• Example: Insect
transmitted virus
diseases
– CMV/tomato system
• New crops should be
isolated from sources of
inoculum (infested
fields, weed hosts, etc)
10
Soil Quality Management Does it affect above-ground pest damage?
Research on European Corn Borer Larry Phelan, Ohio State University
• Compared egg-laying on plants grown soil from organic vs conventional farms
• Significantly more ECB eggs laid on plants in conventional soil
• Nutrients and minerals in plants grown in organic soils more balanced, less suitable for insect pest development
11
Reduced development of Colorado
potato beetle on potato grown in organic
soil
Research by Alyokhin & Atlihan,
2005
Cover Cropping/
Conservation Tillage
• Enhances soil quality
– Healthy soil = healthy
plants better able to
tolerate pests
– Greater abundance and
diversity of soil microbes
– Favors greater numbers
of predatory arthropods
(spiders, beetles, ants)
– Flowering cover crops
attract natural enemies
12
Melon-Virus Experiments Cover crop as camouflage
• Annual rye planted
between rows in late
fall
• Virus incidence lower
in cover crop
treatments
• Reflective mulch also
reduced virus
incidence 0
50
100
2003 2004
Cover
No Cover
% Plants Infected with WMV
Rotation with Biofumigation Crops
• Brassica crops (mustards,
rape, etc.)
• Plant defense compounds
– Glucosinolates converted
to isothiocyanates
• Soil concentrations high
enough to kill pathogens,
weed seeds, soil insects
13
Host Plant Resistance
• Many crop varieties with
disease/nematode
resistance
• Limited application for
control of insect pests in
conventional agriculture
– Efficacy of synthetic
insecticides
– Low tolerance for cosmetic
damage
– Partial plant resistance not
acceptable
Whitefly Damage: Hairy vs.
Smooth Leaf Cotton
Corn Earworm:
Can’t easily penetrate tight husk varieties
`Prince Hairy’ Potato From Cornell Breeding Program
14
Vegetation Management Habitat for Beneficial Insects and Pollinators
• Flowering plants and
perennials provide food
and shelter for natural
enemies and pollinators
– Nectar and pollen
– Overwintering habitat
– Alternative hosts/prey
– Increase longevity,
reproduction
Evaluation of Wildflower Strips to
Enhance Biocontrol in Cabbage Pfiffner et al. 2003
• Treatments
– Strips adjacent
– Strips 10-90 meters
– Cabbage with no strips
• Higher rate of parasitism
next to strips
• Parasitism increased with
proximity to strips
• Scale/size of strips
relative to crops important
15
Hedge Rows: native trees, shrubs, annuals, perennials, grasses
( food, habitat for natural enemies, erosion control)
David Orr’s Native Plant Mix
• Little bluestem
• Butterfly weed
• Common milkweed
• Black-eyed Susan
• Purple coneflower
• Lance leafed coreopsis
• Swamp sunflower
• Showy goldenrod
• Heath aster
16
www.xerces.org
Mixed Cropping (Intercropping)
• May disrupt pest development
• Insect pests – Concentrated areas of
host plants are easier for insect pests to find and colonize
– Mixing crops interrupts host location: (physical barrier, sight, smell)
• Disease spread: – Non-host plants may act
as barrier to spore movement
17
Trap Cropping
• Attractiveness and
relative size in the
landscape are key factors
– Examples:
– Blue Hubbard around
summer squash;
Pumpkins around melons
(cuc. beetle)
– Cherry peppers around bell
pepper (pepper maggot)
– Collards around cabbage
(DBM)
Top; Sam Pair, USDA-ARS, Lane, OK
Bottom: Randy Blackmer, Dale, CT
Release of Biological Control Agents
• Insect Pests
– Introduced predators,
parasitoids
– Microbial agents
• Diseases
– Biological fungicides
• Weeds
– Introduced insects
– Pathogens
– Livestock
• More research needed on how to
integrate BC agents with other
strategies
18
When all else fails… Considerations in use of approved pesticides
• Advance planning; determine how and when to react to a pest outbreak
• What quality does your market require?
• Decide in advance your ‘action threshold’
• Know your organic pesticide choices: what’s allowable, what’s labeled, what works, cost
• In general, organic pesticides not as effective as conventional
Use of approved pesticides in
organic crops
• Thresholds based on:
– Market value of the crop
– Type, severity and timing
of damage
– Cost and effectiveness
of materials
– Comfort level
• Regular monitoring and
recordkeeping
• Maintain list of available,
approved materials for key
pests
• Good spray equipment
(adequate coverage)
19
Specialized Application
Dropleg application of Bacillus thuringiensis var. kurstaki
against lepidopterans in leek.
The application from top and bottom increases spray
coverage and efficacy of Bt applications.
Photo: Eric Wyss, FiBL
• OMRI: determines which input products are allowed in
organic production and processing
• Provides independent review using National Organic
Standards
• Approved products are “OMRI Listed” and suitable for
use in organic production or food processing
• Download and search Products List (free)
• $59 subscription: print and web
version with updates
www.omri.org
20
Input Substitution
• Not feasible
economically
• Does not satisfy NOP
requirements for long-
term, preventative
pest management
planning
• Organic involves a
different approach to
pest management
Using Multiple Stategies Organic Control “Toolbox” for Cucumber Beetle
• Habitat for natural enemies
• Grow cucurbit varieties less attractive
to beetles
• Long distance crop rotation
• Transplant vs direct seeding
• Eliminate crop residues
• Manipulate planting date (may miss
peak markets)
• Row covers (may interfere with
weeding)
• Mulch (may exacerbate other pests)
• Trellis plants (labor)
• Trap crops, baits and sticky traps
(labor, cost)
• Approved materials
– Neem, Beauveria bassiana, kaolin
clay, pyrethrin, spinosad
Source: Univ. of Kentucky Entomology
21
Questions?
