Pest Management Planningfor Organic Vegetable Production

Geoff Zehnder, CoordinatorIPM & Sustainable Agriculture Programs

Clemson Universityzehnder@clemson.edu

My Background• Academics

– M.S. in IPM; Ph.D. in Entomology

• Work Experience– VA Tech: research on

potato ,tomato IPM– Auburn: research on

insect-plant interactions (induced resistance)

– Clemson: Extension training; grad student research

Outline• Principles of organic pest

management• Approaches to pest

management planning• Examples

• General preventative practices

• Targeted practices • Pest management at the

Clemson Student Organic Farm

Landmark Article that Proposed IPM Concept(IPM is the Foundation of Organic Pest Management)

• Recognized that toxic pesticides disrupt the agro-ecosystem– Need to conserve

beneficial insects• IPM

– Integrate multiple strategies

– Insecticides only when necessary based on pest damage thresholds

Authors: Vern Stern, Ray Smith, Robert van den Bosch, and Ken Hagen

Organic Pest Management(Certified Organic Production)

Foundation is in IPM, but: • Preventative pest management 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 if preventative tactics fail

Principles of IPM in Organic Systems

• Not based on input substitution

• View cropping system as part of larger ecosystem– Try to achieve natural

ecosystem balance for pest regulation

– Take advantage of nature’s services

• Integrate control strategies in a compatible manner

Flowering strips in celery production: Tanimura & Antle

Growers, California

National Organic ProgramPest 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

National Organic Programhttp://www.ams.usda.gov/nop

One way to think about transitioning from conventional to

organic IPMLow Level IPMScouting, use of thresholds, timed pesticide applications

Medium Level IPM (multi-tactic approaches)Begin to manipulate habitat, augment biodiversity, crop rotations, resistant varieties

Biointensive IPM • Advance planning to avoid/prevent pests• Emphasis on:

• Habitat to maintain natural enemies year-round• Cultural practices to make crops less suitable for pests

Three Levels of Pest ManagementLevel A (Cultural Practices and Habitat Diversity)The first line of defense in managing weed, insect, and disease pests is a systems-based approach. It is based on the fact that a well-designed and healthy organic system will naturally have fewer pest problems. The system is designed to prevent pest and disease outbreaks.

Level B (Mechanical and physical methods, release of biological control agents)The second line of defense is utilized if the practices of level A are not sufficient to control the weed, insect, or disease problem. Level B generally includes mechanical and physical practices that are traditional in organics, as well as the use of nonsynthetic or natural materials.

Level C (OMRI approved pesticides as a last resort)The third line of defense is used if the level of pest control required is not achieved after A and B control options are applied. Level C practices include the use of inputs such as biologicals and botanicals to control pests.

From: P. Coleman. 2012. Guide for organic crop producers. NCAT.www. attra.ncat.org

Organic Pest Management PlanGeneral Preventative vs. Targeted Practices

• General Preventative Practices– Start with general

preventative practices that can be incorporated as part of the farm plan• Once in place, they will

help to prevent pests from becoming a problem

• Targeted Practices– Maintain a ‘toolbox’ of

more directed or targeted practices for specific pest problems• These can be used if

needed…– Based on knowledge of

key pests that could occur on specific crops, and on pest biology and behavior

FOUNDATION

Some General Preventative Practices(often have multiple functions)

Rolled cover crop before no-till planting of peppers at the Clemson SOF

Cover Cropping/Conservation Tillage

• Multiple functions– Soil quality and fertility

• Organic matter, plant available nutrients.

– Pest Management• Healthy soil = healthy plants

better able to tolerate pests.• Enhances diversity of soil

microbes and arthropods.– Pest and disease

suppression• Flowering cover crops

attract natural enemies.• Weed control.

Melon-Virus ExperimentsCover crop makes plants less attractive to aphids and reduced incidence of watermelon mosaic virus (WMV)

• Annual rye planted between rows in late fall

• Virus incidence lower in cover crop treatments

• Reflective mulch also reduced virus incidence

2003 20040

50

100

CoverNo Cover

% Plants Infected with WMV

Soil Quality ManagementDoes it affect above-ground pest damage?

Research on European Corn BorerLarry Phelan, Ohio State University

• Compared egg-laying on plants grown in soil from organic vs conventional farms

• Significantly more ECB eggs laid on plants in conventional soil

• Mineral Balance Hypothesis: – Organic, microbe-rich soils

release plant nutrients more evenly over time

– More even plant growth rate; less suitable for insect pest development

Microbial Inoculants• Products are proprietary

– Beneficial bacteria, fungi, strain mixtures

• Applied to seedlings in greenhouse and at transplanting in the field

• Benefits – Plant growth promotion – Yield increase– May stimulate plant

defense against disease– Not a silver bullet control

Plant growth-promoting rhizobacteria (PGPR): Experiments with cucumber beetle and bacterial wilt of cucurbits

Rotation with Biofumigation Crops

• Brassica “break crops” (mustards, rape, etc.)– Breaks pest/disease

lifecycle• Direct effects: biocidal toxicity

– Glucosinolates converted to isothiocyanates

– Toxic to pathogens, weed seeds, soil insects

• Indirect effects: – Changes in soil microbial

community

Adding Plant Diversity (Farmscaping)

• Provides food and shelter for natural enemies (predators and parasites) and pollinators– Favorable microclimate– Supply of nectar and pollen– Habitat– Alternative hosts or prey– Research

• Level of bio-control related to seasonal availability of insectary plants and proximity to crops

• Establish habitat on at least 1-5% of production area

www.xerces.org

Other Important Cultural Practices

• Crop rotation• Inter-cropping (mixed

plantings)• Sanitation• Fertility and water

management

Resources listed in the Appendix

More Targeted Practices

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, microbial inoculants

Disease Resistant Varieties

Cornell Vegetable MD Online: http://vegetablemdonline.ppath.cornell.edu/

Vegetable Grafting

www.vegetablegrafting.org

Research, list-serve, training calendar, rootstock lists

Using Knowledge of Insect Behavior

Pickleworm

• Overwinter in Florida

• Don’t arrive in SC until early July

Plant early before moths arrive

Diamondback Moth

• Yellow rocket highly attractive to moths for oviposition, but larvae don’t survive

Use yellow rocket as a trap crop

Colorado PB

• Adults OW in soil• Emerge in spring

when temps are cool

• Find host plants by walking

Mulch interferes with host location

Pest Monitoring/Sampling Plan

• Monitoring Crops– frequency– procedure– pest ID– recordkeeping– action thresholds

• Have approved materials on hand if needed

Use of Approved Pesticides

• Only if other strategies fail– “Input Substitution” not

allowed• Degrade quickly; low

potency; short residual activity

ON THE TROT: Stuart, a 22-year-old former trotter, tows the organic sprayer between the vines at

Seresin winery in New Zealand

Specialized Application

Dropleg application of Bt for control of caterpillars in leek.

Air-assist backpack sprayer

Chelsi Crawford

Shawn Jadrnicek Kelly Gilkerson

Amy Nichols

Pest Management at the Clemson Student Organic Farm

Student Organic FarmStandard Operating Procedures (SOPs)

PESTICIDES

Bt (Dipel, Javelin etc.): Used to control caterpillar damage mainly on Brassica’s but also on summer squash. Apply when butterflies are seen visiting Brassica’s or when white eggs that look like very small grains of rice are found on Brassica leaves or when Brassica leaves are damaged by caterpillars. Apply to summer squash when pickle worms are evident or squash vine borer damage is expected. Re-apply after rain events. Add a squirt of soap as a surfactant. Read and follow label directions before applying.

Copper Hydroxide (Champion): Use on tomatoes if risk of disease is high based on forecasting models ((i.e. TOMCAST, BLIGHTCAST). Use sparingly to prevent copper from building up to toxic levels in the soil. Read and follow label directions before using. Warning: eye irritant.

Daily Farm Log• All farm activities entered

by hand at end of the day– Workers trained to ID

pests/diseases– Pest/disease/weed

conditions are noted daily– Treatment thresholds

based on experience– Pest control actions

including any inputs are recorded

• Log provided during annual organic audit

FarmscapingPonds and Flowering Plants

Successive plantings of cut flowers, sunflower and buckwheatPerennial flowering plants; elderberry, blackberry, J. artichoke, etc

Flea Beetles• Early season

Brassicas– Surround™ before

transplanting in field

May use Pyganic™ for insects on

outside transplants

Ratooning Eggplant

• Mow first planting at 8-10” height

• Surround™ + Pyganic™ if needed to control flea beetles in late summer

• Plants produce fruit 5-6 weeks after mowing

Fruit damage from flea beetle feeding inside flowers

Colorado Potato Beetle

• Hand pick 2-3x per week• Crop rotation; straw mulch• Flame weeding at plant emergence• 1 x Spinosad (Entrust™) if larvae

escape

Planting Windows• Squash (cucurbits)

– Don’t plant late• But, plants grow more

slowly when cool; more susceptible to pests

– Early plantings avoid pickleworm, squash bug and diseases

– At $2/lb you can harvest for a few weeks and terminate crop

Reducing Disease Risk• Vegetable Crops Handbook

– Resistant varieties– Optimal planting date for

vigorous growth

• Crop rotation• Grow lots of storage

vegetables to sell later (winter squash, onions, potatoes, etc)

• Experiment with microbial inoculants

• Grading for drainage– Place drive/walk rows on ridge– Crop rows at 0.5° slope for

drainage– Drainage furrow at end of

rows• Soil can be used to fill

low spots

Yellow Nutsedge• Grows well in wet,

poorly drained soil – Caulk punched holes

in drip tape• Incorporate sweet

potatoes in rotation

Flaming Weeds• Carrots:

– Place clear plastic cover over a section of row

– Flame when carrots emerge under cover

• Stale seed bed; prep beds every 2 weeks– Direct seeded; flame

before plants emerge– Transplants; flame

before transplanting

Cultivating Equipment

Wings reform furrows

Sweeps/tines remove weeds

Spider wheels throw soil against transplants to bury weeds

Organic No-tillDavid Robb (grad student)

Average yield/unit of effort

Weeding and Irrigation– Level (kg/min)– No-till squash A 2.1– Tilled squash B 0.5– Levels not connected by same letter are significantly different.

– Level (kg/min)– No-till tomato A 0.9 – Tilled tomato B 0.1– Levels not connected by same letter are significantly different.

Example: for every minute of maintenance done per row of no-till squash, there was an average yield of 2.1kg.

CROP TOTAL MAINTENANCE (hrs)

TOTAL IRRIGATION

APPLIED (gallons)

NO-TILL SQUASH

2.2 1,150.4

TILLED SQUASH

9.4 1,725.5

NO-TILL TOMATO

2.2 1,604.8

TILLED TOMATO

10.3 2,362.3

Questions?

Articles on Sanitation Methods for Pest Management

University of Florida IFAS: Cultural Controls: Field Sanitation http://ipm.ifas.ufl.edu/pdfs/Field_Sanitation.pdf

Michigan State University: Sanitation is critical to prevent diseases Part 2: field sanitation

http://msue.anr.msu.edu/news/sanitation_is_critical_to_prevent_plant_diseases_part_2_field_sanitation

Purdue University: Managing Pests in Home Fruit Plantingshttps://www.extension.purdue.edu/extmedia/id/id-146-w.pdf

University of Kentucky: Fruit, Orchard and Vineyard Sanitation Fact Sheet http://articles.extension.org/pages/70066/fruit-orchard-and-vineyard-sanitation-fact-sheet

APPENDIX

Articles on Crop Rotation

SARE: Crop Rotation on Organic Farms (case histories from NE farms but also applicable to other regions)http://www.sare.org/Learning-Center/Books/Crop-Rotation-on-Organic-Farms SARE: Managing Plant Diseases with Crop Rotationhttp://www.sare.org/Learning-Center/Books/Crop-Rotation-on-Organic-Farms/Text-Version/Physical-and-Biological-Processes-In-Crop-Production/Managing-Plant-Diseases-With-Crop-Rotation#Table3.5 SARE: Management of Insect Pests with Crop Rotationhttp://www.sare.org/Learning-Center/Books/Crop-Rotation-on-Organic-Farms/Text-Version/Physical-and-Biological-Processes-In-Crop-Production/Management-of-Insect-Pests-with-Crop-Rotation-and-Field-Layout Center for Environmental Farming Systems: Crop Rotations on Organic Farmshttp://www.cefs.ncsu.edu/%5C/resources/organicproductionguide/croprotationsfinaljan09.pdf

APPENDIX

Articles on Over-fertilization and Insect Pests

SARE: Impact of Fertilizers on Insect Pestshttp://www.sare.org/Learning-Center/Books/Manage-Insects-on-Your-Farm/Text-Version/Managing-Soils-to-Minimize-Crop-Pests/Impacts-of-Fertilizers-on-Insect-Pests M. Altieri: Soil Fertility Management and Insect Pestshttp://www.agroeco.org/doc/soil-pestmgmt.pdf California Agriculture: Excess N raises nectarine susceptibility to disease and insect pestshttp://ucanr.edu/repositoryfiles/ca4904p13-69972.pdf

APPENDIX