LESSON NINE: INTEGRATED PEST

MANAGEMENT

High TunnelFruit and Vegetable Production

Objectives

Identify the components of integrated pest management.

Recall the importance of integrated pest management to growers and the environment.

Discuss a variety of control tactics available to manage insects, diseases and other pests.

High Tunnel and Insects

High tunnels create a unique environment May lead to different insect and disease pests

than greenhouse or field production

Even with these differences, the generalities of Integrated Pest Management apply

Integrated Pest Management

Commonly known as IPMCommon-sense, holistic approachUses knowledge of plants, pests, and the

environment sensibly to reduce number of pests. Reducing pests before unacceptable damage is

doneUses a combination of control tactics

Prevention Monitoring Control Techniques

Prevention

Use knowledge of past and potential pests to avoid future problems

Prevention Activities: Choose resistant and adapted species when

available Plant according to best management practices Plant disease- and pest-free transplants and seeds Use sanitation practices Irrigate and use mulch to minimize plant stress Fertilize according to need

Monitoring

Inspection, detection and scouting Find pests and diseases earlyUse of trapping devices and visual inspectionProvides information to aid in pest control

decision-making processInspect plants in high tunnel at least twice a

week Count pests

Specific locations and specific plant parts Take good notes and observations

Pest, crop, number found and stage of insect growth

Control Techniques

Four different types of control techniques Cultural (Prevention Techniques) Biological Mechanical (or Physical) Chemical

The four management tactics can be used alone or in combination Ultimate goal is to reduce or prevent pest

injury

Control Techniques: Cultural

Horticultural practices that limit pest populations or reduce the amount of damage that pests might cause

Essentially the same as prevention measures Control techniques include:

Maintaining plant health Making proper plant selections Choosing resistant varieties Using crop rotation Other practices that maintain healthy, vigorous

plants

Control Techniques: Biological

Also known as bio-controlUses living organisms to suppress or limit

pest populations Keeps populations down, does not eliminate

pests Low level of injury expected Acceptability depends on tolerance level

Use of “natural enemies” Organisms that attack pests Three categories: Predators, Parasitoids,

Pathogens

Control Techniques: Biological

Two main ways to use biological controls Augmentation

Release of specific beneficial organisms for control of existing pest population

Conservation Conserves natural enemies that are already present Reduce use of broad-spectrum pesticides

Pathogens Microorganisms: Bacteria, Fungi, Viruses,

Nematodes Weaken and kill pests by creating disease or

infection

Control Techniques: Mechanical/Physical

This control method separates the pest from the crop by means of a device or action

Actions: Handpicking pests directly from plants Forceful water sprays to dislodge aphids Pruning to remove diseased or infested plant

material Install insect screening over vents and side walls

Excludes larger insects

Control Techniques: Mechanical/Physical

Screening reduces airflow, increases temperatures Often overlooked when growers are unaware May reduce airflow by 5-10% with active

ventilation May result in 45% ‘wind reduction’ in passively

ventilated tunnels – raised air temperature of ~5°F

Increase in temperatures could be partially offset by using peak vents or exhaust fans

Control Techniques: Mechanical/Physical

Screening Standard window screening is an economical choice

Must be cleaned occasionally Does not completely restrict influx of pests, reduces Needed pollinators must be introduced and maintained Biological controls that are naturally occurring outside

the tunnel will be restricted from entering

Not all mechanical controls are effective Ultrasonic and electromagnetic devices Bug zappers Insect traps (yellow sticky cards)

Control Techniques: Chemical

Use of pesticides, naturally occurring or synthetic Adversely affect unwanted insects, weeds or plant

pathogens Affect plant growth Repel insects from an area

Judicious use in combination with other tactics Or, if other tactics do not give desired level of control Thoughtfully chosen and properly timed application Least toxic alternatives Consider use of “soft” or “reduced risk” compounds Consider environmental consequences

Importance to Growers

IPM practices must be compatible with objectives

Practices must be: Economically viable Effective Understandable Practices can be implemented in stages

Importance to Growers

Approach should improve grower’s profitability and reduce risk of crop loss Monitoring used to determine economical

timing

Provides greater peace of mind High tunnel production is large investment Proper field scouting for informed decisions

Importance to Environment

All practices must be environmentally sound

Benefits received from control vs. risks of that control should be considered before practice is developed

Reduces unnecessary pesticide applications Pesticides are generally largest environmental

concern with pest management Fewer unwarranted pesticide applications such

as “calendar sprays”

High Tunnel Insect Control

Major insect and mite pests of high tunnel crops should be given consideration

Avoid having lights on in evening or night near or inside the high tunnel Security lights or lights for convenience Lights attract a range of insects, particularly

moths These insects may inadvertently cause crop

damage

High Tunnel Insect Control

Hornworms/Other Caterpillars of Tomato & Peppers Damage usually occurs from midsummer to fall

Eat irregular holes in leaves and may defoliate plants

Camouflaged – often difficult to seeFruitworms

Feed on green fruit Damage is deep watery cavities on stem end of fruit

Inspect tomato plants for larvae on fruit and leaves Threshold in high tunnel is one caterpillar

Can be handpicked or use insecticide sprays

High Tunnel Insect Control

Whiteflies Tiny, resemble tiny white moths Disperse from plants when disturbed Most common on tomatoes and melons in late

season Damage done when in immature (nymph) stage

Suck sap from plant leaves Spread viral diseases

Inspect plants for off-color or stunted plants Yellow sticky cards will monitor adults Spray with insecticide/insecticidal soap

High Tunnel Insect Control

Aphids Migrate into high tunnel from wild hosts Establish colonies on plants Soft-bodied, pear shaped small insects

Usually on underside of leaves, may be found on stems

Suck sap from plants Leaves curl under, become deformed, weakens plants Can be vectors of plant diseases

Scout plants closest to openings Wide range of control options

High Tunnel Insect Control

Spider Mites Tiny (~.5mm long), live on undersides of plant

leaves Puncture plant cells to feed on the sap

Speckled “bronzing” discoloration of leaves Reduced plant growth Possible early defoliation and death

Thrive in hot, dry weather and are more likely from mid season through fall

High Tunnel Insect Control

Spider Mites (Continued) Inspect leaf undersides for egg webs, cast skins

and all stages Control weeds and practice clean mowing

around tunnel to help prevent movement from outdoors

Begin treatment when symptoms appear Insecticidal soap or other miticide Miticides do not kill eggs so repeat

application should be considered

High Tunnel Insect Control

Thrips Small (1/16 inch long) and elongated Found in flowers or on the undersides of leaves Damage to plants is caused by adults and

nymphs Scrape the surface of leaves with mouthparts

and feed on exuding sap Leaves will have small, silver streaks Plants look as though they have

been sandblasted

High Tunnel Insect Control

Thrips (Continued) Early detection is important Frequently inspect blossoms and leaf

undersides Sticky traps can detect adult winged thrips Apply systemic, targeted insecticides at

transplanting Effective in controlling for ~35 days on certain

crops For control, spray contact

insecticides

High Tunnel Insect Control

Cucumber Beetles Same beetles that that will attack

field-grown cucurbits Transmit bacterial wilt Can damage high tunnel melons

Overwintered adults feeding on transplant leaves and stems can kill small plants Surviving plants may be infected with bacterial wilt

Frequently feed on the fruit surface Reduces aesthetic appeal Creates openings for sap beetles and disease

organisms

High Tunnel Insect Control

Cucumber Beetles (Continued) Can be excluded from transplants by

using row covers in the high tunnel Systemic insecticides applied at transplanting

will provide up to 35 days of control Long enough to reduce bacterial wilt and

infection Foliar insecticides provide further control

through growing season Avoid insecticides that may be toxic to pollinating

insects No effective biological control techniques

High Tunnel Plant Disease Control

High tunnels can reduce disease impact by: Elevating soil temperatures slightly

Enough to prevent common cool weather damping-off and root rots

Keeping foliage dry Preventing establishment of most foliar diseases

Powdery Mildew can germinate Absence of free water Can be even more serious than in a field-grown

crop

High Tunnel Plant Disease Control

Disease management should include the following considerations: Use plastic mulch combined with trickle

irrigation Keeps foliage dry, reduce splash of soil-borne

pathogens Maintain humidity to remove excess moisture

Provides conditions conducive to certain diseases Use ventilation and follow plant-spacing

guidelines Use disease-resistant varieties when possible

Always start with disease-free seed and transplants

High Tunnel Plant Disease Control

Disease management should include the following considerations: Provide optimal growing conditions

Proper irrigation, fertilization, staking, pruning, etc. Increase plant health and vigor

Practice sanitation to remove and destroy infected plants as they are found Pick produce frequently, cleanly and completely Remove all over-ripe and damaged produce Remove all plant residues at the end of the season

Practice crop rotation

High Tunnel Plant Disease Control

Powdery Mildew Major problem for all high tunnel crops Environmental conditions in tunnel favor

development Produces white, powdery colonies

On leaves, petioles, and stems of infected plants Usually appears on lower leaves

Gradually spreads through the canopy Plants become weakened from leaf loss

Fruit size can be significantly reduced

High Tunnel Plant Disease Control

Powdery Mildew (Continued) Choose resistant cultivars when possible Inspect plants regularly, starting at fruit set Many effective fungicides are labeled for

control Includes several synthetic fungicides and organic

products, such as mineral oils & potassium bicarbonate

Alternate synthetic fungicides to prevent the development of resistance