Vegetable IPM Subtitle

Jon Traunfeld- jont@umd.edu

2

Vegetable IPM

What’s going on in our gardens? • Many insecticides and fungicides are no

longer available to home gardeners. • The way you garden and manage pests can

affect my garden. • We need an ecosystem approach that

emphasizes non-chemical strategies for pest management.

IPM philosophy

• IPM is a knowledge-based, wholistic approach to managing pests at an acceptable level.

• Gardens, and landscapes are complex ecosystems; IPM seeks balance between pests and beneficials.

• Emphasizes biological, cultural, and physical methods to prevent and manage problems. Least toxic pesticides may be warranted as a last resort.

IPM: simple steps and common sense “Study”

– “right plant in the right place”; give them what they need.

– know the important pest problems and how to prevent them.

– learn the habits, life-cycle, and weaknesses of key pests.

“Spy” – monitor plants closely for signs and symptoms of

problems. Are symptoms getting worse? – strive for correct diagnosis of problem. “Squish” – take “least toxic” action. – did the action work? Continue to monitor.

Cultural and Environmental Problems • Abiotic = “without life”

• Less than ½ of plant problems are caused by insects, disease, and other critters

•Blossom-end rot (nutritional disorder)

2,4-D herbicide injury Plants burned with

pyrethrum and soap insecticide

Guilt by Association

Brown and Green Stink Bug and Fruit Injury

Emerging Pests: squash beetle

Mexican Bean Beetle- “Skeletonizer”

Knowledge: hornworm lifecycle

Biological Control • Attracting natural, native predators and parasites.

Plant beds of flowering annuals and perennials in these families: – Mint (anise hyssop, thyme – Carrot (dill, yarrow) – Aster (tansy, marigold, zinnia) – Brassica (alyssum, dames rocket, Asian greens)

• Buying and releasing predators and parasites – not generally recommended because they tend to

disperse; effectiveness varies – ok for severe spider mites infestations

Hornworm parasitized by tiny Braconid wasps

Bio-control of aphids

All Hail to the Predators

Lady bird beetles chow down on aphids

Physical control strategies

• Hand-pick pest insects and their egg masses. • Remove badly diseased leaves or plants. • Exclude insects and other pests with a floating

row cover, fence, etc. • Apply a barrier dust or spray- wood ash, lime,

flour, kaolin clay to prevent insect feeding.

Your mission: locate and destroy egg masses

Colorado potato beetle

Squash bug

Floating row cover • Spun-bonded polyester;

gauzy material. Draped over crop, is secured to ground; leave slack to allow crop growth.

• Excludes pests, and increases crop growth in spring and fall by raising temp. and humidity.

• Can be re-used; must be removed before flowering of cross-pollinated crops (cukes, squash, etc.)

Flea Beetles

Eggplant Leaves Coated with Surround

Cultural control strategies • Grow resistant varieties • Clean up and compost plant debris at end

of season • Time your crops to avoid expected pests • Bag up badly infested plants • Plant lots of flowering plants to attract

beneficial insects

Wilted squash- what could be wrong?

Squash vine borer

Squash vine borer

• Very common lethal pest; attacks squashes and pumpkin.

• Pupae over-winter below soil; moths emerge in spring and inconspicuous eggs are laid singly on stems.

• Cream colored larva with brown head; 1 inch long when mature.

• 1-2 generations/year.

Organic management: before signs of injury

• Set out 3-4 week old transplants after danger of frost to get a jump on this pest.

• Cover plants with floating row cover until flowering to prevent egg-laying.

• Dust lower stems with rotenone or pyrethrum or wrap them with aluminum foil.

• Till soil at season’s end to kill/expose svb cocoons. • Butternut and cushaw are resistant; yellow

crookneck less susceptible than zucchini.

Organic management: after signs of injury

• Locate active borers by slitting the vine vertically where frass is kicked out. Kill borer. Mound soil over the wound or wrap with duct tape.

• Seal up infested vines in plastic bag before larvae pupate (break life cycle.)

Early blight (fungal disease)- tomato

Advanced symptoms of early blight

Early blight- Alternaria solani • Principal foliar disease of tomato; also attacks

potato, eggplant. • Splashes up to lower leaves and progresses up

plant; often appears with another disease- Septoria leaf spot.

• First symptom is irregular brown lesions with bulls-eye pattern and yellow halo.

• Can spread rapidly with warm, humid weather and defoliate plants.

• Over-winters in crop debris, wooden stakes, and in soil.

Organic management • Cultivars vary somewhat in susceptibility;

but none with good resistance. • Thick organic mulch can slow upward

splashing of fungal spores. • Give plants more space; improved air

circulation. • Remove badly infected lower leaves. • Spray with fixed copper fungicide; other

organic sprays have not proven effective .

Key points to remember…

• It’s easier to prevent a problem than cure one.

• Look under leaves for pest problems. • Insect pests are more vulnerable to

pesticides in their larval stage. • Never spray insecticides during bloom

period.

IPM web resources

• HGIC’s Plant Diagnostic Section- www.plantdiagnostics.umd.edu

• U. of MD’s IPM Web Site- http://extension.umd.edu/ipm

• Cornell’s Plant Disease Diagnostic Clinic-

www.plantclinic.cornell.edu • National Pesticide Information Center (NPIC)- www.npic.orst.edu

Resources • Home and Garden Information Center (HGIC)

– 800-342-2507 – http://extension.umd.edu/hgic

• Grow-It-Eat-It website – http://extension.umd.edu/growit

• Master Gardener state website – http://extension.umd.edu/mg

This program was brought to you by Maryland Master Gardener Program

Howard County University of Maryland Extension