Vegetable IPM
Jon Traunfeld- jont@umd.edu
College of
Agriculture and
Natural Resources
PART 1
An overview of Integrated Pest Management
Principles and Practices
Vegetable IPM
• Gardeners want to reduce dependence on
pesticides that pose risks to people, nonhuman animals, and natural resources.
• 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
Abiotic = “without life” Problems
•
• Less than ½ of plant problems are caused by insects,
disease, and other critters
•Blossom-end rot
(nutritional disorder)
“Catfacing”caused by
planting too
early.
2,4-D herbicide injury
Plants burned with
pyrethrum and soap
insecticide
Knowledge: hornworm lifecycle
Mexican Bean Beetle- “Skeletonizer”
Emerging Pests: squash beetle
Biological control
• Give mother nature a chance!
– Predators eat pests
– Parasitoids lay their eggs on or in pests
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
Food for our garden buddies
• Many predators and parasites require nectar
and pollen at some point in their life cycle.
• Plant…
mountain mint, anise
hyssop, thyme,
oregano, basil, dill,
yarrow, aster, zinnia,
alyssum, phlox, bee
balm, milkweeds,
butterfly weed,
borage, lamb’s ear
Natural predators
Hornworm parasitized by tiny Braconid
wasps
Wasps- 220; hornworm- 1
Photo: Rosemary Noble
Bio-control of 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,
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 and 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.)
Row cover – flea beetles = healthy eggplant
Flea Beetles
Eggplant Leaves Coated
with Surround
Surround- kaolin clay
• 2006 research shows flea beetle supression- may be
effective with other pests
• About $1 per lb. Rate: 1 cup/1 qt. water
• Spray when leaves are dry. Apply thoroughly to all
leaf surfaces.
• Maintain white film coating on leaves; may take 2-3
applications. Re-apply if rainfall washes off white
coating.
• Can be used up to the date of harvest.
Cultural control strategies
• Grow resistant varieties
• Clean up and compost plant debris at end
of season
• Time your crops to avoid expected pests
• Prune out injury; bag up badly infested
plants
• Plant lots of flowering plants to attract
beneficial insects
Some effective organic pesticides
• Pyrethrins- controls or suppresses a wide
range of insects (Pyganic- 1.4%)
• Neem extract – suppresses beetles and
caterpillars
• Neem oil- insecticide and preventative
fungicide
• Spinosad- controls beetles, caterpillars, flies,
thrips
• Bacillus thuringiensis- controls young
caterpillars; suppresses large caterpillars
Other good organic pesticides
• Hort oil- controls aphids, mites, soft-bodied
immatures
• Insecticidal soap- suppresses aphids, mites,
soft-bodied immatures
• Copper- fungicide
Spinosad
• Derived from Saccharopolyspora spinosa, a soil
bacterium.
• Causes rapid excitation of nervous system.
• Must be ingested; kills within 2 days
• Effective against caterpillars, beetles, sawflies,
leafhoppers, spider mites; BUT NOT true bugs
• Most beneficials not harmed
• Monterey, Ferti-Lome, and Bonide have home
garden products
PART 2
Some of the Common Insect Pests and Diseases
of Concern
Spider mites love it hot and dry
Spider mites
Spider Mites
• 8 legged, non-insect; active on leaf undersides.
Two-spotted and European red are primary pest
species.
• Sucking mouthparts produce “stipples”; tiny
bleached areas on leaf surface; leaves yellow and
die
• Webbing is a sign of severe infestation
• Wide host range; many vegetable plants
• Thrive in hot, dry weather
• Many quick generations each year
Organic Management
• Mites like it hot, dry, and dusty. Hose off plants to
dislodge and repel mites.
• Horticulural oil and insecticidal soap is most
effective on eggs. May be used if leaves are not
too damaged or hot to tolerate it.
• Excessive nitrogen fertilization increases mites
• Mites will migrate from neighboring weeds, so
keep weeds supressed. Clean up garden residues.
Squash bug
Eggs and immatures
Organic management
• Remove plant debris to eliminate
overwintering sites.
• Hand-pick adults and eggs; trap with wooden
boards.
• Cover plants with floating row cover from
transplant to bloom.
• Plant late (mid-June); plant successive crops.
Squash bug parasitoid
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.)
Imported cabbageworm
Imported cabbageworm
• Pupa overwinter in chrysalis; emerge as
butterflies in spring; strong fliers
• Eggs are rarely noticed
• 2-3 generations; early control is essential
• Host plants are all in cabbage family
Cotesia glomerata- parasitoid
Organic management
• Remove all cabbage family crop residues when
crops are finished
• Floating row cover for planting to harvest
• Hand-pick larvae
• Spray with Bt or Spinosad
Spotted cucumber beetle
Striped cucumber beetle
Bacterial Wilt Disease
bacterial ooze
Organic Management
• Difficult to hand-pick; must be controlled
early in season.
• Exclude with floating row cover.
• Protect plants prior to flowering with
organic insecticides (apply to both sides of
leaves).
• Seal up badly infested plants in plastic bag.
• Plant late; plant multiple crops.
Harlequin bug
Harlequin bug nymphs hatching
from eggs
Organic management
• Once or twice a week- search out and crush eggs,
nymphs, and adults.
• Floating row cover from transplant to harvest.
• Spray nymphs with an pyrethrum + oil/soap or
neem + oil/soap (spray must contact bugs).
• Mustard greens and Chinese cabbage are most
vulnerable crops.
• Remove all crop residues when crops are finished
(if composting- make sure piles reach 140 degrees
F. to kill bugs).
• This can become a major pest if you continually
grow cabbage family crops.
Native stink bugs
Brown stink bug nymph
Green stink bug nymph
Southern green stink bug nymph
Brown and Green Stink Bug and
Fruit Injury
BMSB feeds on many fruits &
vegetables
http://www.agnr.umd.edu/news/article.cfm?id=fd26661f0a5a5a8f00985fc62735924d
Brown marmorated stink bug meats
Godzilla!
Egg mass with 1st and 2nd instar nymphs


Each instar is
one week
2nd instar looks
like tiny spiders
or ticks
Photo by Gary Bernon, USDA_APHIS
2nd to 5th instar
USDA ARS
Common fungal diseases of
tomato leaves…
Septoria leaf spot
Early blight
Advanced symptoms of early
blight
Early blight and Septoria leaf
spot
• Principal foliar diseases of tomato.
• Splashes up to lower leaves and progresses up
plant.
• First symptom of early blight is irregular brown
lesions with bulls-eye pattern and yellow halo.
Septoria spots are small and light in color with
dark margins.
• 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.
Resources
• Grow It! Eat It!
http://www.extension.umd.edu/growit
– We have all types of practical food gardening tips and
information. Check out our popular blog!
• Home and Garden Information Center
http://www.extension.umd.edu/hgic
– Here you will find factsheets, photos, and videos. You
can also subscribe to the free monthly e-newsletter.
– We answer gardening questions 24/7…just click
“Ask Maryland’s Garden Experts”
• Maryland Master Gardener Program
http://www.extension.umd.edu/mg
– Consider becoming a trained MG volunteer!
This program was brought to you by the
Maryland Master Gardener Program
Howard County
University of Maryland Extension