Download Potential Bedding Plant Problems

The Who and What of
Greenhouse Problems!
Objective 11.00
11.01: Explain potential problems related to bedding plant
production
11.02: Hypothesize causes of problems with bedding plants
11.03: Propose possible solutions to problems with greenhouse
plant production
Potential Problems (Click to view)
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Cultural Disorders
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Diseases
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Germination Problems
Fertilization Problems
Uneven growth
Tall and spindly growth
Seedlings falling over
Lower leaves brown, rotting, and drying
Insects
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Plants missing
Holes in leaves or plant parts missing
Cultural Disorders
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A cultural disorder is anything that can
cause a plant a problem but is not
caused by a type of pest (disease, weed,
or insect)
Cultural-Germination Problems
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Causes
Improper temperatures
 Over-watering or underwatering
 Chemical residues in medium
 Seed planting depth
 Low quality seeds
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Cultural-Germination Problems
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Correction or Prevention
Use high-quality seeds
 Plant at proper depth
 Use medium with no chemical residues
 Maintain proper temperatures
 Maintain proper moisture levels
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Cultural-Fertilization Problems
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Causes
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Lack of nutrients
Root injury
Improper pH of
medium
Excessive
fertilization
Manganese Deficiency
Cultural-Fertilization Problems

Correction or Prevention
Test soil or media
 Apply correct amounts and kinds of
nutrients
 Use pH correcting materials
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Cultural-Uneven Growth
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Causes
Poor mixing of medium
 Uneven moisture levels
 Unlevel flats
 Poor grading of seedlings
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Cultural-Uneven Growth
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Correction or Prevention
Proper mixing of media
 Even watering
 Grading seedlings by size and quality
 Placing flats level
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Cultural-Tall and Spindly Growth
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Causes
Too much nitrogen fertilizer
 Overwatering
 Low light intensity (too much shade)
 High temperatures
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Cultural-Tall and Spindly Growth
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Correction or Prevention
Use the correct amount of nitrogen
 Reduce frequency of watering
 Lower temperature
 Provide more light
 Use growth retardant such as B-Nine SP
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Cultural-Slime or Algae
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Causes
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Too much watering
Cultural-Slime or Algae
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Correction or Prevention
Water less often
 Clean out fertilizer tanks
 Don’t leave any standing water
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Diseases
Help me! I’m dying.
Disease
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An abnormal condition of an organism
that impairs plant functions
Disease
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Disease is a plant disorder caused by an
infectious pathogen or agent
Three Conditions Necessary for
Diseases
Host plant
 Disease causing organism or pathogen
must be present
 Favorable environment for disease
organism to develop
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Groups of pathogens
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Bacteria
 Fungi
 Viruses
 Parasitic plantsmistletoe, dodder,
lichens (attach to
plants)
Plant Disease
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Must be identified
before they can be
treated
 Warm temperatures
and moist conditions
in greenhouse plant
production make
most horticulture
plant diseases worse
Disease

Preventing plant
disease through
sanitation and insect
control is much
easier than treating
the disease.
Diseases
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Blight
Canker sores
Damping off
Galls
Leaf spot
Mildew
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Mosaic
Rots
Rust
Smut
Wilt
Diseases-Seedlings Falling Over
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Causes
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Stem rot
Damping-off
Diseases-Seedlings Falling Over
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Correction or Prevention
Use sterilized media
 Apply fungicides
 Improve air circulation around plants
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Diseases-Brown, rotting leaves
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Causes
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Botrytis
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a necrotrophic fungus
that affects many plant
species, although its
most notable hosts
may be wine grapes
Diseases-Brown, rotting leaves
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Correction or Prevention
Increase air temperature
 Increase air circulation around plants
 Use proper fungicide
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Damping off
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Fungal disease
 Causes young plants
and seedling to rot
off at soil level
Mildew
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Grows on leaf
surfaces
 Upper and lower
leaves
 Appears as white,
gray or purple spots
 Example is powdery
mildew
Mosaic
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Caused by a virus
 Leaves have
irregular mottled
areas with patterns
 Ranges from dark
green to light green
to yellow to white
Rots
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Causes plants to
decay and die
 Usually has a unique
smell
Rust
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Causes small spots
on leaves
 Resembles yellow,
orange, brown or red
rust
 Mainly on
underneath of leaf
Insects

An arthropod with three pairs of legs and
three body regions; insects may have
one or two pairs of wings
Insects-Plants Missing
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Causes
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Slugs
Snails
Cockroaches
Insects-Plants Missing
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Correction or
Prevention
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Use baits and
pesticides
Insects-Holes in Leaves
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Causes
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Aphids
Mealy Bugs
Scale Insects
Thrips
Whiteflies
Flea beetles
Fungus Gnats
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Leaf miners
Cutworms
Caterpillars
Insects-Holes in Leaves
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Correction or
Prevention
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Use of
recommended
pesticides to control
insects
Insect bad guys!
You’ll never look at a bug the
same.
Damage
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Damage depends on
the type of
mouthpart
 Chewing
 Sucking
Chewing- Beetles
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Eat leaves
Stems
Flowers
Fruits
Nuts
Beetles
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Correction
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Oil or soap
Chewing- Caterpillars
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Larva
Moths
Butterflies
Fuzzy and hair
Eat young leaves
and stems
Roll up in leaves,
makes leaves curl
Caterpillars
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Correction
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Tent Caterpillars-kerosene to burn them
Sucking- Aphids
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Pierce and suck
juices
Plant lice
Cause stunted
growth, yellow
spotted leaves
Sticky substance
and black mold
Attracts ants
Aphids
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Correction
Apple Cider Vinegar
 Oil or Soap
 Malathion
 Lady bugs
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Sucking- Mealy Bugs
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Pierce and suck from
underside of leaves
 Suck in leaf axils
 Causes yellow
appearance
 Sticky secretions
Mealy Bug
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Corrections
Oil or soap
 Neem
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Sucking- Thrips
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Chews and then
sucks
 Causes plant tissue
to become speckled
or whitened
 Leaf tip withers
 Leaf curls and dies
Thrips
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Correction
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Insecticidal Soap
Sucking- Whiteflies
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Feeds on underside
of young leaves
 Little flying white
specks when plants
are shaken
Whiteflies
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Correction
Marathon
 Lady bugs
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Sucking- Mites
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Attack underside of
leaf
 Causes leaves to
turn gray to grayish
 Severe infestations
cause webbing
 Insects can be red
Slugs & Snails
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Problems
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Plants Missing
Slugs & Snails
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Correction or Prevention
Use baits and pesticides
 Beer
 Caffeine (Coffee)
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