1. 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

2. Potential Problems (Click to view)
Cultural Disorders
Germination Problems
Fertilization Problems
Uneven growth
Tall and spindly growth
Diseases
Seedlings falling over
Lower leaves brown, rotting, and drying
Insects
Plants missing
Holes in leaves or plant parts missing

3. Cultural Disorders
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)

4. Cultural-Germination Problems
Causes
Improper temperatures
Over-watering or underwatering
Chemical residues in medium
Seed planting depth
Low quality seeds

5. Cultural-Germination Problems
Correction or Prevention
Use high-quality seeds
Plant at proper depth
Use medium with no chemical residues
Maintain proper temperatures
Maintain proper moisture levels

6. Cultural-Fertilization Problems
Causes
Lack of nutrients
Root injury
Improper pH of medium
Excessive fertilization
Manganese Deficiency

7. Cultural-Fertilization Problems
Correction or Prevention
Test soil or media
Apply correct amounts and kinds of nutrients
Use pH correcting materials

8. Cultural-Uneven Growth
Causes
Poor mixing of medium
Uneven moisture levels
Unlevel flats
Poor grading of seedlings

9. Cultural-Uneven Growth
Correction or Prevention
Proper mixing of media
Even watering
Grading seedlings by size and quality
Placing flats level

10. Cultural-Tall and Spindly Growth
Causes
Too much nitrogen fertilizer
Overwatering
Low light intensity (too much shade)
High temperatures

11. Cultural-Tall and Spindly Growth
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

12. Cultural-Slime or Algae
Causes
Too much watering

13. Cultural-Slime or Algae
Correction or Prevention
Water less often
Clean out fertilizer tanks
Don’t leave any standing water

14. Diseases
Help me! I’m dying.

15. Disease
An abnormal condition of an organism that impairs plant functions

16. Disease
Disease is a plant disorder caused by an infectious pathogen or agent

17. Three Conditions Necessary for Diseases
Host plant
Disease causing organism or pathogen must be present
Favorable environment for disease organism to develop

18. Groups of pathogens Bacteria Fungi Viruses
Parasitic plants- mistletoe, dodder, lichens (attach to plants)

19. Plant Disease Must be identified before they can be treated
Warm temperatures and moist conditions in greenhouse plant production make most horticulture plant diseases worse

20. Disease
Preventing plant disease through sanitation and insect control is much easier than treating the disease.

21. Diseases Blight Canker sores Damping off Galls Leaf spot Mildew Mosaic
Rots
Rust
Smut
Wilt

22. Diseases-Seedlings Falling Over
Causes
Stem rot
Damping-off

23. Diseases-Seedlings Falling Over
Correction or Prevention
Use sterilized media
Apply fungicides
Improve air circulation around plants

24. Diseases-Brown, rotting leaves
Causes
Botrytis
a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes

25. Diseases-Brown, rotting leaves
Correction or Prevention
Increase air temperature
Increase air circulation around plants
Use proper fungicide

26. Damping off Fungal disease
Causes young plants and seedling to rot off at soil level

27. Mildew Grows on leaf surfaces Upper and lower leaves
Appears as white, gray or purple spots
Example is powdery mildew

28. Mosaic Caused by a virus
Leaves have irregular mottled areas with patterns
Ranges from dark green to light green to yellow to white

29. Rots
Causes plants to decay and die
Usually has a unique smell

30. Rust Causes small spots on leaves
Resembles yellow, orange, brown or red rust
Mainly on underneath of leaf

31. Insects
An arthropod with three pairs of legs and three body regions; insects may have one or two pairs of wings

32. Insects-Plants Missing
Causes
Slugs
Snails
Cockroaches

33. Insects-Plants Missing
Correction or Prevention
Use baits and pesticides

34. Insects-Holes in Leaves
Causes
Aphids
Mealy Bugs
Scale Insects
Thrips
Whiteflies
Flea beetles
Fungus Gnats
Leaf miners
Cutworms
Caterpillars

35. Insects-Holes in Leaves
Correction or Prevention
Use of recommended pesticides to control insects

36. You’ll never look at a bug the same.
Insect bad guys!
You’ll never look at a bug the same.

37. Damage
Damage depends on the type of mouthpart
Chewing
Sucking

38. Chewing- Beetles
Eat leaves
Stems
Flowers
Fruits
Nuts

39. Beetles
Correction
Oil or soap

40. Chewing- Caterpillars
Larva
Moths
Butterflies
Fuzzy and hair
Eat young leaves and stems
Roll up in leaves, makes leaves curl

41. Caterpillars
Correction
Tent Caterpillars-kerosene to burn them

42. Sucking- Aphids Pierce and suck juices Plant lice
Cause stunted growth, yellow spotted leaves
Sticky substance and black mold
Attracts ants

43. Aphids
Correction
Apple Cider Vinegar
Oil or Soap
Malathion
Lady bugs

44. Sucking- Mealy Bugs Pierce and suck from underside of leaves
Suck in leaf axils
Causes yellow appearance
Sticky secretions

45. Mealy Bug
Corrections
Oil or soap
Neem

46. Sucking- Thrips Chews and then sucks
Causes plant tissue to become speckled or whitened
Leaf tip withers
Leaf curls and dies

47. Thrips
Correction
Insecticidal Soap

48. Sucking- Whiteflies Feeds on underside of young leaves
Little flying white specks when plants are shaken

49. Whiteflies
Correction
Marathon
Lady bugs

50. Sucking- Mites Attack underside of leaf
Causes leaves to turn gray to grayish
Severe infestations cause webbing
Insects can be red

51. Slugs & Snails
Problems
Plants Missing

52. Slugs & Snails Correction or Prevention Use baits and pesticides Beer
Caffeine (Coffee)