Growing Crops in the Greenhouse

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Growing Crops in the Greenhouse

• What are the general greenhouse practices used in
  the production of ornamental plants?

2
Key Questions

• Why are environmental conditions on greenhouse
  crops important?
• What are the various types of containers used for
  growing greenhouse crops?
• What are the functions of a good growing media
  and the components of soilless media?
• What are the different types of irrigation
  systems used in greenhouse production?
• What is the difference between organic and
  inorganic fertilizers used in greenhouse
  production?
• What are the various methods of applying
  fertilizers to greenhouse crops?
• What are the different methods of pinching
  greenhouse crops?
• How are plant growth regulators used on
  greenhouse crops?
• What are the different practices of greenhouse
  integrated pest management?

3
Why are environmental conditions on greenhouse
crops important?

• Plant height and flowering are 2 commonly
  controlled growth responses controlled by light
• Temperature affects photosynthesis and
  respiration
• Thermotropism- plant growth in response to
  temperature
• Thermoperiodic- plant response to changes in day
  and night temperature

4
Light Intensity

• Allow adequate space for plants
• Clean and maintain greenhouse coverings
• Add artificial light
• Reduce light intensity in summer months as needed

5
Light Duration

• Artificial lights can be used to extend the day
• Light proof covers are used to reduce light
  duration

6
Air

• Contains oxygen and carbon dioxide which are
  essential for respiration and photosynthesis
• Carbon dioxide fertilization uses special burners
  to increase CO2 which increases the rate of
  photosynthesis
• Humidity is water vapor in the air
• Increases in humidity improve the growth rate of
  plants

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What are the various types of containers used to
grow greenhouse crops?

• Rooting containers
• Peat pellets or peat pots- compressed peat moss
• Inorganic plastic or metal pots
• Bedding plant containers
• Most grown in cell packs that fit into 11 x 21
  flats
• 36 or 48 or 72 cells
• Green and Flowering Plant Containers
• Standard pots
• Azalea pots
• Bulb pans
• Hanging Baskets
• Most are plastic 8 x 10 in diameter

8
What are the functions of a good growing media
and the components of soilless media?

• Media influences the cultural practices used
  along with shipping costs and quality of product

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Functions of the growing media

• Moisture-holding capacity and aeration
• Nutrient-holding capacity
• Plant support
• Repoducibility and availability

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Components of Growing Media

• Peat Moss- moisture and nutrients
• Bark- substitution for peat moss
• Sand- increases aeration and drainage
• Perlite- increases aeration and drainage
• Vermiculite- holds nutrients and moisture
• Peat-lite mixes- common formulation of soilless
  media
• Bark-based mixes- commercially prepared bark
  based mixes that are substituted for sphagnum
  moss.

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What are the different types of irrigation
systems used in greenhouse production?

• Hand watering- expensive and boring
• Spaghettti tube irrigation
• Widely used for potted plants.
• Water carried by a ¾ polyethylene tube to each
  pot
• Drip irrigation
• Similar to spaghetti tube irrigation, except tube
  provides a steady drip with little runoff. Used
  with hanging baskets

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• Ebb and flood
• Water is pumped into the system at regular
  intervals, filling benches where containers sit
  in the water
• Capillary mat system
• Form of subirrigation in which pots sit ona moist
  synthetic mat
• Overhead irrigation
• Water is supplied overhead by spray nozzles
  (commonly used for bedding plants

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• Perimeter irrigation
• Used on flowers in beds. PVC pipe is fitted
  around perimeter of the bed with emitters that
  spray over beds
• Soaker hose
• Used in flower beds

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Watering Practices

• Drainage- select growing media with proper
  drainage
• Timing- water prior to plant showing signs of
  deficiency
• Amount- water thoroughly each time they are
  irrigated
• Application- apply to the growing medium and not
  the foliage

15
What is the difference between organic and
inorganic fertilizers used in greenhouse
production?

• Organic fertilizers
• Naturally occurring nutrient materials derived
  from plants or animals
• Inorganic fertilizers
• Synthetic nutrient compounds derived from mineral
  salts

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What are the various methods of applying
fertilizers to greenhouse crops?

• Two methods
• Incorporation
• Used when fertilizers is not subject to leaching
• Topdressing
• Used on long-term crops or weeds
• Fertilizer proportioner
• Used to introduce and meter the concentration of
  soluble liquid fertilizer into an irrigation
  system

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Fertilizer Rates

• Dry formulation is measured by weight instead of
  volume
• Soluble liquid fertilizers are measured and
  applied in parts per million (ppm)

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Monitoring Crop Nutrients

• Visual observations
• What are signs of deficiencies?
• Media Testing
• Foliar analysis

19
What are the different methods of pinching
greenhouse crops?

• Pinching
• Simple form of pruning
• Used to encourage lateral branching
• 3 types
• Roll-out pinch- removal of meristematic tip of
  stem
• Soft pinch- removal of terminal bud and up to ½
  of stem
• Hard pinch- removal of terminal bud and more than
  ½ of stem

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Why are plant growth regulators used on
greenhouse crops?

• Common chemical growth regulators
• Auxin- promotes rooting of cuttings
• Gibberellic acid- increases flowering on azalea,
  geranium, and cyclamens
• Ethephon- initiates flowering
• Height retardant- shortens stem internodes
• Chemical pinching agent- promotes branching

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What are the different practices of greenhouse
integrated pest management?

• Pest entry prevention
• Check all plants entering the greenhouse for
  pests
• 2. Weed control
• Kill weeds inside/outside the greenhouse
• 3. Sanitation practices
• Pasteurize growing media and disinfect benches,
  tools, and containers

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• 4. Crop inspection
• Scout crop regularly for pests
• 5. Environmental manipulation
• Adjust environment to discourage pest development
• 6. Pest eradication
• Identify pest and employ biological control
  measures or use pesticide