Greenhouse Production Techniques

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Chapter 20

• Greenhouse Production Techniques

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• The production of greenhouse crops can be compare
  to the manufacture of nonplant items in one way
  scheduling is important.
• To grow and sell when the season and market are
  best is an example of why timing is important in
  greenhouse production.
• Timing is everything in the flower production
  business.
• To determine whether or not to
• increase or decrease the number of
• plants produced from year to year
• a grower can look at a record of
• last years sales.

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• Four purposes of root media
• Provide nutrients
• Retain water
• Allow aeration
• Anchor the plant
• Drainage is essential when field soils are used
  in greenhouse crop production.
• Three reasons soil pasteurization may be needed
• Weed seeds
• Pathogens
• insects

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• Pasteurization heating soil for 30 minutes at
  180 degrees F to kill undesirable things in the
  soil.
• Four methods of pasteurizing growing media
• Surface steaming
• Buried pipes
• Closed container steaming
• Chemical fumigants
• Pasteurization only kills harmful things in the
  soil while sterilization kills every thing.

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• Three reasons growers need soil test
• Check pH
• Check for nutrient deficiencies
• Measure soluble salt content
• Two factor to consider when selecting containers
• Crop
• Time of year

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• Containers in greenhouse production
• Pots
• Clay containers
• Plastic containers
• Peat pots
• Molded plastic
• Hanging baskets
• Flats

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• Reproduction methods
• Seed bedding plants and geraniums
• Runners spider plants
• Bulbs tulips, other flowering perennials
• Layering fig and rubber plants
• Cuttings geraniums, and many foliage plants
• Grafting some azaleas
• Budding roses
• Division of the crown foliage plants
• Tissue and organ culturing orchids, bromeliad,
  carnation, and chrysanthemums
• Of the numerous methods of reproduction used by
  greenhouse growers, seeds and cuttings are most
  common.

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• The spacing of a crop is very important. Wide
  spacing is costly due to space, material, and
  labor issues. However, it helps plants to grow
  fuller and thicker, allowing them to sell better.
• Fixed spacing no movement of pots after
  planting.
• Expanding spacing crops started in small pots
  with close spacing, then container size and
  spaces can be increased as crop matures.

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• Four conditions from crowded spacing
• Reduce photosynthesis
• Increase possibility of disease
• Reduce air circulation
• Shaded or overly most foliage
• Labeling identifying the plants on the bench.

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• Watering done correctly become irrigation, the
  maintenance of proper balance of both moisture
  and air in the soil of crops.
• Too much water leaves too little airspace, and
  the root system may rot.
• Too little water can also cause shallow root
  development, soluble salt buildup, and reduced
  plant and blossom size.
• Nature can be blamed for a lot that goes wrong in
  a greenhouse, but not a water excess or
  deficiency.
• The first and most difficult thing a new
  greenhouse worker mist be taught is how to water
  properly.

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• Semiautomatic watering methods
• Spray systems deliver water through nozzles
  spaced at intervals.
• Trickle systems deliver water through holes in
  plastic tubes.
• Ooze tubes plastic tubes rolled between plants
  water seeps through small holes.
• Water loops used for irrigating container
  plants use small rings of plastic placed in
  containers.
• Capillary mat a mat of fibrous material that is
  placed under plants it is periodically flooded
  with nutrients which the plants will absorb.
• Ebb and flood irrigation water floods a bench
  and then recedes into a tank.

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Capillary mat
Trickle system
Flood irrigation
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• Two ways fertilizer can be applied
• Dry fertilizers
• Water-soluble fertilizers/greenhouse watering
  system liquid.
• The greenhouse watering system is the most common
  means of applying liquid fertilizer to crops.

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• Three types of systems used in applying liquid
  fertilizer
• Venturi proportioner draws fertilizer through a
  small tube that connects the water hose to the
  fertilizer concentrate.
• Positive displacement pump maintains a uniform
  proportion of fertilizer to water ratio,
  regardless of the water pressure or rate of flow.
• Eductor places the fertilizer concentrate in a
  pliable bag surrounded by water pressure as the
  pressure increases it forces the fertilizer
  through a metering system and into the water
  line.
• The amount of fertilizer applied per application
  depends on strength of the concentrate, dilution
  ratio of the injector, and the amount of water.

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• Greenhouse fertilizers are measured by the number
  of parts of nutrients to a million parts of
  water, or ppm, part per million.
• PPM is determined by percent of element in
  fertilizer X 75.
• Growth retardants are sometimes needed because
  plants get too tall to make desirable potted
  plants.
• The conditions of high temperature and high
  humidity, coupled with close spacing of a
  monoculture, make pest control necessary in
  greenhouse production.

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• Exclusion prevent pests from becoming
  established in greenhouse.
• Eradication remove or eradicate pests.
• Protection place a barrier between crops and
  pests.
• Resistance selection of a resistant variety of
  plant.
• No spray, dust, or fumigant kill 100 of the pest
  population.

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• Pest control in greenhouses is complicated by two
  factors
• Complex life cycle of many insects and some fungi
  that allows them to be unaffected by many
  chemical pesticides throughout much of their
  lives.
• The rapid development of resistance to particular
  pesticides that characterize some pests,
  especially hosts.
• To avoid the buildup of resistant pest
  populations, a grower must rotate the choice of
  pesticides frequently.

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• Ways greenhouse growers apply chemical
  pesticides
• Systemics remain in the plant and kill the pest
  when it arrives. Applied as a soil drench or as
  foliar sprays.
• Sprays material is mixed with water in a
  hydroulic sprayer and applied to the foliage.
• Dusts covers large areas of crops quickly and
  less expensively than sprays.
• Aerosol bombs material is packaged in a
  container with a propellant liquid or gas.
• Smoke fumigants pesticide is packaged with a
  smoke producing material that disperses the
  pesticide.
• Steam line vaporizers- pesticide is painted onto
  cold steam lines and the steam is turned on.

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contd.

• Foggers the grower mixes the pesticides in an
  oil solvent and fills the fogger which heats and
  disperses the pesticide.
• Misters the pesticide is mixed with a solvent
  that evaporates quickly once out of the mister.

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• The safe application of pesticides in the
  greenhouse or elsewhere requires an understanding
  that
• The health of the plant is more important than
  killing the pest.
• The health of the greenhouse staff and consumer
  are more important than the crops or pests.
• The first rule of safe pesticide use is that
  people are more important than plants or pests.

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• Integrated pest management (IPM) uses methods
  other than just pesticides to protect plants. It
  uses temperature and humidity control, resistant
  varieties, screens and other barriers, monitoring
  devices, predatory insects, and pesticides to
  keep problems down.

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• The region is important when selecting crops to
  grow. Different regions have different
  temperatures and different natural pests. A plant
  may not respond well to pests that it has never
  encountered before, or it may not survive in the
  wrong climate.