Plant Growth Requirements

1
Plant Growth Requirements

• Prepared by
• Eric Johannesen
• Iowa-Grant High School.

2
Objectives

• Categorize the 16 essential nutrients needed by
  plants for growth.
• Predict effect of variable levels of the three
  primary elements
• Discuss physical and environmental factors that
  affect plant growth Light, temperature, soil
  conditions
• Discuss methods to manage the factors that affect
  plant growth (spacing, competition, irrigation)
• Discuss the phototropism.

3
Temperature

• Affects many essential plant growth processes
• Higher temperature, increases rate of reaction.
• Photosynthesis is slower at lower temperatures.

4
Temperature

• Photosynthesis increases with temperature until
  it get too hot and then begins to slow again.
• Plant growth functions and rates, such as
  absorption of minerals and water, are determined
  by temperature.
• All plants have an optimal temperature range they
  function the best.

5
Light

• Light effects plants based on its intensity,
  duration, and quality.

6
Light Quality

• Quality
• Normal plant growth requires white light or
  sunlight.
• Chlorophyll absorbs the red and blue portion of
  the light spectrum and appear to be green, since
  the leaf reflects green light.

7
Light Quality
Red and Blue Light waves make purple.
8
Light Quality

• Light quality is therefore important, and must
  contain important wavelengths.
• ROY G BIV
• Red, Orange, Yellow, Green, Blue, Indigo, and
  Violet

9
Light Intensity

• The rate of photosynthesis is effected by the
  availability of water, CO2, and sunlight.
• In the absence of light, plants will grow until
  their food reserves are exhausted.
• The growth will be elongated.
• Phototropism in plants is the tendency to lean
  in the direction of the greatest light intensity.

10
Light Intensity
11
Light Duration

• Photoperiodism
• Growth response to the length of the dark period.
• This effects whether a plant is growing
  vegetative or is in the flowering stage.
• In poinsettias, we force them to bloom.
• Short Day, Long Day, and Day Neutral plants.

12
Light Duration

• Poinsettias require a 12 hour dark period in
  order to bloom.
• Azaleas can be forced to bloom sooner by adding
  light in the greenhouse.
• Dandelions can bloom and initiate flowers at any
  light level.

13
Moisture

• Water carries essential nutrients from the roots
  and acts as a solvent for essential salts and
  minerals.
• Water translocates photosynthetic products from
  the leaves via the phloem
• Water cools the plant

14
Types of water

• Capillary
• Water that moves freely and can be used by plants

15
Types of Water

• Gravitational Water
• Water that is lost to drainage

16
Types of Water

• Hygroscopic Water
• Water that is bonded so tightly to soil particles
  that it is unavailable for plant use.

17
Carbon Dioxide

• CO2 is taken in through the stomata

18
Carbon Dioxide

• Air is usually .03 Carbon Dioxide
• In a greenhouse we can increase these levels to
  around 12 which produces better greenhouse
  roses, carnations, and tomatoes

19
Essential Nutrients

• C HOPKNS Ca Fe Mg B Mn CuZn MoCl
• Primary Nutrients
• N, P, and K (Nitrogen, Phosphorus, and Potassium)
• Secondary Nutrients
• Ca, S, Mg (Calcium, Sulfur, and Magnesium)
• Trace Nutrients
• Mn, Fe, Zn, Cu, Cl, B, and Mo (Manganese, Iron,
  Zinc, Copper, Chlorine, Boron, and Molybdenum)
• Carbon, Hydrogen, and Oxygen