Light and temperature interaction
1 / 51

Light and Temperature Interaction - PowerPoint PPT Presentation

  • Updated On :

Light and Temperature Interaction. Modified by Georgia Agricultural Education Curriculum Office June, 2002. Fall Leaf Color. cool temps - very bright days. Orange. yellow, reds, purples and browns chlorophyll cells die as temperatures get cooler. Yellow. carotenoids

Related searches for Light and Temperature Interaction

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Light and Temperature Interaction' - lyre

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Light and temperature interaction l.jpg

Light and Temperature Interaction

Modified by Georgia Agricultural Education Curriculum Office

June, 2002

Fall leaf color l.jpg
Fall Leaf Color

  • cool temps - very bright days

Orange l.jpg

  • yellow, reds, purples and browns

  • chlorophyll cells die as temperatures get cooler

Yellow l.jpg

  • carotenoids

  • after chlorophyll dies you see the other pigments that are always present

Red purple l.jpg

  • anthocyanins

  • not always present

  • synthesized in cooler temps

  • made from sugar molecules

Brown l.jpg

  • tannins

  • mask or show up more once chlorophyll dies

  • produced in the leaves

Leaf fall l.jpg
Leaf Fall

  • need an abscission layer

  • leaf can no longer translocate carbohydrates out of the leaf

Bright days l.jpg
Bright Days

  • lots of carbohydrates in the leaf

  • anthocyanins get brighter color

The key l.jpg
The Key……

  • cool, short days

Greenhouse effect l.jpg
Greenhouse Effect

  • short, high energy wave lengths of light from sun enters house

  • absorbed by structures and plants

Greenhouse effect11 l.jpg
Greenhouse Effect

  • plants re-radiate green light in longer waves

  • long waves do not have as much energy as the short waves

Greenhouse effect12 l.jpg
Greenhouse Effect

  • longer waves do not have enough energy to escape from the house

  • result is heat

Greenhouse effect13 l.jpg
Greenhouse Effect

  • this is how the earth is heated

  • long waves cannot escape through the clouds

  • cloudy nights are warmer

Light l.jpg

  • energy - electromagnetic radiation

  • wavelengths - distance from peak to peak

  • measured in nanometers “NM”

Far red l.jpg
Far Red

  • color plants use

Infra red l.jpg
Infra Red

  • heat energy

Visible light l.jpg
Visible light

  • light quality - color

  • quantity - intensity, how bright

  • duration - photoperiod

Quality l.jpg

  • blue - 400-510 NM

  • cell elongation

  • photosynthesis - chlorophyll absorbs red and blue light

Quality19 l.jpg

  • phototropism - plant tends to grow or bend toward a light source

Slide20 l.jpg

  • photosynthesis

  • stimulates branching

  • encourage growth of auxiliary buds

Slide21 l.jpg

  • phytochrome - light absorbing pigment

  • seed germination in photoblastic seeds

Slide22 l.jpg

  • flowering responses

  • photoperiod

Far red24 l.jpg
Far red

  • promotes stem elongation

Yellow green l.jpg
Yellow - Green

  • does not effect plants

Intensity l.jpg

  • measured in foot candles

  • amount per unit area on plant

Plants l.jpg

  • shade loving

  • too much sun - leaf burn

  • dehydrate

  • kill chlorophyll

Plants28 l.jpg

  • sun loving

  • low light, pale color

  • new leaves are small

  • lack vigor

Plants29 l.jpg

  • don’t flower properly if at all

Light30 l.jpg

  • Light Compensation Point -”LCP”

  • light intensity where rate of photosynthesis = the rate of respiration

Slide31 l.jpg

  • Lowest intensity you can grow a plat at

  • If a plant is grown below this level, respiration will be greater than photosynthesis

Slide32 l.jpg

  • plant will die

  • for a plant to grow photosynthesis must be greater than respiration

Acclimitization l.jpg

  • preparing plant for lower light intensity conditions

  • expose to lower light intensity

Artificial lights l.jpg
Artificial Lights

  • Incandescent

  • far red, red - elongation

  • low blue

  • 80% of emitted radiation is heat

Incandescent l.jpg

  • 20% visible light

  • 12% utilized by plant

Flourescent l.jpg

  • red, blue

  • 36% heat energy

  • 22% light used by plant

  • spectral flexibility

Flourescent37 l.jpg

  • can change the quality of the light by changing the coating on inside of bulbs

  • Cool White - Ca Halophosphate

Gro lux l.jpg

  • coated with Mg Fluorogerminate

  • not as long life as cool white, 30X more expensive

Metal halide l.jpg
Metal Halide

  • increase light intensity

Low pressure sodium l.jpg
Low Pressure Sodium

  • yellow glow

  • energy efficient

  • yellow - orange light

High pressure sodium l.jpg
High Pressure Sodium

  • red, blue light

  • energy efficient

Photoperiod l.jpg

  • length or duration of the light period

  • biological measurement of relative length of light and dark periods

Photoperiod43 l.jpg

  • effects

  • flowering

  • leaf abscission

  • dormancy - acclimate for winter

Effects l.jpg

  • Sex expression

  • runner formation

  • tuber formation

  • bulb formation

Short day plants l.jpg
Short Day Plants

  • flower when day length is shorter

  • the dark period is critical

  • it’s dark longer than it is light

Short day plants46 l.jpg
Short Day Plants

  • examples

  • Chrysanthemum

  • Christmas Cactus

  • Poinsettia

Long day plants l.jpg
Long Day Plants

  • flower when days are long and nights are short

  • example: lettuce, radish, petunias

Facilitative long day l.jpg
Facilitative Long Day

  • flower any period

  • if long day - flowering is enhanced

  • examples - tomato, begonia

Day neutral l.jpg
Day Neutral

  • flower under long or short day lengths

  • example: African Violet

Poinsettias l.jpg

  • use night interrupted lighting

  • turn on artificial lights from 10 p.m. to 2 a.m.

  • splits up the dark period

Poinsettias51 l.jpg

  • cyclic lighting from 10 p.m. to 2 a.m.

  • lights on for 6 minutes and off for 24 minutes