Light and Temperature Interaction Fall Leaf Color cool temps - very bright days

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    27-Mar-2015

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<ul><li>Slide 1</li></ul> <p> Slide 2 Light and Temperature Interaction Slide 3 Fall Leaf Color cool temps - very bright days Slide 4 Orange yellow, reds, purples and browns chlorophyll cells die as temperatures get cooler Slide 5 Yellow carotenoids after chlorophyll dies you see the other pigments that are always present Slide 6 Red-Purple anthocyanins not always present synthesized in cooler temps made from sugar molecules Slide 7 Brown tanins mask or show up more once chlorophyll dies produced in the leaves Slide 8 Leaf Fall need an abscission layer leaf can no longer translocate carbohydrates out of the leaf Slide 9 Bright Days lots of carbohydrates in the leaf anthocyanins get brighter color Slide 10 The Key cool, short days Slide 11 Greenhouse Effect short, high energy wave lengths of light from sun enters house absorbed by structures and plants Slide 12 plants re-radiate green light in longer waves long waves do not have as much energy as the short waves Slide 13 longer waves do not have enough energy to escape from the house result is heat Slide 14 this is how the earth is heated long waves cannot escape through the clouds cloudy nights are warmer Slide 15 Light energy - electromagnetic radiation wavelengths - distance from peak to peak measured in nanometers NM Slide 16 Far Red color plants use Slide 17 Infra Red heat energy Slide 18 Visible light light quality - color quantity - intensity, how bright duration - photoperiod Slide 19 Quality blue - 400-510 NM cell elongation photosynthesis - chlorophyll absorbs red and blue light Slide 20 phototropism - plant tends to grow or bend toward a light source Slide 21 Red photosynthesis stimulates branching encourage growth of axillary buds Slide 22 phytochrome - light absorbing pigment seed germination in photoblastic seeds Slide 23 flowering responses photoperiod Slide 24 Far Red Slide 25 Far red promotes stem elongation Slide 26 Yellow - Green does not effect plants Slide 27 Intensity measured in foot candles amount per unit area on plant Slide 28 Plants shade loving too much sun - leaf burn dehydrate kill chlorophyll Slide 29 sun loving low light, pale color new leaves are small lack vigor Slide 30 dont flower properly if at all Slide 31 Light Light Compensation Point - LCP light intensity where rate of photosynthesis = the rate of respiration Slide 32 LCP Lowest intensity you can grow a plat at If a plant is grown below this level, respiration will be greater than photosynthesis Slide 33 plant will die for a plant to grow photosynthesis must be greater than respiration Slide 34 Acclimitization preparing plant for lower light intensity conditions expose to lower light intensity Slide 35 Artificial Lights Incandescent far red, red - elongation low blue 80% of emitted radiation is heat Slide 36 Incandescent 20% visible light 12% utilized by plant Slide 37 Flourescent red, blue 36% heat energy 22% light used by plant spectral flexibility Slide 38 can change the quality of the light by changing the coating on inside of bulbs Cool White - Ca Halophosphate Slide 39 Gro-Lux coated with Mg Fluorogerminate not as long life as cool white, 30X more expensive Slide 40 Metal Halide increase light intensity Slide 41 Low Pressure Sodium yellow glow energy efficient yellow - orange light Slide 42 High Pressure Sodium red, blue light energy efficient Slide 43 Photoperiod length or duration of the light period biological measurement of relative length of light and dark periods Slide 44 effects flowering leaf abscision dormancy - acclimate for winter Slide 45 Effects.. Sex expression runner formation tuber formation bulb formation Slide 46 Short Day Plants flower when day length is shorter the dark period is critical its dark longer than it is light Slide 47 Short Day Plants examples Chrysanthemum Christmas Cactus Poinsettia Slide 48 Long Day Plants flower when days are long and nights are short example: lettuce, radish, petunias Slide 49 Facilitative Long Day flower any period if long day - flowering is enhanced examples - tomato, begonia Slide 50 Day Neutral flower under long or short day lengths example: African Violet Slide 51 Poinsettias use night interrupted lighting turn on artificial lights from 10 p.m. to 2 a.m. splits up the dark period Slide 52 cyclic lighting from 10 p.m. to 2 a.m. lights on for 6 minutes and off for 24 minutes </p>