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Topic #2172 Foliage Plants Focus on Poinsettias. By: Alisa Kowalski. Major Foliage Crops. 1. Poinsettias 2. Chrysanthemums 3. Easter Lilies 4. Florist Azaleas. Minor Foliage Crops. 1. African Violets 2. Cineraria 3. Cyclamen 4. Holiday Cacti 5. Kalanchoe 6. Gerbera Daisy 7. Gloxinia.
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Topic #2172 Foliage PlantsFocus on Poinsettias By: Alisa Kowalski
Major Foliage Crops 1. Poinsettias 2. Chrysanthemums 3. Easter Lilies 4. Florist Azaleas
Minor Foliage Crops 1. African Violets 2. Cineraria 3. Cyclamen 4. Holiday Cacti 5. Kalanchoe 6. Gerbera Daisy 7. Gloxinia
Poinsettias I • Euphorbiapulcherrima • Native to Mexico • Named after Joel Poinsett, former US Ambassador to Mexico
Poinsettias II • #1 Potted Flowering Crop in US • Wholesale Value: >$123 million/year • Grown for showy bracts which are modified leaves
Poinsettias III • Cyanthia- small, yellow, bud shaped structures in the center of the bracts (flowers) • Short day or long night plant • Require at least 12 hours of darkness
Poinsettia Cultivars • Annette Hegg Series • Echespoint Series • Gutbier Series • Mikkelsens Series
Poinsettia Cultivation • Vegetatively propagated by tip cuttings • Available rooted or unrooted
Poinsettia Stock Plants I • Cuttings received in March-May • Night interruption lighting • Prevent flower initiation • After rooting • 6”-10” pot • 50ºF- Night Temperature • 80ºF- Day Temperature
Poinsettia Stock Plants II • 2 Pinches before cutting • First pinch • leave 8-11 nodes • 7-10 days after planting • Following pinches • leave 2 nodes on new growth
Poinsettia Cuttings I • Cuttings taken~4 weeks after last pinch • Key factors to success • Cleanliness • Mist System • Optimum Temperatures • 3-4 inches using hands or knife
Poinsettia Cuttings II • Place in • 6 inch pot or • artificial media • examples: rock, wool, or foam • Mist system immediately
Poinsettia Cuttings III • Bottom heat • speeds rooting • Media temperature 70°F -75°F • Misting leaches nutrients • 7-10 days after planting • use a 150ppm-200ppm fertilizer solution
Poinsettia Cuttings IV • Misting • decrease interval after callusing • Remove from mist • when good roots have formed • put in final spacing at this time
Growth Requirements ~ Media • Good Example of Media: Equal parts loam soil, peat moss and perlite • High porosity • High water holding capacity • Sterile • pH= 6.0 to 6.2
Growth Requirements ~ Watering • Require large amounts of water • Should not be allowed to wilt • Overwatering can cause root rot • Examples of watering systems - Spaghetti tubes - Capillary mats - Subsurface Irrigation - With hose
Growth Requirements ~ Fertilizing I • Large amounts of fertilizer requirements Especially Nitrogen • Constant liquid feed of 250-300 should fulfill the requirement for established plants • Amount required may be affected by: • light & temperature levels • Weekly pH & EC test is suggested to measure the effect of these
Growth Requirements ~ Fertilizing II • Poinsettias are sensitive to ammonia toxicity • Caused by an excess of 305 Ammonium nitrogen • Calcium deficiency can cause bract necrosis & weak stems • To combat this a trace element mix should be added once during production
Growth Requirements~ Temperature I • Average Daily Temperature affects development • To enhance bract color • During finishing reduce night temperatures to 55-60F
Growth Requirements~ Temperature II • Average Daily Temperature affects development • Optimal temperatures • Night- 65F • If below- delay flower initiation • Day- 70-75F • If above- reduces flower quality
Growth Requirements ~ Light • To keep plants vegetative • Night interruption of 10 fc from 10 PM to 2 AM • High light levels during the day influence growth • Plants will bloom when days are less than 12 hours • A black cloth may be used to shield plants from outside sources of excess light
Growth Requirements ~ Pinching • No Pinching = One Large Flower • Most plants are pinched 2-3 weeks after transplanting & once the plant has established a sufficient root system • It is common for plants to be pinched to 3-5 nodes
Growth Requirements ~ Pinching • Top 1/2 to 1 inch of plant is removed • More nodes left on stem = more flowers • If more flowers are allowed to form, they will be smaller that if fewer flowers were to flower
Growth Requirements ~ Height Control I • Controlled by adequate spacing • If plants are shaded they will stretch & elongate • DIF can also be used • A DIF of 0 to a negative number can slow growth
Growth Requirements ~ Height Control II • Chemicals can also be used • Common Chemicals include: • Cycocel • B-nine • A-rest • Bonzi • Sumajic • Be Sure to Read the Label and Instructions!
Problems for Poinsettia Growers • Insects • Whitefly • Fungus Gnat • Use IPM to control these insects
Diseases of Poinsettias • Bostrytis- gray mold • Prevent by providing low humidity and good air circulation • Rhizoctonia- stem and root rot • Control with fungicide • Pythium- water mold and root rot • Control with fungicide drench
Physiological Problems I • Bract Burn- Condition in which tips of bract turn brown • Controlled by not applying high ammonium fertilizers and maintaining calcium levels • Center Drop- Condition in which flower buds abscise due to carbohydrate depletion • Controlled by maintaining proper temperature and maximizing light penetration
Physiological Problems II • Stem Splitting-Condition in which the terminal bud is aborted and three shoots develop into a whorl • Controlled by providing appropriate night temperatures
Post Harvest & Handling • Cool finishing temperatures and lessen fertilizer applications • Plants should be sleeved to ship and unsleeved as soon as possible to minimize droopy leaves • Plants should be stored at 50-60F and in bright lights