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Minor Foliage Crops
1. African Violets2. Cineraria3. Cyclamen4. Holiday Cacti5. Kalanchoe6. Gerbera Daisy7. Gloxinia
Poinsettias I
• Euphorbia pulcherrima
• 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 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