1. Topic #2172 Foliage Plants Focus on Poinsettias By: Alisa Kowalski

2. Major Foliage Crops 1. Poinsettias 2. Chrysanthemums 3. Easter Lilies 4. Florist Azaleas

3. Minor Foliage Crops 1. African Violets 2. Cineraria 3. Cyclamen 4. Holiday Cacti 5. Kalanchoe 6. Gerbera Daisy 7. Gloxinia

4. Poinsettias I Euphorbia pulcherrima Native to Mexico Named after Joel Poinsett, former US Ambassador to Mexico

5. Poinsettias II #1 Potted Flowering Crop in US Wholesale Value: >$123 million/year Grown for showy bracts which are modified leaves

6. 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

7. Poinsettia Cultivars Annette Hegg Series Echespoint Series Gutbier Series Mikkelsens Series

8. Poinsettia Cultivation Vegetatively propagated by tip cuttings Available rooted or unrooted

9. 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

10. 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

11. 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

12. Poinsettia Cuttings II Place in –6 inch pot or –artificial media examples: rock, wool, or foam –Mist system immediately

13. 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

14. Poinsettia Cuttings IV Misting –decrease interval after callusing Remove from mist –when good roots have formed –put in final spacing at this time

15. 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

16. 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

17. 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

18. 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

19. Growth Requirements~ Temperature I Average Daily Temperature affects development To enhance bract color –During finishing reduce night temperatures to 55-60  F

20. Growth Requirements~ Temperature II Average Daily Temperature affects development Optimal temperatures –Night- 65  F If below- delay flower initiation –Day- 70-75  F If above- reduces flower quality

21. 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

22. 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

23. 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

24. 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

25. 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!

26. Problems for Poinsettia Growers Insects –Whitefly –Fungus Gnat Use IPM to control these insects

27. 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

28. 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

29. 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

30. 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- 60  F and in bright lights