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Home , Euphorbia

Facts

• Origin is Mexico • Sales begin in early November & end at Christmas • Grown in many different container sizes Euphorbia pulcherrima • Cut flower production is increasing - ‘Winter Rose’ The #1 potted flowering crop

Facts, cont….. Related of Commercial Importance • The poinsettia “flower” is really a modified called a E. milii Crown of thorns • True flowers are cyathia E. marginata Snow -on- the-mt. • Cyathia are subtended by boat -shaped E. fulgens Scarlet plume nectaries

Snow-on-the-mountain

Cultivars The free-branching characteristic is • Free - branching graft transmissible to restricted – numerous axillaries branching – most cultivars • Restricted - branching New cultivars are developed by – 2-4 axillaries grafting to transmit the phytoplasma – Ex: Celebrate

1 Poinsettia Cultivars Cutlivars vary by:

• Today there are 125 cultivars • Height • Growth rates vary • Foliage color • Respond differently to chemical • Response group growth regulators • Leaf retention • Growth can be controlled by • Postharvest life selection • Flowering date

‘Silverstar’ has variegated foliage

Response group = Time from Propagation start of short day to flowering • Terminal stem cuttings are used • Growers can produce their own cuttings or purchase unrooted or rooted cuttings

Vegetative growing point Cuttings are rooted in foam blocks

To propagate their own cuttings, growers….. Important points to remember • Determine whether it is more • Order stock plants to arrive from March economical for your business to start to June your own or purchase cuttings • Allow original rooted (stock • Refer to the Ball Red Book for plant) to develop 9-11 nodes before the scheduling first harvest of cuttings • Cuttings should have thick stems and • Axillary shoots should have only 2 short internodes and be healthy nodes remaining after cuttings are taken • High quality cuttings produce high • Most growers harvest cuttings weekly quality plants

2 Or let the specialist Pinching propagator provide cuttings for you… • Pinching (one cutting per pot) vs. growing straight-up (multiple cuttings • Paul Ecke Ranch www.ecke.com per pot) • Fischer, U.S.A. www.fischerusa.com • Pinch for 4-7 blooms per plant • Oglevee www.oglevee.com • Pinch when are visible on outside of media ball (2 weeks after planting) • No. nodes left = No. flowers produced • “Hard pinch” = leave 3-4 nodes • “Soft pinch” = leave 5-7 nodes

Flowering 4 Events for Scheduling Crop

• are Short Day (SD)/Long Pan date Night plants depends on cultivar and growth • Nights must be at least 11.75 hours Pinch date long to initiate flowers depends on cultivar vigor and pot size (2 - 8 weeks) • Around September 25 (late Sept. - early Oct.) Short days start depends on response group • ‘Freedom’ initiates in early September • Response groups vary from 6.5 - 10 Sell date weeks depends on market

Manipulating photoperiod to Temperature flower for market date

• Early: To market before Thanksgiving, • Propagation 75-77 (media) plants may need SD (blackcloth) before • NT 65-68 (air) September 25 • NT >70 may delay flower initiation • Late: LD (mum lighting) after Sept 15 for • NT >75 may delay flower development late marketing after Dec 10 • NT 55-60 (air) for last 2 weeks • Cultivars respond different to temperature

3 Light Water and Nutrition

• 700 - 900 mmol·s-1m-2 dark foliage • Do not allow plants to wilt - what happens? • 1000-1200 mmol·s-1m-2 for light foliage • 225-300 ppm N (overhead) • In south, 10-30 % shade cloth for 1-2 • 100-225 ppm N (sub-irrigation) weeks after planting rooted cuttings • Optimum EC 1.5-2.0 dark green foliage • 400 mmol·s-1m-2 after are mature and 2.0-2.5 light green foliage will reduce fading (saturated paste) • Optimum pH 5.8 - 6.3

Growth Control Challenges Growth Control

• Cultivar selection • More height specifications from mass marketers • Water application or lack of • More cultivars with various growth • Fertilizer application or lack of habits • DIF or DROP temperature control • More chemicals growth regulators to • Chemical plant growth retardants choose from • Scheduling • Sunny, warm weather = shorter plants

Growth Retardants and Rates Chemical growth regulators are applied:

• Arest • .25 to .5 ppm • Control height • Cycocel • 1000 - 3000 ppm • Darken foliage • B-Nine/Cycocel • 2500/1500 ppm • Bonzi • 10 - 30 ppm • Strengthen stems • Sumagic • 2 - 10 ppm • Increase resistance to stress

4 Possible Undesirable Side PGR Application Effects

• After the pinch • Reduced bract size • When axillaries are 1.5 – 2 inches long • Crinkling of bracts • In the morning when it is cool • Blotchy yellowing of • Never spray late in production because • Marginal leaf burn bract size may be reduced • Delayed flowering

A very good practice is to leave some plants untreated so you can gauge the treatment effects better

Poinsettia Marketing Insects

• Early - pre-Thanksgiving • Whiteflies • Primary -Thanksgiving to Dec. 10 – Greenhouse – Silver leaf • Late - Dec. 11 to 24 • Fungus gnats • Spider mites • Thrips

Diseases Physiological Disorders

• Root and stem rots • Bract necrosis • Botrytis blight • Leaf edge necrosis • Bacterial stem and leaf rot • Cycocel damage • Powdery mildew • Leaf drop • Fungal blight and • Stem breakage leaf spots • Splitting • Viruses Botrytis blight • Leaf crippling

5 Physiological Disorders con’t Postharvest

• Reduce temperature, nutrition and light • Center bud 2-3 weeks before shipping drop • Harvest when bracts are expanded and • Rabbit pollen is visible on 1-2 cyathia tracks • Keep temperatures above 50 during shipping • Sleeving is good but remove promptly to prevent ethylene damage (epinasty)

Rabbit tracks

Minimum direct Stem Breakage Cost in cents/6" costs for a 6-inch due to low light during production Item pinched poinsettia – does not include Rooted cutting 65 Royalty 4 overhead costs. May be reduced by: Shipping 44 1. Leaf removal – the removal of the top 2 leaf 6 inch pot 7-10 Total direct costs = $2.47 blades at the time of pinching to increase pot ring 14 With foil & bow = $3.20 media 15-18 light penetration into plant canopy label 2 Minimum overhead for a Marathon 9 commercial grower = 2. PGR application ASAP after pinch $2.00 Cycocel 6 3. Close spacing at the beginning of production fertilizer 8 to help develop V-shaped stem architecture Banrot .07 Total costs overhead 9 sleeve and direct costs = 60 $5.20 4. Cultivar selection labor 67 foil 5. Use of rings but they add to production costs 6 What are you going bow to sell them for?

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