Journal of
Horticulture and Forestry

  • Abbreviation: J. Hortic. For.
  • Language: English
  • ISSN: 2006-9782
  • DOI: 10.5897/JHF
  • Start Year: 2009
  • Published Articles: 273

Full Length Research Paper

Performance of 40 poinsettia cultivars grown under two different temperatures

Bruce L. Dunn1*, Carla Goad2 and Stephen Stanphill1
  1Department of Horticulture and Landscape Architecture, Oklahoma State University, 358 Ag Hall, Stillwater, OK 74078, USA. 2Department of Statistics, Oklahoma State University 301 MSCS Building, Stillwater, OK 74078, USA.
Email: [email protected]

  • Article Number - CD009D22181
  • Vol.3(3), pp. 72-77, March 2011
  •  Accepted: 20 January 2011
  •  Published: 31 March 2011

Abstract

 

This study evaluated forty poinsettia cultivars to determine which cultivars perform well under cool 
growing temperatures. Poinsettias were grown in separate greenhouses at temperatures of 20°C during 
the day and 17°C at night for cold production, or 25°C during the day and 22°C at night for warm 
production. Number of lateral shoots leading to inflorescences, number of bracts, canopy diameter, and 
stem diameter was determined. A significant (P= 0.03) cultivars by greenhouse temperature interaction 
existed for all parameters measured. Cultivars were then separated into classes based on greatest 
values for each trait. Poinsettia cultivars with the largest stem diameter in both warm and cold 
production systems included ‘39-02B’, ‘7-07’, ‘Classic™ White’, and ‘Enduring™ Red’. Poinsettia 
cultivars ‘HC-18B’, ‘Winter Blush’, ‘Cortez™ Burgundy, ‘Winter Rose™ Early Red’, ‘7-07’, ‘Silverstar™ 
Red’, ‘Topez’™, ‘Classic™ Red’, ‘Enduring™ White’, Novia™ Red’, Advent™ Red’, ‘Silverstar™ Marble’, 
and ‘1232’ had high bract numbers in both warm and cold production. Only one cultivar, '1266', 
produced a large number of lateral inflorescences in both production systems. Poinsettia cultivars 
‘Classic™ White’, ‘Mira™ White’, ‘Novia™ Red’, Early ‘Orion™ Red’, ‘Mars’™ Pink’, and ‘Enduring™ 
Red’ had larger canopy diameters when grown in cool temperatures than under warmer conditions. 
 
Key words: Greenhouse production, temperature, Euphorbia pulcherrima, plant physiology, plant architecture
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