Floriculture and Greenhouse Research

Program Overview:

Research goals for floriculture and greenhouse production at Colorado State University include:

• Modification of current irrigation technologies with the goal to reduce waste water and reduce fertilizer needs.
• Determine water use rates of plants subjected to various irrigation delivery systems including recirculation.
• Develop irrigation models that would be compatible with Colorado greenhouse conditions and adaptable to automated and manual irrigation systems.
• Modify current fertility recommendations for popular greenhouse floral and vegetable crops based on efficient use of water fertilizer and recirculation strategies.

Under controlled conditions using various irrigation and fertility strategies, plant growth responses of popular greenhouse floral and vegetable crops are being monitored. Irrigation technologies studied include trickle tube, ebb and flood, overhead, and hand watering. Plant water status measurements are being integrated with selected environmental factors including but not limited to predicted temperature, light intensity, evapotranspiration, and vapor pressure deficits. Application strategies include traditional irrigation practices such as watering to 10% excess, watering scheduled by tensiometry, evaporation pan or vapor pressure deficit, and pulse irrigation. Currently available and alternative root-zone media are being evaluated in conjunction with the irrigation delivery systems. Systems that use recirculated water are also being incorporated as well as procedures for disinfection of recycled irrigation water. Several crops studied include popular bedding and pot crops, cut flower species and greenhouse vegetables common to the Colorado greenhouse industry. Media evaluated include traditional peat-based media as well as bark-based, rockwool, and alternative media amendments.

Poinsettia Evaluations:

• Crop year 1997
• Crop year 1999
• Crop year 2002
• Crop year 2004

Theses and Dissertations:

Warning, these are large files

• Performance of 19 Species of Bedding Plants and Kentucky Bluegrass Grown at Decreasing Levels of Irrigation
  D. Yvette, Henson, Master of Science Thesis, August 2005
• Selection and Production of Six Herbaceous Flowering Perennial Species as Greenhouse Grown Alternative Cut Flowers
  Andrea Christine Blaine, Master of Science Thesis, December 1999
• Greenhouse production of fresh market basil
  C.Elizabeth Succop, Master of Science Thesis, August 1998
• Pulse Irrigation Strategies for Greenhouse Production
  D. Sean Moody, Master of Science Thesis, December 1996

Selected research reports:

• Adaptation of Waste Tire Rubber for Greenhouse Media and Zinc Fertilizers
• IBTA and NBMA Influences Tomato Fruit Yield
• Use of Oxcide for Treatment of Greenhouse Irrigation Water

Selected publications:

• Photoperiod of poinsettia stock plants influences rooting of cuttings
  HortTechnology 9(1): 41-43. 1997.
• Growth and nutrition of geraniums grown in media developed from waste tire components
  HortScience 32(4):674-676. 1997.
• A naturally occurring compound for controlling powdery mildew of greenhouse roses
  HortScience 34(4):686-689. 1999.
• Role of Ethylene and 1-MCP in flower development and petal abscission in zonal geraniums
  HortScience 36(7):1305-1309. 2001.
• Organic fertilization of fresh market basil in a greenhouse
  HortTechnology 14(2):235-239. 2004.
• Evaluation of Trichoderma harzianum Strains to Control Crown and Root Rot of Greenhouse Fresh Market Tomatoes
  Acta Hort. 635:79-85. 2004.
• The Effect of the Trichoderma harzianum Strains on the Growth of Tomato Seedlings
  Acta Hort. 635:131-135. 2004.
  Effects of Long-Term Recycled Wastewater Irrigation on Visual Quality and Ion Concentrations of Ponderosa Pine
  J. Env. Hort. 23(4):185-189. 2005
• Performance of Selected Herbaceous Annual Ornamentals Grown at Decreasing Levels of Irrigation
  HortScience 41(6):1481-1486. 2006.
• Monitoring Mortality of Pythium Zoospores in Chlorinated Water Using Oxidation Reduction Potential
  Plant Health Progress doi:10.1094/PHP-2008-0922-01-RS.