Our greenhouse staff have combined old and new techniques into a growth system for optimizing corn production in greenhouses and growth chambers. Nutrient deficiencies are reduced and seed yield increased using automated drip irrigation delivering fertilizer solution to a root media of calcined clay, or porous ceramic.

Greenhouse managers will find the system easy to adopt. It eliminates the need for the cumbersome handling of field soils (digging, drying, grinding, pasteurizing and mixing). Watering frequency and fertilizer formulation were kept constant over the life of the plants, seed to harvest. Supplemental fertilizers such as slow release granules were not required. In most cases, transplanting was not required and watering labor reduced to simple inspection of the system. Even experienced growers who have optimized their own systems will find our experiments with growth regulators and stored pollen intriguing, as well as the tips on improving seed yield based on the research of cited works.

Scientists and administrators will appreciate the potential for standardization with the system:

  • Repeatable, reportable methodology
  • Easily adoptable by both low-tech and hi-tech facilities
  • Scalable production system, for large research projects
  • More uniformity by elimination of locally dug field soil

Results of 24 controlled studies (note they were not peer-reviewed) are summarized into FAQ format for ease of understanding. We offer little new discovery—most of the components and techniques have been pioneered by Purdue faculty, our colleagues at other facilities and by NASA. We’ve simply integrated them into a well-documented plant growth system, using photographs of the techniques as well as statistcal analysis of the treatment groups.

Click "GO" to access printable document format from Purdue Libraries e-Pubs. You will then need to press download.

  • [GO] Summary
  • [GO] What is the best root medium?
  • [GO] What is the best pot size?
  • [GO] What is the best irrigation strategy?
  • [GO] What is the best fertilizer formulation and strength?
  • [GO] What is the best lighting and plant density?
  • [GO] Can more than one plant be grown per pot?
  • [GO] Can growth regulators be used to keep plants short?
  • [GO] Can seed yield be improved using cold-stored tassels?
  • [GO] What other ideas for improving seed yield?
  • [GO] What is the best open pollination method?
  • [GO] What prevents calcium deficiency?
  • [GO] How do I keep calcined clay from leaking out of pot?
  • [GO] What if roots need to be clean for analysis?
  • [GO] How can mites be controlled?
  • [GO] Will using calcined clay reduce fungus gnat infestation?
  • [GO] Materials and Methods
  • [GO] References

Technical Analyses


Our Special Thanks to These Companies for Their Support:


Horticulture & Landscape Architecture, 625 Agriculture Mall Drive, West Lafayette, IN 47907-2010 USA, (765) 494-1300

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