Chapter 9

Managing Temperature in Greenhouse Crops

(book excerpts)

The most important environmental parameters that need to be controlled for optimal greenhouse climate are temperature, light, relative humidity, and carbon dioxide (CO2). Temperature is the most important single parameter in greenhouse controls as temperature has a significant role in plant growth and development. For instance, the temperature of plant tissue affects the rate of leaf unfolding, flower bud development, and stem elongation. The optimal temperature depends on the plant species grown and desired level of photosynthetic activity. Different crop species have different optimum growing temperatures and these optimum temperatures can be different for the root and the shoot environment and for the different growth stages during the life of the crop. Temperature can also affect plant quality. Too high temperature reduces plant growth, eventually resulting in plant wilting and death whereas too low temperature limits plant growth. Typical greenhouse temperatures vary between 50 to 68 degrees F (10 to 20°C).

Click on the following topics for more information on managing temperature in greenhouse crops.

Topics Within This Chapter:

  • Temperature Requirements for Greenhouse Crops
  • Cardinal Temperatures for Greenhouse Crops
  • Minimum Temperature
  • Optimum Temperature
  • Maximum Temperature
  • Cold-Tolerant, Cold-Temperate, and Cold-Sensitive Crops
  • Growing Cold-Tolerant, Cold-Temperate, Cold-Sensitive Crops
  • Temperature Requirements for Crop Growth Stages
  • Temperature Influence of Plant Quality
  • Plant Temperaure
  • Day-Night Temperature Differential (DIF) for Conrolling Plant Growth
  • DIF’s Influence on Plant Height
  • Side Effects of Negative DIF
  • Limitations of Applying DIF
  • Computer Control of DIF
  • Temperature Drop (DIP)
  • Average Daily Temperature for Greenhouse Crops