Environmental monitoring is essential for plant growth under field conditions, in greenhouses or under controlled conditions in a growth chamber. Few environmental factors are involved in providing plants with appropriate environmental conditions for healthy growth. Temperature is one of the very basic factors with rather large influence on many different plant processes. For example growth is strongly linked to temperature, photosynthesis or respiration increase with temperature up to a point, flowering may be partially triggered by temperature, sugar storage is increased at low temperature etc.
Temperatures can fluctuate dramatically between bursts of light and cloud cover resulting in large spatial and temporal variation. In controlled chambers the air temperature may be rather constant but depending on the light environment the surface temperature of plants may vary between the upper and lower layers. Greenhouses usually represent semi-controlled conditions and temperature may vary substantially in particular during the season and field conditions represent the most heterogeneous case. The minimum requirement for temperature measurement is the assessment air temperature which is often routinely performed. However, plant surface and soil temperature may largely differ from the air temperature and therefore it is recommended to include these measurements into environmental monitoring (e.g. see Fullner et al. 2012). Very detailed monitoring of the temperature is thus essential.
Fullner, K., et al. (2011) Vertical gradient in soil temperature stimulates development and increases biomass accumulation in barley. Plant, Cell & Environment 35: 884-892.