Temperature affects all major plant physiological processes. Traditional methods of controlling greenhouse temperatures use aerial sensors that do not monitor temperatures within each component of the soil-plant-atmosphere continuum.
Bench, pot, plant canopy, and aerial temperatures were monitored using thermocouples and thermistors processed by environmental computers during a wide range of greenhouse conditions. These include diurnal cycles of high and low solar radiation, night periods with and without artificial lighting, and various ventilation and heating conditions. Spatial temperature gradients of 10-22 °C were discovered during both day and night conditions. These spatial variations cause significant differences in average temperatures between and within benches over diurnal and even seasonal cycles.
Preliminary surveys of microclimatic variations that occur within the greenhouse experimental area are essential for choosing the proper experimental design. Continuous environmental monitoring during the experiment is necessary for interpreting experimental results.