Recently developed stem flow gauges that allow for direct, accurate, non-invasive, and continuous measurement of plant sap flow rates have not been used to monitor transpiration of floricultural plants grown in greenhouses.
A Dynamax SGA10 heat-balance sap-flow sensor was mounted on a potted rose plant's main stem containing a total leaf area of 0.52 m in order to monitor transpiration. The sensor was connected to a CR21X Micrologger for data calculation and temporary storage. The results showed average midday sap-flow rates range from 20-30 g·hr-1 to 50-70 g·hr-1 at low and high levels of PPF, respectively. Nighttime levels of 4-7 g·hr-1 persisted throughout early winter trials. Monitoring transpiration of the same rose stem using a lysimeter revealed a significant linear correlation (r2 = 0.999) between the lysimeter and the stem flow gauge values.
In the future, research will be conducted with the gauge to investigate relationships between microclimatic variables, photosynthesis, and transpiration.
If the inline PDF is not rendering correctly, you can download the PDF file here.