Methodology calibration
Before making plant moisture stress (PMS) measurements, hourly readings need to be taken from daybreak till sunset (7:00 am to 7:00 pm) to obtain the optimum time of the day for physiological readings of the specific species.
Usually the period of time between 1:00 pm and 3:00 pm MDT is the best time to run measurements, due to radiation and leaf temperature stabilization during this time.
It might be better to divide the plant for taking data (especially when no data has been previously taken in that species), into three sectors such as the top, middle and the bottom. A complete set of measurements should be carried out to determine which part of the plant may give the highest water status and the least variation in data.
In addition, several test measurements need to be taken to change and ameliorate the final estimations, specifically when no PMS data is available for a given plant. This may help us to decrease the level of errors when recording readings.