This protocol describes how to measure gres under constant temperature and relative humidity
Procedure
Materials-Equipments
- Paraffine wax
- Scale
- Scanner
- ImageJ
Plant material preparation
- Collect 1 to 1.5 meters long branches
- Cut the end of each branch underwater
- Rehydrate plants overnight by immersing them in water
- Cover the branches with black plastic bags and store them dark conditions
Before starting the measurements
- Recut a 40 cm long branch (weight should not be larger than 100 grams)
- Measure the fresh weight of each branch
- Measure the diameter of the branch at the cut end and at the top of branch
- Seal the end of the branch with parafilm
- Check there is water in the reservoir located inside the box
- Before placing the branches inside the Box,
- Set the temperature and relative humidity values and wait until these stabilize (You can use this VPD Calculator)
- Change the
TareNowflag (located in the Num Display window) fromfalsetotrue
During the measurements
Data Analysis
\[E = \frac{slope(n_w;t)}{LA\ +\ BA }\]
\[g_{res}= \frac{E}{VPD}\ \times 101.6\]