HRM – パパイヤとアブラヤシ樹のヒートレシオ原理を利用した樹液流測定 (Sap Flow in Papaya & Oil Palm)
The first area of application of the HRM deals with the morpho-physiological attributes responsible for the superior vigor of the papaya hybrid "PocosÍ". The second area of application of the HRM has to do with the diagnosis, early detection and treatment of a putatively physio-pathological disorder known as "PC", affecting compact, high-yielding oil palm clones in Coto 47, Costa Rica.
The PSY1 Stem Psychrometer was installed on Eucalyptus to measure the xylem water potential. The water potential was logged every 10 minutes. The summer in Australia is October to March. The data is for late October. Winter is April to September and is cool and usually with rainfall. The initial 6 day period shows a water potential of -0.8 MPa on sunny cloud free days (Figure 1, Days 1,2 and 5).
Cloudy days with reduced evaporative demand have lower xylem water potential. Figure 1 shows this as -0.6 MPa (Day 6) and below -0.4 MPa (Day 7) on rainy days. In fact after the rainfall event on Day 6 the night time water potential was 0.0 MPa (Day 6) for the first time.
These trees are well watered having received large amounts of rainfall in the proceeding winter months. Then the water potentials of -0.8 MPa on sunny cloud free days is expected to become more negative as summer progresses, temperatures increase and the soil becomes drier.
The PSY1 Stem Psychrometer was installed on common garden Squash. This vegetable is widely grown for domestic use in Australia. The xylem water potential was logged every 10 minutes. The initial 4 days of monitoring is shown in Figure 1. Day 1 was cloudy with rainfall. Subsequent days were sunny. The values typically being -1.5 to -1.7MPa on sunny days. The squash are well watered. The squash has a soft stem and further testing in regard to this application is being undertaken.
コーヒーの渇水ストレスと回復 ステム水ポテンシャルの連続モニタリング (Coffee - Continuous monitoring of stem water potential under drought stress and recovery)
Stem water potential of coffee plants can very easily and accurately be measured using the PSY1 stem psychrometer. The anatomy of the coffee plant is ideally suited to installing the psychrometer and does not exhibit any aggressive wounding around or within the psychrometer chamber. Accurate, reliable and valid data were able to be continuously collected for a period of 45 days in this experiment, measurements could easily have continued for much longer without issue. It is expected that a single installation could remain viable for the duration of the growing season.