What is a Pressure Bomb?
A tree pressure chamber is a tool used to measure the water stress levels in trees. The gadget consists of a small chamber and outer pressure gauge. First, a leaf sample is collected. This is usually done by selecting a leaf and enclosing it in a special envelope. In the early afternoon, when demand for water is at its highest, the leaf is picked from the tree so that measurements can be taken. The leaf or small stem piece is placed into the chamber. The leaf stem (petiole) protrudes from the chamber and is separated by a valve. Pressure is then applied until water appears from the leaf stem. The appearance of water from leaf stem relates directly to the amount of water stress in which the tree is experiencing. High pressure readings indicate a great need for water, while lower readings show less stress on the trees. Readings allow farmers to fulfill the specific water needs of trees in relation to the current conditions in the orchard, thus, making the tree pressure chamber an invaluable tool for proper orchard management. Although there are a few different methods in which farmers take pressure readings from this device, growers should always take proper safety precautions when doing so. Depending upon the state of water stress, these pressure chambers can reach extremely high PSI readings. Hence, the colloquial name, “pressure bomb.” While not common, chamber failure can result in serious injury. Proper training and purchase from a reputable source is vitally important when considering the use of this tool for measuring water in trees.
