Frequently Asked Questions
Does the sensor damage the plant?
No. Sensors have been installed sensors into almonds, grapes, and apple trunks for multiple years. We have not seen evidence of detrimental effects. To minimize potential issues, sensors should be installed in vines or trees with trunks larger than 2” in diameter.
What is the minimum branch size for sensor install?
We recommend installation in branches or trunks at least 2” in diameter (50 mm). A sensor for use in smaller crops is under development.
How long does the sensor last?
We have tested the sensors to last at least a growing season or longer. In specific crops, we have seen that sensors become less accurate in the second season due to wound closure. We currently recommend that new sensors be installed at the beginning of each growing season
Do you need one in every plant?
No. When a new field is set up, irrigation blocks are shaped so that the soil and plants in each block have similar characteristics and thus will have similar water status. We recommend the use of 1-3 sensors per irrigation block to get a good average of the block water status. It would be logical to install the sensors at or near the sites you have used for pressure chamber monitoring.
Do you need cell reception?
Our datalogger uses a cell modem to send the sensor information to the cloud through 2G/3G or 2G/4G signal (depends on the logger version). Thus, you will need adequate cellular reception to use the FloraPulse dataloggers. Our sensors are sold individually and you can connect them to third-party dataloggers with other connection modalities.
Can the sensors withstand a tree shaker?
We recommend that FloraPulse-instrumented trees be harvested by hand and not shaken. The vibrations can damage the sensor and will destroy the datalogger.
What is the best measurement for deciding when to irrigate?
Water potential is the best measurement in understanding the level of “thirst” a plant feels. The performance of plants (growth, opening of stomatal pores on leaves to allow photosynthesis and evaporative cooling, movement of sugars and minerals, etc.) depends on the plant’s water potential, which is the plant’s ability to draw water from the soil. For this reason, we developed the FloraPulse microtensiometer – a special sensor that goes directly into the plant and can provide day-to-day water potential measurements.
What is the difference between water content versus water potential?
When dealing with any wet material such as soil or plant tissue, there are two important properties related to water. Water content is how much water the material holds, expressed as 30% water or 0.3 grams of water per cubic centimeter of soil. The water potential is how tightly the tissue holds the water. This can be illustrated by thinking of a sponge and a chunk of clay. It is easy to squeeze almost all the water out of a wet sponge, but much harder to squeeze of out of the wet clay even though both may have the same water content when wet.
What is a microtensiometer and how do we use it?
A microtensiometer is our patented plant sensor that is in direct contact with the plant, and thus is able to track day-to-day water potential of the plant. The measurements that the microtensiometer takes are stored in a datalogger as part of the installation. The datalogger uploads the measurements to the cloud and ports the data to the end-users.
How have you tested the microtensiometer?
FloraPulse has done season-long field trials in fruit and nut crops. We corroborated that our patented sensor measures plant water-stress accurately and that our measurements agree with the gold standard: the pressure chamber. As a result, our sensors could save growers on time and effort in measuring plant stress manually in the field.
Do you gather data over the winter?
Yes – the sensors measure the plant water status over the winter, even when there are no leaves. This data could help ensure that plants are not water-stressed when the growing season re-starts in the spring. But this capability is still under study and development. Keep in mind, the sensors will freeze and break if temperatures drop substantially below 0 °C.