Frequently Asked Questions
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 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.
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.
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?
Individual sensor sites do not need cellular connectivity, but we require cellular connectivity somewhere in or near the property. Our newest dataloggers can send data directly through cellular networks or through LoRaWAN technology to an internet-connected gateway.
How long does the sensor last?
We have shown sensors can last for at least one growing season. More testing is underway to determine if the same sensor can be used for multiple growing seasons. We currently recommend that sensors be replaced at the beginning of each season.
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 it is 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.
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 helps ensure that plants are not water-stressed when the growing season re-starts in the spring.
Can the sensors withstand a tree shaker?
Probably. We have not tested shaking trees where the sensors are installed. Our customers generally shake sentinel trees manually.