Despite the multitude of sensors and DSSs currently available, estimating stomatal conductance and transpiration at orchard level remains a challenge. ArboDroughtStress is a validated model which applies a direct parameterization of the Penman–Monteith equation to compute diurnal courses of orchard canopy conductance (gc) from sap flow in sub-hour resolution for both day and night conditions.
Technology validated in lab.
Basic technological components are integrated to establish that they will work together. This is relatively “low fidelity” compared with the eventual system. Examples include integration of “ad hoc” hardware in the laboratory.
Business plan completed
The BRIGAID Business Development Programme has been successfully completed. A MAF+ assessment has been conducted and its results have been enriched and incorporated into a business plan document.
Following the definition of TRL, we have tested the model in specific environments and tree species. There is still work to be done to validate the model and especially to use the IoT tools to provide the data on drought stress (stomata closure) very easy for farmer usage and linked to the automation of the irrigation system.

How does it work?

Sap flow sensors are installed in some trees within the plantation for monitoring purposes. A portable meteorological station measures net Radiation (Rn), air Temperature (Ta) and Relative Humidity (RH) of air. Atmospheric vapour pressure Deficit (D) is calculated from temperature and relative humidity. Our modeling approach is different as it uses diurnal courses of variables instead of commonly used daily means (see dattached paper for details of the model). The farmers can monitor the field conditions from anywhere, especially the stomata closure due to drought stress which limits photosynthesis and therefore tree productivity. The innovation is precise farming and is highly efficient when compared with the conventional approach.