Stem Water Potential Calc app for iPhone and iPad

The application provides a value of stem water potential for a fully watered of almond and walnut trees. The value is calculated with a model that uses temperature and relative humidity.

Values of temperature and relative humidity are pull from the nearest weather station or the users can introduce their own measured values on the site.

User will have to measure with a pressure chamber the actual stem water potential, and introduce this on the application.

The applications provides advice on the next schedule irrigation. Also provides the weather forecast for the next seven days, and the evolution of the estimated stem water potential value for a well irrigated tree.

There are several advantages to using midday stem water potential as an adjunct to monitoring soil moisture or using evapotranspiration based irrigation scheduling. Measuring soil moisture gives you an idea what is going on in only a limited volume of soil where your measurement device is placed. It can be difficult to decide where to monitor soil moisture since tree roots can be quite deep and variable depending on irrigation system design (i.e. variable roots under drip irrigation) and method of operation (i.e. deep versus shallow irrigations).

Midday stem water potential can be used as an adjunct to either soil or evapotranspiration based irrigation scheduling to help refine your irrigation scheduling.

The advantage to using midday stem water potential is that it integrates soil factors for the entire tree root system as well as environmental factors giving you an accurate picture of the level of stress the tree is experiencing.

The application allows to e-mail a PDF file with report.