Weather-based Models and Seasonal Alarms

By Brian Henriott
Hortau Grower Support Specialist

ST8 in Almonds

Fall is here and winter is just around the corner!

With harvest wrapping up or completed, this is the perfect time to get your frost alarms set and chill hours recording. There are a number of activities that begin this time of year. Post-harvest irrigations, early frost watch, and calculating chill hours and chill portions to name a few. Below are a few of the alarms and recordings Hortau users can create in Irrolis to help them stay on top of soil tension and weather monitoring over the course of the winter.

Tension Alarms

First of all, just because the weather is cooling down, it doesn’t make irrigation any less important.  In many of the tree and vine crops, irrigations are stopped or greatly reduced moving into harvest.  After harvest, it is not uncommon to see soils extremely dry, above 80 kPa for sustained periods. When the soil tension is that high, it can take a long time to replace the moisture in the profile.

With an average clay soil at a tension of 80 kPa you may need to apply 4 inches of water or more just to refill the top 3 feet of soil. Once the profile is refilled, remember to re-enable the irrigation alarms. These alarms are tension based and can be set at a range of your choosing. The notifications can come in the form of a phone call, text message, or an email. There are many other on-farm activities post-harvest and using tension-based alarms is one way to help balance the workload of managing irrigation during this time of the year.

Hortau Frost AlarmsFrost Alarms

Don’t be caught off guard by a frost event. We have already had some early cool temperatures. Depending on the crop, an early frost can be just as damaging as a spring frost. Frost alarms can help give enough of a warning to get the frost protection up and running before your crop is damaged. Hortau frost alarms can be set up in just a few minutes and can be delivered via text, phone call or email.

Chill Hours and Chill Portions

Chill hours and chill portions are important tools to help schedule winter activities such as dormant sprays.  Traditionally, both chill hours and chill portions start accumulating Nov. 1, so get those calculated points enabled now. If Nov. 1 passes before the accumulations have been reset, don’t worry. The data needed for chill portions and chill hours is recorded and can be setup retroactively. Alarms for chill hours and chill portions can also be setup as a reminder that specific thresholds have been met.

If you have any questions about alarms and calculated points such as chill hours, please get in touch with your regional Grower Support Specialist. If you’re not a Hortau customer but are interested in learning more about the Hortau precision irrigation management system and weather alerts, set up a consultation with a representative in your area HERE.

About the Author

Brian Henriott is Hortau’s grower support specialist for Mid-Northern Central Valley. He is a native Californian originally from the Bay Area, and attended Cal Poly San Luis Obispo, majoring in horticultural production as an undergrad and then in plant protection as a grad student. At Cal Poly, Brian developed a passion  for entomology, eventually transitioning that interest into a two-year lecturer position at Cal Poly. After college, Brian worked for four years on the Central Coast as a harvest manager in the vegetable industry before joining Hortau full-time to help growers integrate soil tension management into their operation.

Send Us Your Questions

Have something you’d like us to discuss on The Hortau Blog? Email us at media@