The beginning of a new season is a time of great promise. It is the promise that we will replicate the successes (and avoid the mistakes!) of past seasons. Concerned with producing the perfect canopy size to meet their production goals this year, growers compare this year’s conditions to past experience to inform spring irrigation decisions.

With the new improvements to Tule’s canopy monitoring tool, you can quantitatively see how your fields performed over the last five years, pick a target canopy size based on the last five years, and remotely monitor this season’s canopy growth compared to your target canopy. Tule’s irrigation recommendations will also provide a guide for helping you achieve this target canopy again this year.

How to choose your Target Canopy (PRI)?
Plant Response Index (PRI) is Tule’s metric for monitoring canopy growth in your field. Now you can change the default Target Canopy based on your production goals for this season.
View the Site Settings page for each sensor to review the default setting and make any changes to your Target Canopy. There are two ways to choose a Target Canopy for each sensor site:

1. Choose a target based on the historical performance of the field where the sensor is located.

   Looking back at the last 5 years, you can choose the canopy size of your field from a previous year which best represents the canopy size desired for your field this year. If you had a Tule sensor installed in previous years, the max canopy size (Max PRI) was determined by the measured evapotranspiration in your field. If the sensor was installed more recently, the max canopy size was determined using historical satellite imagery converted to a Max PRI value.

2. Choose a target based on the performance of similar fields.

   Looking back at the last 5 years, you can review the average canopy size of fields similar to your field. Choose from a previous year which best represents the canopy size desired for your field this year. The description in this section will tell you more about the similar fields in this category.

Note: When the historical satellite data and similar fields data is insufficient for your region or crop type, the Target Canopy will be set to a value derived from academic literature.

Setting the Canopy Development Start Date and End Date
The start date of the canopy development period should be at budbreak for perennials, or the planting date for annuals. This date should be updated to reflect your specific field conditions for the current year.

The end date is determined by actual ET measurements taken by a Tule sensor in your field. For most winegrapes, this end date will be in June. For most almonds, this end date will be in May. You can view the anticipated end date for your crop and region on the site settings page.

A few important reminders about Canopy Development and the Plant Response Index:

• Since cover crop ET influences PRI, the PRI graph should be used only after cover crop has senesced or has been disced. Before that time, the Spring Water Budget report will provide support for early season irrigation recommendations.
• Once the canopy has grown in, the FieldStat portion of the dashboard will become active for monitoring crop water stress throughout the crop development part of the season. Don’t forget to let us know your goals for the crop development part of the season by setting your FieldStat targets.
• Throughout the season, Tule’s irrigation recommendations are actively providing insights into your fields irrigation needs. Learn more here.
• Want to learn more about monitoring canopy growth with ET measurements? Read this blog post.

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