Fresno State research staff and plant faculty have created an online pistachio predictor to assist San Joaquin Valley growers in predicting harvest yields for one of the area’s most popular crops.

The free website will help growers with their harvest, market and budget planning, and was created by Shawn Ashkan, a Center for Irrigation Technology campus research agricultural engineer, and Dr. Gurreet Brar, a campus plant science faculty member.

To get a predicted yield, website users are asked to enter several recent online chill portion totals from their orchard’s nearest or a representative CIMIS station, the previous year’s per acre yield, and if the predicted year is a normally higher or lower year in its naturally alternating cycle.

“Pistachio farmers haven’t had any highly developed, predictive tools like this, so we wanted to create an easy-to-use site that can apply to orchards of all sizes and different locations,” said Shawn. “The best part is its dynamic machine learning model that gets more accurate as people enter more and more data that sharpens the predictive algorithms, just like in our own personal lives when we use Microsoft, Google and Amazon.”

The dynamic model’s chill portion units are based on time and temperatures that the orchard experiences in its dormant stages from early October through mid-March. More emphasis is placed on temperatures in the 35 to 55 degree range, but the model accounts for temperature fluctuations as well.

To build the website, Shawn and a campus student assistant inputted weather station data from 25 California Irrigation Management Information Systems (CIMIS) from Bakersfield to Merced.

They also collected harvest data from area growers with help from Gurreet and University of California Extension farm advisors Phoebe Gordon (Madera) and Mae Culumber (Fresno), respectively, and tied the data to nearby CIMIS stations. Additional information was added from 22 years of county commissioner growers’ data dating back to 1996.

Shawn also partnered with Dr. Mark Keith, Brigham Young University associate professor of information systems, to design the website and its analytical model formulas.

The project was funded by a specialty crop block program grant from the California Department of Food and Agriculture. Shawn did background investigation on a grant proposal in 2015 with Gurreet, then a Fresno UC extension advisor, then submitted a final proposal when Gurreet returned from a one-year stint at the University of Florida to accept the university’s Rodger B. Jensen Professorship in Pistachio Physiology and Pomology.

“Pistachios are one of our most chill-dependent orchard crops, so this is a vital tool,” Gurreet said. “As we see our winter climate fluctuate more, the dynamic model continues to adjust, which is really important based on the crop’s dormancy sensitivity. This calculator is a perfect example of how our university can work with researchers, extension agencies and industry to lead agriculture in new directions, and one of the reasons why I came back to the Central Valley.”

California has over 312,000 acres of pistachio orchards that account for 99 percent of the domestic pistachio supply. The San Joaquin Valley is the state’s leading production area of the crop that was first grown commercially in the United States in 1976. Growers accounted for a record 900 million pound harvest nationally in 2016.

For more information, contact Shawn at 559.278.8652 or sashkan@csufresno.edu.