Fall is date harvest season. In Arizona, harvesting the sweet fruit is in full swing at one Arizona State University campus. That’s where one of the country’s largest diverse date palm farms is located.
In a corner lot on the south end of ASU’s East Valley Polytechnic Campus there are rows of palm trees. At a quick glance, they look like a pile of unmanicured dead trees. Look a little closer and what’s inside those palm branches are dates, by the bunch. This is the ASU date palm germplasm.
“A germplasm is like a genetic bank where we have a lot of different varieties here in the U.S.,” said Deborah Thirkhill of ASU. She’s cutting palm branches heavy with hundreds of dates hanging from them. She oversees the date farm. “In this date palm grove we probably have the biggest genetic variety anywhere in the U.S. other than the Middle East.”
These trees are believed to be native to the Middle East. Over the years date palms were introduced to desert climate areas in the U.S. ASU had several date palms decorating its campuses and were used for occasional research. Today, the school has taken a more active role in participating in date genomic research.
“All the research scientists at the USDA know about this grove and understand the significance of it. We’re well known outside the U.S. too,” Thirkhill said.
That’s because this date farm is one of four in the country. The largest is in California managed by the US Department of Agriculture. The second largest is this Polytech campus date farm—it’s cultivated by volunteers at the ASU Arboretum throughout the year. The farm has 138 palm trees with more than 40 varieties of dates, including the Majewel, Zahidi and Arizona’s hybrid Black Sphinx, and it also has rare varieties. And this was created against all odds.
“It is sentimental value for me, date farms,” said Ali Salih, one of those volunteers. He’s also the person who began caring for the farm when the college decided about 10 years ago to relocate most of its date palms to this East Valley location. “When I first started volunteering, ASU was not doing anything with it and it was left on its own. I actually broke into the water system so that I could get water to the line to irrigate the trees and if we did not do that this whole 150 trees would’ve been wiped out.”
Salih explains date palms flowers have to be hand pollinated. In the spring volunteers take the pollinating flower from the male trees, grind them into a baking flour-like dust and walk across the grove spreading it so to land on the female producing flowers. Each date palm can produce hundreds of pounds of dates each season. Each fall, the university’s arboretum offers classes to the public on the care and farming of date palms. And Deborah Thirkhill takes a handful of volunteers to the grove to picks the ripest dates. Then they’re packed and delivered to campus dining halls. They’re also sold at farmer’s markets, college bookstores and school events.
As students pack the dates, the research continues. ASU is one of several sites working with New York City University’s Abu Dhabi campus. A program there is creating a gene map of a hundred varieties from around the world. With ASUs sample, researchers are establishing a more precise understanding of the variations and origins.