Researchers Develop Self-Pollinating Almond With Gold Mine of Tasty Traits

One day, Yorizane may be synonymous with almonds and California. So what is a Yorizane and what does it have to do with almonds? Yorizane is a new self-pollinating almond variety developed by USDA's Agricultural Research Service with superb consumer traits such as size, color, and flavor.

But it is Yorizane's ability to produce an abundant harvest of nuts without needing to be pollinated by insects or having another almond variety planted in the same orchard—unlike almost all other commercial trees—that makes it so important to California's $6-billion-a-year almond industry.

About Tuono

Self-fertile almonds actually are not new, explained research geneticist Craig A. Ledbetter. He is with the ARS Crop Diseases, Pests and Genetics Research Unit in Parlier, California, and Yorizane's breeder. A variety called Tuono, originally from Spain has been around for centuries. But it has few of the other characteristics that have made California almonds so popular. The main problem is that, unlike California's quintessential almond variety Nonpareil, Tuono's outside seed coat has a hairy texture.

The Most Planted Almond Tree

Still, Tuono is reliably self-pollinating, so it is not surprising that Ledbetter used it as the pollen-donating parent when he began breeding a new almond in 1996, crossing it with California-adapted almond cultivars and selections. 

One successful selection eventually came to be named Yorizane. It hit the genetic jackpot, getting Tuono's genes for self-fertility along with almost all of the traits of Nonpareil, the most planted almond tree since it was first introduced in the 1880s.

More Than 60 Almond Varieties Tested

In 2019, the Almond Board of California tested more than 60 almond varieties from around the world for growth characteristics and consumer attributes including ease of harvest, ease of cracking, resistance to kernel damage, yield, bloom date, harvest date, and especially aroma, shape, texture, taste, and color. Yorizane consistently scored near the top in almost every category, in the end, making it one of the best-rated varieties. "One of the things you really notice is that once roasted, Yorizane almonds have the most audible crunch," Ledbetter said.

Small amounts of Yorizane budwood have been made available through Foundation Plant Services for research and breeding. Nurseries have been enthusiastic about reproducing Yorizane trees so that growers can start adding them to their orchards beginning in 2022.

Know What is Yorizane

But what is a Yorizane? Yorizane is the surname of the family that originally owned and raised stone fruit orchards on the 138 acres that became the ARS San Joaquin Valley Agricultural Sciences Center in 1991. The Center wanted to honor the generations of Yorizane’s who maintained that land.