Despite hot summers and cold winters, UC Cooperative Extension specialist Mary Lu Arpaia believes the San Joaquin Valley could be home to expanded California avocado production, reported Gregory Barber on Wired.com. 

Currently, most of the state's avocados are grown in the mild coastal areas of San Diego and Ventura counties, where consumer-favorite Hass avocados flourish. But high land value and low water quality are limitations on the industry. The vast and fertile San Joaquin Valley beckons, but summer temperatures that frequently top 100 degrees and occasional winter freezes aren't ideal for Hass.

Arpaia has planted a variety of avocado cultivars at the UC Lindcove Research and Extension Center in eastern Tulare County to determine which trees produce creamy, nutty avocados, and maintain other desirable traits - such as high yield and small tree size - while subjected to the valley's climate extremes.

The California Avocado Commission funded the orchard's establishment.

"The industry wasn't really too keen about me putting a site here (at Lindcove)," Arpaia said. "But I'm stubborn and that's why it's here."

Each year three new avocado varieties are planted in the orchard. Though the breeding process is slow, Arpaia dreams that one day avocados will be sold in supermarkets much like the wide variety of apples.

"We're probably 20 years behind the apple industry at this point," Arpaia said. "Do we have anything out here that's going to achieve that dream?"

Finding an avocado variety ideal for valley temperatures has other benefits. It would give citrus farmers another option should their industry be threatened by Huanglongbing (HLB) disease. Already, the pest that spreads HLB, Asian citrus psyllid, is established in some parts of the valley and spreading. Once a tree is infected with HLB, it cannot be cured.

“Growers have made good money on avocados,” Arpaia said. “In the San Joaquin Valley, water is relatively cheap and we have better water quality than San Diego County. There are good, well-drained soils. Avocados' frost sensitivity is similar to lemons. If farmers have property where they can grow lemons, they could try avocados.”

Avocados planted in a research plot at the UC Lindcove Research and Extension Center.