Land of the lost

Imagine that a destructive fungus arrives next year in the Sacramento Valley. This pest takes very well to Juglans regia, the Persian walnut, and holds a remarkable resistance to pesticides. In a year, most of the Valley’s orchards are infected, and in 10 years’ time, many farms have become barren yards of stunted trees and wooded skeletons, and the great California nut industry is dead. Or is it?

“We’re like the Noah’s Ark of fruit and nut crops,” said Howard Garrison, farm manager at the Wolfskill Experimental Orchards 10 miles east of Davis. First settled and cultivated in the 1840s by a private grape and citrus farmer named John Wolfskill, this 70-acre parcel of land is now maintained in cooperation by researchers from UC Davis and the U.S. National Plant Germplasm System. Since 1980, they have planted the property with numerous species of fruits and nuts, keeping two “copies” each of several thousand varieties. The goal here is to maintain genetic diversity among the Central Valley’s commercially significant food plants and—in the worst-case scenario—be able to locate somewhere on the premises an individual tree or vine with a natural resistance to a particular disease and employ that gene to defend against the invading pest.

On a daily basis, however, the Wolfskill Experimental Orchards involves itself in less-sober affairs. The staff sometimes leads fruit-tasting tours or hosts picnics in the shady groves for magnates of the wine and food industry. Plant breeders, botanists, farmers and amateur gardeners frequently check in, too, to request clippings of rare trees.

“This is basically a library here,” said Bernard Prins, horticulturalist and grape expert at the orchard. “Others come to us to get materials for their research. We’ll send clippings free of charge to almost anyone.”

In recent years, the orchard has seen the public’s interest in figs increase dramatically.

“We’ve had a huge increase in fig requests,” said Garrison. “There were a few articles and books written in the last few years, and the interest has skyrocketed. I think if people had access to some of our really good varieties, there’d be even more interest.”

Aside from the common commercial breeds of figs, like Black Mission, Kadota and Brown Turkey, there grow rows and rows of virtually unheard-of varieties in the Wolfskill fig orchard, such as Violette de Bordeaux; Panache; and Pied de Boeuf, French for “foot of beef.” In all, Wolfskill hosts 274 varieties of figs from the genus Ficus. Some of these fig trees produce red fruits; others, yellow; and some, striped—and nearly all these figs are perfectly good to eat.

Figs originated in the eastern Mediterranean region and have been cultivated for thousands of years. Popular among the ancient Greeks and Egyptians, the first fig trees made their way to California with the Spanish missionaries in the late 18th century. Various sorts continued to arrive in the following decades, and through experimental grafting, plant breeders have produced many varieties unique to California, including the Stanford, Sierra, Conadria, Tena and DeRido figs.

In the late 1800s came the well-liked Smyrna fig—today called the Calimyrna in America—from Turkey, but several years later the young Central Valley orchards still bore no fruit. Suspicions arose.

“The farmers felt they’d been duped by the Turks into buying barren fig trees,” said Garrison.

At last, farmers and botanists discovered that these trees, unlike most other figs, required pollination from an insect known in Europe simply as the “fig wasp.” This insect dwells for long periods of time inside the inedible caprifig, which provides the required pollen. Between 1890 and 1899, farmers secured numerous shipments of this fig from Greece, Algeria and Asia Minor. It took some time and experimentation, but in 1900 Central Valley growers finally succeeded at pollinating their orchards and producing California’s first crop of Smyrna figs. Today the state’s commercial fig industry is centered mostly around Fresno and occupies 13,000 acres of land.

Other residents of the Wolfskill Experimental Orchards include nearly 500 varieties of walnuts, 150 varieties of pomegranates, 200 varieties of pistachios, 1,200 varieties of plums and 140 varieties of olives. The farm also grows numerous apricots, cherries, persimmons, mulberries, kiwis, almonds and peaches.

However, the most prominent inhabitant of Wolfskill is the grape. Along the eight miles of trellis grow 3,000 different varieties. Among these are such tasty oddities as the Suavis grape, which is said to possess a flavor so strong it hits one like ingested perfume, and the Sultana Marble, a delicious yet completely colorless albino variety. In all, there are approximately 600 quality table grapes in the Wolfskill vineyard and that many more that may produce marketable wine. Who would have known? Not the average Californian, who is likely most familiar with just a few varieties of Vitis vinifera, like Thompson Seedless, Merlot and Zinfandel, which together occupy 800,000 acres of California vineyards.

“As plant breeding advances, a lot of these older varieties get left behind,” said Ed Stover, curator and research leader at Wolfskill. “But we hang on to them to preserve the genetic material and keep them from falling to the wayside.”

About a dozen new breeds enter the vast Wolfskill collection each year, and Stover is currently bushwhacking through the remote forests of the nation of Georgia, just east of the Black Sea, to collect more specimens. In particular, he is seeking new varieties of grapes while keeping a sharp eye out for Vitis sylvestrus, the original wild descendant of all the wine and table grapes we know today. While several nations in the eastern Mediterranean and Caucasus region claim to be the ancient motherland of grapes, Stover feels his best shot is in the Georgian backwoods.

“And hopefully Ed will find some new figs while he’s there,” mused Garrison, who meanwhile tends to the Wolfskill orchards, eliminating weeds, trimming the trees and sampling the ripening fruits.

The Wolfskill Experimental Orchards represents just one of 32 locations nationwide of the U.S. National Plant Germplasm System. This organization received a sharp increase in funding from the U.S. Department of Agriculture after a fungal disease nearly destroyed the nation’s corn crop in 1970. Botanists managed to stop that plague by reverting to sturdier corn hybrids that most farmers had long since abandoned, but the event served as a heavy warning of what might easily happen in the absence of a ready supply of genetic material for use in crossbreeding.

“We’re protecting against future calamities,” said Prins. “Who knows what disease could come along in the next 50 years?”

He pointed to a case in the 1870s in which an aphid called the grape phylloxera spread across much of southern Europe, killing millions of grapevines before a wild American grape species was transported overseas and utilized as a bug-resistant rootstock. Farmers then grafted their traditional European wine-grape varieties on top and thereby re-established the damaged industry.

“By keeping a broad spectrum of genetics here, hopefully somewhere in our selection we’ll always have individuals that can fight a disease,” Prins explained. “I like to think this is one of the better uses of the nation’s tax dollars.”