Valencia oranges, under siege in California, fight to survive

PAUMA VALLEY, Calif. — The vista from the foothills of Mt. Palomar recalls classic citrus labels, a sea of green dotted with bright orange fruits. Frost-free, with south-facing slopes, pure water and good drainage, this is among the best land in Southern California for growing Valencia oranges and one of the last redoubts for an iconic but besieged crop.

Bob Polito, 62, grows 42 acres of Valencias in Pauma Valley and nearby Valley Center and sells top-quality oranges and juice at the Santa Monica, La Cienega and Venice farmers markets. Easygoing and phlegmatic, he loves the groves he has farmed since 1981 but is pessimistic about his industry. Water cutbacks and sky-high water prices forced him to remove a third of his trees. Next to one of his groves lie rows of tangled debris from dead Valencia trees, uprooted by a neighbor who gave up the fight.

Now Polito fears that huanglongbing, a bacterial disease deadly to trees and spread by a tiny insect called the Asian citrus psyllid, will destroy his groves. The psyllid, first detected in 2008, has spread throughout Southern California; the disease was found in just one tree, in Hacienda Heights last year, but a new infection could be discovered at any time. The best hope for long-term survival is to kill the psyllids, but Polito thinks it’s futile to spray his home ranch in Valley Center, where neglected small plantings and backyard trees abound.

In Pauma Valley larger growers prevail, and they have banded together to conduct area-wide spraying, the only efficient method. But it is unclear if they can succeed while nearby areas provide a source of psyllids for reinfestation. The fate of Southern California’s most emblematic crop hangs in the balance.

Scientists long ago found oranges resembling Valencia in China but have not been able to trace it to specific parents. The variety that would eventually be called Valencia was sent in the early 1860s from the Azores to Thomas Rivers, an English nurseryman. He shipped trees to a nursery on Long Island, which sent the variety to A.B. Chapman of San Gabriel in 1876.

It took a few decades to catch on in California, but the Valencia’s exceptionally fine flavor and late season led to its prevalence as the state’s most widely grown citrus fruit until 1970, when navel oranges regained the first ranking. At its peak 60 years ago California grew 123,000 acres of Valencias, 90% of them in Southern districts, from Ojai to Escondido.

Today just 38,000 acres remain statewide and a 10th of the Southern plantings, 11,000 acres. Production is still declining, although not as rapidly as before.

What happened? Competition increased from navels, both domestic and imported; from many other fresh summer fruits; and from orange juice shipped from Brazil in supertankers. Consumers opted for more convenient packaged juice in supermarkets. As orchards aged and became infected by disease (particularly phytophthora, a water mold, and tristeza, a virus), they bore lighter crops and smaller, less valuable fruit. Facing an uphill battle to remain profitable, most growers succumbed to development.

Even so, Valencias are still among the most abundant crops at local markets, and for quality and availability there is nowhere better in the world. Used for juicing and for eating fresh, Valencias have a few seeds and don’t peel as easily as navels, but their juice has a richer flavor, and it doesn’t develop delayed bitterness after a few days, as navel juice does.

In the Central Valley, which grows three-quarters of the state’s crop, the season starts in March and runs through October but peaks in the spring and fall. Shipments slow in summer, when fruits in many groves become green again as chlorophyll returns to the rind and carotenoid content decreases; although regreened fruits become less attractive, their flavor is unimpaired.

Southern California Valencias are somewhat smaller and have thinner skins but arguably superior flavor. Valencias grow best in intermediate climatic zones, such as Santa Paula to Piru in Ventura County or Pauma Valley and Valley Center in northern San Diego County, where it is often cool in the mornings and evenings and hot in the afternoons. Some Southern California growers harvest as early as April, when the fruit is tart, but peak quality arrives now, in early summer. Regreening is only a problem in the hottest areas.

About half of California’s Valencia crop is exported, mostly to Eastern Asia, which pays premium prices for first-grade fruit.

The commercial harvest ends in late fall, when local navels begin and Valencias get too soft to ship, but many farmers market growers pick through the winter. Late-harvest Valencias are easier to peel, and their juice is dark, syrupy and super-sweet, too much so for some tastes. When too mature the fruits become puffy, with creased rinds and open centers, acidity drops and the flavor become insipid.

Early in the season the largest fruit are the first to sweeten, but by now all sizes should be good. Smaller fruit remains in prime condition on the tree later in the season. Packinghouses pay the most for larger fruit, which is most in demand for export; for juicing, smaller fruit, which tend to be less expensive, are more suitable.

Citrus scientists classify Valencias as common sweet oranges: “common” because they don’t have unusual features like a navel or red flesh, and “sweet” to distinguish them from sour oranges, which historically have been considered another species (Citrus aurantium). Valencia is the most widely cultivated sweet orange in the world because of its high quality and because it is adapted to a broad range of growing areas.

The sweet orange (C. sinensis) arose through natural crossing thousands of years ago, probably in southern China or Southeast Asia. It is 5/8 mandarin and 3/8 pummelo, as scientists recently determined from analyses of molecular markers. It derived sweetness and rich aromatics from mandarin and greater size and firmness from pummelo.

Sweet oranges likely originated from a single tree and then were propagated by humans because of these desirable characteristics, which made them ideal for eating fresh and for juice and reasonably suited for shipping or storing. In the past orange trees could be readily multiplied because most bear true from seed, but they are propagated today by grafting. All sweet oranges are genetically similar but small mutations over the centuries account for variations like Valencia’s late season.

Over the decades growers and nurserymen have further distinguished several dozen selections of Valencia, most of them indistinguishable to the layman, such as Cutter and Olinda, the two main strains grown in California. Three with more significant differences are Rohde Red, which has deeper orange colored flesh; Delta, which has fewer seeds; and Midknight, which is low-seeded, earlier maturing and develops excellent flavor in the Central Valley, where it is commonly grown.

Noncommercial variations include a variegated form, a light blood sport (Burris), and even a Fuzzy Valencia with a freaky beard of spine-like projections protruding from its blossom end. Most intriguingly, scientists and nurserymen in South Africa and Brazil are studying pink-fleshed mutations of common sweet oranges like Valencia, which are pigmented with lycopene (like red grapefruit and Cara Cara navel oranges) and eventually may provide a commercial source of pink orange juice.

Domestically Florida is by far the largest Valencia-producing state, with 240,000 acres in 2012. More than 97% of its harvest goes to commercial juicing, whereas more than 80% of California Valencias are sold fresh. Florida dominates the juice market because groves in its more humid, tropical climate yield more pounds of solids per acre, the most significant measure of production for juice. California dominates the fresh market because its Valencias are more attractive, with deeper orange colored rinds and flesh, and the flavor is higher in acidity, richer and more concentrated.

The harvest season for Florida Valencias is earlier, February to June. The fruits have pale rinds that typically are cosmetically blemished and flesh with more chewy “rag” (membranes and core) than California Valencias. Many of the Florida Valencias sold fresh come from younger trees, which produce fruit with fewer blemishes, but these tend to be somewhat lighter in color and flavor.

Over the last century Florida growers have faced many diseases but none have frightened them like huanglongbing, which is endemic throughout the state. This year’s Valencia production was a third lower than the average from a decade ago, as acreage declined and many fruits dropped from the sick trees. Although scientists are working furiously to come up with solutions, remaining growers fear that they may be out of business in a decade.

With a few discoveries of infected trees, California soon could be on the same path. Valencias have been a major crop in California since before anyone alive today was born, and it is easy to take for granted that they will always be available. Anyone who loves oranges can only encourage their farmers to fight and support them by enjoying the fruit and the juice while it is still grown in the state.

food@latimes.com