Building a Better Berry : UC Research in Irvine, Davis Yields 6 New Plant Varieties

IRVINE —  The Cuesta strawberry, known until recently as C-202, is sharply sweet on first bite, then becomes tart. The Camarosa, formerly variety C-25, has no taste for the first instant. But when chewed, it bursts into a sharp, sweet flavor with a hint of sour aftertaste.

By contrast, the variety of strawberry Southern Californians find most often at the market--the Chandler--tastes familiar, even ordinary.

The Cuesta and Camarosa are two of six new strawberry varieties introduced by the University of California last month for commercial use--the first such release in six years. Among them are the Anaheim strawberry, the Laguna strawberry and the Carlsbad strawberry.

Strawberry production, which generated $512 million in revenue for farmers statewide last year, represents an important segment of one of California’s leading industries. The Golden State produces 75% of the nation’s strawberry crop and ships 12% of its berries overseas to Japan, Australia and Canada.

California ships fresh strawberries every month but December--and even then it’s possible, depending on the weather. Strawberries are the No. 1 crop for Santa Cruz County and No. 2 in Monterey, Ventura and Orange counties; statewide, they are the 11th-largest cash crop.

A dozen private companies and several universities have competed with the UC system to breed a better strawberry. But after more than 50 years of experiments at field stations in Irvine and Davis, the UC system has managed to produce varieties that are used in nearly 90% of the world’s commercial production.

Advances in breeding have made the strawberry popular, especially where land is limited. Through the years, plant scientists have enabled growers to produce 20 tons of strawberries from one acre of land, compared with about 1 ton per acre at the turn of the century.

California strawberries are bigger now too, weighing as much as 50 grams. By contrast, their ancestors--like those still grown on the East Coast--weighed about 10 grams at their largest.

“We all started with something wild that would grow in meadows,” said Kirk D. Larson, a horticulturist who runs the UC field station in Irvine. “But we’ve been able to make that much more progress in the California program.”

Breeders make a new strawberry by cross-pollinating “parent” berries in the hope that the next generation will inherit the proper characteristics. The possible combinations are vast: Each berry has eight sets of chromosomes, compared with the two sets found in humans.

The six varieties just released are, in general, heartier, with firmer skin to allow for durability in shipping. They taste better, their creators believe, and they are more resistant to disease.

The plants also have the potential to produce more berries in January and February, which is a window of opportunity for Southern California--the time of year when no one in the nation can match this region’s berry production and quality. Southern California’s most popular variety, the Chandler, produces some berries early but does not hit peak production until April.

June is the end of Southern California’s strawberry season, and growers are picking berries now to be frozen. They will plant other row crops during the summer--tomatoes or celery--and begin with strawberries again in October.

For each of the new varieties, 20,000 to 25,000 strawberry plants were grown and tested. It’s still anybody’s guess, though, whether the new varieties will meet with grower approval.

“The C-25 (the Camarosa) looked excellent” in terms of production yield, size, flavor and appearance, said Bill Ito, whose Ito Farms in Cypress and Irvine grew some sample plants this season.

“The other (varieties) had good and bad to them,” said Ito, whose family has been farming Orange County soil for three generations. “I’d like to have another year looking at them. But, at this point, at least (the Camarosa) looks real good.”

Larry Galper, a grower who has been testing these “super” berries in the Central Valley, said that a couple of the new varieties seem to have potential. He too is reserving judgment for another season.

“That so many of the (new varieties) have come this far--that they’ve been named and that they look as good as they look--is cause for real excitement,” said Galper, who is also chairman of the research committee for the Watsonville-based California Strawberry Advisory Board, a trade association.

There is a sentimental attachment to the new varieties as well. Four of them are the work of Victor Voth, 72, who staffed the UC system’s Irvine field station for 41 years until his retirement this year.

“This is Victor’s last hurrah, and I think he would like something to go out with,” said Galper. “The whole industry has its fingers crossed that that will happen. Vic has put a lot of people in Mercedeses and Cadillacs.”

The University of California and the growers began working together around 1910, about a decade after strawberries first began to be raised commercially in the state.

At that time, strawberry plants in the Watsonville area of the Central Valley had begun coming up stunted and yellow. Growers brought the plants to the department of plant pathology at UC Berkeley.

After 15 years of study, the Berkeley scholars determined that aphids were transferring a virus called xanthosis from plant to plant. They began cross-pollinating strawberry plants to create some that were more resistant to the virus, and the UC breeding program was born.

In 1945, UC fruit scientists Harold Thomas and Earl Goldsmith introduced five new strawberry varieties. The Lassen and Shasta, especially, were hailed as quantum improvements on East Coast varieties. They produced more and better fruit, resisted disease and kept growing throughout the nearly year-round California season.

Ironically, just as the program was meeting with success, the University of California listed it as “nonessential” to the World War II effort and abandoned it.

Racism may have played a part in the decision. At the time, many California growers were Japanese-American. Today, about half of those who grow strawberries in Orange County are Japanese-American.

With the program closed, the university’s fruit scientists, officially called pomologists, formed a private, nonprofit enterprise, the Strawberry Institute of California. The institute evolved into a commercial breeder and grower, Driscoll Strawberry Associates Inc., now based in Watsonville. Driscoll has patented its own strawberry varieties but does not license them to other growers.

By 1952, the University of California had reopened its strawberry breeding program. This time, it was run by UC Davis, with field stations in Davis and Irvine. Pomologist Victor Voth was on staff in the south, with Royce Bringhurst working up north.

The pair, during their years with the program, released more than 40 varieties of strawberries, each an attempt to improve upon existing crops. Three have proven the most durable and are the dominant California varieties today: Chandler, Douglas and Selva.

Voth and Bringhurst also perfected breeding and cultivating methods. They introduced drip irrigation to berry production, fertilizer buried at root level instead of scattered on the soil, wide beds and optimal planting dates.

In 1985, Bringhurst retired and was replaced at the Davis station by Douglas V. Shaw, a specialist in genetics and plant breeding.

Shaw developed two of the six varieties released in May--the Sunset and the Cuesta. Voth bred and named the other four, the Camarosa, Anaheim, Laguna and Carlsbad.

Today, the University of California funds about 40% of the cost to run the two field stations. Strawberry growers tax themselves a nickel a tray to pay the other 60%, or more than $400,000, of the $700,000 annual budget.

While the strawberry breeding program may have made some California farmers wealthy, it has also worked out well for the university.

In 1992, the school collected $1.69 million in royalties for the varieties produced by its researchers. And UC strawberry research is known worldwide; UC-created varieties are now grown from Spain, Italy and North Africa to Mexico, Chile and Australia.

Larson, the horticulturist at the Irvine field station--nestled between stately eucalyptus trees and the Santa Ana foothills--has worked in the breeding program for two years alongside Voth and will now take over.

Each year, Larson plants 7,000 seedlings derived from different parent plants. He takes notes on those plants for four or five months before selecting 2%, or about 150, to be propagated during the next season.

The following year, Larson narrows those selections down to 30, then to 10. He bases his decisions on the look and taste of the fruit and the production and health of the plant. The varieties are grown at different distances from one another--14 inches, 18 inches--to determine which is optimal.

At the same time, 7,000 more seedlings are planted each season.

It takes four to seven years to decide whether a new variety is good enough to be named and released for commercial use.

Part of what Larson does for a living he calls “the ugliness of life.”

“It can be a daily grind,” he said. But each time he takes the next step--narrowing the field of 7,000, say, to 150--he gets “a whole new feeling about it. It’s very exciting work.”

Because his predecessors made so many important advances, Larson said, he will be pleased if he accomplishes one-tenth of what they did.

Within a few days, the strawberry industry expects to learn whether it faces a new hurdle. The federal Environmental Protection Agency has been considering outlawing methyl bromide, a clear, odorless gas used in the soil to kill insects, mites, rodents, weed seeds and soil-borne diseases that attack strawberries.

The EPA may label methyl bromide a “Class 1” danger to the Earth’s ozone layer, said Frank Westerlund, research director for the Strawberry Advisory Board. If it does so, the chemical must be abandoned, per the Clean Air Act, by the year 2000.

It is unlikely that another such efficient chemical solution will be found to kill strawberry predators, Westerlund said, because alternative solutions were thoroughly explored in the 1940s and 1950s. He is focusing his own research efforts, in conjunction with UC Davis, on disease-resistant plants.

Westerlund began his 17-year career as a plant pathologist, working with vegetables. Some years ago, he switched to strawberries, then back to vegetables. But he felt he had to return to strawberries.

“There’s something about strawberries that fascinates” plant scientists, Westerlund said. Because of its profitability and the huge advances made in the field, he said, “growing strawberries is probably the ultimate in scientific farming.”

Big Berry Business

Orange County strawberry growers will have six new varieties to choose from, thanks to researchers at University of California field stations in Irvine and Davis. Among the new varieties are those that ripen in January and February, making local growers more competitive. The county strawberry scene for the five years: 1992: Acreage: 1.7 (In thousands) Production: 52.6 (In thousands of tons) Wholesale value: $40.3 (In millions) Source: Orange County Agricultural Commissioner