University of California Cooperative Extension farm advisors believe the papaya, a fruit most often associated with the year-round mild and humid climates below the Tropic of Cancer, could be a profitable new specialty crop for California farmers.

Growing specialty crops can be like shooting at a moving target, farm advisors say. When a new crop proves successful, it's not long before more farmers jump in and a glut forces prices down. That has UCCE's small-scale farm advisors continuously searching the globe and field-testing new ideas to share with California growers.

Six UCCE farm advisors visited the state of Veracruz, Mexico, in May 2003, to study crops and growing methods for a wide array of exotic fruit, including mangos, tamarind, pineapple, soursap, zapote, cashew fruit, vanilla, papaya, mangosteen and lychee. Despite the vast difference in climate, many have potential for California farms and greenhouses.

Papayas, for example, are currently under study at the UC Kearney Research and Extension Center near Parlier. UCCE Tulare County farm advisor Manuel Jimenez believes the tropical delicacy could be a part of some small-scale farmers' rotations.

“Papaya is very inexpensive to grow, even when compared to traditional vegetables, such as squash,” Jimenez says. In contrast, blueberry, an increasingly popular specialty crop, is “outrageously expensive to start,” he said.

Papayas don't seem to mind Central California's warm summer sun, and even though Jimenez's first crop at the Research and Extension Center didn't ripen last year, he is not deterred. Unripe papayas are suitable for cooking and popular with consumers of Asian descent. The unripe fruit may be baked like winter squash or pumpkin or used for chutney.

Hawaii, mexico

Most of the ripe papayas found in California grocery stores are imported from Hawaii or Mexico. The smooth-textured, vitamin C-rich melon-like fruit has yellow to orange flesh and skin color that ranges from green to orange to rose.

Commercial papaya production has been troubled worldwide by the plants' high susceptibility to plant viruses. Most papayas grown in Hawaii are genetically modified to be resistant to disease. In Veracruz, Mexico's No.1 papaya producing state and the site of the recent Mexico study tour, farmers are finding that growing the perennial tree as an annual crop helps alleviate viral losses.

At Rancho Neveria, a small farm near the Veracruz city of Cardel, agronomist Honorio Fernandez spoke to the UC farm advisors from meticulous handwritten notes about the ranch's annual papaya production system. Fernandez outlined details from the soil mix for growing seedlings to plant spacing in the field. About 2,700 seedlings are transplanted per hectare. Before harvest, a quarter of the plants have been pulled due to viral infection.

Nevertheless, the approximately 2,000 remaining plants produce a profitable crop before succumbing to disease.

At Rancho Neveria, plants are started in the screenhouse and field planted any time of year, giving farmers the option of aiming to market fruit at a time when prices are expected to be at their highest.

In California, the climate gives farmers less flexibility. A typical San Joaquin Valley winter will kill the plant, squeezing the growing season between February and November. However, Jimenez says he will try to plant papaya in late summer, and then protect the small bush under a movable “hoop house,” which many vegetable producers already own.

“This is an exciting crop to grow,” Jimenez said. “I'd be happy to see a few farmers attempt a crop like papaya.”

For more information, contact Jimenez at mjjimenez@ucdavis.edu.