(Corrects headline and paragraph 8 to read "structures" instead of "homes" after Ventura County fire officials corrected their earlier statement)
By Steve Gorman
LOS ANGELES, Nov 1 (Reuters) - A fast-moving scrub fire threatened orchards, oil fields and homes while displacing thousands of residents in Southern California on Friday, even as diminishing winds helped fire crews tame a rash of wildfires elsewhere across the state.
The latest in a spate of conflagrations that have kept California firefighters on the go for weeks roared to life on Thursday evening near the hilly farm community of Santa Paula, about 70 miles (112.65 km) northwest of Los Angeles.
As the Maria fire raced across nearly 9,000 acres (3,642 hectares) of dry brush and chaparral, firefighters scrambled to protect tens of millions of dollars worth of citrus and avocado crops in harm's way, as well as nearby oil industry infrastructure.
The blaze also threatened high-voltage power lines in the vicinity, along with radio and communications towers at the top of a large hill called South Mountain, where the flames originated, Ventura County fire officials said.
"There is still cause for caution and concern. We are not out of the woods yet," county fire chief Mark Lorenzen told an evening news conference. "We still have 24 hours of critical fire weather ahead of us."
He said an estimated 1,300 firefighters, many from elsewhere in California and the Western United States, were assigned to the blaze.
By sunset, the fire was threatening some 2,700 homes and other structures, with roughly 10,800 people under evacuation orders, Sheriff Bill Auyb told reporters.
No injuries were reported, but at least two structures were destroyed, county spokeswoman Natalie Hernandez told Reuters by phone.
Oil production equipment at stake, belonging to California Resources Corp, includes wells, pipelines, storage tanks and pumping plants, Hernandez said, adding there was little vegetation immediately surrounding those facilities.
"The oil fields have good fire clearance, so that works to their favor," she said.
The overall fire zone also encompasses a lemon and avocado crop valued at between $95 million and $120 million, said Korinne Bell, the county's chief deputy agricultural commissioner.
Preliminary assessments have found trees scorched and burned around the perimeter of a number of orchards, though the full extent of damage has yet to be determined due to limited access, Bell told Reuters.
She said avocado orchards are more susceptible to fire because they have a higher oil content than citrus and accumulate more "leaf litter" at the base of their trees, making them more flammable.
"There are a lot of avocados, but far more lemons, which is good news because lemons don't burn as easily as avocados do," she said.
Crop inspectors also found many trees covered in flame-retardant slurry dropped by firefighting airplane tankers during the day, she said.
The fire erupted just as fierce Santa Ana desert gusts had begun to subside after howling across much of Southern California for two days. But strong, erratic winds were expected to persist through Saturday in many mountainous and foothill areas, including the Santa Paula fire zone.
Elsewhere, subsiding winds helped in gaining control of several fires in the region that had broken out earlier.
Just 30 miles (48.28 km) to the east in Simi Valley, a blaze that raged to the edge of the hilltop Ronald Reagan Presidential Library on Wednesday was 60% contained on Friday, while containment on a separate fire that had threatened the Getty Center art museum and thousands of homes in west Los Angeles on Monday was listed at 66% contained.
East of Los Angeles, the 200-acre (80-hectare) Hillside fire that burned several homes early on Thursday in the north end of San Bernardino was 70% contained by Friday.
The latest recurrence of seasonal Santa Ana winds coincided with extremely low relative humidity levels and a prolonged lack of rainfall that has left vegetation tinder-dry in the region.
While all the latest fires remain under investigation, wind-related damage to power lines has been implicated in a number of major California blazes, including the Getty fire.
Pacific Gas and Electric Co acknowledged last week that the Kincade Fire, which charred 77,000 acres (31,160 hectares) of Sonoma County wine country north of San Francisco, started last week near a damaged PG&E transmission tower at about the time a high-voltage line on that tower malfunctioned.
That blaze, which destroyed at least 349 homes and other structures, was listed as 65% contained on Thursday evening. (Reporting and writing by Steve Gorman in Los Angeles; Additional reporting by Jonathan Allen in New York; Editing by Jonathan Oatis and Sandra Maler)