NORTH COUNTY -- Four states are still refusing to accept any California nursery products after the discovery of a tree-killing fungus at nurseries in San Marcos and Azusa last month and a subsequent federal inspection program intended to declare nurseries free of fungus.

The discovery of the sudden oak death fungus prompted the U.S. Department of Agriculture to issue general quarantine and inspection guidelines that would allow fungus-free nurseries to resume shipping their products. The disease was first discovered in California in 1995 and has been blamed for killing thousands of oak and other trees in this state and in Oregon.

Despite the federal guidelines and inspections by the San Diego County Department of Agriculture, Weights & Measures that have deemed 80 of the county's largest wholesale nurseries fungus-free, the states of Florida, Kentucky, West Virginia and Louisiana are still banning imports of California nursery products.

"We are still in the same position as we were because, while USDA declared the quarantine and inspection program so material could be shipped, the department still has not published the specific rules," said Janet Kister, owner of Sunlet Nursery in Fallbrook and president of the San Diego County Farm Bureau.

The federal government's plan to publish those rules today should lead to a lifting of the import ban, according to Cathy Neville, San Diego County deputy agricultural commissioner.

In early March, the fungus known as Phytophthora ramorum was discovered at Monrovia Nursery in Azusa in Los Angeles County. A few days later, the fungus was discovered in a container of plants shipped from the Monrovia nursery to Specialty Plants in San Marcos. The two discoveries prompted 10 states to immediately block all California nursery imports.

While six of the states have dropped the barrier, the remaining four are still refusing shipment and the states of Oregon and Washington have announced their own rules governing the importation of California nursery products, Kister said.

Nursery operators in San Diego County, which has an estimated 1,000 wholesale and retail nurseries, are reporting sales losses ranging from $10,000 to as much as $250,000, according to Kister.

"This is definitely affecting us," Kister said Thursday. "We have a very small window to ship these products to these states because they have a limited spring. When the weather heats up, they won't buy our products so we end up selling nothing."

Eric Larson, executive director of the county farm bureau, said the California Farm Bureau is working with elected officials and its contacts in Washington, D.C., to make certain the rules regarding the quarantine and inspection program are published. Agriculture officials in other states want to know all the rules before deciding whether the federal inspection program is sufficient.

The fact there has been no other discovery of the fungus at any of the inspected nurseries points to how isolated the problem is, Larson said.

"Our local ag department is doing all it can to show that there has been no expansion of the disease and the problem can be traced to a single location," he said. "That clearly shows things are under control."

Neville said county agricultural inspectors have been working overtime and on weekends to get the nurseries that sell products out of state inspected and cleared of having the fungus, whose spores are spread by moisture in plant material.

Until last month's discovery in Azusa, the fungus was thought to be limited to a 12-county region in Northern California where nurseries have been under the federal inspection program for years. There are about 40 plant species that can act as a host for sudden oak death. In plants such as camellia and rhododendron, the disease can be identified through spots on their leaves.

California's nursery industry rakes in more than $12 billion a year in combined wholesale and retail sales, according to agricultural officials. In San Diego County, the nearly 9,000 acres devoted to nursery and flower crops had a combined value of $855 million in 2001, according to county agriculture officials. Many of those nurseries are in North County, particularly in the Fallbrook, Rainbow and Vista area as well as Carlsbad and San Marcos.

At Specialty Plants in San Marcos, company President Paul Stevens said the fungus was found in a 1-gallon container of camellia shipped from Monrovia Nursery.

Stevens has termed the response of other states an "overreaction" and said his nursery is operating on a business-as-usual basis for all sales except those to the states that have instituted the ban.

Contact staff writer Mark Walker at (760) 731-5794 or mlwalker@nctimes.com.