China has reopened its doors to California citrus exports.

Exeter-based California Citrus Mutual received written confirmation Aug. 4 of an earlier verbal commitment to reopen markets, which had been closed since April 2013 after brown rot was found in shipments.

Joel Nelsen, Citrus Mutual’s president, credited the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service with finalizing the agreement, which ran into roadblocks after meetings in November and June.

“USDA educated officials on the merits of what we discussed, and the Chinese government said OK,” Nelsen said.

California ships about 4 million to 5 million cartons of citrus annually to China, making it one of the state’s leading export markets.

Chinese and American officials met in California in June, but a deal was not finalized there. One sticking point, Nelsen said, was a disagreement over the level of standardization growers and packers need to observe to prevent brown rot.

In the final agreement, U.S. officials made some minor changes but did not change the protocol to reflect the Chinese desire for what Nelsen called more “regimentation.”

“USDA said that what the industry was doing was as good as can be to prevent the spoilage problem they were concerned about. They said it’s as regimented as it’s going to get.”

Chinese markets technically opened for California exports as soon as the agreement was signed, but practically speaking, orange shipments to China are finished for the season and won’t resume again until the 2014 crop begins shipping to China, likely in December, Nelsen said.

Exports to China and other markets in 2014-15 will be disproportionately affected by lower California production caused by drought problems, as shippers look to take care of domestic customers first, Nelsen said.

The California industry will have a better handle on the drought’s affects on 2014 production when the California Agricultural Statistics Service releases its estimate the second week of September, Nelsen said.