The newly-revised Good Agricultural Practices Manual for California pistachio growers features new information to help reduce the risk of food-borne contaminants.

The 31-page publication is now available online at: www.acpistachios.org/growers.htm

The manual, originally published by the California Pistachio Commission, has been updated by the California Pistachio Research Board in response to the recall of pistachios in April due to concerns about possible salmonella contamination.

Bob Klein, who manages the board, as well as the Administrative Committee for Pistachios, a Federal Marketing Order that sets maximum aflatoxin tolerance levels and mandatory inspection and certification procedures for pistachios produced and handled in California, says, “We thought it was important to encourage growers to look more closely at the potential for microbial contamination of pistachios — where it might occur, how it might get into pistachios and what they can do about it.”

The 2009 edition contains new chapters, covering topics not presented in earlier editions or providing more specific information than before. Among the updated recommendations:

• Aflatoxin. Noting that nuts damaged by early splits and navel orangeworm account for over 90 percent of the aflatoxin present in pistachios at harvest, the manual urges growers to harvest earlier rather than later, even though that’s not always possible because of limited harvest equipment and hulling capacity. Growers with large acreages are encouraged to consider split harvest, with a light shake to remove the earliest-maturing nuts and a second shake to remove the later-maturing crop.

• Water quality testing. In addition to checking wells for microbial contamination prior to irrigating, the manual suggests conducting the test when contamination risk is highest — especially during the rainy season, when contaminants can be leached into wells through cracked casings and improperly-positioned wellheads. This also allows time to correct problems before irrigation is needed.

• Field sanitation. Nuts that fall to the ground can become contaminated with bacteria, manure, compost or animal feces. “It borders on the ridiculous,” the manual notes, “to carefully control field activities to reduce potentially microbe-laden dust contaminating the nuts on the tree, and then turn around and throw a shovelful of dirt and nuts into the bin or bulk loader while gleaning the fallen or spilled pistachios.

• Sanitation and hygiene. Even if a farm labor contractor provides a portable latrine for worker use, the manual advises growers to make sure the facilities are adequate, because growers bear the risks associated with poor field hygiene. Regardless of who supplies the latrine, growers should have a plan in place for properly disposing of wastes, as well as contingency plans for containing and cleaning up any leakage or spills.

Klein also recommends producers complete the revised Pistachio Grower Self Audit before harvesting and delivering nuts to processors. The audit, designed to help growers understand how to apply Good Agricultural Practices to their operations, has been developed by the California Pistachio Research Board.

The latest self-audit (also available at www.acpistachios.org/growers.htm) is much shorter than earlier versions.

“You should keep these self-audits and give them to processors at their request,” Klein says. “This is an important part of the comprehensive food safety program necessary to insure the long-term stability and profitability of the pistachio industry, as well as insuring consumer confidence in our product.”