Organic tree fruit growers in the Pacific Northwest are concerned that the National Organic Standards Board might drop its approval of the antibiotic Mycoshield (oxytetracycline or tetracycline) for organic production in 2012. The product is used to manage fireblight in apples and pears.

The NOSB has a list of more than 200 products that are synthetic, but allowed in organic production. Under a sunset clause, products that have been on the list for five years are removed, unless the board decides otherwise, according to Marty Beagle, program manager for the Washington State Department of Agriculture’s Organic Program.

Dr. Mike Willett, vice president of scientific affairs with the Northwest Horticultural Council, said the board routinely does sunset reviews to find out if organic alternatives are available yet. In addition, the NOSB conducted a special review of antibiotics in general after it was asked to approve an additional formulation of oxytetracycline.

Public comments about products on the list can be submitted to the board in writing or at meetings held twice a year. The written comment period for tetracycline ended in March.

Organic apple grower Gary Middleton of Eltopia, Washington, testified on behalf of the Washington tree fruit industry and Washington Tilth at a meeting of the board held in late April in Woodland, California.

Speaking from the perspective of a small, family orchardist, Middleton told the board he has a 16-acre block of Gala apples in which he has lost more than 4,000 trees to fireblight over the past five to seven years. Without Mycoshield, he would have two options: either go back to conventional production or continue to remove trees as they become infected until it’s no longer feasible to keep the orchard.

Biological products have been introduced for fire­blight control, such as BlightBan (Pseudomonas fluorescens A506) and Bloomtime (Pantoea agglomerans strain E325), but Middleton said they’re more expensive than antibiotics and only suppress fireblight rather than control it. “I have used them in our orchard, and I can tell you, the results are not positive. We would love to embrace a truly organic product that works.”

Middleton said he felt so strongly about maintaining the use of Mycoshield that he traveled for 29 hours to the California meeting to give his allotted five minutes of testimony. In an effort to dispel the notion that there would be widespread use of antibiotics if they continue to be approved, he told the board that the risk of fireblight is highest in certain varieties, such as Pink Lady, Gala, and Fuji, and particularly when the trees are on dwarfing rootstocks, such as Malling 9 or 26. Antibiotics are only applied to sensitive varieties and when conditions are highly conducive to fireblight, as indicated by Washington State University’s CougarBlight model. They are only used in bloom, which is the only time they’re ­effective.

“I think the philosophy is we’re just going to go out and use antibiotics on all our orchards regardless of the ­infection in the orchard,” he commented afterwards. “I tried to give them the message that we don’t go out and just spray on an all-the-time basis or just because we think there might be fireblight out there. We’re doing it in strict conditions. We don’t want to use it more than we have to.

“But once you get fireblight in your orchard, your options are pretty much gone. You’d better be very ­aggressive in the treatment of the fireblight.”

Oregon Tilth members and Bob McClain of the ­California Pear Advisory board also spoke in support of maintaining approval for antibiotics.

Beagle said the Washington Organic Program submitted written comments to the National Organic Program saying that tetracycline is the only available effective substance to combat fireblight in apples and pears, although alternatives are being researched.

The board will make a recommendation to the National Organic Program on which products should continue to be approved. The board voted on several products following its April meeting, but might not make a decision on the rest (including tetracycline) until the fall, Beagle said.