WASHINGTON, DC (March 3, 2014) – With approved antibiotics for fire blight control expiring for organic apple and pear growers this fall, The Organic Center has released an essential report featuring existing practices and emerging research to help growers control fire blight while maintaining organic certification.

“Grower Lessons and Emerging Research for Developing an Integrated Non-Antibiotic Fire Blight Control Program in Organic Fruit” – available here – collects critical knowledge from U.S. apple and pear growers who already practice fire blight prevention without the commonly used antibiotic oxytetracycline that the National Organic Standards Board (NOSB) will begin sunsetting in October 2014.

Funded by The Organic Center, the 28-page report arrives as up to 70 percent of growers in a surveyed region said they may transition from organic to conventional management in face of NOSB’s changes if proven alternative organic fire blight control methods are not available.

Organic Growers Exposed, Supply at Risk as Standards Phase Out Antibiotics
Unlike some fruit pathogens, fire blight doesn’t just damage or destroy a season’s fruit – it can kill the entire tree under severe conditions. It is caused by the bacteria Erwinia amylovora, spreads easily among trees and orchards, and can infect at different points in the growing season.

For decades, the primary control of fire blight in U.S. organic production has been the antibiotics streptomycin and oxytetracycline. But, NOSB has approved a proposal for phasing out their use beginning this October. Dr. Ken Johnson, Oregon State University, is leading a three-state USDA-OREI project on non-antibiotic control of fire blight in organic orchards to be completed in 2015.

“The interim year between approved antibiotics sunsetting and release of the OREI project findings leaves growers with minimal guidance and experience for non-antibiotic fire blight control,” said Dr. Jessica Shade, Director of Science Programs for The Organic Center. “It’s unfortunate timing, as organic apple and pear demand are at all-time highs. If U.S. production declines, organic apple and pear prices could spike, or imports from South America – where the disease is not present – could greatly increase.” 

Organic Center Encourages Testing Alternatives Now
“Grower Lessons and Emerging Research” encourages organic apple and pear growers to begin testing alternatives now with integrated non-antibiotic fire blight control options that have proven successful for some organic growers.

The report is based on field experiences from organic growers who have already developed various approaches to non-antibiotic fire blight control – particularly exporters to Europe, which does not allow antibiotics – along with preliminary results from a range of research trials on new materials and strategies.

The study suggests successful non-antibiotic fire blight control combines orchard management practices with an integrated systems approach for prevention. The report features suggestions for fungal control, insect control, bloom thinning, spray coverage, tree training, soil and foliar nutrients, and cultivar and root stock selection. It also provides detailed considerations for each stage of apple and pear production. Some of the research is now validating the grower practices, such as the fire blight control from lime sulfur blossom thinning sprays.

According to Dr. Shade, once Oregon State’s findings are available in 2015, growers can combine the university’s recommendations with The Organic Center’s report to get the benefit of the latest research as well as field-proven strategies.

The study’s co-authors are Harold Ostenson, a Washington-based tree fruit consultant, and David Granatstein, Sustainable Agriculture Specialist for the Washington State University Center for Sustaining Agriculture and Natural Resources.

(Source: organic trade association)