Onion growers talk options

Lyndon Johnson, with Nunhems USA-Bayer Crop Science, talks with growers about onion varieties and seed during the annual Idaho and Malheur County Onion Growers’ Associations meeting in Ontario Tuesday.

ONTARIO—How federal water quality rules will shake out in the end has yet to be decided, but local onion growers have hope there is now enough flexibility in the proposed regulations to allow them to stay in business.

Under the Food Safety Modernization Act, in the agricultural water standards originally proposed by the U.S. Food and Drug Administration, the water that comes into direct contact with a crop’s harvestable portion could have no more than 235 colony-forming units of generic E. coli per 100 milliliters of water. If there was more generic E.coli than that, growers would be required to stop using that source of irrigation water.

That proposal brought heavy pushback from onion growers around the region, with lawmakers from Oregon, Washington and Idaho weighing in, as very little irrigation water would meet the standard. The rule was seen as a threat to the onion industry.

Then Malheur County intervened.

With research from the Malheur Experiment Station showing that most, if not all, E. coli on onions died off after irrigation stopped, before the onions were harvested, the FDA agreed to make changes to its proposed rule in regard to dry storage onions.

Those changes were a topic of discussion at the annual meeting of the Idaho and Malheur County Onion Growers’ Associations Tuesday at Four Rivers Cultural Center in Ontario. Joy Waite-Cusic of Oregon State University said the FDA’s revised rules offer growers more flexibility.

“One water test will not push [a water source] out of compliance,” Waite-Cusic said.

Under the proposed rules, 20 water samples would need to be taken to establish a baseline for the status of the water quality, followed by annual verifications, as close to harvest as possible.

Waite-Cusic, who is an assistant professor of food science and technology, said the new rules also allow for some pre-harvest E. coli levels above the standard because of the die-off that occurs after irrigation ends.

While the proposed allowance for die-off in the rules is just days long, Stuart Reitz, OSU extension agent, noted the time between the end of irrigation and harvest is usually weeks.

In his presentation, Reitz said the proposed revised rules focus on an average colony-forming units of E. coli. If the average exceeds the standard, there are effective treatment options that can help farmers meet the standards.

For drip irrigation, chlorine dioxide, in the right amounts, has proved effective in killing off E. coli in the water, while controlling the build-up of algae in the drip tapes.

For furrow irrigation, copper sulfate has been shown to be effective in reducing E. coli, Reitz said. However, delivery techniques need to be refined, and there are concerns about the toxicity of copper in fish, he said.

Growers were reminded, though, that the revised rules have not been finalized.

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