EPA restricts use of slug bait
Metaldehyde subject to new labels
By MITCH LIES
For the Capital Press
Beginning this year, the Environmental Protection Agency is imposing new restrictions on commonly used slug baits.
Metaldehyde slug baits will not be cleared for use on crops such as clovers, peas, beans, root crops and wheat on new pesticide labels the product registrant, Lonza, and formulators are expected to roll out this year.
However, the Oregon Department of Agriculture is working with Oregon State University Extension to ensure that uses on clover grown for seed will remain intact under a Special Local Needs label until a second-round of new labels can be issued.
“We hope to be there with a Special Local Needs label, so those growers are not left without coverage,” said Rose Kachadoorian, a pesticide specialist with ODA.
A special local needs label, or 24C label, is a state-specific label issued by a state department of agriculture. The 24C label will allow use only on non-food and non-feed clover crops.
Grass seed, berry crops, Swiss chard, rhubarb, mint, ornamentals, lettuce, brassicas, spinach, tomatoes and corn will be included on the new labels, according to Joe DeFrancesco, an integrated pest management specialist at OSU.
Working through the national IR4 Program, the Field Research Center at OSU’s North Willamette Research and Extension Center recently submitted tolerance data for clover seed, peas and beans. But tolerances for those crops are not expected until 2015 at the earliest. Data for wheat and hops are in the process of being submitted to EPA, DeFrancesco said.
DeFrancesco said the department is not planning to issue a 24C label for metaldehyde on food crops, such as peas and beans. He said he is exploring the possibility of obtaining an emergency use exemption for metaldehyde on those crops and some root vegetables “if there is not enough product to get through the season.”
Growers can use metaldehyde formations registered under the “old label” on all crops listed on the label until that product is exhausted, DeFrancesco said.
“If growers have product on hand with their crop listed on the label, it is perfectly legal to use it,” he said. “And if they buy old product with their crop on the label, it is perfectly legal to use.
“It is only if they go out and buy new product and their crop is not on the label, is it then illegal to use,” DeFrancesco said.
Growers rely on metaldehyde baits, available in several formulations, to control slugs, which in recent years have emerged as one of the biggest pest problems in many Willamette Valley crops.
No-till and other modern crop management practices have created an ideal environment for slugs to flourish, and growers have struggled to keep populations under control.
Slugs feed on plant roots and foliage. At high numbers, the pest can decimate a new stand of grass seed, clover or any other newly planted, emerging crop.
The recent action by EPA to require new data on metaldehyde baits dates back to 2006, when the agency issued a re-registration-eligibility document stating that the registrant needed to establish tolerances, or safety data, for each crop that metaldehyde is used on.
In 2007, OSU and the IR4 Program, began working on establishing tolerances on several crops, including grass seed, berry crops, mint, rhubarb, Swiss chard and corn.
The IR4 program works to ensure that pesticides are available for minor crops that are commonly grown in Oregon.
EPA issued tolerances for grass seed, berry crops, rhubarb, Swiss chard and mint this past November, ensuring those crops will be on the new labels.
The new labels will allow use of metaldehyde baits on food and feed crops that are listed on the label, in addition to the non-food, non-feed uses.