SALEM (AP) — The growers of Marionberries want to make sure that their customers get that sweetness and tang that doesn’t come from just any old blackberry.

Marionberries are a cultivar of blackberries.

But they are sensitive to frost, yields are lower, and prices tend to be higher, creating an opening for Marionberry fraud and damage to the Marionberry’s reputation.

“You don’t want some other product coming in and stealing your thunder,” said Dave Dunn, general manager of the Willamette Valley Fruit Co. and chairman of the Oregon Raspberry and Blackberry Commission.

So growers and a state agency have started a voluntary program to certify Marionberries.

Up to 100 Marionberry fields are expected to be verified this season, about half the fields in the state, said Gary Neuschwander, district manager of the ODA’s commodity inspection division.

Inspectors from the ODA will travel to grower fields to look for the leaf structure and color, thorniness and bud shape particular to Marionberries, said Neuschwander.

The state will issue certificates on a field-by-field basis, record the acreage information and check it against the production data reported by participating processors, whose records will be subject to audits.

The Marionberry “identity preservation” program will be funded through inspection fees to growers and processors. On average, field inspections cost about $40 to $50, while processing plant inspections cost about $300, said Neuschwander.

The goal of the program isn’t to hike prices for Marionberries, but to provide food buyers with the confidence that they’re getting what they’re paying for, said Dunn.

“The rumor mill is this is another program to try to raise price,” he said. “It’s about truth in labeling.”