PRESQUE ISLE — The Maine potato industry may decide to import certified russet seed from Midwestern states to halt the spread of viruses in certified seed and to supply local processors.

McCain Foods Inc. of Easton has asked the industry to recommend extension of a waiver granted last year that raised the state’s tolerance level of virus in the Shepody variety from 5 to 7 percent. This time McCain wants the waiver to include russet varieties.

The issue stemmed from results released last week from the Florida seed testing farm that showed readings above 5 percent in mosaic, a potato virus Y, especially in the russet varieties.