The Agricultural Research Service has released five potato breeding lines that resist powdery scab and black dot diseases.

Outbreaks of the fungal diseases can cause up to 25 percent yield losses and prevent tubers from sizing.

Of the two, black dot can be chemically controlled with fungicides, according toa news release. But multiple applications are needed, increasing production costs.

ARS geneticist Chuck Brown has conucted studies since 2004 with Washington State University colleagues in Prosser to screen existing wild and cultivated potato varieties for genetic sources of resistance.

The resulting condidates wild species from Mexico and a recent commercial release, Summit Russet.

These lines won't be released for production. Instead, they'll be made available to potato breeders for incorporation into their programs.