Doug Gross should thank the Japanese consumer.

With all the attention focused on a long run of high prices in the potato market and domestic shortages, a little-noticed explosion is under way in Japan's demand for french fries."We think it's a sleeping giant out there," said Gross, a Wilder potato farmer.

Between 1985 and 1989, U.S. imports of frozen potatoes to the island nation have grown 123 percent, said the Japan Frozen Food Association.

Behind the growth is a hunger for American-style potato products all over the Far East, from Indonesia and Singapore to Japan and South Korea, experts say.

While still a small part of the total U.S. potato crop, the robust exports show few signs of ending. That leads may experts to believe Idaho farmers may be entering a period where prices may stay relatively high.

In July, the average monthly price for Idaho's most important crop was $12 per hundred pounds, a record. The preliminary August average price of $8.45 is 37 percent higher than one year ago.

Virtually all of the 240.2 million pounds of frozen potatoes sent to Japan last year came from the Pacific Northwest. Idaho accounted for between 25 percent and 50 percent of the volume, said The Potato Board, a quasi-governmental marketing group based in Denver.

Another 112 million pounds were exported in 1989 to other Asian countries, including Taiwan, South Korea and Hong Kong. Total value of all the exports was $108 million, Potato Board spokesman Linda McCashion said.