The government on Tuesday lifted an 11-year import ban on potatoes grown in Idaho, the largest U.S. potato producer, after confirming a lowered risk of crop pest invasion, sources said.

Japan suspended imports of all potatoes grown in the United States in 2006 and later resumed imports of U.S. potatoes except those grown in Idaho, the origin of a pest known as the pale potato cyst nematode.

Most fresh potato imports are used for making potato chips, and their demand has been on the rise lately.

The government appears to have decided that the influence of imports on major potato-producing regions in the country, such as Hokkaido, will be limited, since the current volume of potato imports is considerably small compared with the volume grown domestically.

In April 2006, the Ministry of Agriculture, Forestry and Fisheries announced the suspension of U.S. potato imports after pale potato cyst nematode infestations were detected in Idaho, but it lifted the ban on condition that soil tests, among other measures, were performed, in February 2007, except for Idaho potatoes.

The farm ministry dispatched experts to the United States and checked pest management conditions before lifting the ban this time, and Tokyo has already notified the U.S. government of the decision, the sources said.

Last spring, some major potato chip makers in Japan suspended sales of some of their products due to a potato shortage, following a poor harvest last year in Hokkaido caused by low temperatures and typhoons.

The amount of raw potatoes imported from the United States last year reached around 28,000 tons, over 3.5 times the amount five years ago.