Consumers may almost double rice purchases this fiscal year, driven in part by contamination "rumors" surrounding thenuclear disaster, as demand outstrips crimped domestic production.

Hoarding may result in purchases of as much as 15 million metric tons, from about 8 million tons last year, making it impossible for farmers to meet demand after a quake-generated tsunami washed over paddies in an area representing 18 percent of the country's output, Akio Shibata, head of the research unit at Marubeni Corp., said in Tokyo on Monday.

"Stockpiles may be depleted, creating a shortage and boosting imports," Shibata said. Effects of the March 11 quake and tsunami, which swept aside machinery and damaged farms in the Tohoku region, could last "for years," he said.