FARGO (AP) - A federal laboratory here has developed a genetic tool for researchers seeking to develop varieties of durum wheat that are resistant to scab disease.

Prem Jauhar, research geneticist with the U.S. Department of Agriculture's Agricultural Research Service, has helped to develop a new line of germ plasm, which is a plant's genetic material.

"I must emphasize, this isn't meant for use by farmers in their fields," said Jauhar, who works at the Northern Crop Science Laboratory.

Instead, it will be used by scientists working on scab-resistant durum, a wheat that is used to make pasta.

"It's a nice breakthrough," said Neal Fisher, administrator of the North Dakota Wheat Commission.

North Dakota produces two-thirds of the country's durum, but acres in the state have plummeted from 3 million in 1996 to 1.3 million last year. The increasing popularity of other crops, particularly corn and soybeans, accounts for some of the decline, but scab problems also are a reason.

Scab severity is linked to wet weather, which has been common in North Dakota over the past decade.

Grain growers nationwide have lost about $3 billion to scab since 1990, according to USDA.

Existing durum varieties have little or no tolerance to scab. The new germ plasm line contains genetic material from a wild grass that is almost immune to scab.

Jauhar would not speculate on how long it will take to develop scab-resistant durum varieties that farmers can plant.

"It's slow, tedious work," he said.

Noonan durum grower Bruce Verlinde said any progress in the fight against scab is good.

"We need it," he said.