Control districts that restrict crop production in specific areas are nothing new for state departments of agriculture.

Idaho has several such districts designed to protect potato-seed and vegetable-seed production.

Canola is banned in the majority of Idaho's fertile Treasure Valley, where vegetable seeds flourish. And commercial potato production is banned in certain high elevations where potato seed is grown.

Idaho also has areas where isolation distances are required between industrial rapeseed and edible canola.

Canola is grown as a biofuel, as an industrial lubricant and as a food-grade oil.

In Idaho, citizens must petition to establish the control districts.

"We get some gripes in the Treasure Valley now and then, especially when the biodiesel thing was big," said Mike Cooper, bureau chief for the Idaho Department of Agriculture's plant industries division. "But it comes and goes."

In Washington, the state has several control districts to protect production of potato seed, vegetable seed and edible canola.

In 2008, the Washington State Department of Agriculture established two brassica seed production districts where canola is regulated, but not banned.

District 1 includes areas in five Northwest Washington counties. District 2 includes portions of Grant and Adams counties in Eastern Washington.

-- Mitch Lies

Growers can produce canola in the districts under a permit. So far, no one has applied for a permit, said Jason Kelly, WSDA communications director.

Oregon has several control districts related to pest control. Its only control districts blocking crop production are four canola control districts and one banning production of genetically modified bentgrass in the Willamette Valley.

The gmo bentgrass control district has little impact. The USDA has yet to deregulate the crop.

In California, the state restricts production of certain cotton varieties in its quality cotton district to ensure quality standards, according to Steve Lyle, director of public affairs for the California Department of Food and Agriculture.

--Mitch Lies