Prohibited and Restricted Weeds

During the purity test, the seed lot sample is examined for the presence of Restricted and Prohibited Noxious Weed seed. Each state has its own list of Prohibited and Restricted Noxious Weeds. Prohibited noxious weeds are not allowed in any lot of seed. Restricted noxious weeds are allowed in seed but the amount of weed seed is restricted. Prohibited and Restricted noxious weeds vary from state to state, but any seed lot must meet the regulations of the state where it is sold. These lists are assembled from input provided by seed growers, crop improvement associations, seed dealers, and others. They are part of each states' seed laws. They do not necessarily include weeds that every group considers noxious.

By the Federal Seed Act and state laws, seed lots can not be sold when they contain any prohibited noxious weed seeds. The analysis must indicate that no prohibited noxious weed seeds are present. Seed lots may contain only a small percentage of Restricted Noxious Weed seeds.

The name and number of seeds per pound of any restricted noxious weeds must be listed on the label. This means that any one of the weed seeds on the Restricted List can be included in a Certified seed lot up to the maximum number of seeds allowed by law. Each state requires similar information. The main differences are in the Prohibited and Restricted Weed lists from state to state.

You should identify your particular state's requirements so you know what you are legally entitled to or legally obligated to do. By law, seed that comes from a state that has less restrictive weed lists must meet the more restrictive requirements of the receiving state. Contact the State Department of Agriculture or the crop improvement association in your state for specific information.

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Last Modified: 07/05/2007