Purity & Noxious Weed Exam

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The Ransom Seed Laboratory performs purity and noxious weed exams on a wide variety of species. Upon request, tests can be analyzed according to A.O.S.A., I.S.T.A. or Canadian Methods and Procedures.

We also provide, on request, soil and sclerotia tests that are required for shipping seed to certain countries, like Japan.

For a list of required purity weights, please click HERE.

The Purity Test is an analysis that determines the physical composition of a seed sample. The results of a purity test are expressed in four components:

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  1. Pure seed refers to the percentage by weight of the pure seed units for the species under consideration.

  2. Other crop seed is separated from the purity working sample. It consists of seeds of plants grown as crops, other than the pure seed present. A classification scheme for such seeds has been published by A.O.S.A. in the Uniform Classification of Weed and Crop Seeds, Handbook No. 25.

  3. Inert matter is separated from the purity working sample. It consists of all material not classified as seed. We generally define inert as broken seed, soil, sclerotia, sticks, chaff, stone and plant material.

  4. Weed seed is separated from the purity working sample. It consists of seeds, florets, bulblets, tubers or sporocarps of plants recognized as weeds by laws, official regulations, or by general usage.

The Noxious Weed Exam is done on a specified sample size that provides approximately 25,000 units. Noxious weed seed is a plant propagule that is specified by law as being especially undesirable, troublesome, and difficult to control.