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United States Department of Agriculture

Agricultural Research Service

Title: Uniform Classification of Weed and Crop Seeds

Authors
item Lionakis, Deborah - ASSOC. OF SEED ANALYSTS
item Wiersema, John

Submitted to: Complete Book
Publication Type: Book / Chapter
Publication Acceptance Date: October 30, 1999
Publication Date: N/A

Interpretive Summary: Seeds provide a major form of international trade in agriculture valued at billions of dollars annually for the United States. To safely import and exchange seeds it must be inspected and deemed to be free of harmful contaminants, thus seed lots for trade are inspected and certified to be safe. Toward this end, one of the major seed inspection organizations, the eAssociation of Official Seed Analysts, provides guidelines for their customers. These guidelines include an official classification scheme for all weeds and crop seeds involved in this trade. The publication lists the accurate scientific and common names of all such plants as well as the classification and comments on any recent changes. This book is used as a standard reference for seed analysts throughout the world who are working to certificate that seed lots are safe for international shipment.

Technical Abstract: The function of a seed analyst is to determine the quality of seed samples. Services most commonly requested include purity analysis, noxious weed seed examination and estimation of viability. Procedures for these laboratory tests are found in the Association of Official Seed Analysts Rules for Testing Seeds. Section 10 of the Rules for Testing Seeds refers to this document for the classification of contaminating species found during a purity analysis. The classification scheme is based on the species class of the pure seed component. All contaminating species are classified as either other crop seed or weed seed based on the pure seed species class. This classification scheme was developed by Dr. Arnold Larsen and the Handbook 25 Revision Committee in the early 1990's. The goal of the committee was to improve upon the classification scheme developed in 1952 by Dr. O. L. Justice. To achieve this goal Dr. Larsen sought assistance from commercial and governmental seed laboratories and plant specialists from all over the United States and Canada. The earlier versions of Handbook 25 contained less than 350 species. The version developed by Dr. Larsen and an his committee included more than 2000 species. This document more accurately reflected the increased number of species in the marketplace, and the expanding number of contaminating species encountered by seed analysts today. Nomenclature used in the handbook was based on the USDA Germplasm Resources Information Network (GRIN).

Last Modified: 10/30/2014
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