Visual identification of small oilseeds and weed seed contaminants

1. Introduction

Visual Identification of Small Oilseeds and Weed Seed Contaminants, Grain Biology Bulletin No. 3 has been produced as a tool for assisting grain inspectors in seed identification related to grain grading of small oilseeds crops. Users should be aware that weed seeds discussed in the bulletin represent a very small number of species of weed seeds that could potentially occur in oilseeds crops. The weed seeds discussed in this bulletin were selected based on being problematic in grain cleaning, end product quality or similarities in visual seed identification to oilseeds crops or other weed seeds of concern.

Seed descriptions are based on sound seed and what is generally considered normal. With any seed there can be variations from the norm due to: maturity, environmental factors such as weathering, disease and other factors which may change the visual features of the seeds. These factors can impact on the size, shape, colour and overall appearance of a given seed.

Basic information has been provided to assist inspectors in the task of seed identification, however, the skills and knowledge required to be a qualified seed analyst proficient in identifying a wide range of weed seeds is beyond the scope of this bulletin. If in doubt as to the identification of a seed, it is recommended that grain inspectors consult with an accredited seed analyst or seed testing laboratory.

Notes: Seed descriptions are from reference sources where indicated and from the author's personal observations. References are numbered to correspond to the bibliography.

Seeds used for the author's observations are maintained in the Grain Biology Seed Herbarium by the Grain Biology Unit, Grain Research Laboratory, Canadian Grain Commision. Seeds were verified by the Seed Biology Unit, Canadian Food Inspection Agency, Agriculture Canada.

A glossary of terms used is included at the end of the manual.