Crown vetch as a dangerous weed of agricultural crops

Crownvetch (family Fabaceae — FABACEAE Lindl.) poses a serious threat to cereal crops. The main problem for an agronomist is that the small pod segments of this weed are extremely difficult to separate from cereal grains during the cleaning of the heap. When they end up in the general grist, the ground weed seeds give the flour a distinct bitter taste, which sharply reduces its quality.

The weed infests plant products in the European part of the country (mainly in the central and southern regions), the Caucasus, Western Siberia, and Central Asia.

Morphological characteristics of crownvetch pods and seeds

• Number of segments in a pod — 38
• Pod length — 3050 mm
• Radicle length — 1/2 the length of the cotyledons

Crownvetch fruits are straight or slightly curved pods that easily break apart into individual segments. Pod segments are cylindrical, somewhat compressed, quadrangular, and indehiscent, tapering slightly towards the ends. The surface of the segments is longitudinally wrinkled, rough, and matte, with colors ranging from brown and pale brown to pinkish. They can be distinguished by the following features:

• The upper segment of the pod ends in a curved remnant of the style;
• The lower segment has a remnant of the pedicel;
• The middle segments are straight-truncated at the apex and base.

The weed seeds have a cylindrical, oval-elongated, and compressed shape. A thick radicle fits tightly against the cotyledons. The seed hilum is located on the side of the seed; it is round, furnished with a white membrane, and surrounded by a dark stripe. The seed surface is smooth and matte, with a reddish-brown color.