Infestation of Seeds

the presence in seeds of disease agents and pests. It is determined by control-seed analysis and is expressed as a percent of mass or in seeds per kg. Sources of seed infestation are smut saccules, the sclerotia of various fungi, spores and bacteria on the surfaces of seeds, and mycelia or bacteria inside the seeds. The most widespread pests are insects, arachnids (ticks), and worms (nematodes). Seed infestation by pests occurs in storehouses (weevils, moths, ticks) or in the field (pea beetle, shield bug, millet midge, wheat nematode). Two forms of seed infestation by pests—overt and hidden—may be distinguished. In the overt form, live pests and their larvae appear and the seeds have a gnawed surface and apertures. In the hidden form, the presence of pests and damage can be established only with special reagents, by cutting open the seeds, or by roentgenography. Seed infestation decreases the yield and its quality; hence, there should be no disease agents or pests in seed material. Seeds that do not meet standards are disinfested or discarded.