Vigour

Abstract

In the scientific literature on seeds the word ‘vitality’ is taboo, and the word ‘vigour’ occurs almost exclusively in agronomic, rather than physiological, verbiage. Vigour is tantamount to the property of seeds which promotes a satisfactory performance; its antithesis has often been referred to as ‘weakness’ (de Tempe, 1961, 1964, 1966); and in this double sense it has become widely accepted. It is perhaps significant of the complexity and elusiveness of the term that the first documented use of its German near-equivalent was by Hiltner (Hiltner and Ihssen, 1911), a plant pathologist who showed that cereal seeds infected by Fusarium diseases were capable of germinating, but that the resulting seedlings were incapable of penetrating a 30–40mm thick layer of Ziegelgrus (brick grit) of 2–3 mm particle diameter under specified conditions of temperature and moisture. He called this ability Triebkraft, and the term was later adopted, irrespective of the disease factor, to denote that seeds could not only germinate but also grow well. The term Triebkraft is, intentionally or not, a play on words, meaning both ‘shoot strength’ and ‘driving force’. For a time this test was adopted in Germany (Eggebrecht, 1949) to indicate a quality of seeds beyond mere germinability; but it lost some of its appeal, and its result, expressed as a percentage of successful seedlings, was renamed Ziegelgrus value (Lindenbein and Bulat, 1955) when it became clear that, except for infected cereal seeds, the results obtained in brick grit were hardly ever worse, and sometimes better, than those from the official germination tests.