Germination of grain amaranth (Amaranthus hypochondriacus x A-hybridus): effects of seed quality, temperature, light, and pesticides

Seven experiments were conducted in incubators to determine the effects of several factors on the germination of two amaranth cultivars. Investigated factors were year of harvest, crop type of the mother plant, seed position on the mother plant, stage of maturity, temperature, light, and seed dressing. Percentage germination and germination speed were recorded. Most effects appeared in interaction with cultivars. Percentage germination was above 80% with temperatures higher than 16 degrees C. The germination speed was closely related to temperature and decreased with decreasing temperature. Light and even short illumination inhibited germination and slowed it down at temperatures below 25 degrees C, presoaking accelerated germination. Seed dressing with the fungicide Dichlofluamid had the desired effect on fungi, but the suceptibility of genotypes to the insecticide Imidachloprid differed. The portion of dormant seeds increased during the course of seed ripening. Seed storage of more than 1 year decreased the percentage germination. An early harvest of homogenous and dense amaranth crops is recommended for amaranth seed production. More research is needed concerning presowing treatments of amaranth seeds. (C) 1998 Elsevier Science B.V.