The germination requirements of four taxonomically related taxa of Dianthus (D. arenarius L. subsp. borussicus Vierh., D. carthusianorum L., D. gratianopolitanus Vill., and D. deltoides L.) were studied under controlled conditions in a laboratory. A set of experiments were conducted to evaluate seed germination responses to storage period and cold stratification, different hydrogen ion concentrations (pH), potassium nitrate ([Formula: see text]), temperatures, and light conditions. Experiments were also performed to study the effects of sowing depth and water supply on seedling emergence. There were no differences in germination between seeds incubated under light or dark conditions for any of the taxa we studied. Germination percentages increased significantly with increases in temperature. The taxa of Dianthus we studied showed similar responses to sand burial, i.e., seeds placed on or near the soil surface had maximum emergence, and emergence declined with increasing depth of seed burial. In the studied taxa, germination was reduced by declining osmotic potentials. Cold stratification increased the germination rate, but did not affect final germination percentage of Dianthus seeds. A higher concentration of nutritious solutions (KNO3) negatively affected the germination percentage. The results show that seeds of the studied taxa are potentially germinable in the species’ habitat at any time between April and October.
Promotion of Seedling Emergence of Paddy Rice from Flooded Soil by Coating Seed with Potassium Nitrate.