Effect of Presowing Seed Treatments on Germination and Seedling Emergence in Taraxacum platycarpum

Several presowing seed treatments have been used to facilitate the seed germination and seedling emergence. The study was performed to design a model of presowing seed treatments in Taraxacum platycarpum. Germination and seedling growth responses to temperature, drying, chilling, and priming were investigated to know the optimum germination conditions and presowing treatment. The optimum temperature condition for germination and seedling growth were at dark condition. The seeds exposed to infra red light, however, did not germinate. The moisture content of seeds dried at for 3.5 hours was returned to the level of unimbibed seeds. The germination of seeds dried under dark condition was better than those dried under infra red light. Prechilling treatment imposed for 6 weeks showed higher germination rate than treatment or priming. In field test, the highest field emergence was observed in the seeds dried after prechilled for 6 weeks and followed by drying followed by > low temperature > priming. Imbibition with 0.1 mM solution for 2 hours then drying at 35 for 3.5 hour under dark condition was effective to the practical presowing treatment for Taraxacum seeds.