Seed Priming and Pericarp Removal Improve Germination in Low-Germinating Seed Lots of Industrial Hemp

Industrial hemp (Cannabis sativa L.) is experiencing a resurgence in North America as an agricultural commodity. Germplasm improvement for locally adapted and stable cannabinoid production is an industry priority. This study used seed priming and pericarp removal to recover seedlings in low-germinating seed lots that could prove important for plant breeding and germplasm conservation. Both seed priming and pericarp removal improved early seed germination, but pericarp removal was more effective in improving overall final germination percentages. On average, pericarp removal improved final germination in low-germinating seed lots by approximately 38% compared to intact seed germination. In seeds with the pericarp removed, the initial germination substrate had an impact on normal seedling development following transplanting: those germinated for 2 to 3 days on rolled towels produced more normal seedlings compared to those started in Petri dishes. There was a dramatic increase in abnormal seedlings produced in the low-germinating seed lot initially germinated in a Petri dish wetted with 6 mL water where nearly 80% never transitioned to normal actively growing seedlings.