Freshly harvested seeds of seabeach amaranth (Amaranthus pumilus Raf.) were stratified (moist-prechilled) for 0, 30, 60, 90, or 120 days. Following stratification, seeds were germinated at 25C (77F) or an 8/16 hr thermoperiod of 30/20C (86/68F) with daily photoperiods at each temperature of 0 (total darkness) or 16 hr. Germination was recorded every 3 days for 30 days. Regardless of photoperiod or duration of stratification, germination at 25C (77F) was negligible. After 120 days of stratification, total (30-day) germination at 25C (77F) with photoperiods of 0 or 16 hr was 4 and 3%, respectively, whereas considerable germination occurred at 30/20C (86/68F). Germination increased linearily with increasing durations of stratification for both photoperiods when seeds were germinated at 30/20F (86/68F). In addition, germination increased when seeds were exposed to light. After stratification of 30 days and germination in the dark at 30/20C (86/68F), germination of 20% was observed by day 12 and increased to 27% by day 30, whereas for seeds exposed to a 16-hr photoperiod, 16% germination was noted by day 12 increasing to 38% by day 30. Following stratification of 120 days and germination in the dark at 30/20C (86/68F), germination of 49% was observed by day 12 increasing to 50% by day 30, whereas for seeds exposed to light, 82% germination was realized by day 12 increasing to 85% by day 30.
This research was funded in part by the North Carolina Agricultural Research Service (NCARS), Raleigh, NC 27695-7643 and by a grant from the Specialty Crops Program of the Golden LEAF Foundation. Use of trade names in this publication does not imply endorsement by the NCARS of the products named nor criticism of similar ones not mentioned. Assistance of the staff of the Southeastern Plant Environment Laboratory (NC State University Phytotron) is greatly acknowledged in addition to the assistance of L. Eric Hinesley regarding preparation of the figures.
3Agricultural Extension Agent, New Hanover County Extension Service, 6206 Oleander Drive, Wilmington, NC 28403.
4Agricultural Research Technician.