Vernonia anthelmintica: A Potential Seed Oil Source of Epoxy Acid. III. Effects of Line, Harvest Date, and Seed Storage on Germination1

Abstract

AbstractPre‐ and post‐frost harvested seeds of three lines of Vernonia anthelmintica (L.) Willd. were stored for 96 weeks under combinations of cold (0.6 C with 30 to 35% R.H.), room (25 to 30 C with uncontrolled R.H.) and barn (ambient temperature and R.H.) conditions to determine the effects of storage conditions on germination. The seed yield from the pre‐frost harvest of VS63‐40 significantly exceeded that of PI 283729. Seed yields of both lines from the post‐frost harvest were very low because of shattering. Pre‐frost harvested seeds were very dormant with an initial germination of 8 to 12%. Tetrazolium tests indicated viabilities of 86 to 89% for the three lines. The average initial germination of post‐frost harvested seeds was 12% and the viability was less than 50%.Seeds in cold storage lost dormancy slowly, while seeds in room and barn storage reached maximum germination by 24 or 48 weeks. After this period, a gradual decline in germinability occurred. The best storage treatment used was 24 weeks at room conditions followed by cold storage. Seeds of VS63‐40 germinated higher than those of PI 283729 and VS65‐224. Seeds of VS65‐224 were the most dormant and were not suitable for planting without 48 weeks or more of room or barn storage. Seeds from frostkilled plants should not be used for planting purposes.