Methods for overcoming seed dormancy in jimsonweed (Datura stramonium L.)

This study aimed to examine dormancy-breaking of jimsonweed seeds. Seeds were collected from Hamedan. They were subjected to different treatments: (a) concentrated sulfuric acid for 1, 1.5, and 2 min; (b) hot water at 80°C and 90°C for 5 and 10 min; (c) mechanical scarification with sandpaper; (d) light exposure for 10, 20, and 30 days; and (e) fluctuating temperature (5–15°C). The highest germination (90%) was for seeds scarified with sandpaper, but it did not differ significantly from that of seeds scarified with sulfuric acid for 1.5 min. Hot water treatment increased germination percentage but it was lower than sandpaper and acid treatments. Superior treatment affected radicle and plumule length, vigor index, mean germination time, and seedling length. Lower α- and β-amylase activities were detected in dormant seeds, and these enzymes’ activity increased significantly in superior treatment. It seems that scarification by sandpaper or sulphuric acid for 1.5 min is a general requirement for breaking dormancy of jimsonweed seeds. So, they are recommended.