Effect of seed storing temperature on germination of wild mustard (Sinapis arvensis) seeds

Seed dormancy of wild mustard (Sinapis arvensis) could be changed through seed storing. The seeds were collected from four regions: Fars, West Azarbaijan, Khuzestan and Mazandaran provinces. They were stored at three different temperatures (-18, +3 and 22-25°C) for 3, 6, 9, 12 and 15 months. They were then put under suitable condition for germination. Mean germination time for seeds was measured during 6, 12 and 18 months storage. The results showed that the dormancy level and germination speed of seeds showed some differences after different time periods of storage. Also large differences in percentage of germination were found among populations. The results suggest that the most effective factor on seed germination is environmental maternal conditions at seed production stage. Because of the secondary dormancy, the storage temperature is not suitable to promote seed germination. Despite the increased germination speed of seeds at room temperature, the amount of this increase was not similar in all populations. It was contrary to the seeds from Mazandaran Province where the seed germination speed was reduced. According to the results, the secondary dormancy, which causes low germination and high contamination of soil with the seeds, is considered an important factor in management of wild mustard weeds.