Seed Harvesting Time Affects Seedling Emergence, Vigour and Growth: Case Study of Rumex turcomanicus Czerep. (Polygonaceae)

Rumex turcomanicus Czerep., belonging to family Polygonaceae, is one of native green vegetable in Northeast Iran. Despite the high consumption, its seed germination and dormancy aspects is inconsiderable. In order to investigate the effects of seed harvesting date on seedling emergence, vigour and growth traits of R. turcomanicus Czerep., the seeds were harvested at five different times, i.e., two weeks after fruiting (WAF), 6WAF, 8WAF (mature seeds), 2 month after seed ripening (MASR) and 4MASR, and were sowed immediately, at agricultural college of Ferdowsi university of Mashhad, Iran in 2012-2013. The results was showed that the highest and lowest of seedling emergence percentage, seedling emergence rate, seedling vigour index, seedling fresh and dry weight, seedling root and shoot length, total seedling length and %final normal seedling (%FNS) was obtained in the seeds which were sowed 4MASR and 2WAF, respectively. Maximum and minimum of mean emergence time (MET) was observed in the seeds which were sowed 2WAF and 4MASR, respectively. Relationship between %FNS and MET and between %FNS and emergence percentage was highly significantly negative (-0.961) and positive (+0.962), respectively. Based on the results of this experiment, it seems that the problem of germination in most of the Rumex turcomanicus Czerep. seeds, is probably due to a kind of morphological dormancy, which is remained in most of the fresh seeds (collected 2WAF), and eliminated in the mature seeds (collected 2MASR). Also dry seed storage of the mature seeds for two months was improved seedling emergence and vigour, significantly.