Effect of Priming Treatment and Sowing Date on Synchronization of Developmental Stages and Yield of Maize Inbred Lines for Hybrid Seed Production

The present research was conducted under laboratory and field condition to determine seed priming effects on maize inbred line's germination, emergence, and grain yield. Seeds of two maize inbred lines include of Mo17 (as paternal line) and B73 (as maternal line with cytoplasmic sterility) in the laboratory conditions were subjected to hydropriming for 12, 24, 36 and 48 h, or osmoticpriming with solution of polyethylene glycol-6000 and urea solution for 96 h (with osmotic potential -1.2 MPa), then germination performance was considered. Results of laboratory experiment showed that both inbred lines responded to priming treatments approximately similar. Maximum invigoration was observed in seeds hydroprimed for 36 h as indicated by lower mean germination time and higher values of radicle and coleoptile length. However, osmoprimed seeds behaved similar to or even poor than that of control. The most promising laboratory seed treatment with 3 sowing dates of paternal line were advanced to field experiment where seedling emergence, phenological growth trend, and yield components were assessed. The experimental design was spilt plot on a randomized complete block design with 4 replications that main plots were assigned to pre-sowing seed treatments (control and hydropriming for 36 h) and sub-plots were assigned to 3 sowing date of paternal line (b1=same sowing date for both parental lines, b2= sowing of paternal line basis on 2cm radicle emergence of maternal line, b3= sowing of paternal line basis on 4cm radicle emergence of maternal line). Result showed that extent of seedling emergence was greater for hydroprimed seeds. On the other hand, sowing of paternal line basis on 2cm radicle emergence of maternal line was the most effective to achieve of high synchronization between silking and anthesis of parental lines; also this treatment significantly improved the yield components.