Lower seed rates favor seed multiplication ratio with minimal impact on seed yield and quality

Field and laboratory studies were conducted in split plot design of three replications to determine effects of four sowing rates (50, 75, 100, 125 kg ha -1 ) and three row spacing (10, 20, 30 cm) on seed multiplication ratio, seed yield, and seed quality of wheat at Kulumsa and Assasa from 2012 to 2014. Results indicated that lower seed rates gave better seed multiplication ratio at both locations. Increasing seed rate from 50 to 125 kg ha -1 has increased seed yield at Assasa site from 3838 kg ha -1 to 4687 kg ha -1 though seed yield difference between seed rates of 75 and 125 kg ha -1 was statistically non-significant (p>0.05). Increasing seed rate from 50 to 100 kg ha -1 has continuously improved seed yield from 4171 to 4389 kg ha -1 at 20 cm row spaces at Kulumsa, but the difference was statistically non-significant. Laboratory studies indicated that seedling vigor index-II of seeds harvested from plots of 20 cm spacing and seed rate of 100 kg ha -1 have given highest value (1096.1 mg.%). In conclusion, seed rates as low as 50 kg ha -1 can be used at row space of 20 cm to accelerate early generation seed supply within the fast track variety release program in Ethiopia.