The effects of sowing depth and date on emergence and growth of barnyard grass, Echinochloa crus-galli.
In field trials conducted at Odolena Voda, Czech Republic, during 1989-91, the effects were evaluated of sowing depth (1, 5, 8, 12 and 25 cm) and date on the emergence and final shoot wt of E. crus-galli. Percentage emergence at sowing depths of 1, 5, 8 and 12 cm were 18.7-45.1, 9.3-36.8, 7.2-13.9 and 0.8-3.3, resp. Emergence was highest on av. in June-July. Emergence duration (d from sowing to the emergence of the 1st seedling) varied with sowing date and increased as sowing depth increased. Sowing to a depth of 1 cm generally resulted in the greatest percentage emergence and the lowest emergence duration, except on 3 occasions when low moisture content in the surface soil layer decreased and delayed emergence. A sowing depth of 5 cm resulted in the greatest shoot wt. A sowing depth of 12 cm greatly reduced plant size. It was concluded that sowing depth and date significantly affect the proportion of seeds removed by germination from the seed bank and plant size at reproduction.