Producers are interested in whether crop productivity can be maintained with pre-seeding glyphosate application 2 to 3 wk prior to direct seeding with sweeps. A wider window for glyphosate application would be beneficial, particularly for producers with a large number of hectares. An experiment was conducted at Scott and Melfort, SK, Canada, in 1997 and 1998 to assess glyphosate application 2 to 3 wk before, 1 d before, and 3 to 4 d after (just before crop emergence) the time of seeding in narrow-hoe and simulated-sweep (cultivation immediately followed by a narrow-hoe drill) direct-seeding systems. Wheat grain yield was 25% lower when glyphosate was applied 2 to 3 wk before rather than just prior to seeding only with the narrow-hoe direct-seeding system at Scott in both years. This yield reduction corresponded with the greater median grass weed fresh weight. Yields were 15% lower for both direct-seeding systems at Scott when glyphosate was applied 3 to 4 d after seeding. Barley grain yield was 46% greater (1997) or 25% lower (1998) in the narrow-hoe compared with the simulated-sweep direct-seeding system at Melfort. These yield responses corresponded with opposite responses for median grass weed fresh weight. The tillage effect of sweeps at the time of seeding can improve the control of grass weeds compared with seeding implements equipped with narrow hoes. However, a narrow-hoe system with glyphosate applied just prior to sowing consistently provided the greatest cereal yields. Key words: Barley, wheat, reduced tillage, glyphosate, early-season weed control