CRITICAL WEED FREE PERIOD IS 3 - 8 LEAF CORN
The above photo is meant to depict a light weed infestation.Though this corn is approaching the Critical 3 leaf stage there is no urgency here to need to apply Glyphosate or a tank mix partner.Research will show that when weed pressures are light applications can be made by the 4th or 5th leaf and yields will not be suppressed
The above photo is meant to depict an average weed pressure.In this case weeds are more prevalent and the potential for them suppressing yield is very real.Though these weeds are very small they still represent a competitive factor to small 3 leaf corn plants.Glyphosate and any tank mix partner should be applied immediately to avoid possible yield loss due to their presence.In this case because weed pressures are heavier and the crop very small a residual tank mix partner would be recommended.
The above photo is meant to depict a very high weed pressure.With weed pressures this high the grower may have been better off applying a pre -emergent residual spray and then waiting to the 6-7th leaf stage of corn to apply glyphosate as a final spray application.This grower should have already applied his glyphosate and tank mix residual partner.YIELD OPPORTUNITY IN THIS CASE HAS ALREADY BEEN JEOPARDIZED.